outer planet communication technologies radio science · future radio science technologies •...
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Outer Planet Communication Technologies andRadio Science
Joseph Lazio, Les Deutsch, Stephen Townes
© 2018 California Institute of Technology. Government sponsorship acknowledged.
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The Interplanetary Network View
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OPAG Technology Forum 2
Planetary Sciences Vision 2050 3
Exciting and Ambitious!We Have a Challenge …
MRO (max)
Remote Sensing at Other Planets as at Earth
DATARATES
(bits/s)1E+04 1E+05 1E+06 1E+07 1E+08
Data for Science
Direction of IncreasingData Richness
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Cassini(max)
OPAG Technology Forum
Synthetic Aperture Radar, Hyper-Spectral Imagers, High-Resolution Mass Spectrometry, …
Flyby, Orbit, Land, Rove, …
Required Improvement
✔ ✔/2 ✔
History of Downlink Difficulty
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Equi
vale
nt D
ata
Rat
e fro
m J
upite
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1012
1010
108
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10-2
10-4
10-6
1950 1960 1970 1980 1990 2000 2010
Mas
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64-m
An
tenn
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Impr
oved
Cod
ing
Impr
oved
Sp
acec
raft
Ante
nna
Ante
nna
Arra
ying
1st flyby of Mars
1st gravity assist to visit multiple
planets: Mercury and Venus
1st close-up study of outer
planets
Jupiter orbiter
Ka-B
and
Saturn orbiter
Ka-b
and
Arra
y
TV relayed by satellite
1st Mini Computer
1st Cell Phone
IBM PC Released
Internet made Public
1st Hand-Held GPS Receiver
iPhone Released
Discovery of 1,000th planet
1st US Spacecraft to fly
by the Moon
History to date:Performance has improved by 1013 so far
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Ice Giant Mission Concepts
OPAG Technology ForumPre-decisional - For planning and discussion purposes only. 6
Neptune Orbiter with Probe, SEP,
and 50 kg payload
Uranus Orbiter with Probe and 50 kg
payloadCassini with Huygens Probe
Ice Giant Mission ConceptsWhy Do I Care?
OPAG Technology ForumPre-decisional - For planning and discussion purposes only. 7
Neptune Orbiter with Probe, SEP,
and 50 kg payload
Uranus Orbiter with Probe and 50 kg
payload
• More capable instrumentsHigher spectral resolution spectrometers, higher spectral resolution mass spectrometers, higher angular resolution imager
30 km spatial resolution on a moon vs. 100 km spatial resolution
• More capable missionsStereo vision on a moon via multiple looks
Decade 0.5+: 10× Improvement over Today
OPAG Technology Forum 8
• Remove bottlenecks on spacecraft and DSN
– Universal Space Transponder (UST)
– Common Platform DSN signal processor
• Increase use of Ka band (32 GHz)over X band (8 GHz)
– Factor ~ 4× improvementcf. Cassini, Juno Radio Science
Decade 0.5+: 10× Improvement over Today
OPAG Technology Forum 9
+
=
+ +• Antenna arraying– DSN Aperture Enhancement Project
emplacing additional 34m antennas
– Provides backup for 70 m as well as arraying beyond 70 m
DSS-56 foundationMadrid
DSN Aperture Enhancement Project (through 2025)Deep Space Network
10Canberra Goldstone Madrid
+ backend digital signal processing
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International Deep Space Network
New NorciaCebrerosMalargüe
CanberraGoldstone
Madrid
UsudaUchinoura Byalalu
11OPAG Technology Forum
Indicates flow of water before the mountain formedStrata at Base of Mt Sharp
OPAG Technology Forum 12
The DSN and the Interplanetary Internet
OPAG Technology ForumPre-decisional - For planning and discussion purposes only. 13
Extends today’s Internet across the Solar System
Mars
Titan
Icy Moon
Moon
z
High Performance Optical Terminal
To be demonstrated on Pysche
Hybrid RF/Optical Antenna
Potential reuse of existing infrastructure, in development today
Dedicated 12m Stations
NASA + International partnerships
Decade 2+: 100× Improvement over TodayDedicated Comm Relays
Extend the Internet to Mars and enable public engagement
14OPAG Technology ForumPre-decisional - For planning and discussion purposes only.
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Laser Communication
Deep Space Optical Communications (DSOC) to be demonstrated!
OPAG Technology ForumPre-decisional - For planning and discussion purposes only.
DSOC Overview
Photon-Counting Camera
Isolation Pointing Assembly
Point-Ahead Mirror
Single strut photoflight-like electronics
FLIGHT LASER TRANSCEIVER (FLT)
Electron microscope detail of 320 µm active area tungsten silicide (WSi) superconducting nanowire single photon
detector (SNSPD) array
Laser Transmitter Average Power 4 W
Packaged Nanowire Array
GROUND TECHNOLOGYAluminum Optical Transceiver
Assembly
SiC Flight Laser Transceiver (FLT)
DSOC Technologies & Advances
Palomar Observatory/Hale Telescope 5 m
z
High Performance Optical Terminal
To be demonstrated on Pysche
Hybrid RF/Optical Antenna
Potential reuse of existing infrastructure, in development today
Dedicated 12m Stations
NASA + International partnerships
Decade 2+: 100× Improvement over TodayDedicated Comm Relays
Extend the Internet to Mars and enable public engagement
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… In the Inner Solar System
OPAG Technology ForumPre-decisional - For planning and discussion purposes only.
OPAG Technology ForumPre-decisional - For planning and discussion purposes only. 18
… In the Outer Solar SystemDecade 2+: 100× Improvement over Today
Increased Data Volume
Laser Communication
??SMAP 6 m antenna (NG
Astro.)
• Diameter (6 m?)• Mass• Surface accuracy• Pointing and stability• …?
Radio Frequency Communication
• Diameter (50 cm?)• Pointing• Laser power?• Spacecraft isolation• …?
Radio ScienceApparent even with early missions that occultations by planetary atmospheres would affect radio communications• Mio dio! Tragedy!• Or one person’s annoyance is
another’s data --- Study atmospheric properties!
“Occultation Experiment: Results of the First Direct Measurement of Mars's Atmosphere and Ionosphere” (Kliore et al. 1965, Science)
• Can also study planetary interior! Turn the DSN+spacecraft
into one giant science instrument
Radio Science in the Outer Solar System
OPAG Technology ForumPre-decisional - For planning and discussion purposes only.
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Future Radio Science
Technologies• Simultaneous dual
frequency links (Cassini, Juno use X- and Ka bands)to difference the Doppler and cancel dispersive noise effects
• Water vapor radiometer to calibrate Earth’s tropospheric noise contribution
“We have identified 12 priority science objectives for ice giant exploration. […] The two most important objectives relate to the formation, structure, and evolution of ice giants (…): • Constrain the structure and
characteristics of the planet’s interior, including layering, locations of convective and stable regions, and internal dynamics.
• Determine the planet’s bulk composition ….Ice Giants Pre-Decadal Study Final Report
Interiors of Moons: Earth’s MoonRadio Science
GRAIL mission made precise measurements of separation between two spacecraft orbiting the Moon• Changes in separation due to acceleration of one
of the spacecraft
• Changes in acceleration result from changes in mass along spacecraft trajectory
• Could also use small spacecraft to study planetary atmospheres
Role for small spacecraft in outer solar system?
OPAG Technology Forum 22
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Conclusions
Ambitious science missions realized iffsufficient data returnedCommunication technologies improvements possible over next decadesRadio Science making and will continue to make valuable contributions
DSN Now
The DSN as a Science Instrument 24http://eyes.nasa.gov/dsn/dsn.html