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National Aeronautics and

Space Administration

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Optical Communications – an emerging technology at NASA

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Abhijit Biswas

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Jet Propulsion Laboratory,

California Institute of Technology,

4800 Oak Grove Drive,

Pasadena, CA 91109

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Jet Propulsion Laboratory

California Institute of Technology

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© 2018 California Institute of Technology. Government sponsorship acknowledged.

ISDC 2018 Moon Development

© 2018 California Institute of Technology. Government sponsorship acknowledged.

National Aeronautics and

Space Administration

​

Jet Propulsion Laboratory

California Institute of Technology

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Introduction

  • Pursued since the invention of lasers in the early 1960’s.
  • Space-to-ground and space-to-space demonstrations from geostationary (GEO) and low-earth orbiting (LEO) satellites demonstrated in past decade
  • NASA demonstrated successful bi-directional demonstration of optical communication
    • Lunar orbiting spacecraft called the Lunar Atmospheric Dust Environment Explorer (LADEE).
    • LEO-to-Ground demonstration from the International Space Station called Optical Payload for Lasercom Science (OPALS)
  • NASA is planning advanced demonstrations in the next decade.
    • Laser Communication Relay Demonstration (LCRD) to cover Earth, geostationary and eventually LEO nodes,
    • The Deep Space Optical Communications (DSOC) Project is planning to demonstrate the first optical communication link from astronomical unit (AU) distances.
    • Optical to Orion (O2O) demonstration on the first crewed EM-2 mission
  • A brief summary of the highlights of the past demonstrations will be presented.

Optical Communications

- an emerging technology at NASA

ISDC 2018 Moon Development

© 2018 California Institute of Technology. Government sponsorship acknowledged.

National Aeronautics and

Space Administration

​

Jet Propulsion Laboratory

California Institute of Technology

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  • Graphical summary of possible optical communications (lasercom) links

Interstellar/Exoplanets

Near-Earth bi-directional

(LEO, MEO, GEO, Moon

Orbiter-to-lander or rover

(Moon, Mars, other bodies)

Downlink from deep-space

(Mars, Venus, Jupiter Saturn

Inter-satellite

(Moon, Mars, other bodies)

Uplink to deep-space

ISDC 2018 Moon Development

© 2018 California Institute of Technology. Government sponsorship acknowledged.

National Aeronautics and

Space Administration

​

Jet Propulsion Laboratory

California Institute of Technology

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Laser Communications Systems

Generic Transceiver Block Diagram

OPTICS

MOD

LASER

Pointing

Control

1550 nm

DATA

Encode

Pointing

Sensor

OCTL Telescope

Ground

Telescope

Flight Transceiver

ISDC 2018 Moon Development

© 2018 California Institute of Technology. Government sponsorship acknowledged.

National Aeronautics and

Space Administration

​

Jet Propulsion Laboratory

California Institute of Technology

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Moon

39, 78

155, 311

622 Mb/s

DOWNLINK

10, 20 Mb/s

UPLINK

Lunar Atmospheric Dust Environment Explorer (LADEE), ARC

Lunar Lasercom Space Terminal

(LLST), MIT-LL

39, 78

Mb/s

DOWNLINK

BEACON

Lunar Lasercom Operations

Center (LLOC), LL-MIT

Science Ops.

Center,

GSFC

Lunar Laser Optical Ground Station (LLOGS)

ESA Ground Station,

Tenerife, Canary Islands

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Table Mtn

CA

NASA-GSFC

Greenbelt, MD

LL-MIT

Boston,

MA

Lunar Laser Communication Demonstration (LLCD)

Oct. 18 – Nov. 22, 2013

Lunar Lasercom

OCTL Terminal

(LLOT), JPL

First laser communication demonstration from Lunar distance

Lunar Lasercom Ground Terminal (LLGT), LL-MIT, White Sands, NM

LLCD & Lunar Lasercom OCTL Terminal (LLOT)

Demonstrated optical links

  • Day & Night ops
  • Site diversity
  • Link Handover

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ISDC 2018 Moon Development

© 2018 California Institute of Technology. Government sponsorship acknowledged.

National Aeronautics and

Space Administration

​

Jet Propulsion Laboratory

California Institute of Technology

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Downlink Acquisition

  • Downlink average power falls within the predicted bounds
    • Link analysis
    • Current best estimates during testing of LLOT

Focus

Close

Loop

Switch

VBS

ISDC 2018 Moon Development

© 2018 California Institute of Technology. Government sponsorship acknowledged.

