Communications

Final High-Fidelity Down-Conversion Source for Secure Communications Using On-Demand Single Photons

The basic idea is to array, cascade, or time multiplex the output from several parametric down-conversion sources.

John H. Glenn Research Center, Cleveland, Ohio

Secure communication over long distances requires robust encryption. While current encryption algorithms exist using classical methods, there are no unconditionally secure methods of distributing encryption keys classically. However, by exploiting the quantum nature of individual photons, quantum key distribution (QKD) can be proven as an unconditionally secure method for the distribution of encryption keys. Because QKD operates via the transmission and detection of single photons, there are major challenges for practical use in terms of both key generation rate and the maximum distance over which a secret key can be established.

Posted in: Briefs, TSP, Communications, Security systems, Telecommunications, Security systems, Telecommunications
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Space Telecommunications Radio System Memory Test Application

NASA’s Jet Propulsion Laboratory, Pasadena, California

This software provides a portable, flexible memory testing application meeting the NASA Space Telecommunications Radio System (STRS) specification. As an STRS-compliant application, the tester application is portable to any STRS-compliant hardware/software platform. Thanks to configurable properties, the tester application can be adjusted for many different memory environments.

Posted in: Briefs, Communications, Computer software / hardware, Computer software and hardware, Radio equipment, Telecommunications, Computer software / hardware, Computer software and hardware, Radio equipment, Telecommunications
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Functional Enhancements to the FPGA Implementation of the Advanced Orbiting System Data Link Protocol

NASA’s Jet Propulsion Laboratory, Pasadena, California

Dynamic frame sizing was added to the existing AOS Packet Service FPGA implementation. This capability provides in-flight system calibration functionality, allowing the spacecraft and ground station the means to optimize a communication link by dynamically adjusting the Advanced Orbiting System (AOS) transfer frame size.

Posted in: Briefs, TSP, Communications, Communication protocols, Communication protocols, Spacecraft
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Communication System and Method Over High-Latency, Low-Bandwidth Networks

Lyndon B. Johnson Space Center, Houston, Texas

In high-latency, low-bandwidth networks such as those employed when communicating with an extraterrestrial object via wireless communication over hundreds or thousands of miles, it may be difficult or expensive to communicate large quantities of information in a reliable manner. Each data stream that is transmitted may require error correcting, redundancy, or other bandwidth-heavy techniques to ensure the information received matches the information transmitted. This may often lead to a total reduction of communicated information, with little regard for the importance of the underlying data.

Posted in: Briefs, Communications, Telecommunications, Telecommunications, Data management
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CASH: Framework for Streamlined, Daily Updates

NASA’s Jet Propulsion Laboratory, Pasadena, California

Secure, efficient, and effective communication is critical for the multinational Cassini mission to Saturn. Cassini teams share information through the use of internal Web pages. The challenge was to develop dynamic Web pages that did not require special understanding of HTML complexities and the implementation of complex Web server access controls.

Posted in: Briefs, TSP, Communications, Telecommunications, Telecommunications
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SCaN Optical Link Budget Tool

John H. Glenn Research Center, Cleveland, Ohio

In response to the requirements of the Space-Based Relay Study (SBRS) undertaken by NASA in 2013, as well as the Integrated Radio and Optical Communications (iROC) project being conducted by NASA Glenn Research Center (GRC) beginning in 2012, a calculation procedure was required to rapidly assess the operation of optical communication links originating from within deep space (in particular, from around Mars in the case of iROC), as well as within the near-Earth scenarios of LEO (low-Earth orbit) and GEO (geostationary Earth orbit) in the case of SBRS. Such an assessment included the specification of the design components of the optical system to achieve reliable communications as prescribed by one or several metrics that indicate overall system operation.

Posted in: Briefs, TSP, Communications, Optics, Telecommunications, Optics, Telecommunications, Satellites
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Mars Relay CubeSat

Small relay stations can take the place of a small number of large ones.

NASA’s Jet Propulsion Laboratory, Pasadena, California

When NASA and other agencies send landers to Mars and other planets, they rely on existing orbiters to relay the data during the critical entry, descent, and landing (EDL) phase. The current orbiters are aging and there are no current NASA plans to replace them. Future landers have a critical challenge to communicate during a very risky mission phase. The InSight mission will land on Mars in September 2016 with no direct-to-Earth radio link. Instead, Insight expects the Mars Reconnaissance Orbiter (MRO) to be fully functional and placed in an orbit to be in view of the EDL time and place. MRO will take many hours to play back the data to Earth, leaving the project staff without knowledge if their valuable spacecraft has made it safely.

Posted in: Briefs, TSP, Communications, Relays, Relays, Satellites, Spacecraft
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VCSEL Laser Array for Communications

Ames Research Center, Moffett Field, California

Optical communications in terrestrial and space environments require transmitted signals on the order of 40 GHz and higher, because of the uncertain and changing transmission environments. A robust communications system is needed that will provide these frequencies and substantial discrimination between different signals, which permit switching times on the order of 0.25 ps, and that permit the use of two or more distinct signals.

Posted in: Briefs, Communications, Satellite communications, Satellite communications
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Providing a Real-Time Audible Message to a Pilot

This real-time weather and environmental data reporting approach is useful for commercial airlines.

Ames Research Center, Moffett Field, California

An aircraft pilot would prefer to receive information on weather patterns, obstructions, and other conditions that may interfere with a flight plan, formal or informal, as the pilot’s flight proceeds, with a latency of no more than a few minutes. Learning of, and reacting to, a changing environment within minutes after the change is first observed and reported is not possible with pilot’s reports (PIREPs), as presently provided. Instead, receipt of a pilot’s report (PIREP) often occurs offline, before a pilot’s own flight has begun, and with an associated latency of one to six hours. The present invention, described as an audio twitter approach, removes most of the latency associated with a PIREP and allows expansion of, and selective filtering of, information that is directly useful to the recipient pilot (RP).

Posted in: Briefs, Communications, Flight management systems, Telecommunications, Flight management systems, Telecommunications, Reaction and response times, Noise, Noise
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Pass Plan Formatter (PPF) for Earth Sciences Ground Support System

Goddard Space Flight Center, Greenbelt, Maryland

The TRMM (Tropical Rainfall Measuring Mission) and Terra ESMO (Earth Science Mission Operations) Ground Systems needed a method of passing scheduling data through the Goddard Mission Services Evolution Center (GMSEC) bus to other subsystems without modifying the Planning and Scheduling systems and their planning data output. The original output data is used by other subsystems and not just for automation with GMSEC.

Posted in: Briefs, TSP, Communications, Satellite communications, Satellite communications, Data management
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