NASA’s Optical Communications Programs · 2019-05-24 · •Sharing optical communication ground...
Transcript of NASA’s Optical Communications Programs · 2019-05-24 · •Sharing optical communication ground...
National Aeronautics andSpace Administration
NASA’s OpticalCommunications Programs
Bernard L. EdwardsNASA Goddard Space Flight Center21 May 2019
https://ntrs.nasa.gov/search.jsp?R=20190025298 2020-06-04T18:46:31+00:00Z
Resiliency is the ability of a mission to endure the loss of one or more nodes, satellites or ground system elements — perhaps degraded but still operational. The mission may continue to function by use of augmented capabilities available from other sources.
Resilience drives:• Disaggregated systems• Affordability to allow sparing and system redundancy• Interoperability with other missions/systems• Density of the constellation
Overview
Small optical communication systems can lead to large affordable constellations providing resilient communications in space
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NASA’s Space Network Today
• The NASA Space Network or Tracking and Data Relay Satellite System is comprised of a constellation of Tracking and Data Relay Satellites (TDRS) in geosynchronous orbit and associated ground stations and operation centers.
• NASA is developing technologies for the next generation of relay satellites.3
Laser Communications Relay Demonstration (LCRD) for 2020
Scheduled launch: August 2020
Mission duration: Two year ops demoSix years ops
Hosted payload: US Air Force’sSpace Test Program Satellite – 6 (STPSat-6)
Ground stations: CaliforniaHawaii
Partnership: NASA Goddard Space Flight CenterNASA Jet Propulsion LaboratoryMIT Lincoln LaboratorySTMD/Technology Demonstration Missions Space Communications and Navigation
Flight payload:
• Two 10.8 cm Optical Modules and Controller Electronics Modules
• Two software-defined DPSK Modems with 2.88 Gbps data rate (1.244 Gbpscoded user rate)
• 622 Mbps Ka-band RF downlink• New High Speed Switching Unit to
interconnect the three terminals
Key for NASA’s Next-Gen Earth Relay
Guest investigators welcome!
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NASA’s Optical Plan Forward:User Terminals for LEO and the Moon
User Terminals for ISS and Orion EM‐2
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TeraByte InfraRed Delivery (TBIRD)200 Gbps Cubesat Demo in Early 2020
100+ Gbps optical link enables delivery of many TeraBytes/day from low-Earth
orbit
Space terminal based on telecom optical components,
small enough for CubeSat
~Foot-class ground terminal aperture is low cost and widely deployableMIT
Lincoln Laboratory
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TBIRD Proto-Flight HW at MIT Lincoln Laboratorybased on Integrated Photonics and Coherent DSP ASIC
TBIRDMass: 2.24 kgPower: 120W(5 minute ops)Volume: 1.8 U
MITLincoln Laboratory
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NASA’s Optical Plan Forward: Deep Space Optical Communications (DSOC in 2022)
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PPM TransmitterWith PhotonCounting Receiver
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9DEEP SPACE GATEWAY CONCEPT SCIENCE WORKSHOP | FEBRUARY 27-MARCH 1, 2018
Orion MPCV233 Mbps – 2.1 Gbps
20+ Mbps Forward1000+ Mbps Return
CubeSat4 – 500 Mbps
Lunar Surface100 Mbps – 2.1 Gbps
Optical Data Trunk to/from Earth Gateway-Enabled Lunar Network
Laser Communications for Lunar Orbital Platform-Gateway
Laser communications enables data returns from Gateway comparable to today’s ISS and high-rate proximity links for an optical lunar network
High-rate, low-latency dataPositioning, navigation and timing
e.g. high-res multi-spectral imaging
e.g. low-latency tele-robotics;In-situ analysis
Increasing Communications ResiliencyThrough Standardization and Resource Sharing
• Resiliency in both space and on the ground can be increased by sharing communications resources
• Sharing optical communication ground stations or relay satellites would also allow agencies to share the cost of the communications infrastructure.
– For example, due to cloud blockage, it is critical to have multiple ground stations in use during space-to-ground optical operations to provide high availability.
• International cross support for civil space agencies is being worked within the Interagency Operations Advisory Group (IOAG) and the Consultative Committee for Space Data Systems (CCSDS).
