Surveyor E Press Kit

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NATIONAL AERONAUTICS AND SPACE ADMINISTRATION WO 2-4155NEWS ~~TELS. O362w WASHINGTON, D.C. 20546 W O 3-6925FOR RELEASE: THURSDAY A.M.RELEASE NO: 67-227 August 31, 1967PROJECT: SURVEYOR E

(To be launched no

SURVEYOR

contentsGENERAL RELEASE --------------------------------------- 1-5SURVEYOR BACKGROUND ------------------------------------ 6-8SURVEYOR E SPACECRAFT- -------------------------------------- 9Spaceframe, Mechanisms and Thermal Control---------------9-11

Power Su bsys tem n----------------cc eeeeeeeeee---------------2ll-T eleco m m un ications--------------------------------- ---- 12-13Propulsion ----------------------------------------------- 13-14Flight Control Su bsy stem ----------------------------- 1416Television --------------------------------------------- 16-17Alpha Scattering Experiment------------------------ -- 18d19Magnetic Test -------------------------------------------- 19-20Engineering Instrumentation -----------------------------20ATLAS-CENTAUR LAUNCH VEHICLEc-------------------------------- 1

Launch Vehicle Characteristics -------------------------- 1-22Atlas-Centaur Flight Sequencec---------------------------23TRACKING AND COMMUNICATION------------------------------- c 24-25

9 TRAJECTORY ---------------------------------------------e 26-27ATIAS-3ENTAUR 13/SURVEYOR E FLIGHT PLANc--------------------- 8Launch Periods------------------------------------------- 8Atlas Phase---------------------------------------------- 8* Centaur Phase-------------------------------------------- 29

Separation ---------------------------------------------e 29First Surveyor Events------------------------------------30-31Canopus Acquisition ------------------------------------- 32Midcourse Maneuver------- ----------- e32-33Termnal Sequence --------------------------------------c 33-34Post-landing Events -------------------------------------- 35

ATLAS-CENTAUR AND SURVEYOR TEAMS--------------------------- 36 -42

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NATIONAL AERONAUTICS AND SPACE ADMINISTRATION WO 2-4155NW WASHINGTON,D .C . 20546 TELS. WO 3-6925FOR RELEASE: THURSDAY A.M.August 31, 1967RELEASE NO: 67-227

FIFTH SURVEYORSOFT-LANDER

DUE FOR LAUNCH

A fifth Surveyor soft-lunar-landing spacecraft is beingprepared for launch at Cape Kennedy, Fla. Seven Surveyors areplanned in the series.

The launch by an Atlas-Centaur is planned for the periodno earlier than Sept. 8 - 13.

Like the four previous Surveyors, Surveyor E's mission isto perform a soft-landing in the Apollo area of interest on theMoon and to take television pictures of the lunar surface aroundits landing site.

Surveyor E will be the first of the series, however, tocarry an instrument to study the chemical characteristics ofthe lunar soil and it will be the first to attempt a landingin the eastern portion of the Aoollo zone.

The planned landing site is at 24 degrees East longitudeand one degree North latitude. This is in the southern partof the Sea of 'Tranquility, 60 miles east of the crater Sabineand 24 miles north of the crater Moltke. The site is 36 milessouthwest of the landing site of Ranger VIII.

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The landing in the East will put great demands on Surveyor'ssoft-landing system. If the launch is on Sept. 8, the spacecraftwill approach its landing target at 47 degrees off the vertical,requiring a large gravity turn during the crucial terminal des-cent sequence. For the succeeding days of the launch period, theangle of approach is a few degrees less from the vertical. Bycontrast, Surveyor I's angle of approach was only six degrees andSurveyor III's was 25 degrees.

The study of the chemical characteristics of the lunar sur-face will be carried out by an alpha scattering experiment. Thealpha scattering instrument is lowered to the lunar surface andbombards it with alpha particles from a radio-active source. Bymeasuring the interaction of the particles with atomic nuclei ofelements in the lunar surface, it is possible to determine whichelements are present.

The alpha scattering device replaces the surface sampler

which was flown on Surveyors III and IV.

In another change from previous spacecraft, Surveyor E'stwo mirrors which permit taking pictures under the spacecraftwill be convex instead of flat to increase the field of view.In addition, the smaller of the two mirrors has been repositionedso that it views the area of the lunar surface which the alphascattering instrument will contact when it is deployed.

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-3-The launch vehicle for this mission will be Atlas-Centaur

13 which has a two-burn capability so that it can launch Sur-veyor E toward the Moon from a parking orbit.

Surveyor E's flight will last 65 hours from lift-off totouchdown. A large solid propellant retrorocket and threesmall vernier rocket engines under radar control will slowSurveyor from a lunar approach speed of 6,ooo miles per hourto about three miles per hour. The engines cut off at the 13-foot mark and the spacecraft falls free to the lunar surface,touching down about 10 miles per hour.

On the first day of the launch period, Sept. 8, liftoffcan occur between 3:39 a.m. and 5:30 a.m. EDT.

At launch, Surveyor E will weigh 2,216 pounds. The retro-motor, which is jettisoned after burnout, weighs 1,395 pounds.After expenditure of liquid propellants and attitude controlgas, Surveyor E will land on the Moon weighing about 616 pounds.

In addition to data provided by the TV camera and surfacesampler, Surveyor E will also provide data on the radar re-flectivity, mechanical properties, and thermal conditions ofthe lunar surface.

Surveyor I soft-landed on the Moon June 2, 1966, and re-turned 11,150 high-quality photographs of the lunar surface.

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-4-Surveyor II was launched Sept. 20, 1966, but the mission

failed when one of the three vernier engines failed to igniteduring an attempted midcourse maneuver. Surveyor III soft-landed on the Moon April 19, 1967, returned 6,319 photographsand provided 18 hours of operation of the surface sampler.

Launched July 14, 1967, Surveyor IV performed well untilthe last few seconds of burn of the retromotor when all communi-cations with the spacecraft were lost. An engineering teamwhich studied the failure could not pinpoint the cause of thefailure of the mission, and determined that the Surveyor E mis-sion should proceed, since there was a relatively low proba-bility of recurrence of the several postulated causes studied.

The Surveyor program is directed by NASA's Office of SpaceScience and Applications. Project management is assigned toNASA's Jet Propulsion Laboratory operated by the CaliforniaInstitute of Technology, Pasadena. Hughes Aircraft Co., undercontract to JPL, designed and built the Surveyor spacecraft.

NASA's Lewis Research Center, Cleveland, is responsiblefor the Atlas first stage booster and for the second stage Cen-taur, both developed by General Dynamics/Convair, San Diego, Cal.Launch operations are directed by Kennedy Space Center, Fla.

Tracking and communication with the Surveyor is the re-sponsibility of the NASA/JPL Deep Space Network (DSN).

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The DSN stations assigned to the Surveyor program arePioneer, at Goldstone in California's Mojave Desert; Robledo,Spain; Ascension Island in the South Atlantic; Tidbinbillanear Canberra, Australia; and Johannesburg, South Africa. Datafrom the stations will be transmitted to the Space Flight Opera-tions Facility in Pasadena, the command center for the mission.

(END OF GENERAL RELEASE; BACKGROUND INFORMATION FOLLOWS)

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-6-SURVEYOR BACKGROUND

Surveyor I performed th, first fully-controlled softlanding on the Moon on June 1, 1966, after a 63-hour, 36-minuteflight from Cape Kennedy. surveyor I landed at a velocity ofabout 7.5 miles per hour at, 2.45 degrees South of the lunarequator and 43.21 degrees lest longitude in the southwest por-tion of Oceanus Procellar.m (Ocea. of Storms).During the six weekF. following the perfect, three-pointlanding, the spacecraft',: survey television camera took 11,150

high-resolution pictureE of the lunar surface for transmissionto Earth receiving stat-ons. Resolution in some of the close-ups was one-halt millimeter or about one-fiftieth of an inch.The television pictures showed that the spacecraft cameto rest on a smooth, nearly level site on the floor of a ghostcrater. The landing site was surrounded by a gently rollingsurface studded with craters and littered with fragmental de-bris. The crestlines of low mountains were visible beyond thehorizon.By July 13, Surveyor Its 42nd day on the Moon, the space-

craft had survived the intense heat of the lunar day (250 de-grees i'), the cold o the two. week-long lunar night (minus 260degrees F) and a second full lunar day. Total picture countwas: first; lunar day -- June i to June 14 -- lO338; secondday -- July 7 to July 13 -- 812. The total operating time ofSurveyor I (time during which signals were received from thespacecraft) was 612 hours.Althbugh the battery was not designed to endure the rigorsof the lunar environment over an extended period, Surveyor con-tinued to accept Earth commands and transmit TV pictures throughthe second lunar sunset. Communications with Surveyror I were

re-established at intervals through January 1967 but no TV pic-tures were obtained after the July 1966 activity.Surveyor II was launched on Sept. 20, 1966, toward! .LnusMedii in the center of the Moon. An attempt to perform themidcourse maneuver was unsuccessful who one of the three liquid fuelvernier engines failed to fire. The thrust imbalance caused thespacecraft to begin tumibliag. The spacecraft impacted the Moonsoutheast or the crater Copernicus at a velocity of nearly 6,ooomiles per hour.Intensive tavestigation inter possible causes of the Sur-veyor II failure by a team of propulsion experts did not re-sluit in the identification of the. exact cause.

