Scout Vehicle Development Flight Air Density Drag Measurements Experiment Press Kit

8/8/2019 Scout Vehicle Development Flight Air Density Drag Measurements Experiment Press Kit

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NEWS R E L E A S ENATIONAL AERONAUTICS AND SPACE ADMINISTRATION1 5 2 0 H S T R EE T , N O R T H W E S T ' W A S H I N GT O N 2 5 . D . C .T E L E P H O NE S : D U D L EY 2 - 6 3 2 5 . E X E C U T IV E 3 - 3 2 6 0FOR RELEASE: HOLD FOR RELEASE UNTILRELEASE NO. 60-310 LAUNCH

SCOUT VEHICLE DEVELOPMENT FLIGHT(AIR DENSITY-DRAG MEASURENENTS EXPERIMENT)National Aeronautics and Space Administration will launch the

third in a series of Scout research rocket vehicles from Wallops Station,Wallops Island., Virginia, in an orbital flight which has two scientificpurposes.

The principal aim is to study the performance, structuralintegrity and environmental conditions of the 72-foot, 36,600-poundfour-stage Scout research vehicle and the guidance-controls system.

The second objective is to inject into orbit an inflatablelbpound, 12-foot-diameter spherical satellite, fabricated ofmylar plastic film and aluminum foil, for use in studying thecharacteristics of space -- primarily to measure air drag to deter-mine the density of the earth's atmosphere on the fringe of space.(For a detailed description of past experiments in this f i e l d , seeSupplement No, 1 to this press kit,)

The l.aunch, part of NASA's Scout development program to pro-vide the United States with a small, reliable and flexible solid-fuel booster capable of deep space probes and of orbital missions,w i l l be a pioneering venture In cwo respects:

1. This will be the first orbital attempt by the U, S. usinga solid-fuel rocket - - culminating two years of development work by

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- 2 -the NA SA Langley Research Center's Scout Project Group, in cooperationwith industry and other Federal agencies.

2, It will mark the first orbital attempt with any vehiclefrom NASA's Wallops Station, where more than 3,500 rocket-propelledaerospace research models have been launched since the facility wasestablished in July 1945 on the Eastern Shore of Virginia,

3rd Test of Complete VehicleThis will be the third flight test of the complete Scout launch

vehicle in the development series, all conducted from Wallops Island.The first flight test of the complete Scout vehicle was made onJuly 1, 1960, on a ballistic trajectory. The second test was madejust two months ago on October 4, 1960, when the four-stage vehiclereached an altitude of 3,500 statute miles and impacted 5,800statute miles down range,

Experience gained during these launching operations and develop-ment flights is being applied to improve performance of Scout as afuture space research vehicle, Wallops Island facilities completedearlier this year are being used in Scout launchings. These includea pad, launch tower, block house, and related ground support,electronics and tracking equipment.

The present determination of atmospheric density at satellitealtitudes is inferTed from calculations of tracking data obtainedfrom numerous satellites of different sizes and shapes. The airdensity-drag measurements experiment will provide accurate infor-


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- 3 -mation on the characteristics of space between altitudes of about 400down to 100 statute miles-- giving scientists a firm basis for moreaccurately predicting the orbital life of satellites and other vehicles.

In the air density-drag measurements experiment, the orbitingspherical satellite will be the measuring instrument. As the satellite,an object with a known mass and frontal area and highly sensitive todrag, begins to descend and dip more and more into the earth'satmosphere, it will lose energy. Worldwide radio and opticaltracking measurements of the resultant changes in orbit will allowcomputations of atmospheric density.

Payload ConstructionPayload of the Scout vehicle weighs 87 pounds. This includes

the 14-pound inflatable satellite and 73 pounds of satelliteejection and inflation equipment, the fourth stage telemetersystem, and necessary hardware-- including the metal containerin the nose of the Scout fourth stage. The fourth stage rocketmotor and the attached payload container which will follow thesphere into orbit will weigh about 130 pounds.

