Leslie J. Deutsch

A comparison of VLSI architecture of finite field multipliers using dual, normal, or standard bases

Three different finite-field multipliers are presented: (1) a dual-basis multiplier due to E.R. Berlekamp (1982); the Massey-Omura normal basis multiplier; and (3) the Scott-Tavares-Peppard standard basis multiplier. These algorithms are chosen because each has its own distinct features that apply most suitably in particular areas. They are implemented on silicon chips with NMOS technology so that the multiplier most desirable for VLSI implementation can readily be ascertained. >

A VLSI design of a pipeline Reed-Solomon decoder

A pipeline structure of a transform decoder similar to a systolic array is developed to decode Reed-Solomon (RS) codes. The error locator polynomial is computed by a modified Euclids algorithm which avoids computing inverse field elements. The new decoder is regular and simple, and naturally suitable for VLSI implementation.

Prospects for a Next-Generation Deep-Space Network

A next-generation deep-space network is currently under consideration by the National Aeronautics and Space Administration. Building upon its many past successes, this network will be required to meet the needs of current and planned missions. These will, no doubt, include the familiar suite of telemetry, command, tracking, and navigation services, with performance levels derived from analysis of the probable future mission set. Additionally, it will be expected to provide enabling capabilities for missions still on the drawing boards. Traditionally, the network serves the robotic deep-space exploration fleet. However, at this time, consideration of the special needs of planned future human lunar missions is appropriate, as well as the evolution to the eventual human exploration of Mars.

Integrated network architecture for sustained human and robotic exploration

The National Aeronautics and Space Administration (NASA) Exploration Systems Mission Directorate is planning a series of human and robotic missions to the Earths Moon and to Mars. These missions will require telecommunication and navigation services. This paper sets forth presumed requirements for such services and presents strawman lunar and Mars telecommunications network architectures to satisfy the presumed requirements. The paper suggests that a modest ground network would suffice for missions to the near-side of the Moon. A constellation of three Lunar Telecommunications Orbiters connected to a modest ground network could provide continuous redundant links to a polar lunar base and its vicinity. For human and robotic missions to Mars, a pair of areostationary satellites could provide continuous redundant links between a mid-latitude Mars base and Deep Space Network antennas augmented by large arrays of 12-m antennas

Selecting Codes, Modulations, Multiple Access Schemes and Link Protocols for Future NASA Missions

NASAs Space Communication and Navigation (SCaN) office has been designing an agency-wide space communication and navigation architecture to support NASA space exploration and science missions out to 2030. SCaN chartered a study in 2007 to select codes, modulations, multiple access techniques and link protocols for this architecture. The study was conducted by Goddard Space Flight Center, the Jet Propulsion Laboratory and consultants to NASA. This paper provides an overview of the study, describes the process used to carry out the study, and summarizes study results. Companion papers at this conference provide detailed technical information and analyses.

Formulation of Forward Error Correction Coding Recommendations for Future NASA Space Communications

NASA has undertaken a study to recommend and justify coding, modulation, and link protocol (CMLP) designs for the Space Communications and Networking (SCaN) office. This paper reports on the coding part of the CMLP study, which is chartered with identifying the forward error correction (FEC) codes suitable for NASA space exploration and science missions through 2030.

Resolving the Cassini/Huygens relay radio anomaly

NASAs Cassini mission to Saturn carries the European Space Agencys (ESAs) Huygens probe, which it will release shortly before an encounter with Saturns moon, Titan, a possible location for extraterrestrial life within our Solar System. As it parachutes towards Titans surface, Huygens will acquire scientific information which will be relayed to Earth through Cassini. Comprehensive testing of this relay radio link was not performed prior to Cassini launch and cannot be done during cruise. A test using NASAs Deep Space Network (DSN) to mimic the probes signal was performed in 2000 and uncovered an anomaly that, unchecked, would result in nearly complete loss of the Huygens mission. An international team of experts from NASA and ESA was assembled to solve this problem: the Huygens Recovery Task Force (HRTF.) This team, co-chaired by the author, performed extensive testing, modeling, and simulation to understand the failure mechanism. Each Huygens science team determined mission impacts for various scenarios based on these results. This led to a suggested modification to the Cassini trajectory that will result in nearly complete data return for Huygens with minimal impact on Cassini.

A single chip VLSI Reed-Solomon decoder

A new VLSI design of a pipeline Reed-Solomon decoder is presented. The transform decoding technique used in a previous design is replaced by a simple time domain algorithm. A new architecture which realizes such algorithm permits efficient pipeline processing with a minimum of circuits. A systolic array is also developed to perform erasure corrections in the new design. A modified form of Euclids algorithm is developed with a new architecture which maintains a real-time throughput rate with less transistors. Such improvements results in both an enhanced capability and significant reduction in silicon area, thereby making it possible to build a pipeline (255,223) RS decoder on a single VLSI chip.

A Sustained Proximity Network for Multi-Mission Lunar Exploration

The Vision for Space Exploration calls for an aggressive sequence of robotic missions beginning in 2008 to prepare for a human return to the Moon by 2020, with the goal of establishing a sustained human presence beyond low Earth orbit. A key enabler of exploration is reliable, available communication and navigation capabilities to support both human and robotic missions. An adaptable, sustainable communication and navigation architecture has been developed by Goddard Space Flight Center and the Jet Propulsion Laboratory to support human and robotic lunar exploration through the next two decades. A key component of the architecture is scalable deployment, with the infrastructure evolving as needs emerge, allowing NASA and its partner agencies to deploy an interoperable communication and navigation system in an evolutionary way, enabling cost effective, highly adaptable systems throughout the lunar exploration program.

NASA's X2000 program—An institutional approach to enabling smaller spacecraft

Abstract The number of NASA science missions per year is increasing from less than one to more than six. Individual mission budgets are smaller, though, so they can no longer afford dedicated technology developments. As a result, NASA formed the X2000 Program. X2000 is divided into a set of “deliveries” that provide basic avionics, power, communications, and software for future missions. X2000 First Delivery, to be completed in 2001, will provide a one MRAD-tolerant flight computer, power switching electronics, efficient radioisotope power source, and a transponder with services at 8.4 GHz and 32 GHz bands. The X2000 Second Delivery, to be completed around 2003, will enable complete spacecraft of 10–50 kg. Capabilities delivered by X2000 will be commercialized within the US so they will be available to others. Although the immediate customers for X2000 are deep space missions, most capabilities are generic in nature and will be equally applicable to Earth Observation missions.