National Aeronautics and Space Administration Next Generation DSN Jet Propulsion Laboratory California Institute of Technology A Vision for the Next Generation Deep Space Network Bob Preston Chief Scientist Interplanetary Network Directorate, JPL
Les Deutsch QuickTime™ and a Architecture and Strategic Planning TIFF (LZW) decompressor Interplanetary Network Directorate, JPL are needed to see this picture.
Barry Geldzahler Program Executive, Deep Space Network Science Mission Directorate, NASA
BP/LD/BG - 1 5/4//06 National Aeronautics and Space Administration Next Generation DSN Jet Propulsion Laboratory California Institute of Technology 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
BP/LD/BG - 2 5/4//06 National Aeronautics and Space Administration Next Generation DSN Jet Propulsion Laboratory California Institute of Technology What is the Present Deep Space Network?
• 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
Goldstone Canberra Madrid BP/LD/BG - 3 5/4//06 National Aeronautics and Space Administration Next Generation DSN Jet Propulsion Laboratory California Institute of Technology 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 BP/LD/BG - 4 5/4//06 National Aeronautics and Space Administration Next Generation DSN Jet Propulsion Laboratory California Institute of Technology NASA’s Science Missions are Changing
• 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
Preliminary solar Detailed Orbital system reconn. via Remote Sensing. brief flybys.
In situ exploration In situ exp. via long- via short-lived lived mobile human & probes. robotic elements. Low-Earth-orbit solar Observatories located and astrophysical farther from Earth. observatories. (e.g., Spitzer, JWST)
Single, large spacecraft Constellations of small, for solar & low-cost spacecraft. astrophysics obs. (e.g., MMS, MagCon) BP/LD/BG5 - 5 Evolution of the Deep Space Network 5/4//0609/09/05 National Aeronautics and Space Administration Next Generation DSN Jet Propulsion Laboratory California Institute of Technology Doing Similar Remote Sensing at Other Planets as We do Today at Earth
Cassini Communication Direction of Increasing Data Richness Capability Synthetic Aperture Radar
Data for Science Multi-Spectral & Hyper-Spectral Imagers
DATA Planetary Images RATES (bits/s) 1E+04 1E+05 1E+06 1E+07 1E+08
Video Data for Public
Required Improvement HDTV
Direction of Increasing Sense of Presence IMAX
BP/LD/BG - 6 5/4//06 National Aeronautics and Space Administration Next Generation DSN Jet Propulsion Laboratory California Institute of Technology The DSN and Outer Planets Missions
A capable DSN is especially critical to outer planet missions since communication is much more difficult compared to the inner solar system
Relative Difficulty Place 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
BP/LD/BG - 7 5/4//06 National Aeronautics and Space Administration Next Generation DSN Jet Propulsion Laboratory California Institute of Technology DSN’s Future Mission Drivers
Projected Number of Downlinks 120 100 Links 80 60 Spacecraft • Probable future DSN mission sets are 40 20 frequently analyzed Missions 0 – All NASA missions beyond 2005 2010 2015 2020 2025 2030 geosynchronous Earth orbit Projected Downlink Rate 1,000,000 500 MHz of Ka Bandwidth – Science and exploration missions 100,000 Max Rate 10,000 Ave Rate • Analysis shows that by 2030 DSN must be 1,000 100 ready to support: 10
– 1000X downlink performance increase Downlink Rate (Kbps) 1 (likely more for certain missions) 2005 2010 2015 2020 2025 2030 Projected Downlink Difficulty – 2X number of spacecraft increase 1.E+07 1.E+06 )
2 Max Link Difficulty 1.E+05 1.E+04 1.E+03 Ave Link Difficulty 1.E+02 (kbps x AU 1.E+01
1.E+00 BP/LD/BG - 8 2005 2010 2015 2020 20255/4//06 2030 National Aeronautics and Space Administration Next Generation DSN Jet Propulsion Laboratory California Institute of Technology DSN Performance Gap Jupiter Edge of GEO Moon Mars Pluto Solar System 1 Pbps
1 Tbps C urre (7 nt 0m D a SN nte S 1 Gbps nn en a si at tiv X-b ity an d)
1 Mbps
Mission Requirements out to 2030
1 Kbps
1 bps 10,000 km 100,000 km 1 Mkm 10 Mkm 100 Mkm 1 Bkm 10 Bkm 100 Bkm
• 1,000-fold increase is needed to support planetary missions • Adequate sensitivity already exists for all lunar and Earth libration point missions
BP/LD/BG - 9 5/4//06 National Aeronautics and Space Administration Next Generation DSN Jet Propulsion Laboratory California Institute of Technology Planning for the DSN Future
Planning process:
• 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
