Administration Next Generation DSN Jet Propulsion ... · Les Deutsch Architecture and Strategic Planning Interplanetary Network Directorate, JPL ... • Science and human exploration

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Next Generation DSNNational Aeronautics and Space AdministrationJet Propulsion LaboratoryCalifornia Institute of Technology

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A Vision for theNext GenerationDeep Space NetworkBob PrestonChief ScientistInterplanetary Network Directorate, JPL

Les DeutschArchitecture and Strategic PlanningInterplanetary Network Directorate, JPL

Barry GeldzahlerProgram Executive, Deep Space NetworkScience Mission Directorate, NASA

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The Challenge for Deep Space Communications

• Over the next 30 years deep space communication will have to accommodate orders-of-magnitude increase in data to and from spacecraft and at least a doubling of the number of supported spacecraft

• The present DSN architecture is not extensible to meet future needs in a reliable and cost effective manner

• NASA must develop a new strategy for deep space communications that meets the forthcoming dramatic increase in mission needs

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What is the Present Deep Space Network?

CanberraGoldstone

Madrid

• Three major tracking sites around the globe, with 16 large antennas, provide continuous communication and navigation support for the world’s deep space missions

• Currently services ~ 35 spacecraft both for NASA and foreign agencies– Includes missions devoted to planetary, heliophysics, and astrophysical

sciences as well as to technology demonstration• Spigot for science data from most spacecraft instruments exploring the

solar system, as well as a critical element of radio science instruments• A $2B infrastructure that has been critical to the support of 10’s of $B of

NASA spacecraft engaged in scientific exploration over the last few decades

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Why Does NASA Need a Next Generation DSN? • Many of the current DSN assets are obsolete or well beyond the end of their

design lifetimes– The largest antennas (70m diameter) are more than 40 years old and are not suitable for

use at Ka-band where wider bandwidths allow for the higher data rates required for future missions

– Current DSN is not sufficiently resilient or redundant to handle future mission demands

• Future US deep space missions will require much more performance than the current system can provide

– Require ~ factor of 10 or more bits returned from spacecraft each decade– Require ~ factor of 10 or more bits sent to spacecraft each decade– Require more precise spacecraft navigation for entry/descent/landing and outer planet

encounters– Require improvements needed to support human missions

• NASA has neglected investment in the DSN, and other communications infrastructure for more than a decade

– Compared to 15 years ago, the number of DSN-tracked spacecraft has grown by 450%, but the number of antennas has grown only by 30%

• There is a need to reduce operations and maintenance costs beyond the levels of the current system

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NASA’s Science Missions are Changing

Low-Earth-orbit solar and astrophysical observatories.

Single, large spacecraft for solar & astrophysics obs.

Preliminary solar system reconn. via brief flybys.

In situ exploration via short-lived probes.

Observatories located farther from Earth.

(e.g., Spitzer, JWST)

Constellations of small, low-cost spacecraft.(e.g., MMS, MagCon)

Detailed Orbital Remote Sensing.

In situ exp. via long-lived mobile human &

robotic elements.

• MGS, Mars Odyssey, & MRO will obtain high resolution images of only about 1% of Mars surface

– Data rate is a constraint on the ability to understand the planet• Science and human exploration missions need remote sensing as now done for the Earth

509/09/05Evolution of the Deep Space NetworkEvolution of the Deep Space Network

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Next Generation DSNNational Aeronautics and Space AdministrationJet Propulsion LaboratoryCalifornia Institute of Technology Doing Similar Remote Sensing at

Other Planets as We do Today at Earth

Required Improvement

Synthetic Aperture Radar

DATARATES(bits/s)

Data for ScienceData for Science

Data for PublicData for Public

1E+04 1E+05 1E+06 1E+07 1E+08

Planetary Images

Video

Multi-Spectral & Hyper-Spectral Imagers

HDTV

Direction of IncreasingData Richness

Direction of IncreasingSense of Presence IMAX

Cassini CommunicationCapability

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The DSN and Outer Planets Missions