• The goal is to develop optical communications cross support by various agencies as we have today in traditional Radio Frequency (RF) communications.
Traditional InternationalRF Cross Support
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NASA and CCSDS International Optical Communication Standards in Development
100Gbps
10Gbps
1 Gbps
100Mbps
10Mbps
102 103 104 105 106 107 108 1010Km Km 109
GEO
light second light minute light hour
LEO SATSVENUS
MERCURYMARSNEAR-EARTH
SATS MOON JUPITERSATURN URANUS
NEPTUNE
PLUTOLagrange
MOON Lagrange 1 AU
1 Gbps @1 AU SCaN
Goal
Range of Communication Link (km)
LCRDEDRSJDRS
LOP‐G
O2O
Next Gen IOC
DSOCPsyche Gen 2 DSOC
TBIRD Demo
CCSDSHigh DataThroughput
CCSDSHigh PhotonEfficiency
CommercialLEO
CrosslinksOr Direct‐to‐
Earth Using OOKTo Commercial
OGS
CCSDSOptical On‐Off
Keying
100XMore Loss
so PPM
1,000,000XMore Loss so PPM, Large
OGS
100XMore Loss so PSK
Detection Sensitivityin Optical Communications
ReceivedSignalLocal
Oscillator
PowerDetection
10
1
0.1
Phot
ons
per b
it Coherent
PhotonCounting
Quantum Limit
OpticallyPreamplified
LO shot noise limited
ASE noise limited
“noiseless”
Unknown architecture
CCSDSOptical On‐Off
Keying
CCSDSHigh DataThroughput
CCSDSHigh Photon
Efficiency PPM
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National Aeronautics andSpace Administration
Questions?
Please feel free to contact me at:
Bernie EdwardsNASA Goddard Space Flight Center
BACKUP
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Integrated Laser Communication Relay DemonstrationPayload at NASA Goddard Space Flight Center
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Modem1
Modem2
Space Switching
Unit 1
Space Switching
Unit 2
OpticalModule
1
OpticalModule
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The Key to Reducing SWaP and Cost:Photonic Integrated Circuits
1 cm
For NASA, this means that optical systems for communications and sensors can be reduced in size, mass, and cost by >> 100x by leveraging this commercially‐available technology (some customization may be required)
US Industry has commercialized “Integrated photonics” to allow many electro‐optical components, even glass fibers, to be “squeezed down”…..
…into the optical equivalent of a micro‐electronics “integrated circuit”
COTS Laser Comm Modem
..based on Integrated Photonics
Clouds are primary source of attenuation
Characterization and prediction of the atmospheric channel are critical to inform space link handovers, select ground sites, and to maximize system availability
CCSDS Books will:◆ Provide a narrative on
atmospherics and explain why it is critical to accurately characterize
◆ Explain how long‐term statistics of atmospherics are used to choose an optimal network of geographically diverse ground sites
◆ Provide content on the required instruments and parameters to support long‐term site characterization and real‐time decision making
Atmospheric Characterization and Predictionfor Optical Communications
High Data Throughput 1550 nm Link Scenarios
Space
Air
Ground
SpaceRelay
Optical or RF Trunks
Crosslinks
Users
OpticalDirect‐to‐Earth
Link
Atmosph
ere
Optical Link
RF Link
High Data Rate 1550 nm Signaling Overview
FEC:DVB‐S2, RS, or
G.975 I.3
Convolutional Channel
Interleaver
Physical Layer Framing RandomizerQ‐Repeat
To amplifier ortelescope
Modulation:Burst‐Mode PSK@1550nm
CCSDS Transfer Frames
SlicerFrame Sync Marker
Attachment
High Data Rate 1550 nm Relay Link Example
Space Pkt
AOS Frame
FEC/ILV/ Q‐Repeat
Physical Link
User Platform
User Terminal
Phy Frame
Relay Platform
Relay Terminal 1
Phy FrameRelay Terminal 2
Physical Link
Ground RelayService I/F
AOS Frame
Ground Network
Switch
Optical relay serves as a transparent link‐layer bridge between User Platform and Ground Relay
Phy Frame
Random
Modulation
De‐Random
De‐Mod
Random
Modulation
FEC/DeILV/ De‐Q‐Rep.
Phy Frame
De‐Random
De‐Mod
Transparent Bridge
2005/10/17