About twice the thickness of the cellophane on a cigarettepackage, the satellite is constructed of four alternate layersof mylar plastic film and aluminum foil. The fabricationsequence i s a l aye r of plastic film an the i n s i d e , an outer l aye rof aluminum foil., another layer of plastic film, and a final layerof aluminum foil on the exzerior surface. Each layer is 0.0005

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- 5 -Three Baker-Nunn camera s t a t i o n s a r e i n t h e United S t a t e s - - a t

Ju p i t e r , F lo r id a ; Maui, Hawaii, and Oregon Pass, N ew Mexico. Thosei n f o r e i g n c o u n t r i es a r e l o c a t e d a t O l i f a n t s f o n t e i n , South Afr ica ;Woomera, A us t ra l ia ; San Fernando, Spain ; Tokyo, J apan ; Naini T a l ,In di a; Arequipa, Peru; Shi raz, Ir an ; Curacao, Netherlands WestIndies ; and V i l l a Dolores, Argentina.

S c i e n t i s t s a t the Langley Research Center w i l l ana lyze thes a t e l l i t e t r ac ki ng data f o r the de te rmina t ion of th e atmosphericd e n s i t y .

The de fl at ed mylar-aluminum f o i l s a t e l l i t e i s folded accordi0.n-f a sh ion and sc i en t i f i ca l l y packaged ins id e a metal tube 8% inchesi n d iameter and about 19 inc hes long-- mounted on th e f r o n t end oft he four th - s t age rocke t . The s a t e l l i t e and i t s a t t ached t r ack ingbeacon components a re i n s e r t e d i n s i d e t h e f ron t end of the tubeto occupy a space approximately 8-& inches i n d iameter and 11 inchesl on g. Behind t h e f o l d e d s a t e l l i t e i s an e j e c t i on be llows, a s t e e li n f l a t i o n b o t t l e conta in ing ni t rogen gas under a pressure of about1,800 pounds p er squ are inch, followed by a four th - s t age t e l eme te rand i t s b a t t e r i e s .

O r b i t a l DataThe s p h e r i c a l s a t e l l i t e w i l l b e launched i n a s o u t h e a s t e r l y

d i r e c t i o n on an e l l i p t i c a l f l i g h t p a t h . The pe r igee w i l l b e about410 s ta t u te mi les and apogee about 1,275 s t a t u t e miles. The beltcovered by t h e i n i t i a l o rb i t s w i l l extend 38 degrees nor th and

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- 6 -south o f t h e e q ua t or . The s a t e l l i t e i s programmed t o t r a v e l a t ave lo ci ty of approximately 16,600 mph as i t i s i n j e ct e d i n t o o r b i tand a t per igee .Time of the s a t e l l i t e ' s i n i t i a l o r b i t a l pe rio d i s es t imated a t112$ minutes

S a t e l l i t e speed a t apogee w i l l be about 14,000 mph,

The f i r s t o r b i t w i l l ca r ry t he sphe re ac ros s the sou thern p a r tof Af ri ca and mid-Aus tralia, and i t begins i t s f i r s t pass over t h eUnited Sta tes on t h e i n i t i a l o r b i t n e a r San Fr an ci sc o. I t w i l lc ross t h e lower h a l f o f t h e country before pass ing over t h e e a s tcoast and t h e A t la n t ic Ocean above Charle ston, South Car olin a.During t w i l i g h t and evening the sphere, when overhead, w i l l b ev i s i b l e to the naked eye a t per igee bu t w i l l b e o nl y b a r e l y v i s i b l ea t apogee without t h e use of b inocu l a r s o r t e l e scopes .

Sequence of EventsAf ter l aunch, S co ut fs f i r s t s tage remains a t t ached to the

v e h i c l e u n t i l i t i s b l a s t e d o f f a t second s t a ge i g n i t i on a t130,OQO f e e t , The burned out second s ta ge coast s w i t h t he veh i c l eto 315,000 f e e t a n d i s b la s t - se pa ra te d as t h e guidance programmeri g n i t e s t h e t h i r d s tage rocket motor and the drag and hea t f a i r i ngson t h e t h i r d and f o u r t h s t a g e s a r e j e t t i s o n e d . The spen t t h i r ds t age , w i t h its guidance and control s y s t e m opera t i ng , coas t s t ot h e i n j e c t i o n a l t i t u d e a t ta c he d t o t h e fou r th s tage . The fo ur ths t a g e i s t h e n spun t o a b o u t 150 rpm by small sp in rocke t s , i gn i t ed ,and se pa ra te d from t h e t h i r d s t age . The ve loc i ty increment ga inedduring f o u r t h s tage burning places t h e pay load and four th s t agei n t o o r b i t .