Relative DifficultyPlace Distance Difficulty

Geo 4x104 km Baseline

Moon 4x105 km 100

Mars 3x108 km 5.6x107

Jupiter 8x108 km 4.0x108

Pluto 5x109 km 1.6x1010

A capable DSN is especially critical to outer planetmissions since communication is much more difficultcompared to the inner solar system

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1

10

100

1,000

10,000

100,000

1,000,000

2005 2010 2015 2020 2025 2030

Dow

nlin

k R

ate

(Kbp

s) Projected Downlink Rate500 MHz of Ka Bandwidth

Max RateAve Rate

DSN’s Future Mission Drivers

1.E+00

1.E+01

1.E+02

1.E+03

1.E+04

1.E+05

1.E+06

1.E+07

2005 2010 2015 2020 2025 2030

Projected Downlink Difficulty

(kbp

s x

AU

2 ) Max Link Difficulty

Ave Link Difficulty

0

20

40

60

80

100

120

2005 2010 2015 2020 2025 2030

Projected Number of Downlinks

Links

Spacecraft

Missions

• Probable future DSN mission sets are frequently analyzed – All NASA missions beyond

geosynchronous Earth orbit– Science and exploration missions

• Analysis shows that by 2030 DSN must be ready to support:– 1000X downlink performance increase

(likely more for certain missions)– 2X number of spacecraft increase

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DSN Performance Gap

1 bps

1 Kbps

1 Mbps

1 Gbps

1 Tbps

1 Pbps

10,000 km 100,000 km 1 Mkm 10 Mkm 100 Mkm 1 Bkm 10 Bkm 100 Bkm

GEO Moon MarsJupiter

PlutoEdge of Solar System

Current DSN Sensitivity

(70m antenna at X-band)

Mission Requirements out to 2030

• 1,000-fold increase is needed to support planetary missions• Adequate sensitivity already exists for all lunar and Earth libration point missions

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Planning for the DSN Future

• NASA and JPL have generated a roadmap for the DSN based on requirements derived from analysis of probable future mission sets

• This DSN roadmap is being integrated into an overall NASA Space Communications Program Plan by the NASA Space Communications Architecture Working Group (SCAWG)

• The SCAWG made recommendations about the future of space communications to the NASA Administrator (Griffin) and the NASA Strategic Management Council

• The NASA Administrator declared that NASA has neglected the DSN and communications infrastructure investment and asked that a plan be ready to deliver to Congress in February 2007

Planning process:

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A Plan for the DSN Future

• Radio communication with large arrays of small antennas will be the backbone of deep space communications (#2 recommendation of SCAWG, after next generation TDRSS)

– Would serve all missions, large and small, new and old

– Technology is mature and low-risk

– Costs will be recovered over time through reduction of DSN operations and maintenance costs

• Orbital data relays at the Moon, Mars, and perhaps other planets will allow the highest possible communication volumes from spacecraft at those bodies

• Optical communication would allow the transfer of extremely high data rates on “trunk lines” from Mars or the Moon to Earth, or for special missions (but would require implementation of an extensive reception infrastructure)

Recommended key elements of future DSN:

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The Next Generation DSN: Arrays of Small Antennas

Arrays of small radio antennas will provide:

• More resilience and redundancy: – Graceful degradation in performance in case of antenna

or receiver failures – fewer single points of failure

• Much greater data flow to and from spacecraft:– Meets the data rate requirements of most future NASA

missions and instruments

• Easily scalable architecture when growth is required

• Significant growth in the number of spacecraft that can be simultaneously tracked

– Each with just the required aperture

• Higher precision spacecraft navigation– Required for precision entry/descent/landing and for

outer planet exploration• Improved cost-effectiveness

– Substantially reduces operations and maintenance costs: Plug-and-play components with longer lifetimes

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Arrays: What Has Already Been Accomplished

U.S.Australia

DSN arrays enabled Galileo to succeed after its HGA failed to deploy

6-m DSN Array breadboard antenna

1309/09/05

• Radio astronomers have used arrays since the 1970s

• DSN supported Voyager’s Uranus and Neptune encounters with arrays of antennas (including international radio telescopes)

