A report describes the NASA Spacecraft Transponding Modem (STM) — a spacecraft transponder now under development for planned use on deep-space missions scheduled for launch in the year 2003. In comparison with a traditional deep-space transponder, the STM will be smaller and less power hungry; the reductions in size and power demand will be effected by use of custom application-specific integrated circuits. The STM will perform all of the traditional deep-space-transponder functions, plus some coding, decoding, and time-tagging functions: The STM will track an X-band uplink signal and transmit both X- and Ka-band downlinks. A command detector, a code-block processor, and hardware command decoder will be integral parts of the STM. Coding functions will include Reed-Solomon coding, convolutional coding, and turbo coding for downlink telemetry. Downlink symbol rates could be ramped linearly to match the expected gain/noise temperature of a receiving station. Data could be transmitted by any of three different phase-modulation schemes at rates from 5 b/s to 24 Mb/s. Other functions will include standard turnaround ranging, regenerative pseudonoise ranging, and differential one-way ranging.
This work was done by Brian Cook, Charles Kyriacou, Constantine Andricos, Gary Burke, James Kowalski, James Layland, Jeff Berner, Jonathan Perret, Narayan Mysoor, Selahattin Kayalar, Amy Holst, Bryan Bell, Vatche Vorperian, and William Whitaker of Caltech for NASA's Jet Propulsion Laboratory. To obtain a copy of the report, "The NASA Spacecraft Transponding Modem," access the Technical Support Package (TSP) free on-line at www.nasatech.com/tsp under the Electronics & Computers category.
In accordance with Public Law 96-517, the contractor has elected to retain title to this invention. Inquiries concerning rights for its commercial use should be addressed to
Intellectual Property group
JPL
Mail Stop 202-233
4800 Oak Grove Drive
Pasadena, CA 91109
(818) 354-2240
Refer to NPO-21004, volume and number of this NASA Tech Briefs issue, and the page number.
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The NASA Spacecraft Transponding Modem
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Overview
The document discusses the NASA Spacecraft Transponding Modem (STM), a spacecraft transponder currently under development for deep-space missions scheduled for launch in 2003. The STM is designed to be smaller and more power-efficient compared to traditional deep-space transponders, achieved through the use of custom application-specific integrated circuits.
The STM will perform all standard deep-space transponder functions while also incorporating additional capabilities such as coding, decoding, and time-tagging. It will track an X-band uplink signal and transmit downlinks in both X-band and Ka-band frequencies. Integral components of the STM include a command detector, a code-block processor, and a hardware command decoder. The modem will utilize various coding techniques, including Reed-Solomon coding, convolutional coding, and turbo coding, to enhance downlink telemetry.
The STM is designed to support flexible downlink symbol rates, which can be adjusted to match the expected gain/noise temperature of receiving stations. Data transmission will be possible using three different phase-modulation schemes, with rates ranging from 5 bits per second to 24 megabits per second. Additionally, the STM will feature standard turnaround ranging, regenerative pseudonoise ranging, and differential one-way ranging capabilities.
The development of the STM was carried out by a team of engineers and scientists from the Jet Propulsion Laboratory (JPL) at the California Institute of Technology, under contract with NASA. The document also notes that the contractor has retained title to the invention in accordance with Public Law 96-517, and inquiries regarding commercial use rights should be directed to the Technology Reporting Office at JPL.
The document emphasizes that references to specific commercial products or services do not imply endorsement by the U.S. Government or JPL. It serves as a technical support package, providing insights into the STM's capabilities and the collaborative efforts behind its development. Overall, the STM represents a significant advancement in spacecraft communication technology, poised to enhance the efficiency and effectiveness of future deep-space missions.
