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All sourcesNASA NTRSDOE OSTI
NASA NTRSDate not supplied

Demonstration of a Modular, Scalable, Laser Communication Terminal for Manned Spaceflight Missions

Free-space laser communication systems are increasingly implemented on state of the art satellites for their high-speed connectivity. This work outlines the design, analysis and test of the Modular, Agile, Scalable Optical Terminal (MAScOT) we have developed to support Low-Earth Orbit (LEO) to deep-space communication links. In LEO, the MAScOT will be implemented on the International Space Station to support the Integrated Laser Communications Relay Demonstration (LCRD) LEO User Modem and Amplifier Terminal (ILLUMA-T) program. ILLUMA-T’s overarching objective is to demonstrate high bandwidth data transfer between LEO and a ground station via a geosynchronous (GEO) relay satellite. Outside of GEO, MAScOT will also be implemented on the Artemis-II mission to demonstrate high data rate optical communications to and from the moon as part of the Orion EM-2 Optical Communications (O2O) program. Both missions leverage the same modular architecture despite varying structural, thermal, and optical requirements. To achieve sufficient performance, the optical terminal relies on a coarse/fine nested tracking loop to realize sub-arcsecond pointing across +/- 120 deg elevation and +/- 175 deg azimuth field of regard. An integrated analysis of the MAScOT in support of both missions will be outlined in addition to scalable versions of this terminal for future missions.

Steven R. Gillmer↗
NASA NTRS1997

Reduction of ETS-VI Laser Communication Equipment Optical-Downlink Telemetry Collected During GOLD

Free-space laser communications experiments were conducted between the laser communication equipment (LCE) on board the Japanese Engineering Test Satellite VI (ETS-VI) and the ground station located at the Table Mountain Facility (TMF) during late 1995 and early 1996. This article describes the on-line data reduction process used to decode LCE telemetry (called E2) downlinked on the optical carrier during the Ground/Orbiter Lasercomm Demonstration (GOLD) experiments. The LCE has the capability of transmitting real-time sensor and status information at 128 kbps by modulating the onboard diode laser. The optical downlink was detected on the ground, bit synchronized, and the resulting data stream stored on a data recorder. The recorded data were subsequently decoded by on-line data processing that included cross-correlation of the known telemetry data format and the downlink data stream. Signals obtained from the processing can be useful not only in evaluating the characteristics of the LCE but also in understanding uplink and downlink signal quality.

Toyoshima, M.↗
NASA NTRS1988

A laser communication experiment utilizing the ACT satellite and an airborne laser transceiver

The Advanced Communications Technology Satellite (ACTS) will carry a laser communications transmitter package in order to attempt the experimental reception of signals transmitted from earth orbit. The ACTS laser package includes both a heterodyne transmitter and a direct-detection transmitter. The laser receiver will be installed in an aircraft that is fitted with the requisite signal window. The anticipated capability of this signal detector is noted.

Provencher, C.↗
NASA NTRS1970

Laser communication experiment. Volume 1: Design study report: Spacecraft transceiver. Part 1: Transceiver design

The ATS-F Laser Communications Experiment (LCE) is the first significant step in the application of laser systems to space communications. The space-qualified laser communications system being developed in this experiment, and the data resulting from its successful deployment in space, will be applicable to the use of laser communications systems in a wide variety of manned as well as unmanned space missions, both near earth and in deep space. Particular future NASA missions which can benefit from this effort are the Tracking and Data Relay Satellite System and the Earth Resources Satellites. The LCE makes use of carbon dioxide lasers to establish simultaneous, two-way communication between the ATS-F synchronous satellite and a ground station. In addition, the LCE is designed to permit communication with a similar spacecraft transceiver proposed to be flown on ATS-G, nominally one year after the launch of ATS-F. This would be the first attempt to employ lasers for satellite-to-satellite communications.

Source record↗
NASA NTRS2004

The Mars laser communication demonstration

This paper provides the status of the Mars Laser Communication Demonstration Project, a joint project between NASA's Goddard Space Flight Center (GSFC), the California Institute of Technology Jet Propulsion Laboratory (JPL), and the Massachusetts Institute of Tecnology Lincoln Laboratory (MIT/LL). It reviews the current ideas/designs for the flight and ground segments, the critical technologies required, adn the concept of operations. The laser communication (lasercom) flight terminal will be flown on the Mars Telecom Orbiter (MTO) to be launched by NASA in 2009, and will demonstrate a technology which has the potential of vastly improving NASA's ability to communicate throughout the solar system.