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A - 7 -I n j e c t i o n i n t o o r b i t i s scheduled t o occur about 104 minutes

a f t e r l i f t o f f - - about 1 ,325 s ta tu te miles down range approximatelya t 52 degrees west longi tude and 35 d e g r e e s n o r t h l a t i t u d e .i n t h e payload container i s i g n i t e d and a c t i v a t e s t h e i n f l a t i o nmechanism-- opening the in f la t i o n b o t t l e valve and per mit t ing th ei n f l a t i o n gas t o f l o w i n t o t h e e j e c t i on bel lows . The bellows expandimmedia te ly and push t he f o lded s a t e l l i t e ou t of the f ron t end ofthe con t a ine r .a disconnect mechanism during t h e i n f l a t i o n p r oc e ss , A f te r i t i sf u l l y i n f l at e d , t h e sphere i s r e l e a s e d by the disconnect mechanismand a s e p a r a t i o n s p ri n g pushes t h e s a t e l l i t e ahead o f the combi-n a t i o n payload conta in er - four th s ta ge . The small t racking beaconbecomes ope ra tiv e f o r t h e f i r s t time automat ical ly upon th es a t e l l i t e ' s e j ec t i o n f rom t h e p ay l o ad conta iner . I t r e q u i r e s 4%minutes t o e j e c t , i n f l a t e and s e p a r a t e %he s a t e l l i t e from the rocket .

A squib

The s a t e l l i t e remains a t t a c h e d t o the bel lows by

The combination f ou rt h s ta ge roc ket motor-payload con tain erand t he i n f l a t ed sphe re are expected t o become increas ingly separatedLn o r b i t because of d i ffe re nc es i n dlaag. Since t h e sphere i shundreds of times more sensi t ive t o atmospheric drag t han t h eheav i e r s a t e l l i t e s which have been launched, it i s expected t oremain i n o rb i t from a f e w weeks t o p o s s i b l y a y e a r b e f o r e s p i r a l i n gi n t o t h e lower atmosphere apid burning up, The pre dic te d or bi ta ll i fe t i me of the spen t rocket motor is much longer.

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NEWS R E L E A S ENATIONAL AERONAUTICS AND SPACE ADMINISTRATION1520 H S T R E E T , N O R T H W E S T . W A S H I N G T O N 2 5 , D . C .T E L E P H O N E S : D U D L E Y 2 - 6 3 2 5 . E X E C U T I V E 3-3260FOR RELEASE: Sunday December 4, 1960

RELEASE NO. 60-310ANNM F

Wallops Island, Virginia - National Aeronautics and SpaceAdministration announced that a Scout research rocket vehicle launchedhere today on its first orbital fli$ht attempt at 4:14 PM EST did notperform as programmed, I

The first stage performed normally. tlhe vehicle control systemappeared to be working normally. A

The second stage was programfned to ignite 70 seconds afterlaunch at an altitude of l30,OOO ft. The second stage did not ignite.

The vehicle impacted in the Atlantic Ocean about 80 statute mileseast of the launch site.

NASA is investigating to determine the cause of the abort.

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NATIONAL AERONAUTICS AND SPACE ADMIMSTRATIONWASHINOTON 25 , D. C.

RELEASE NO , 60-310Press K i t Supplement No. 3

INFLATABLE SPHERICAL SATELLITESThe 12- foot in f l a t a b l e sp he r i ca l s a t e l l i t e employed as a

r e sea rch veh ic l e b y NASA w a s conceived, fa br ic at ed , and packageda t t h e Langley Research Center b y a team of sc ie nt i s t s , engineers ,tec hn ici an s, and s k i l l e d modelmakers. The material f o r t h e Scouts a t e l l i t e was l aminated t o NASA sp ec i f i ca t io ns by t h e ReynoldsMetals Company.

T h e s a t e l l i t e was developed under d ir ec t i on of W i l l i a m J .OISullivan, J r . , head of Lan gley 's Space Ve hi cle s Group and ap i on e er i n t h e f i e l d of research w i t h i n f l a t a b l e a n d e r e c t a b l espace s t r u c t u r e s . H e d i r e c t e d t h e design, development, andpackaging of the Echo I pass iv e communica tions sa t e l l i t e whichhas been i n o r b i t s i n c e l a s t August 12 .

O'Sul l ivan f i r s t proposed i n January 1956 t h e u s e of l i g h t -weight s p h e r i c a l s a t e l l i t e s i n measuring t h e minute aerodynamicdrag experienced by e a r t h s a t e l l i t e s i n t h e o u t e r f r i n g e s of t h ee a r t h ' s atmosphere-- t o o b ta i n d e n s i ty data by observa t ion ofthe o rb i t decay .