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-7-As a result of this investigation, however, a number ofchanges in testing procedures were recommended for Surveyor IIIand subsequent spacecraft to provide better diagnostic capa-bility in the vernier propulsion system during preflight testingas well as during the mission.Surveyor III was launched April 17, 1967, and successfullysoft-landed on the Moon April 19, 1967, on the east wall of a650-foot diameter crater in the Ocean of Storms. The spacecrafttouched down three times in the landing when its vernier enginesdid not cut off at the prescribed 14-foot mark but continued fir-ing to the surface. A command from Earth shut down t'ie enginesafter the second touchdown at 2.94 degrees South latitude and23.34 degrees West longitude. Surveyor III was equipped with asurface sampler instrument to provide data on lunar soil charac-teristics. The device dug four trenches, made seven bearingstrength tests and 13 penetration tests during a total of 18hours of surface sampler operation from the second day aftertouchdown through lunar sunset on May 3.Operation of the television camera yielded 6,315 pictures.These included pictures of a solar eclipse as the Earth passed

in front of the Sun, the lunar terrain, portions of the space-craft, surface sampler operations and the crescent of the Earth.Attempts to reactivate the spacecraft during the second lunarday were *.unsuccessful.Surveyor IV was launched on July 14, 1967, again towardSinus Medii in the center of the Moon. The mission proceedednormally until the last few seconds of burn of the retromotorwhen there was an abrupt loss of communications with the space-craft. Repeated efforts to re-establish communications failed.A teal of engineers which studied the mission failure listed

four possible causes but did not pinpoint any one cause as moreprobable than the others. They said the communication lesscould have resulted from:- The breakage of a critical power lead in a wiring harness,or the failure of a connector or solder Joint;- Rupture of the main retromotor case, resulting in damageto spacecraft circuitry;- A transmitter failure, causing power to drop a pointwhich would have prevented transmissions over the 238,557 miles

from Moon to, Earth;- Rupture of a pressure vessel such as a helium or nitrogentank, a shock absorber, or a propellant tank aboard '.he space-craftt which resulted in damage or cutting of electrical circuits.-more-


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-8-The engineers described the four possible causes of failureas having "relatively low probability" of recurrence in futuremissions and specifically recommended that no hardware changesbe made to future Surveyor spacecraft. However, they recommendedthat studies be conducted to find improved preflight inspectiontechniques, that data obtained from Surveyor IV be furtherstudied for additional clues to the cause of the telemetry loss,and that modifications to ground equipment and operational pro-

cedures be made where possible to obtain additional data shouldthe same problem reoccur on future flights.

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-9-SURVEYOR E SPACECRAFT

Spaceframe, Mechanisms and Thermal ControlThe spaceframe of the Surveyor is a triangular aluminumstructure which provides mounting sulfaces and attachments forthe landing gear, main retrorocket engine, vernier engines andassociated tanks, thermal compartments, antennas and otherelectronic and mechanical assemblies.The frame is constructed of thin-wall aluminum tubing, withthe frame members interconnected to form the triangle. A mast,which supports the planar array high-gain antenna and singlesolar panel, is attached to the top of the spaceframe. The basicframe weighs less than 60 pounds and installation hardware weighs23 pounds.The Surveyor stands about 10 feet high and, with its tri-pod landing gear extended, can be placed within a 14-foot circle.A landing leg is hinged to each of the three lower corners ofthe frame and an aluminum honeycomb footpad is attached to the

outer end of each leg. An airplane-type shock absorber andtelescoping lock strut are connected to the frame so that thelegs can be folded into the nose shroud during launch.Blocks of crushable aluminum honeycomb are attached to thebottom of the spaceframe at each of its three corners to absorb

part of the landing shock. Touchdown shock also is absorbed bythe footpads and by the hydraulic shock absorbers which compresswith the landing load.Two omnidirectional, conical antennas are mounted on theends of folding booms Which are hinged to the spaceframe. The

booms remain folded against the frame during launch until re-leased by squib-actuated pin pullers and deployed by torsionsprings. The antenna booms are released only after the landinglegs are extended and locked in position.An antenna/solar panel positioner atop the mast supportsand rotates the planar array antenna and solar panel in eitherd4.rection along four axes. This freedom of movement allows theantenna to be oriented toward Earth and the solar panel towardthe Sun.

Two thermal compartments house sensitive electronic ap-paratus for which active thermal control is needed throughoutthe mission. The equipment in each compartment is mounted ona thermal tray that distributes heat throughout the compartment.An insulating blanket, consisting of 75 eheats of aluminizedMylar, is sandwiched between each comparf-.&ent's inner shell andthe outer protective cover.

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SURVEYOR(LANDED POSITiON)

HIGH-GAINANTENNASOLAR PANEL

OMNIDIRECTIONAL - |ANTENNA A |i-THERMALLY CONTROLLED TV CAMERACOMPARTMENT A THERMALLY CONTROLLEDCOMPARTMENT BALPHA SCATTERING

INSTRUMENT ELECTRONICSRADAR ALTITUDE- CANOPUS STAR SENSORDOPPLER VIFLOCITYSENSOR t MNIDIRECTIONALPROPLLAA B

OOAFOOTPAD 3VERN IER X->-/PROPELLANT - 7-TANKS e >/ s\\/ - ATTITUDE CON;,Rt-OL\

FOOTPAD 2 /= // GAS TANK \ VERNIER ENGINF 3CRUSHABLE (NITROGEN) VERNER PROPELLANTBLOCK \ PRESSURIZING GASTANK ( HELIUM)

ALPHA SCATTERING INSTRUMENT

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The tops of the compartments are covered by mirrored glassthermal radiators to dissipate heat.Compartment A, which maintains an internal temperature be-tween 40 degrees and 125 degrees F, contains two radio re-ceivers, two transmitters, the main battery, battery charge reg-ulator, main power switch and some auxiliary equipment.Compartment B, kept between zero and 125 degrees F, housesthe central command decoder, boost regulator, central signal pro-cessor, signal processing auxiliary, engineering signal processor,and low data rate auxiliary.Both compartments contain sensors for reporting temperaturemeasurements by telemetry to Earth, and heater assemblies tomaintain the thermal trays above their allowable minimums, Thecompartments are kept below the 125-degree maximum with thermalswitches which provide a conductive path to the radiating sur-faces for automatic dissipation of electrically generated heat.Compartment A contains nine thermal switch s and compartment B,six. The thermal shell weight of compartment A is 25 pounds,

and compartment B, 18 pounds.Passive temperature control is provided for all equipment,not protected by the compartments, through the use of paintpatterns and polished surfaces.Twenty-nine pyrotechnic devices mechanically release orlock the mechanisms, switches and valves associated with theantennas, landing leg locks, roll actuator, retrorocket separa-tion attachments, helium and nitrogen tanks, shock absorbers andthe retromotor detonator. Some are actuated by command from theCentaur, and others are actuated by ground command.A solid propellant, spherical retrorocket fits within thecenter cavity of the triangular frame and supplies the mainthrust for slowing the spacecraft on approach to the Moon. Theunit is attached at three points on the spaceframe near thelanding leg hinges, with explosive nut separation points forejection after burnout. The motor case, made of high-strengthsteel and insulated with asbestos and rubber, is 36 inches indiameter. Including the molybdenum nozzles the unfueled motorweighs 144 pounds. With propellant, the weight is about 1,444pounds, or more than 60 per cent of the total spacecraft weight.Electrical harnesses and cables interconnect the spacecraftsubsystems to provide correct signal and power flow. The harnessconnecting the two thermal compartments is routed through a ther-mal tunnel to minimize heat loss from the compartments. Coaxialcable assemblies, attached to the spaceframe by brackets andclips, are used for high frequency transmission.