National Aeronautics and

Space Administration

​

Jet Propulsion Laboratory

California Institute of Technology

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SpaceX CRS-3 Launch April 18, 2014

OPALS in Dragon trunk post separation

Robotic transfer to ELC-1

OVERVIEW Optical Payload for Lasercomm Science (OPALS)

ISDC 2018 Moon Development

© 2018 California Institute of Technology. Government sponsorship acknowledged.

National Aeronautics and

Space Administration

​

Jet Propulsion Laboratory

California Institute of Technology

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FUTURE SYSTEMS

ISDC 2018 Moon Development

© 2018 California Institute of Technology. Government sponsorship acknowledged.

National Aeronautics and

Space Administration

​

Jet Propulsion Laboratory

California Institute of Technology

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Laser Communication Relay

Demonstration (LCRD)

  • Twin terminals on GEO platform
    • Data transmitted from OCTL at Table Mountain
    • Relayed to Ground Station at White Sands, NM

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  • JPL to deliver the ground station at OCTL
    • Key challenge is to implement an Adaptive Optics System
    • Based on wave-front sensor,
      • Less power than self-referencing interferometer
    • Lower bandwidth but GEO links do not have slew rates
    • Bi-directional DPSK @ 1.2 Gb/s
    • Downlink? PPM at 311 Mb/s

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Planned in 2019-2020

Pre-Decisional Information -- For Planning and Discussion Purposes Only

ISDC 2018 Moon Development

© 2018 California Institute of Technology. Government sponsorship acknowledged.

National Aeronautics and

Space Administration

​

Jet Propulsion Laboratory

California Institute of Technology

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NASA Near-Earth Lasercom Development LEMNOS

-10

ILLUMA-T Laser Comm Terminal on ISS/LEO

LCRD/

GEO

O2O Laser Comm on Orion/Lunar Orbit

1.2 Gbps

52 Mbps

80 Mbps

20 Mbps

500,000 km

40,000 km

Ground Stations

622 Mbps

20 Mbps

LLCD Laser Comm on LADEE/Lunar Orbit

400,000 km

LEMNOS

  • LEMNOS: Laser-Enhanced Mission Communication Navigation and Operational Services
  • ILLUMA-T: Integrated LCRD LEO (Low-Earth Orbit) User Modem and Amplifier Terminal
  • O2O: Orion EM-2 Optical Comm  
  • LLCD: Lunar Laser Communication Demonstration
  • LCRD: Laser Communication Relay Demonstration 

Pre-Decisional Information -- For Planning and Discussion Purposes Only

ISDC 2018 Moon Development

© 2018 California Institute of Technology. Government sponsorship acknowledged.

National Aeronautics and

Space Administration

​

Jet Propulsion Laboratory

California Institute of Technology

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Ground Laser Receiver (GLR)

Palomar Mtn., CA

5m-dia. Hale Telescope

Ground Laser Transmitter (GLT)

Table Mtn., CA

1m-OCTL Telescope (5 kW)

Deep-Space Optical Communications

(DSOC) Concept

1064 nm uplink

1.6 kb/s < 1 AU

Psyche

Ops

Center

DSOC

Ops Ctr.

1550 nm downlink

Flight Laser Transceiver (FLT) 4W, 22 cm

Deep Space Network (DSN)

Psyche

Spacecraft

(2022)

  • OBJECTIVES:

Advance NASA’s enhanced communication goals by:

  • Demonstrate optical communications from deep space to validate:
    • Link acquisition/re-acquisition and laser pointing control
    • High photon efficiency signaling (implement emerging CCSDS standard)

Data-rate (Mb/s)

Distance (AU)

132

< 0.25

14

> 0.25 <1.0

2

> 1 < 2.0

0.2

> 2 <2.6

Pre-Decisional Information -- For Planning and Discussion Purposes Only

ISDC 2018 Moon Development

© 2018 California Institute of Technology. Government sponsorship acknowledged.

National Aeronautics and

Space Administration

​

Jet Propulsion Laboratory

California Institute of Technology

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Summary

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  • Future activities planned in next decade

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  • Maturing optical communications is compelling

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  • Technology development and conops will advance in the next two decades

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  • Advances in space laser communications over past two decades

Pre-Decisional Information -- For Planning and Discussion Purposes Only

ISDC 2018 Moon Development

© 2018 California Institute of Technology. Government sponsorship acknowledged.

National Aeronautics and

Space Administration

​

Jet Propulsion Laboratory

California Institute of Technology