There have been th re e previo us att emp ts t o o r b i t smalls p h er i ca l s a t e l l i t e s i n a i r density-drag measurements experimentsfrom Cape Canaveral.on A p r i l 13, 1959, on a Vanguard ve hi cl e. The o th e r two were

Smal les t was a 3 0-i nc h s a t e l l i t e lau nc he d


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- 2 -12-footers-- the first on October 22, 1958, in a Jupiter C rocket andthe second in a Juno I1 vehicle on August 14, 1959. In all threeflights, the launch vehicle failed to make orbit.

The plastic film in the four-ply laminated 12-foot sphere to belaunched in a Scout vehicle gives the satellite the toughness itrequires to be folded into a compact package for ease of transportinto orbit. The aluminum foil serves several purposes-- making thesatellite stiff, highly reflective of sunlight and radio waves,electrically conductive, helping regulate satellite temperature,and protecting the plastic film from the intense ultravioletradiation in the area beyond the protective filter cover of theearthDs atmosphere.

By providing stiffness, the aluminum foil permits the satelliteto remain spherical without internal pressure as it orbits theearth.the internal pressure in the sphere equalizes with the outsideenvironmental pressure through an open valve stem in the satellite.A n y remaining inflation gas is expected to be lost throughpunctures made in the satellite structure by micrometeorites.

After separation of the satellite and payload container,

In making the satellite highly reflective of sunlight, thealuminum foil permits the sphere to be tracked optically through-out the world. Studies conducted at Langley indicate that theshiny aluminum foil will reflect about 80 per cent of the sunlightwhich falls upon the satellite in orbit.

By making the satelliteis outside surface electricallyconductive through use of aluminum foil, the sphere itself serves

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- 3 -as an antenna f o r the small radio beacon attached to it for trackingpurposes. The satellite is separated into hemispheres by a l&inch-wide equatorial gap of an insulating material (mylar), permittingthe two hemispheres to form the antenna f o r the tracking beacon.

The aluminum foil will not keep the temperature of the satellitewithin the limits required for satisfactory operation of the trackingbeacon components. In an effort to obtain better heat balancecharacteristics, about 20 per cent of the satellite surface areahas been covered with a scientific application of white epoxy paintin a pattern consisting of approximately 3 , ' c oO two-inch-diameterwhite d o t s ; in a circle 36 inches in diameter around both thetransmitter and battery packages of the beacon, there are about210 one-inch-diameter dots. For protection against heat whilethey are in sunlight, the beacon and battery package are coveredby 8 by 10-inch rectangles of white paint.package are thermally decoupled from the satellite throughapplication of the thermos bottle principle for protection againstcold while they are in shadow.

The beacon and battery

The equatorial gap separating the satellite into two hemisphereshas an application of white paint to protect the plastic materialand prevent the sun from shining through the transparent plasticonto the transmitter and battery packages located inside thesurface of the sphere.

The tracking beacon components, consisting of a radio trans-mitter, a storage battery package, and f o u r solar cell packages--

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- 4 -each containing 70 solar cells-- were designed and contracted by theRadio Corporation of America t o NASA design specifications. Eachsolar cell package is located on the outside skin of the satellitein an arrangement to permit continuous charging of the storagebatteries while the satellite is in sunlight. The radio transmitterand the storage battery package are located on the inside skin ofthe satellite, near the equatorial gap. Printed cable interconnectsthe various components of the tracking beacon system, The storagebatteries will operate the transmitter while the satellite is inshadow, making it possible to have continuous day and night tracking.

Claude W. Coffee, Jr., of Langley's Space Vehicles Group andproject engineer of the air density-drag measurements experiment,has been a Langley research scientist since October 1947. He wasborn February 24, 1921, in Sanford, Florida, and now makes hishome in Newport News, Virginia. He graduated from the Universityof Florida with a bachelor of science degree in mechanicalengineering in July 1942 and returned t o the University in 1946after World War I1 Army service and received a degree in industrialengineering in June 1947. During his NASA service, he has beenauthor or eo-author of a dozen technical publications.

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NATIONAL AERONAUTICS AND SPACE ADMINISTRATIONWASHINOTON 25 , 0. C.