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Electrical interface with the Centaur stage is establishedthrough a 51-pin connector mounted on the bottom of the space-frame between two of the landing legs. The connector mates withthe Centaur connector when the Surveyor is mounted to the launchvehicle. It carries pre-separation commands from the Centaurprogrammer and can handle emergency commands from the blockhouseconsole. Ground power and prelaunch monitor also pass throughthe connector.Power Subsystem

The power subsystem collects and stores solar energy, con-verts it to usable electric voltage, and distributes it to theother spacecraft subsystems. The subsystem consists of the solarpanel, a main battery, a battery charge regulator, main powerswitch, boost regulator, and an engineering mechanism's auxiliary.The solar panel is the spacecraft's primary power sourceduring flight and during operations in the lunar day. It con-sists of 3,626 solar cells arranged on a thin, flat surface ap-proximately nine square feet in area. The solar cells aregrouped in 518 separate modules and connected in series-parallelto guard against complete failure in the event of a single cellmalfunction.The solar panel is mounted at the top of the Surveyor space-craft's mast. Wing-like, it is folded away during launch and de-ployed by Earth-command after the spacecraft has been injectedinto the lunar transit trajectory.When properly oriented during flight, the solar panel cansupply about 85 watts in transit, most of the power required forthe average operating load of all on-board equipment.During operation on the lunar surface, the solar panel canbe adjusted by Earth-command to track the Sun within a few de-grees, so that the solar celils remain always perpendicular tothe solar radiation.In this lunar-surface mode, the solar panel is designed tosupply a minimum of 81 watts power at a temperature of 143 de-grees F, and a minimum of 60o5 watts at a temperature of 250degrees F.A 14-cell rechargeable, silver-zinc main 'battery is th espacecraft's power reservoir. It is the sole source of powerduring launch; it stores electrical energy from the solar panelduring transit and lunar-day operations; and it provides a back-up source to meet peak power requirements during both of thoseperiods.

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Fully charged, the battery provides 3,800 watt-hours at adischarge rate of 1.0 amperes. Battery output is approximately22 volts direct current for all operating and environmental con-ditions in temperatures from 40 degrees to 125 degrees F.The battery charge regulator and the booster regulator arethe two power conditioning elements of the spacecraft's electri-cal power subsystem.The battery charge regulator couples the solar panel to themain battery for maximum conversion and transmission of the solarenergy necessary to keep the main battery at full charge.It receives power at the solar panel's varying output volt-age, and it delivers this power to the main battery at a con-stant battery terminal voltage.The battery charge regulator includes sensing and logiccircuitry for automatic battery charging whenever battery volt-age drops below 27 volts direct current. Automatic battery

charging also maintains battery manifold pressure at approxi-mately 65 pounds per square in'eh.Earth-command may override the automatic charging functionof the battery charge regulator.The booster regulator unit receives unregulated power from17 to 27.5 volts direct current from the solar panel, the mainbattery, or both, and delivers a regulated 29 volts direct cur-rent to the spacecraft's three main power transmission lines.These three lines supply all the spacecraft's power needs, ex-cept for a 22-volt unregulated line which serves heaters, switches,

actuators, solenoids and electronic circuits which do not requireregulated power or provide their own regulation.Telecommunications

Communications equipment aboard Surveyor has three func-tions: to provide for transmission and reception of radio sig-nals; to decode commands sent to the spacecraft; and to selectand convert engineering and television data into a form suitablefor transmission.The first group includes the three antennas: one high-

gain, directional antenna and two low-gain, omnidirectional an-tennas, two transmitters and two receivers with transponderinterconnections. Dual transmitters and receivers are used forreliabil ty.more


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The high-gain antenna transmits 600-line television data.The low-gain antennas are designed for command reception andtransmission of other data including 200-line television datafrom the spacecraft. The low-gain antennas are each connectedto one receiver. The transmitters can be switched to eitherlow-gain antennas or to the high-gain antenna and can operateat low or high-power levels. Thermal control of the three an-tennas is passive, dependent on surface coatings to keep tem-peratures within acceptable limits.The command decoding group can handle up to 256 commandseither direct, (on-off) or quantitative (time-intervals). Eachincoming command is checked in a central command decoder whichwill reject a command, and signal the rejection to Earth, ifthe structure of the command is incorrect. Acceptance of a com-mand is also radioed to Earth. The command is then sent to sub-system decoders that translate the binary information into anactuating signal for the function command such as squib firingor changing data modes.Processing of most engineering data, (temperatures, vol-

tages, currents, pressures, switch positions, etc.) is handledby the engineering signal processor or the auxiliary processor.There are over 20C engineering measurements of the spacecraft.None are continuously reported. There are four commutators inthe engineering signal processor to permit sequential samplingof selected signals. The use of a commutator is dependent onthe type and amount of infornation required during variousflight sequences. Each commutator can be commanded into opera-tion at any time and at any of the five bit rates: 17.2, 137.5,550, 1,100 and 4,400 bits per second.Commutated signals from the engineering processors are

converted to 10-bit data words by an analog-to-digital converterin the central signal processor and relayed to the transmitters.The lcw bit rates are normally used for transmissions over thelow gain antennas and the low power levels of the transmitters.Prop .!Ior

The propulsion system consists of three liquid fuel vernierrocket engines and a solid fuel retromotor.The vernier engines are supplied propellant by three fueltanks and three oxidizer tanks. There is one pair of tanks,

fuel and oxidizer, for each engine. The fuel and oxidizer ineach tank is contained in a bladder. Helium stored under pres-sure is used to deflate the bladders and force the fuel andoxidizer into the feed lines. Tank capacity is 170.3 poundseach.-more-


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The oxidizer is nitrogen tetroxide with 10 per cent nitricoxide. The fuel is monomethyihydrazine monohydrate. An'igni-tion system is not required for the verniers as the fuel andoxidizer are hypergolic, burning upon contact. The throttlerange is 30 to 104 pounds of thrust.The main retro is used at the beginning of the terminaldescent to the lunar surface and slows the spacecraft from anapproach velocity of about 6,000 miles per hour to approximately

250 miles per hour. It burns an aluminum, ammonium-percholorateand polyhydrocarbon, case bonded composite type propellant witha conventional grain geometry.The nozzle has a graphite throat and a laminated plasticexit cone. The case is of high strength steel insulated withasbestos and silicon dioxide-filled buna-N rubber to maintainthe case at a low temperature level during firing.Engine thrust varies from 8,000 to 10,000 pounds over atemperature range of 50 to 70 degrees F. Passive thermal con-trol, insulating blankets and surface coatings will maintain

the grain above 50 degrees F. It is fired by a pyrogen igniter.The main retro weighs approximately 1,444 pounds and is sphericalshaped, 36 inches in diameter.Flight Control Subsystem

Flight control of Surveyor, control of its attitude andvelocity from Centaur separation to touchdown on the Moon, isprovided by: primary Sun sensor, automatic Sun acquisitionsensor, Canopus sensor, inertial reference unit, altitude mark-ing radar, inertia burnout switch, radar altimeter and Dopplervelocity sensors, flight control electronics, and three pairsof cold gas jets. Flight control electronics includes a digitalprogrammer, gating and switching, logic and signal data converterfor the radar altimeter and Doppler velocity sensor.The information provided by the sensors is processedthrough logic circuitry irn the flight control electronics toyield actuating signals to the gas jets and to the three liquidfuel vernier engines and the solid fuel main retromotor.The Sun sensors provide information to the flight controlelectronics indicating whether or not they are illuminated bythe Sun, This information is used to order the gas jets tofire and maneuver the spacecraft until the Sun sensors are ona direct line with the Sun. The primary Sun sensor consistsof five cadmium sulphide photo conductive cells. In flightSurveyor will continuously drift off Sun lock in a cycle lessthan plus or minus 0.3 degrees. The drift is continuouslycorrected by signals from the primary sensor to the flightelectronics ordering the pitch and yaw gas jets to fire tocorrect the drift.

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Locking on to the star Canopus requires prior Sun lock-on.Gas jets fire intermittently to compensate for drift to main-tain Canopus lock-on and thus control spacecraft roll duringcruise modes. If star or Sun lock is lost, control is automati-cally switched from optical sensors to inertial sensors (gyros).The inertial reference unit is also used during missionevents when the optical sensors cannot be used. These eventsare the midcourse maneuver and descent to the lunar surface.This device senses changes in attitude and in velocity of thespacecraft with three gyros and an accelerometer. Informationfrom the gyros is processed by the control electronics to ordergas jet firing to change or maintain the desired attitude. Dur-ing the thrust phases the inertial reference unit controlsvernier engine thrust levels, by differential throttling forpitch and yaw control and swiveling one vernier engine for rollcontrol. The accelerometer controls the total thrust level.The altitude marking radar will provide the signal forfiring of the main retro. It is located in the nozzle of theretromotor and is ejected when the motor ignites. The radarwill generate a signal at about 60 miles above the lunar sur-face. The signal starts the programmer automatic sequence aftera pre-determined period (directed by ground command); the pro-grammer then commands vernier and retro ignition and turns onthe Radar Altimeter and Doppler Velocity Sensor (RADVS).The inertia burnout switch will close when the thrust levelof the main retromotor drops below 3.5 g, generating a signalwhich is used by the programmer to command jettisoning of theretromotor and switching to RADVS control.Control of the spacecraft after main retro burnout isvested in the Radar Altimeter and Doppler Velocity Sensor.There are two radar dishes for this sensor. An altimeter/velo-city sensing antenna radiates two beams and a velocity sensingantenna two beams. Beams 1, 2, and 3 give vertical and trans-verse velocity. Beam 4 provides altitude or slant range infor-mation. Beams 1, 2, and 3 provide velocity data by summing inthe signal data converter of the Doppler shift (frequency shiftdue to velocity) of each beam. The converted range and velocitydata is fed to the gyros and circuitry logic which in turn con-trol the thrust signals to the vernier engines.The flight control electronics provide for processing sen-sor information into telemetry signals and to actuate spacecraftmechanisms. It consists of control circuits, a command decoderand an AC/DC electronic conversion unit. 7Tse programmer con-trols timing of main retro phase and generates precision timedelays for attitude maneuvers and midcourse velocity correction.