• DSN helped save Galileo through routine use of antenna arrays (including Parkes)

• Mid 80s plan to expand DSN with 34m antennas rather than 70m assumed arrays

– DSN currently offers 34m arraying as a standard service (used often by Cassini)

• Array breadboard task is underway as a technology demonstration

– Developing 3 antennas (6- and 12-m diameter) and components that can be mass-produced for low cost

– Demonstrating signal combining algorithms

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End-to-End RF Communication Performance

Current DSNSpacecraft: X-band, 10W, 1.5m ant; DSN: 70m ant

Next Gen DSN AntennasFactor of 10 over today’s 70m

Advanced Coding & CompressionFactor of 5 over today

Ka-Band Deployment on all AssetsFactor of 4 enabled by Next Gen DSN

High Power S/C Transmitter100W

1

10

100

1000 Flight Enhancements

Ground Enhancements

Flight/Ground Enhancements

Per

form

ance

Impr

ovem

ent

• Future end-to-end communication performance will rely on more than just improvements to ground facilities

• Additional enhancements are under development

• X 1,000 performance increase possible for most deep space missions• Some missions might achieve more – up to 1,000,000

– Via higher power transmitters, larger spacecraft antennas, or optical communication

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Example Benefits of Future DSN to NASA Missions

• Orders of magnitude increase in downlink data rates– Video instead of single images– Improved multi-spectral imaging

• Increased temporal and/or spatial resolution• Increased wavelength and/or geographical coverage

– Room to grow to support the human exploration era• Including intense robotic exploration of Mars

• Orders of magnitude increase in up uplink data rates– Enables expected growth of software uploads and human

communication needs• Same instrument performance much farther from Earth• Direct-to-Earth transmission can enable new mission

concepts for probes, rovers, and balloons– Hemispherical planet coverage (e.g., for multiple probes,

longer communication periods)– Improved position/velocity measurements (e.g., for winds)

• Improved mission parameters/cost– Higher link sensitivity could be used to lower spacecraft

power, mass, pointing accuracy requirements, …• Improved data-rate from low-gain antennas during descent

and landing or spacecraft emergencies

Single high performance user, or

Multiple users on sub-arrays

Flexibility of the Array Architecture

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Next Generation DSNNational Aeronautics and Space AdministrationJet Propulsion LaboratoryCalifornia Institute of Technology DSN: Looking Forward

1.E-06

1.E-04

1.E-02

1.E+00

1.E+02

1.E+04

1.E+06

1.E+08

1.E+10

1.E+12

1950 1960 1970 1980 1990 2000 2010 2020 2030

Base

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(Firs

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enna

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Con

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Mariner IV

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LJD - 1611/18/04

Opt

ical

Com

m

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Today’s DSN

Global coverage of Deep SpaceCurrent state of the art

Optical Communications

High bandwidth communicationsLow mass spacecraft componentsBeginning of technology growth curve

NASA Space Networking

High reliabilityHigh Performance: ≥ x1000 by 2015Cost effectivePlanetary networks, seamless connectivity

DSN Array

Modular and expandableLow cost manufacturing and operationsx40 performance

Planetary Networks

High performance explorationIncreased accessibilityImproved navand position locations

1706/25//05Evolution of the Deep Space Network

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Summary

• NASA mission models indicate that orders-of-magnitude growth in network capacity are required over the coming decades

• To meet these future requirements a new end-to-end DSN architecture is envisioned that includes antenna arrays, local networks at the Moon and Mars, and eventually optical communications on some links

• All subsequent NASA deep space missions would be orders-of-magnitude more science-capable

• The schedule for implementation of the next generation DSN will depend on NASA budgetary and programmatic decisions, in addition to the pressure of future mission requirements

– The science community is free to express their opinion to NASA

• Until the new DSN is in place NASA is committed to ensuring that the current DSN can meet mission commitments

Documents

Administration Next Generation DSN Jet Propulsion ... · Les Deutsch Architecture and Strategic Planning Interplanetary Network Directorate, JPL ... • Science and human exploration