DePaula, Ramon↗
NASA NTRS1998

A Combined Laser-Communication and Imager for Microspacecraft (ACLAIM)

ACLAIM is a multi-function instrument consisting of a laser communication terminal and an imaging camera that share a common telescope. A single APS- (Active Pixel Sensor) based focal-plane-array is used to perform both the acquisition and tracking (for laser communication) and science imaging functions.

Laser Communication Optical Communication Science ↗
NASA NTRS1989

Performance and modeling of the GSFC pointing acquisition and tracking system for laser communications

In this paper the NASA Goddard Space Flight Center (GSFC) laser communication pointing, acquisition, and tracking laboratory demonstration program is discussed. This program entails the construction of a flexible brass-board simulation tool, and a supporting computer simulation effort. The result of this program will be a viable test bed to support the design and specification of space-based laser communication terminals and, additionally, to address critical performance issues such as tracking robustness in the presence of background (e.g., stellar or earth) noise and/or internally generated thermal noise.

Fox, N. D.↗
NASA NTRS1970

Laser communication experiment. Volume 1: Design study report: Spacecraft transceiver. Part 3: LCE design specifications

The requirements for the design, fabrication, performance, and testing of a 10.6 micron optical heterodyne receiver subsystem for use in a laser communication system are presented. The receiver subsystem, as a part of the laser communication experiment operates in the ATS 6 satellite and in a transportable ground station establishing two-way laser communications between the spacecraft and the transportable ground station. The conditions under which environmental tests are conducted are reported.

Source record↗
NASA NTRS1977

Wideband heterodyne receiver for laser communication system

A heterodyne receiver for laser communication is described which includes a front end having a cooled photomixer contained in a hermetically sealed spaced quality housing designed for wide bandwidth transmission. The photomixer is coupled through a wideband preamplifier to the receiver back end which includes a frequency tracking network and demodulating equipment. The receiver is capable of tracking a Doppler frequency shift of 750 MHz, positive or negative, and has an instantaneous intermediate frequency information bandwidth of 400 MHz. The receiver system is also capable of operating over a wide temperature range and is designed to be suitable for use in outer space communication.

Flattau, T.↗
NASA NTRS2013

Free Space Laser Communication Experiments from Earth to the Lunar Reconnaissance Orbiter in Lunar Orbit

Laser communication and ranging experiments were successfully conducted from the satellite laser ranging (SLR) station at NASA Goddard Space Flight Center (GSFC) to the Lunar Reconnaissance Orbiter (LRO) in lunar orbit. The experiments used 4096-ary pulse position modulation (PPM) for the laser pulses during one-way LRO Laser Ranging (LR) operations. Reed-Solomon forward error correction codes were used to correct the PPM symbol errors due to atmosphere turbulence and pointing jitter. The signal fading was measured and the results were compared to the model.

laser communication↗
NASA NTRSDate not supplied

Early Results from NASA’s Laser Communications Relay Demonstration (LCRD) Experiment Program

The National Aeronautics and Space Administration’s (NASA) Laser Communications Relay Demonstration (LCRD) mission began its two-year Experiment Program in June 2022. This experimental phase includes long-term measurement of the effects of the atmosphere (turbulence, weather) on the performance and availability of lasercom. Furthermore, various future operational scenarios including robotic and exploration missions and various network service configurations are being emulated. In addition to experiments and demonstrations proposed by the LCRD Investigator Team, NASA enables individuals and groups from government agencies, academia, and industry to propose experiments under the LCRD Guest Experimenters Program. This conference paper provides highlights of the early LCRD experiments and a preview of the future experiments, including relaying data to and from the Integrated LCRD Low-Earth Orbit (LEO) User Modem and Amplifier Terminal (ILLUMA-T) on the International Space Station. The LCRD geosynchronous payload includes two laser communications terminals interconnected via an onboard electronic switch, and can relay information between two optical ground stations located in California and Hawaii. LCRD is a joint project involving NASA Goddard Space Flight Center (GSFC), the NASA Jet Propulsion Laboratory (JPL), and Massachusetts Institute of Technology Lincoln Laboratory (MIT LL).

lasercom↗
NASA NTRSDate not supplied

Early Results from NASA’s Laser Communications Relay Demonstration (LCRD) Experiment Program

