Author Topic: Next generation of TDRS (4th Gen) with both RF and Optical Communication  (Read 2802 times)

Offline manboy

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A Geosynchronous Orbit Optical Communications Relay Architecture

Highlights:
"There are currently three different generations of spacecraft in orbit and NASA is studying the requirements for a future generation to be launched around the 2025 timeframe."

"While the exact requirements are currently unknown, NASA is investing in communications technologies that could be deployed on the satellite to provide new communications services. One of those new technologies is optical communications."

"An optical space to ground link is particularly attractive as the downlink data rate from the relay increases. It is easy to envision Earth relays in the not-so-distant future with tens of Gb/s of downlink. However, the availability of an optical space to ground link would be impacted by clouds. To provide high availability, the Earth relay would have to use a combination of RF and optical space to ground links and onboard storage, or employ a number of optical communication ground stations to support the relay. For example, a future Earth relay could have onboard memory and an RF space to ground link at 1 or 2 Gbps, coupled with an optical space to ground link at 10 Gbps. Thus, some data could be transmitted to Earth via RF, even if all of the optical ground stations were covered by clouds. The RF space to ground link could be eliminated by increasing the amount of onboard storage or the number of available optical ground stations."

"The spacecraft design concept consists of the current TDRS-like spacecraft augmented with: (1) a 2 m telescope aperture for Deep Space optical communications and (2) a smaller 10 to 30 cm telescope for high rate LEO optical communications and support out to the Sun-Earth Libration points L1 and L2 (~ 1 million miles from earth)."
"Cheese has been sent into space before. But the same cheese has never been sent into space twice." - StephenB

Offline manboy

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Commercialization and Standardization Progress towards an Optical Communications Earth Relay

Highlights:
"Several space agencies are currently working on space based optical communications. The primary motivation stems from the expectation that substantially higher (at least 10 times) data rates than Radio Frequency (RF) based solutions might be feasible with similar user spacecraft onboard terminal burden (mass, volume and power). In addition, optical communications can also be used at comparable RF data rates in order to lower the user communication system’s required mass, volume, and power. Finally available RF spectrum is also becoming an issue in high data rate applications."

"In order to enhance the use of optical communications worldwide and to allow the sharing of communications infrastructure such as optical ground stations and optical relay satellites, the world’s major space agencies are engaged in developing international standards for space optical communication systems as has been done with radio frequency (RF) communications"

"To facilitate the adoption of optical communications by NASA science and exploration missions, a commercial supplier of space terminals compatible with terminals on the next generation Tracking and Data Relay Satellites need to exist. Ideally, more than one commercial source should be developed and terminals from one source should be compatible with the terminals from another source."

"A set of standards for space optical communications needs to be developed to enable inoperability between terminals from different commercial sources. Ideally, an international standard will be developed and accepted by the major space agencies worldwide. An international standard will allow optical communications terminals built by one space agency to use the infrastructure of another. Collaboration in optical communications will lower mission cost and risk and likely enable missions which otherwise are unaffordable by one nation on their own. This is the evolutionary next step to today’s existing RF cross support."

« Last Edit: 07/23/2016 07:01 PM by manboy »
"Cheese has been sent into space before. But the same cheese has never been sent into space twice." - StephenB

Offline TrevorMonty

Optical comms between cislunar (L1-L2) space vehicles and these relays would free up time on the big expensive earth receiving stations. Plus higher data through from put these vehicles.

I do wonder if it is possible to add optical relays to existing missions. Have satellite with optical comms position its self near existing space craft eg mars orbiter, use high speed rf (few kms) to communicate with space craft and optical for earth link.

Offline Bob Shaw

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Plus, lasers. Got to have lasers. BIG lasers. And sharks.

Offline Asteroza

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Might want to keep an eye on these guys. Need to build out a ground station network to do heavy receiving, in light of weather issues though.

http://bridgesatinc.com/

Offline russianhalo117

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Might want to keep an eye on these guys. Need to build out a ground station network to do heavy receiving, in light of weather issues though.

http://bridgesatinc.com/
It has been stated before that new terminals would be likely be built at high altitudes and in desert areas where the weather obstruction is very unlikely. Other wavelengths can be used that aren't obstructed by weather.
« Last Edit: 08/24/2016 01:41 AM by russianhalo117 »

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