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The attitude jets provide attitude control to the space-craft from Centaur separation to main retro burn. The gas jetsystem is fed from a spherical tank holding 4.5 pounds of nitro-gen gas under high pressure. The system includes regulating anddumping valves and three pairs of opposed gas jets with solenoid-operated valves for each jet. One pair of jets is located atthe end of each of the three landing legs. The pair on leg num-ber one controlsmotion in a horizontal plane, imparting roll mo-tion to the spacecraft. Pairs two and three control pitch andyaw.

TelevisionThe Surveyor spacecraft carries one survey televisioncamera. The camera is mounted nearly vertically, pointed at amovable mirror. The mounting containing the mirror can swivel360 degrees, and the mirror can tilt either down to view a landingleg or up above the horizon.The camera can be focused, by Earth command, from four feetto infinity. Its iris setting, which controls the amount oflight entering the camera, can adjust automatically to the lightlevel or can be commanded from Earth. The camera has a variablefoc4l length lens which can be adjusted to narrow angle, 6.4 x6.4 field of view, to wide angle, 25.4 x 25.4 field of view.A focal plane shutter provides an exposure time of 150 mil-liseconds. The shutter can also be commanded open for an in-definite length of time. A sensing device coupled to the shutterwill keep it from opening if the light level is too intense. Atoo-high light level could occur from changes in the area ofcoverage by the camera, a change in the angle of mirror, in thelens aperture, or by changes in Sun angle. The same sensor con-trols the automatic iris setting. The sensing device can be

overridden by ground command.The camera system can provide 200 or 600-line pictures.The 600-line pictures require that the high gain directionalantenna and the high power level of the transmitter are both -operating. The 600-line mode provides a picture each 3.6 sec-onds and the 200-line mode every 61.8 seconds.A filter wheel can be commanded to one of fbur positions

proTiding clear, colored or polarizing filters.Two convex beryllium mirrors are mounted on the spacecraftframe near leg number one to provide additional coverage of thearea under the spacecraft for the television camera. The largermirror is 10 inches x 9 inches; the smaller is 31 inches x 9inches.

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The large mirror provides a view of the lower portion ofcrushable block number three and the area under vernier enginenumber three. The small mirror provides a view of the area thatwill be covered by the alpha scattering instrument when the lat-ter is deployed to the lunar surface.The purpose is to produce pictures of the lunar soil dis-

turbed by the spacecraft, landing, the amount of damage to crush-able block number three and examination of the alpha scatteringexperiment deployment area prior to deployment.Principal television investigator is Dr. Eugene Shoemaker,U. S. Geological Survey.


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-17A-SURVEYOR SURVEY TV CAMERA

HOOD iMIRROR

~-M IRRORMIRROR AZIMUTH LEVATIONDRIVE MOTOR P DRIVE ASSEMBLY

VARIABLE FILTER WHEELASSEMBLYFOCAL LENGTHLENS ASSEMBLYFOCUSPOTENTIOMETERIRIS IPOTENTIOMETER

VIDICON TUBESHUTTER mASSEMBLY -IIO

RADIATORELECTRONICCONVERSIONUNIT

ELECTRICALCONNECTOR

-IfQP'

m_ _ _ _ _ _ _ __ _ _ _ _ _ _ __ _ _ _ _ _ _ _ 1


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Alpha Scattering ExperimentThe purpose of this experiment is to provide an analysisof the constituents of lunar soil.The chemical composition of an extraterrestrial body isone of the basic scientific findings that can be determinedabout that body. Chemical analysis of the Moon can providea clue to the history and present stage of development of

the Moon.The analysis might determine if any of the meteoritesfalling on the Earth are of lunar origin.The alpha particle scattering experiment is a newtechnique for chemical analysis, which detects the interactionof alpha particles with the atomic nuclei of elements presentin the lunar surface. Alpha particles striking these nucleiare scattered in a known manner depending on the type ofnuclei. Some nuclei when struck by alpha particles also emitprotons with known characteristics.The instrument is designed to bombard the lunar surfacewith alpha particles from a radio-active source, Curium 242.Two types of detectors in the instrument, two for alphaparticles and four for protons, provide a measurement of theenergies of the scattered alpha particles and protons and thenumber of scattered alpha particles and protons.The energy and number of scattered alpha particles andprotons will vary depending on the type of atoms encounteredin the lunar soil by the alpha particles emitted by the radio-active source. The alpha scattering detector-analyzer system

detects scattered alpha particles from all elements excepthydrogen, helium and lithium. The proton detector systemdetects protons from boron, nitrogen, fluorine, sodium,magnesium, aluminum,silicon, phosphorus, sulfur, chlorineand potassium. Sensitivity of the measurement varies fromone element to another.The instrument is carried in-flight folded up againstthe spacecraft. After landing the system is checked byanalysis of an onboard material of known composition. Theinstrument is then partially deployed to obtain a backgroundmeasurement and then lowered by a nylon line to contact the

lunar surface. The alpha particles will penetrate a thin,top layer of lunar soil to a depth of about one-thousandthof an inch.

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SURVEYOR ALPHA SCATTERING INSTRUMENTALPHA DETECTORS (2) IDENTIFYLUNAR SURFACE ATOMS BY RADIOACTIVE SOURCES(6)MEASURING ENERGY OF ALPHA OF ALPHA PARTICLESPARTICLES REFLECTED FROMNUCLEI OF ATOMS

PROTON DETECTORS (4)f \ IDENTIFY LUNAR SURFACEATOMS BY MEASURINGENERGY OF PROTONS

SPLIT OFF NUCLEI OF ATOMS gBY ALPHA PARTICLES

ALPHA PARTICLES PENETRATESURFACE ABOUT 1/1000OFAN INCH


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The instrument is packaged in two parts, the sensorhead, which is deployed to the lunar surface, and the digitalelectronics package. The sensor head contains the radio-active source, alpha detectors, proton-detectors, sensor headelectronics and a heater.The electronics package contains command decoder logiccircuitry, power supply, and the logic circuitry required toconvert the various values detected into binary data for

transmission. The electronics package is contained in aspecial thermal compartment on the spacecraft. Each binaryword will contain nine bits, one sync bit, seven data bitsand a parity check bit.The instrument is attached to the spacecraft by abracket and metal arm. The checking sequence is performedwithout deploying the instrument. The instrument is deployedby lowering it to the lunar surface by a nylon cord attachedto an eye-bolt on the sensor head. The cord is wrapped arounda geared cylinder that unwinds under the pull of lunar gravityand allows the device to drop to the lunar surface in a series

of controlled steps. However, during the partial deploymentsequence the cord is restrained from unwinding by a lockmechanism. Sufficient slack is provided in the cord for thepartial deployment. The lock is released by firing anexplosive squib on Earth command, for full deployment.The sensor head, electronic compartment and deploymentdevice total 28 pounds.Principal investigator for the experiment is Dr. A.Turkevich, University of Chicago; co-investigators areErnest Franzgrote, JPL, and James H. Patterson, Argonne

National Laboratory.Magnetic Test

The purpose of this test, utilizing a small magnetattached to a footpad, is to determine whether magneticparticles are present in the surface layer of lunar soil.The magnet is a bar, two inches long by i inch wide by1/8 inch thick, mounted vertically on a footpad #2 in view ofthe television camera. Photographs of the bar taken atvarious Sun angles would show magnetic particles attractedto the magnet if there are any on the lunar surface.A second bar -- nonmagnetic-- is also mounted on the foot-pad to serve as a control for the test by permitting a com-parison of the amount of material adhering to the nonmagneticbar, if any, with the amount adhering to the magnetic bar.

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PARALLEL TO G*LE G CENTER LINE - or

Ir.

/LNON-MAGNETIC BARBRACKET MAGNETIC BAR

2 x 1/2 x 1/8 IN .

--


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-20- A

The magnet is made of an iron-nickel-cobalt-aluminumalloy. The control bar is an alloy of iron-nickel-cobaltwhich has a very low magnetic permeability. The two barsare screwed to a mounting bracket which is attached to thefootpad. Weight of the entire assembly is about two ounces.The bars and mounting are painted droll light blue for con-trast to dark lunar material.Engineering Instrumentation

Engineering evaluation of the Surveyor flight will beaugmented by an engineering payload including an auxiliaryprocessor for engineering information, and instrumentationconsisting of extra temperature sensors, strain gauges forgross measurements of vernier engine response to flightcontrol commands and Chock absorber loading at touchdown,and extra accelerometers for measurements of vernier engineresponse to flight control commands and shock absorber loadingat touchdown, and extra accelerometers for measuring structuralvibration during main retro burn.The auxiliary engineering signal processor provides twoadditional telemetry commutators for determining the per-formance of the spacecraft. It processes the information inthe same manner as the engineering signal processor, pro-viding additional signal capacity and redundancy.