BP/LD/BG - 10 5/4//06 National Aeronautics and Space Administration Next Generation DSN Jet Propulsion Laboratory California Institute of Technology A Plan for the DSN Future
Recommended key elements of future DSN:
• 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) BP/LD/BG - 11 5/4//06 National Aeronautics and Space Administration Next Generation DSN Jet Propulsion Laboratory California Institute of Technology 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 BP/LD/BG - 12 5/4//06 National Aeronautics and Space Administration Next Generation DSN Jet Propulsion Laboratory California Institute of Technology Arrays: What Has Already Been Accomplished
• 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 arrays enabled Galileo • DSN helped save Galileo through routine use of antenna arrays to succeed after its HGA (including Parkes) failed to deploy • 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) Australia U.S. • 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
6-m DSN Array breadboard antenna BP/LD/BG13 - 13 5/4//0609/09/05 National Aeronautics and Space Administration Next Generation DSN Jet Propulsion Laboratory California Institute of Technology End-to-End RF Communication Performance
• Future end-to-end communication performance will rely on more than just improvements to ground facilities • Additional enhancements are under development
1000 High Power S/C Transmitter Flight 100W Enhancements
100 Advanced Coding & Compression Factor of 5 over today Flight/Ground Ka-Band Deployment on all Assets Enhancements 10 Factor of 4 enabled by Next Gen DSN Next Gen DSN Antennas Ground Factor of 10 over today’s 70m Performance Improvement Enhancements 1 Current DSN Spacecraft: X-band, 10W, 1.5m ant; DSN: 70m ant
• 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 BP/LD/BG - 14 5/4//06 National Aeronautics and Space Administration Next Generation DSN Jet Propulsion Laboratory California Institute of Technology Example Benefits of Future DSN to NASA Missions
• Orders of magnitude increase in downlink data rates Flexibility of the – Video instead of single images Array Architecture – 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 Single high performance user, or • 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 Multiple users on sub-arrays and landing or spacecraft emergencies BP/LD/BG - 15 5/4//06 National Aeronautics and Space Administration Next Generation DSN Jet Propulsion Laboratory California Institute of Technology DSN: Looking Forward
1.E+12
Mariner 69
1.E+10 Mariner 10 Galileo
Kepler 1.E+08 Mariner IV Voyager Optical Comm MRO Pioneer IV 1.E+06
1.E+04 20-W S-Band TWT, Block Coding (G & S/C) 10.5m Spacecraft Antenna (S/C) 1.5-m S-/X-Band Antena (S/C) DSN Array -DSN Array Phase 2 (G) Improved Antenna (G) DSN Array -DSN Array Phase 1 (G) 1kW Ka-Band Transmitter (S/C)
1.E+02 70-m Antenna (G) Reduced Microwave Noise (G) 64-m Antenna (G) Array: 70-m + 2 34-m (G) Array: Advanced Coding and Compression (G & S/C) Video Data Compression (G & S/C) 10-W S-Band TWT (S/C) Array: 64-m + 1 34-m (G) Array: Ka-Band Systems (G & S/C)
1.E+00 100W Ka-BandTransmitter (S/C) X-Band Maser Maser X-Band (G) Improved Coding (15/1/6) (G & S/C) 3.7-m X-/X-Band Antenna (S/C) Maser (G) Equivalent Data Rate from Jupiter Equivalent Data
1.E-02 Reduced Transponder Noise (S/C) 3-W, 1.2-m S-Band Antenna (S/C)
1.E-04 Concatenated Coding (7, 1/2) + R-S (G & S/C) Interplexed, Improved Coding (G & S/C) Reduced Ant Surf Tolerances (G) Reduced Microwave Noise (G) 1.E-06 Baseline (First Deep Space mission) 1950 1960 1970 1980 1990 2000 2010 2020 2030 BP/LD/BGLJD - 16 5/4//0611/18/04 National Aeronautics and Space Administration Next Generation DSN Today’sJet Propulsion DSN Laboratory High California Institute of Technology Planetary performance Networks exploration Increased accessibility Improved nav and position Global coverage of Deep locations Space Current state of the art DSN Array
NASA Space Networking Optical Communications
Modular and expandable Low cost manufacturing and operations x40 performance
High bandwidth communications High reliability Low mass spacecraft components High Performance: ≥ x1000 by 2015 Beginning of technology Cost effective growth curve Planetary networks, seamless connectivity
BP/LD/BG17 - 17 Evolution of the Deep Space Network 06/255/4//06//05 National Aeronautics and Space Administration Next Generation DSN Jet Propulsion Laboratory California Institute of Technology 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
BP/LD/BG - 18 5/4//06