RELEASE NO . 60-310Press K i t Supplement No. 1

SCIENTIFIC BACKGROUND AND EXPERIMENT DESCRIPTION

Scient if ic BackgroundT h i s i n f l a t a b l e s a t e l l i t e exp erim ent i s t h e l a t e s t i n a long

s e r i e s of s t u d i e s of t h e a i r envelope which surrounds t h e ear th .Inst rum e nt - ca r ry ing ba l loons, sound ing roc ke t s and e a r l i e r s a t e l l i t e sa l l have c on tr ib ut ed knowledge of t h e e a r t h ' s atmosphere.

The e a r t h ' s atmosphere, t rapped i n plac e by gr av i t y , i s h e a v i e s ta t the s u r f a c e t hi n n i n g o ut t o a vir tual vacuum a t f a r t h e r d i s t a n c efrom t h e p l a n e t .

Instrumented bal loon s f i r s t explored t h e upper atmosphere t ohe igh t s o f 20 miles.i n c r e a s i n g a l t i t u d e . P l o t t e d on a graph, a i r de ns i t y de c r e a ses

Telemetry showed a i r d e n s i ty t h i n s o ut w i t h-

w i t h a l t i t u d e i n a smooth curve.Earl y sounding rock et experiments a f t e r World War I1 r e i n -

fo r c e d the se f ind ings .I t was found, however, t h a t i n a d di t io n t o a l t i tu d e , a i r

d e n s i t y i s a f f e c t e d by a t least t h r ee o t h e r f a c t o r s : time of day,time of year , and s o l a r r a d i a t i o n .

A i r d e n s i t y was found t o be grea te r dur ing dayl i gh t hours thana t night because o f hea t ing of t h e upper atmosphere by t h e sun.Seasonal variations were shown t o a f f e c t t h e a l t i t u d e of t h e tropopause

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which marks divisions of temperatures at high altitudes; below thetropopause temperatures drop with increasing altitude, while abovethey increase. Solar radiation also affects air density at highaltitudes similar to atmosphere heating caused by sunlight.

Standard sea level atmosphere at zero degrees Centigrade con-tains 26,850,000,000,000,000,000 ir molecules per cubic centimeter,Using instrumented balloon measurements, scientists in 1946 projectedatmospheric density predictions to altitudes not yet explored by man,warning that it might be in error by a factor of 1000 at great heights,

Subsequent sounding rocket studies showed that at 110 miles, thenumber of air molecules per cubic centimeter drops off to 5,810,000,000New projections on higher altitudes were made, estimated by physiciststo be accurate within a factor of four to six.

In October, 1958, computations on the decay of the orbit ofSputnik I showed the upper atmosphere more dense than predicted inthe later projection. Air drag studies on later Sputniks, and U. S.Explorer and Vanguard satellites, showed that at 400 miles altitude,air density is about 6,0QQ,OCQ molecules per cubic centimeter,

If these molecules, each with a diameter of .OOO,OOO,O3centimeter (three one-hundred-miblionkhs of a centimeter), werescaled up t o tennis ball size, each b a l l WOUIid be more than tenmiles from its nearest neighbor at that 400-mile altitude,

Yo m k e additional air drag measurements, an inflatable sphereis am. ;Gcal instrument because its light weight and comparative larges i z e rmke it considerably more sensitive than other satellites toair C--?p , effects.


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- 3 -A 12-foo t sphere , f o r example has a f r o n t a l area of 113 square

f e e t and a mass of about 1 4 pounds, I t s f r o n t a l area p e r u n i t ofmass, t h e r e f o r e , i s about 8 squa re f ee t p e r pound. That comparesw i t h t h e 6 , 4 pound Vanguard I s a t e l l i t e which has a f r o n t a l areap e r u n i t of mass of .070 square feet per pound. So a 12-foot spherei s 115 times more se ns i t i ve t o a i r drag than the Vanguard s a t e l l i t e ,

The only o t h e r s p h e r i c a l s a t e l l i t e s which have been i n o rb i ta r e Vanguard 11 and Sputnik I , and Echo I . Other s a t e l l i t e s , whichar e not spheres , and a r e not as w el l s u i t e d f o r a i r density measure-ments , p resent varying f ro nt a l areas as the y tumble, and th er ef or ea r e u n s ui t ed f o r a i r drag measurements.

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Scout Vehicle Development Flight Air Density Drag Measurements Experiment Press Kit