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ATLAS-CENTAUR LAUNCH VEHICLESurveyor E will be launched toward the Moon by a morepowerful, stretched-out version of the Series D Atlas booster.Called the Standard Launch Vehicle (SLV-3C), the newbooster, combined with the Centaur second stage, has thecapability to launch a 2,500-pound Spacecraft on a two-burn,parking orbit trajectory to the Moon. Surveyors E, F and G.which will complete the Surveyor lunar program, are allscheduled to be launched to the Moon using two-burn tra-jectories.Basic changes in the SLV-3C booster are:1. Propellant capacity has been increased by some 21,000pounds by lengthening the booster 51 inches. TheSLV-3C booster now has a total propellant capacityof 271,000 pounds, including 187,000 pounds ofliquid oxygen and 84,000 pounds of RP-1, a refinedkerosene fuel.2. Thrust of the SLV-3C ha3 been increased by 7,000pounds, giving the booster a total liftoff thrustof 395,000 pounds. The two booster engines wereincreased 3,000 pounds each to 168,000 and the singlesustainer engine was increased from 57,000 to 58,000.The thrust increase was achieved by resetting theengine regulators to provide maximum performance.The added propellant capacity and increased engineperformance means the SLV-3C will burn some 10 seconds longerduring booster flight. The modifications also provide a

significant increase in SLV-3C/Centaur's payload capabilityfor lunar and planetary niissions.LAUNCH VEHICLE CHARACTERISTICS

(All figures approximate)Liftoff weight: 322,300 lbs.Liftoff height: 117 feetLaunch Complex: 36-BLaunch Azimuth: Variable: 78-115 degrees

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-22-SLV-30 Booster Centaur Stage

Weight: 284,500 lbs. 37,800 lbs.Height: 79 feet (including 48 feet (with pay-interstage adapter) load fairing)Thrust: 395,000 lbs. (sea 30,000 lbs.level) (vacuum)Propellants: Liquid oxygen and Liquid hydrogenRP-1 and liquid oxygenPropulsion: MA-5 system (2- Two 15,000-1b.-168,000-lb.-thrust thrust RL-10 enginesengines, 1-58,000,2-670)Velocity: 5800 mph at BECC 23,600 mph at8200 mph at SECO injectionGuidance: Pre-programmed auto- Inertial guidancepilot through BECO

AC-13 consists of an SLV-3C booster combined with aCentaur second stage. Both stages are 10 feet in diamenterand are connected by an interstage adapter. Both the Atlasand Centaur stages rely on pressurization for structuralintegrity.The Atlas first stage is 79 feet high, including theinterstage adapter, and uses an uprated MA-5 propulsion system.It consists of two booster engines and a sustainer engine,

developing 395,000 pounds of thrust. Two vernier engines of670 pounds thrust each provide roll directional control.The Centaur second stage including the nose fairing is48 feet long. It is powered by two improved RL-10 hydrogen-oxygen engines, designated RL-16 A-3-3. The RL-10 was thefirst hydrogen-fueled engine developed for the space program.Centaur carries ins latlon panels and a nose fairing whichare jettisoned after tht- vehicle leaves the Earth's attaos-phere. The insulation panels, weighing about 1,200 pounds,surround the second stage hydrogen tanks to prevent the heatof air friction from causing excessive boil-off of liquidhydrogen during flight through the atmosphere. The nose fair-ing protects the payload from this same heat environment.

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ATLAS-CENTAUR FLIGHT SEQUENCE*NOMINAL TIME, ALTITUDE SURFACE MILES, VELOCITYEVENT SECONDS STATUTE MILES STATUTE MILES MPH

Liftoff o O 0 0Booster Engine Cutoffand Booster Jettison 153 37 48 5,800Jettison Insulation 198 61 111 6,700

PanelsJettsion Nose Fairing 228 75 161 7,500Sustainer Engine Cutoff 248 84 197 8,200and Atlas SeparationCentaur Engine Start 260 88 219 8,200Centaur Engine Cutoff 580 108 1,089 16,500Coast in Earth Orbit ---Centaur Second Burn 1,042 108 3,213 16,500Centaur Engina Cutoff 1,155 114 3,733 23,600Spacecraft Separation 1,219 142 4,o80 23,60cStart Centaur Re- 1,224 145 4,107 23,600orientationStart Centaur Retro- 1,459 440 5,310 22,600thrust*Nominal times of events are directly influenced by the time of launch which determinesthe parking orbit duration. Nominal times given are for a launch azimuth of 78 days andparking orbit coast time of 7.7 minutes.

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TRACKING AND COMMUNICATIONThe flight of the Surveyor spacecraft from injectionto the end of the mission will be monitored and controlledby NASA's Deep Space Network (DSN) and Space Flight OperationsFacility (SFOF) operated by the Jet Propulsion Laboratory.Some 300 persons will be involved in Surveyor flightmonitoring and control during peak times in the mission. Onthe Surveyor I flight more than 100,000 ground commands were

received and acted on by the spacecraft during flight andafter the soft landing.The Deep Space Network consists of five permanent spacecommunications stations in Australia, Spain, South Africaand Califcrnia; a spacecraft monitoring station at CapeKennedy; and a spacecraft guidance and a command station atAscension Island in the South Atlantic. The two Australiastations are at Woomera and Canberra; the Spain station nearMadrid comprises two antenna facilities; the Californiastation comprises three facilities. One facility is atJohannesburg, South Africa.Of the DSN facilities those assigned to the Surveyorproject are Pioneer at Goldstone, Calif.; Robledo, Spain;Tidbinbilla in the Canberra complex, Australia; AscensionIsland; and Johannesburg, South Africa.The Goldstone facility is operated by JPL with theassistance of the Bendix Field Engineering Corp. TheTidbinbilla facility is operated by the Australia Departmentof Supply. The Robledo facility is operated by JPL under anagreement with the Spanish government and the support ofInstituto Nacional de Tecnica Aeroespacial (INTA) and the

Bendix Field Corp. The Ascension Island DSN facility isoperated by JPL with Bendix support under a cooperativeagreement between the United Kingdom and the U.S.The DSN uses a ground communications system foroperational control and data transmission between thesestations. The ground communications system is a part of alarger net (NASCOM) which links all of the NASA stationsaround the world. This net is under the technical directionof NASA's Goddard Space Flight Center, Greenbelt, Md.The DSN supports the Surveyor flight in tracking thespacecraft, receiving telemetry from the spacecraft, andsending it commands. The DSN renders this support to a ll ofNASA's unmanned lunar and planetary spacecraft from the timethey are injected into planetary orbit until they completetheir missions.

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-25-Stations of the DSN receive the spacecraft radio signals,amplify them, process them to separate the data from thecarrier wave and transmit required portions of the data tothe command center via high-speed data lines, radio links,and teletype. The stations are also linked with the centerby voice lines. All incoming data are recorded on magnetictape.

The information transmitted from the DSN stations to theSFOF is fed into large scale computer systems which translatethe digital code into engineering units, separate informationpertinent to a given subsystem on the spacecraf X and drivedisplay equipment in the SFOF to present the information to theengineers on the project. All incoming data are again recordedin the computer memory system and are available on demand.Equipment for monitoring television reception fromSurveyor is located in the SFOF.Some of the equipment is designed to provide quick-lookinformation for decisions on commanding the camera to changeiris settings, change the field of view from narrow angle towide angle, change focus, or to move the camera eitherhorizontally or vertically. Television monitors display thepicture being received. The pictures are received line byline and each line is held on a long persistence televisiontube until the picture is complete. A special camera systemproduces prints of the pictures for quick-look analysis.Other equipment will produce better quality pictures fromnegatives produced by a precision film recorder.Commands to operate the camera will be prepared inadvance on punched paper tape and forwarded to the stationsof the DSN. They will be transmitted to the spacecraft fromthe DSN station on orders from the SFOF.Three technical teams support the Surveyormission in the SFOF: one is responsible for determining thetrajectory of the spacecraft including determination of launchperiods and launch requirements, generation of commands forthe midcourse and terminal maneuvers; the secoi. I is responsiblefor continuous evaluation of the condition of the spacecraftfrom engineering data radioed to Earth; the third is responsiblefor evaluation of data regarding the spacecraft and forgenerating commands controlling the spacecraft operations.