The National Aeronautics and Space Administration’s (NASA) Laser Communications Relay Demonstration (LCRD) mission began its two-year Experiment Program in June 2022. This experimental phase includes long-term measurement of the effects of the atmosphere (turbulence, weather) on the performance and availability of lasercom. Furthermore, various future operational scenarios including robotic and exploration missions and various network service configurations are being emulated. In addition to experiments and demonstrations proposed by the LCRD Investigator Team, NASA enables individuals and groups from government agencies, academia, and industry to propose experiments under the LCRD Guest Experimenters Program. This conference paper provides highlights of the early LCRD experiments and a preview of the future experiments, including relaying data to and from the Integrated LCRD Low-Earth Orbit (LEO) User Modem and Amplifier Terminal (ILLUMA-T) on the International Space Station. The LCRD geosynchronous payload includes two laser communications terminals interconnected via an onboard electronic switch, and can relay information between two optical ground stations located in California and Hawaii. LCRD is a joint project involving NASA Goddard Space Flight Center (GSFC), the NASA Jet Propulsion Laboratory (JPL), and Massachusetts Institute of Technology Lincoln Laboratory (MIT LL).

lasercom↗
NASA NTRS1994

Integration and test of high-speed transmitter electronics for free-space laser communications

The NASA Lewis Research Center in Cleveland, Ohio, has developed the electronics for a free-space, direct-detection laser communications system demonstration. Under the High-Speed Laser Integrated Terminal Electronics (Hi-LITE) Project, NASA Lewis has built a prototype full-duplex, dual-channel electronics transmitter and receiver operating at 325 megabit S per second (Mbps) per channel and using quaternary pulse-position modulation (QPPM). This paper describes the integration and testing of the transmitter portion for future application in free-space, direct-detection laser communications. A companion paper reviews the receiver portion of the prototype electronics. Minor modifications to the transmitter were made since the initial report on the entire system, and this paper addresses them. The digital electronics are implemented in gallium arsenide integrated circuits mounted on prototype boards. The fabrication and implementation issues related to these high-speed devices are discussed. The transmitter's test results are documented, and its functionality is verified by exercising all modes of operation. Various testing issues pertaining to high-speed circuits are addressed. A description of the transmitter electronics packaging concludes the paper.

Soni, Nitin J.↗
NASA NTRS2013

Conceptual Design of the Adaptive Optics System for the Laser Communication Relay Demonstration Ground Station at Table Mountain

The Laser Communication Relay Demonstration will feature a geostationary satellite communicating via optical links to multiple ground stations. The first ground station (GS-1) is the 1m OCTL telescope at Table Mountain in California. The optical link will utilize pulse position modulation (PPM) and differential phase shift keying (DPSK) protocols. The DPSK link necessitates that adaptive optics (AO) be used to relay the incoming beam into the single mode fiber that is the input of the modem. The GS-1 AO system will have two MEMS Deformable mirrors to achieve the needed actuator density and stroke limit. The AO system will sense the aberrations with a Shack-Hartmann wavefront sensor using the light from the communication link's 1.55 microns laser to close the loop. The system will operate day and night. The system's software will be based on heritage software from the Palm 3000 AO system, reducing risk and cost. The AO system is being designed to work at r(sub 0) greater than 3.3 cm (measured at 500 nm and zenith) and at elevations greater than 20deg above the horizon. In our worst case operating conditions we expect to achieve Strehl ratios of over 70% (at 1.55 microns), which should couple 57% of the light into the single mode DPSK fiber. This paper describes the conceptual design of the AO system, predicted performance and discusses some of the trades that were conducted during the design process.

optical communications↗
NASA NTRS2016

A Day in the Life of the Laser Communications Relay Demonstration Project

This paper provides an overview of the planned concept of operations for the Laser Communications Relay Demonstration Project (LCRD), a joint project among NASA's Goddard Space Flight Center (GSFC), the Jet Propulsion Laboratory, California Institute of Technology (JPL), and the Massachusetts Institute of Technology Lincoln Laboratory (MIT/LL). LCRD will provide at least two years of bi-directional optical communications at user data rates of up to 1.244 Gbps in an operational environment. The project lays the groundwork for establishing communications architecture and protocols, and developing the communications hardware and support infrastructure, concluding in a demonstration of optical communications' potential to meet NASA's growing need for higher data rates for future science and exploration missions. A pair of flight optical communications terminals will reside on a single commercial communications satellite in geostationary orbit; the two ground optical communications terminals will be located in Southern California and Hawaii. This paper summarizes the current LCRD architecture and key systems for the demonstration, focusing on what it will take to operate an optical communications relay that can support space-to-space, space-to-air, and space-to-ground optical links.

Communications↗