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TRAJECTORYThe determination of possible launch days, specific timesduring each day and the Earth-Moon trajectories for the Sur-veyor spacecraft are based on a number of factors, or

constraintseA primary constraint is the time span during each day theSurveyor can be launched -- the launch window -- which is de-termined by the requirement that the launch site at launch timeand the Moon at arrival time be contained in the Earth-Moontransfer orbit plane. With the launch site moving eastward asthe Earth revolves, acceptable conditions occur only once eachday for a given plane.The launch azimuth constraint of 78 to 115 degrees is im- #posed by th e range safety consideration of allowing the initiallaunch phase only over th e ocean, not over land masses.The time of fl ight, or the time to landing, about 61-65holrs, is determined by the constraint placed upon the trajec-tory engineer that Surveyor must reach the Moon during the view-ing period of the prime Deep Space Net station at Goldstone inthe California Mojave Desert.Landing sites are further limited by the curvature of theMoon. The trajectory engineer cannot pick a site, even if it

falls within the acceptable band, if the curvature of the Moonwill interfere with a direct communication line between th espacecraft and the Earth.Two other factors in landing site selection are smoothnessof terraln and a requirement for Surveyor to land, in areas sex-lected for the Apollo manned lunar mission,,Thum th e trajectory engineer must tie together the launchcharacteristics, th e landing site location, the declination ofthe Moon and fl ight time, in determining when to launch, inwhich direction, and at what velocity.His chosen trajectory also must not violate constraints onthe time allowable that the Surveyor can remain in the Earthtsshadow. Too long a period can result in malfunction of com-ponents or subsystems. In addition, the Surveyor must not re-main in the shadow of the Moon beyond given l im its.

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SURVEYOR TRAJECTORIES TO THE MOON

PARKING ORBIT TRAJECTORYON DIRECT ASCENT LAUNCH WITH 2 FIRINGS OF SECOND STAGE ENGINES,EN D OF SECOND STAGE ENGINES' AND COAST PHASE BETWEEN, SURVEYOR CANSINGLE FIRING ALWAYS ENDS REACH ANY MOON POSITION ABOVE OR BELOWNEAR CAPE ABOVE EOUATOR EARTH'S EQUATORDIRECT ASCENT TRAJECTORY*WITH SINGLE FIRING OF SECOND STAGE ENGINESSURVEYOR CAN REACH MOON ONLY WHEN MOONax / / \IS BELOW EARTH'S EOUATOR

COAST PHASE /ON PARKING ORBIT LAUNCH -- -EN D OF SECOND FIRING OFSECOND STAGE ENGINES CANOCCUR BELOW EQUATOR BYINCREASING COAST TIMEBETWEEN FIRINGSi-'

DOTTED LINES SHOW MAXIMUM AMOUNT DIRECT ASCENTTRAJECTORY CAN BE ADJUSTED TO REACH DIFFERENTMOON POSITIONS

MOONeS ORBIT -''EARLY SURVEYORS WILL BE LAUNCHED ON DIRECTASCENT TRAJECTORIES

. ~~~~~~~~~~- .-..-i,-----


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The velocity of the spacecraft when it arrives at the Moon.tst also fall within defined limits. These limits are definedby the retrorocket capability, The velocity relative to theMoon is primarily correlated with the flight time and the Earth-Moon distance for each launch day.So, a further requirement on the trajectory engineer is theamount of fuel available to slow the Surveyor from its lunar ap-proach speed of 6,ooo mph to nearly zero velocity,13 feet abovethe Moon's surface. The chosen trajectory must not yield velo-cities that are beyond the designed capabilities of the space-craft propulsion system.Also included in trajectory computation is the influence onthe flight path and velocity of the spacecraft of the gravita-tional attraction of primarily the Earth and Moonand to a lesserdegree the Sun, Mercury, Venus, Mars, and Jupiter.It is not expected that the launching can be performed withsufficient accuracy to impact the Moon in exactly the desiredarea. The uncertainties involved in a launch usually yield atrajectory or an injection velocity that vary slightly from thedesired values. The uncertainties are due to inherent linita-tions in the guidance system of the launch vehicle. To compen-sate, lunar and deep space spacecraft have the capability of per-forming a midcourse maneuver or trajectory correction. To alterthe trajectory of a spacecraft it is necessary to apply thrust,or energy, in a specific direction to change its velocity, thetrajectory of a body at a point in space being basically deter-mined by its velocit.y.For example, a simple midcourse might involve correcting a

too high injection velocity. To correct for this the spacecraftwould be commanded to turn in space until its midcourse engineswere pointing in its direction of travel. Thrust from the en-gines would slow the craft. However, in the general case themidcourse is far more complex and will involve changes in speedand direction of travel.A certain amount of thrust applied in a specific directioncan achieve both changes. Surveyor will use its three liquidfuel vernier engines to alter its flight path in the midcoursemaneuver. It will be commanded to roll and then to pitch or yawin order to point the three engines in the required direction.

The engines then burn long enough to apply the change in velocityrequired to alter the trajectory.The change in the trajectory is very slight at this pointand a tracking period of about 20 hours is required to determinethe new trajectory. This determination will also provide the datarequired to predict the spacecraft's angle of approach to theMoon, time of arrival, and its velocity as it approaches the Moon.


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E - - *. -

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ATLAS-CENTAUR 13/SURVEYOR E FLIGHT PLANThe Atlas-C ntaur 13 vehicle must inject the Surveyor Espacecraft on a lunar intercept trajectory with sufficientaccuracy so that the midcourse maneuver required of thespacecraft is within its capability. The Centaur stage willexecute a retromaneuver after spacecraft separation to ensurethat the vehicle and spacecraft are adequately separated.Surveyor E will be launched toward the Moon followingprimary boost by an Atlas, injection of the Centaur stageand spacecraft into a 100-statute mile Earth parking orbit,and final injection of the spacecraft to the Moon followinga variable-length coast phase. Depending on time of launch,the coast phase will vary from 2 to 15 minutes.

Launch Periods

Launch WindowDate Open CloseSept. 8 3:39 a.m. 5:29 a.m.Sept. 9 5:06 a.m. 6:29 a.m.Sept. 10 5:56 a.m. 7:30 a.m.Sept. 11 6:17 a.m. 8:30 a.m.Sept. 12 6:25 a.m. 9:29 a.m.Sept. 13 6:29 a.m. 10:23 a.m.

Atlas PhaseAfter liftoff AC-13 will rise vertically for the first15 seconds, then roll to the desired flight plane azimuthbetween 78 and 115 degrees. During booster engine flight,the vehicle is steered by the Atlas autopilot.After 153 seconds of booster flight, the booster enginesare shut down (BECO) and jettisoned. The Centaur guidancesystem then takes over flight control. The Atlas sustainerengine continues to propel the AC-13 vehicle to an altitudeof about 84 miles. Prior to sustainer engine shutdown, thesecond stage insulation panels are jettisoned, followed bythe nose fairings.The Atlas and Centaur stages are then separated by anexplosive, shaped charge and retrorockets mounted on the Atlas.

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SURVEYOR FLIGHT PROFILE

SEPARATION ATLAUNCH PLUS37 MIN.CANOPUS ACQUISITIONABOUT LAUNCH PLUS 6 HRS

.- COMPtETES CRUISE ATTITUDE PRE-RETRO MANEUVERSTABILIZATION 30 MIN. BEFORE LANDINGSUN

SUN ACQUISITIONABOUT LAUNCH STAR / 63 HRSPLUS 1 HR CANOPUS / /\ S0C/ \ SUN AND CANOPUS REACQUISITIONIMMEDIATELY AFTER MIDCOURSE OC

MIDCOURSE CORRECTION CORRECTION [jABOUT LAUNCH PLUS 15 48 HRS

'024 HRS

MOONAT LAUNCH

-- - .r- - -- i ^-


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Centaur PhaseCentaurts hydrogen engines are then ignited fo r a planned I 2320-second burn. This will place Centaur and the Surveyorspacecraft into a 100-mile Earth parking orbit.As Centaur's engines are shut down and the coast phasebegins, two 50-pound-thrust hydrogen-peroxide rockets are firedto settle the propellants.Two hydrogen-peroxide ullage rockets, each with threepounds thrust, are then fired continuously during the coastperiod to retain the propellants in the lower part of thetanks.About 40 seconds before Centaur's second burn, the two50-pound thrusters are again used to insure proper propellantsettling.Once Centaur is in the proper position to inject theSurveyor toward the Moon, the hydrogen-fueled main enginesare ignited fo r an approximate 113-second burn. The second-burn command and duration of the burn are determined byCentaur's inertial guidance system, as are all command andsteering functions following Atlas booster engine cutoff andjett ison.

SeparationThe Surveyor spacecraft is separated from Centaur andinjected toward the Moon.Following spacecraft separation, the Centaur vehicle willperform a 180-degree reorientation maneuver, using its attitude

control system.Centaur's velocity is then changed by retro-thrusting.The thrust fo r this maneuver is produced by two 50-poundhydrogen-peroxide thrusters as well as by 'blowing" residual,or unused, propellants through Centaur's main engines.As a result of this retromaneuver the Centaur and thespacecraft will be separated by at least 200 statute miles,five hours after launch.The Centaur vehicle will continue in a highly-elliptical

Earth orbit with a period ranging from ten to thirteen days.

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ma\- Ar-..

-30-First Surveyor Events

Shortly after Centaur engine shutdown, the programmercommands Surveyor's legs and two omnidirectional antennasto extend and orders the spacecraft's transmitter to highpower.After Surveyor separates from the Centaur, an automaticcommand is given by the spacecraft to fire explosive boltsto unlock the solar panel. A stepping motor then moves thepanel to a prescribed position. Solar panel deployment canalso be commanded from the ground if the automatic sequencefails.

Surveyor will then perform an automatic Sun-seeking man-euver to stabilize the pitch and yaw axes and to align itssolar panel with the Sun for conversion of sunlight to elec-tricity to power the spacecraft. Prior to this event thespacecraft main battery is providing power.The Sun acquisition sequence begins immediately afterseparation from Centaur and simultaneously wiith the solar paneldeployment. The nitrogen gas jet system, which is activatedat separation, will first eliminate random pitch, roll andyaw motions resulting from separation from Centaur. Then asequence of controlled roll and yaw turning maneuvers iscommanded for Sun acquisition.Sun sensors aboard Surveyor will provide signals to theattitude control gas jets to stop the spacecraft when it ispointed at the Sun. Once locked on the Sun, the gas jetswill fire intermittently to control pitch and yaw attitude.Pairs of attitude control jets are located on each of the tireelanding legs of the spacecraft.In the event the spacecraft does not perform the Sunseeking maneuver automatically, this sequence can be com-manded from the ground.The next critical step for Surveyor is acquisition ofits radio signal by the Deep Space Net tracLing stations atAscension Island and Johannesburg, South Africa, the firstDSN stations to see Surveyor after launch.It is critical at this point to establish the communi-cations link with the spacecraft to receive telemetry to

quickly determine the condition of the spacecraft, for com-mand capability to assure control, and for Doppler measure-ments from which velocity and trajectory are computed.

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The transmitter can only operate at high power forapproximately one hour without overheating. It is expected,however, that the ground station will lock on to the space-craft's radio signal within 40 minutes after launch and ifoverheating is indicated, the transmitter can be commandedto low power.The next major spacecraft event after the Sun has beenacquired is Canopus acquisition. Looking on the starCanopus provides a fixed inertial reference for the rollorientation.

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Canopus AcquisitionCanopus acquisition will be commanded from the groundabout six hours after launch. The gas jets will fire to rollthe spacecraft at 0.5 degree per second. When the sensorsees the predicted brightness of Canopus (the brightest starin the Southern Hemisphere) it will order the roll to stopand lock on the star. The brightness of the light sourceit is seeing will be telemetered to Earth to verify thatit is locked on Canopus.Verification can also be provided by a ground commandordering a 360 degree roll and the plotting of each light sourcethe sensor sees that is in the sensitivity range of the sensor.(The sensor will ignore light levels above and below givenintensities.) This star map can be compared with a map pre-pared before launch to verify that the spacecraft is locked onCanopus.Now properly oriented on the Sun and on Canopus, Sur-veyor is in the coast phase of the transit to the Moon.Surveyor is transmitting engineering data to Earth andreceiving commands via one of its omnidirectional antennas.Tracking data is obtained from the pointing direction ofground antenna and observed frequency change (Doppler).The solar panel is providing electrical power andadditional power for peak demands is being provided by one oftwo batteries aboard. The gas jets are firing intermittentlyto keep the craft aligned on the Sun and Canopus.The engineering and tracking information is receivedfrom Surveyor at one of the stations of the Deep Space Net.The data is communicated to the Space Flight OperationsFacility (SFOF) at the Jet Propulsion Laboratory in Pasa-dena where the flight path of the spacecraft is carefullycalculated and the condition of the spacecraft continuouslymonitored.

Midcourse ManeuverTracking data will be used to determine how large atrajectory correction must be made to land Surveyor in thegiven target area. This trajectory correction, called themidcourse maneuver, is required because of many uncertain-ties in the launch operation that prevent absolute accuracyin placing a spacecraft on a trajectory that will interceptthe Moon precisely at the desired landing point.The midcourse maneuver is timed to occur over the Goldstonestation of the DSN in the Mojave Desert, the tracking stationnearest the SFOF at JPL.

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SURVEYOR MIDCOURSE CORRECTION

CRUISE ATTITUDE

-I. aYAW (O R HTCH) TURN

,STAR me --swCANOPUS

SUN AN D CANOPUSROLL TURN -REACQUISITION

VERNIER ENGINES BURN


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-33-The thrust for the midcourse maneuver will be provided bythe spacecraft's three liquid fuel vernier engines. Total thrustlevel is controlled by an accelerometer at a constant accel-eration equal to 0.1 Earth g (3.2 ft/sec/sec). Pointingerrors are sensed by gyros which can cause the individualengines to change thrust level to correct pitch and yawerrors and swivel one engine to correct roll errors.Flight controllers determine the required trajectorychange to be accomplished by the midcourse maneuver. Ino 'der to align the engines in the proper direction to applythrust to change the trajectory, or flight path, Surveyor willbe commanded to roll, then pitch or yaw to achieve thisalignment. Normally, two maneuvers are required, a roll-pitchor a roll-yaw.The duration of the first maneuver is radioed to thespacecraft, stored aboard and re-transmitted back to Earthfor verification. Assured tnat Surveyor has received the

proper information, it is then commanded to perform thefirst maneuver. When completed, the second maneuver ishandled in the same fashion. With the spacecraft now alignedproperly in space, the number of seconds of required thrust istransmitted to the spacecraft, stored, verified and thenexecuted.In the event of a failure of the automatic timer aboardthe spacecraft which checks out the duration of each maneuverturn and firing period, each step in the sequence can beperformed by carefully timed ground commands.After completion of the midcourse maneuver, Surveyorreacquires the Sun and Canopus. Again Surveyor is in thecruise mode and the next critical event will be the terminal

maneuver.Terminal Sequence

The first step starts at about 1,000 miles above theMoon's surface. The exact descent maneuvers will depend onthe flight path and orientation of the Surveyor with respectto the Moon and the target area. Normally they will be aroll followed by a yaw or a pitch turn. As in the midcoursemaneuver, the duration times of the maneuvers are radioedto the spacecraft and the gas jets fire to execute the re-quired roll. and pitcrh and yaw. The obJect of the maneuveris to alian the main retro solid rocket with the descentpath. To perform the maneuvers, the spacecraft will breakits lock on the Sun and Canopus. Attitude control will bemaintained by inertial sensors. Gyros will sense changes inthe attitude and order the gas jets to fire to maintain thecorrect attitude until the retrorocket is ignited.

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-33A- I4SURVEYOR TERMINAL DESCENTTO LUNAR SURFACECRUISE ATTITUtE -1CRS (Approximate Altitudes and Velocities Given)

PRE-RETRO MANEUVER 30 MIN.BEFORE TOUCHDOWN ALIGNSMAIN RETRO WITH FLIGHT PATH

MAIN RETRO START BY ALTITUDEMARKING RADAR WHICH EJECTSFROM NOZZLE, CRAFT STABILIZEDBY VERNIER ENGINES AT60 Mi. ALTITUDE, 6,100 MPH

t MAIN RETRO BURNOUT AND EJECTION,VERNIER RETRO SYSTEM TAKEOVER AT25,000 FT, 240 MPH

VERNIER ENGINES SHUTOFFAT 13 FT , 3'/2 MPH

A~ TOUCHDOWN AT 10 MPH-wire-


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With the spacecraft properly aligned, the altitude mark-ing radar will be activated, by ground command, at approximately200 miles above the Moonrs surface. All subsequent terminalevents will be automatically controlled by radars and theflight control programmer.At approximately 60 miles' slant range from the Moon'ssurface, the marking radar starts the flight control program-mer clock which then counts down a previously-stored delaytime and then commands ignition of the solid propellant mainretro and the three liquid fueled, throttleable vernierengines. The vernier engines maintain a constant spacecraftattitude during main retro firing in the same manner as duringmidcourse thrusting.The spacecraft will be traveling at approximately 6,000miles-per-hour. The main retro will burn out in 40 secondsat about 25,000 feet above the surface after reducing thevelocity to about 250 miles-per-hour. The casing of the mainreti-o is separated from the spacecraft, on command from theprogrammer 12 seconds after burnout, by explosive bolts andfalls free.After burnout the flight control programmer will controlthe thrust level of the vernier engines until the Radar Alti-meter and Doppler Veloctty Sensor (RADVS) locks up on itsreturn signals from the Moon's surface.Descent will then be controlled by the RADVS and thevernier engines. Signals from RADVS will be processed by theflight control electronics to throttle the three vernierengines reducing velocity as the altitude decreases. At 13feet above the surface, Surveyor will have been slowed tothree miles per hour. At this point the engines are shut offand the spacecraft free falls to the surface.Immediately after landing, flight control power isturned off to conserve battery power.

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* S

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Post-landing EventsOf prime interest to the engineers who designed Surveyorwill be the engineering telemetry received during the descentand touchdown. Touchdown will be followed by periods ofengineering telemetry to determine the condition of the

spacecraft. Then a series of wide angle, 200-line televisionpictures will be taken.The solar panel and high-gain planar array antenna willthen be aligned with the Sun and Earth., respectively. Ifthe high-gain antenna is successfully operated to lock onEarth, transmission of 600-line television pictures will begin.If it is necessary to operate through one of the low-gain,omnidirectional antennas, additional 200-line pictures will betransmitted.The lifetime of Surveyor on the surface will be determined

by a number of factors such as the power remaining in thebatteries in the event that the Sun is not acquired by thesolar panel and spacecraft reaction to the intense heat of thelunar day and the deep cold of the lunar night.

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-36-ATLAS-CENTAUR AND SURVEYOR TEAMS

NASA HEADQUARTERS, WASHINGTON, D.C.Dr. Homer E. Newell Associate Administrator forSpace Science andApplicationsOran W. Nicks Director, Lunar and Planetary

ProgramsBenjamin Milwitsky Surveyor Program ManagerV. L. Johnson Director, Launch Vehicle and

Propulsion ProgramsT. B. Norris Centaur Program ManagerJET PROPULSION LABORATORY, PASADENA, CALIF.Dr. William H. Pickering DirectorGen. A. R. Luedecke Deputy DirectorHoward H. Haglund Surveyor Project ManagerKermit S. Watkins Assistant Project Manager for

Surveyor OperationsRobert G. Forney Surveyor Spacecraft System

ManagerDr. Leonard Jaffe Project ScientistDEEP SPACE NETWORKDr. Eberhardt Rechtin Assistant Laboratory Directorfor Tracking and Data Ac-quisition, JPLDr. Nicholas A. Renzetti Surveyor Tracking and DataSystems Manager, JPLW. E. Larkin JPL Engineer in Charge,

Goldstone

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- - V~~~~~~ .- -- -

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J. Buckley Pioneer Station Manager,GoldstoneR. J. Fahnestock JPL DSN Resident in Australia 31R. A. Leslie Tidbinbilla Station ManagerPhil Tardani JPL DSN Resident in SpainDonald Meyer Robledo Station ManagerAvron Bryan Ascension Station ManagerLEWIS RESEARCH CENTERS CLEVELAND, 0.Dr. Abe Silverstein DirectorDr. S. C. Himmel Assistant Director for LaunchVehiclesEdmund R. Jonash Centaur Project ManagerKENNEDY SPACE CENTER, FLA.Dr. Kurt R. Debus DirectorRobert H. Gray Director of Unmanned LaunchOperationsJohn D. Gossett Chief, Centaur OperationsPRINCIPAL SCIENTIFIC INVESTIGATORSDr. Eugene Shoemaker TelevisionU.S. Gweological SurveyX-Dr. Anthony L. Turkevlch Aloha Scattering ExperimentUniversity of ChicagoHUGHES AIRCRAFT COMPANY, CULVER CITY, CALIFDr. Robert L. Roderick Surveyor Program ManagerAssistant Manager -- Lunar

-' ProgramsRobert E. Sears Associate Program ManagerRichard R. Gunter Assistant Program Manager

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GENERAL DYNAMICS/CONVAIR. SAN DIEGO, CALIF.Grant L. Hansen Vice President, Launch VehicleProgramsPRATT AND WHITNEY AIRCRAFT DIVISION OF UNITED AIRCRAFT CO .WEST PAUI BEACH, FLA.Richard Anchutze RL-10 Engine Project ManagerHONEYWELL, INC.. ST. PETERSBURG, FLA.Paul V. Yingst Centaur Guidance ProgramManager

SURVEYOR/ATLAS-CENTAUR SUBCONTRACTORSSurveyor

AiResearch Division Ground Support EquipmentGarrett Corp.Torrance, Calif.Airite Nitrogen TanksEl Segundo, Calif.Airtek Propellant TanksFansteel Metallurgical Corp.Compton, Calif.Ampex Tape RecorderRedwood City, Calif.Astrodata Decortunutators and SubcarrierAnaheim, Calif. Discriminator SystemsBell & Howell Co. Camera LensChicago, Ill.Bendix Corp. Landing Dynamics StabilityProducts Aerospace Division StudySouth Bend, Ina.Borg-Warner Tape RecorderStata Ana, Calif.Brunson Optical Alignment EquipmentKansas City, Kan.Carleton Controls Helium RegulatorBuffalo, N. Y.

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-39-Eagle-Picher Co. Auxiliary BatteriesJoplin, Mo.Electric Storage Battery Main BatteriesRaleigh, N.C.Electro-Development Corp. Strain Gage ElectronicsSeattle, Wash.Electro-Mechanical Research DecommutatorsSarasota, Fla.Electro-Optical Systems, Inc. Solar Panel Assembly and TestingPasadena, Calif.Endevco Corp. AccelerometersPasadena, Calif.General Electro Dynamics Vidicon TubesGarland, Tex.General Precision, Inc. Spacecraft TV Ground DataAdvanced Products Division Handling SystemLink Group Sunnyvale, Calif.Heliotek Solar ModulesSylmar, Calif.Hi-Shear Corp. Separation DeviceTorrance, Calif.C. G. Hokanson Mob. Temperature Control UnitSanta Monica, Calif.Holex SquibsHollister, Calif.Honeywell Tape Recorder/ReproducerLos Angeles, Calif.General Precision, Inc. Floated Rate Integrated GyrosKearfott Systems DivisionWayne, N.J.Kinetics Main Power SwitchSolana Beach, Calif.Lear Siegler T.V. Photo RecorderSanta Monica, Calif.Menasco Gas TanksLos Angeles, Calif.

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I-4

Meteom Magnetron AssemblySalem, Mass.Motorola, Inc. Subcarrier OscillatorsMilitary Electronics DivisionScottsdale, Ariz.National Water Lift Co. Landing Shock AbsorberKalamazoo, Mich.Northrop/Norair Landing GearHawthorne, Calif.Ryan Aeronautical Co. Radar Altitude Doppler VelocitySan Diego, Calif. SensorSanborn L. F. OscillographWaltham, Mass.Scientific-Atlanta System Test StandAtlanta, Ga.Singer-Metrics F. M. CalibratorBridgeport, Mass.Telemetrics SimulatorSanta Ana, Calif.Thiokol Chemical Corp. Main Retro EngineElkton DivisionElkton, Md.Trhiokol Chemical Corp. Vernier Propulsion SystemReaction Motors DivisionDenville, N. J.Tinsley Laboratories, Inc. Spacecraft MirrorsBerkeley, Calif.United Aircraft Corp. Subcarrier OscillatorNorden DivisionSouthhampton, Pa.Vector Subcarrier OscillatorSouthhampton, Pa.

Atlas-CentaurRocketdyne Division of MA-5 Propulsion SystemNorth American Aviation, Inc.Canoga Park, Calif.

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-41-

Thiokol Chemical Corp. LOX and Fuel Staging ValvesReaction Motors DivisionDenville, N. J.Hadley Co., Inc. Valves, Regulators and

Dis connect CouplingFluidgenics, Inc. RegulatorsGeneral Precision, Inc. Displacement GyrosKearfott DivisionWayne, N.J.Honeywell, Inc. Rate GyrosAeronautical DivisionFifth Dimension, Inc. CommutatorsBendix Corp. Telepaks and OscillatorsBendix Pacific DivisionFairchild-Hiller LOX Fuel and Drain ValvesStratos Western DivisionBourns, Inc. Transducers and PotentiometersWashington Steel Co. Stainless SteelWas'iington, Pa.General Dynamics Insulation Panels and NoseFort Worth Division FairingFort Worth, Tex.Pesco Products Division of Boost Pumps for RL-10 EnginesBorg-Warner Corp.Bedford, 0.Bell Aerosystems Co. of Attitude Control SystemBell Aerospace Corp.Buffalo, N. Y.Liquidometer Aerospace Division Propellant Utilization SystemSimmonds Precision ProductsInc.Long Island, N.Y.General Precision, Inc. Computer for Iner'tial GuidanceKearfott Division SystemSan Marcos, Calif.

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Goodyear Aerospace Division Handling TrailerGoodyear Tire and Rubber Co.Akron, 0.Systems and Instruments Div. DestructorsBulova Watch Co.Flushing, N. Y.Consolidated Controls Corp. Safe and Arm InitiatorEl Segundo, Calif.Borg-Warner Controls Division InverterBorg-Warner Corp.Santa Ana, Calif.Sippican Corp. Modules for PropellantMarion, Mass. Utilization SystemGeneral Electric Co. TurbineLynn, Mass.Vickers Division of Hydraulic PumpsSperry Rand Corp.Troy, Mich.Edcliff Instruments, Inc. Transducers and SwitchesMonrovia, Calif.Rosemount Engineering Co. TransducersMinneapolis, Minn.Scientific Data Systems ComputersSanta Monica, Calif.W. 0. Leonard, Inc. Hvdrogen and OxygenPasadena, Calif. Vent Valves

Documents

Surveyor E Press Kit