Passing the Chips at 43,000 MPH:Special Purpose Computers Protect Integrity of Data on Pluto-bound NASA Probe and on Future Missions
Wednesday, January 9 2008
Jan. 9, 2008 POST FALLS, Idaho – University of Idaho special purpose computers are hurtling toward the edge of the solar system at speeds in excess of 43,000 mph aboard NASA’s New Horizons probe. The probe carrying the university’s Center for Advanced Microelectronics and Biomolecular Research’s (CAMBR) EDAC5 chip will be more than 882 million miles from Earth on Jan. 19, 2008; it was launched Jan.19,2006. The CAMBR chip is essential to the probe’s solid state recorder (SSR) board, where nearly all data from the spacecraft is stored before being transmitted back to Earth. The chip provides error correction of the data New Horizons is gathering on its groundbreaking mission. “The board employs flash memory that can be altered by single-event upsets caused by radiation in space,” explained Chris Hersman, an engineer at the Johns Hopkins University Applied Physics Laboratory (JHUAPL), where the spacecraft – including its SSR board and communications system – was designed and built. “The (CAMBR-developed) chip stores Reed-Solomon error correction and detection codes with the data, so that if in an upset occurs, we can correct the error before the data is down linked to earth,” said Hersman. Although the chip’s capabilities are much faster, it operates at 40 megabits per second aboard New Horizons, Hersman added. It is run at a slower speed to conserve energy. The probe is collecting physical and atmospheric data of the celestial bodies it encounters while moving toward the outer limits of earth’s solar system. The ultimate objective of New Horizons’ mission is to gather information on the dwarf planet Pluto and the unexplored Kuiper Belt region beyond it. The probe is expected to arrive at Pluto in 2015. Star Treks: The Next Generation Since the launch of the New Horizons Probe, CAMBR has developed even more efficient data correction technologies and cutting-edge methods of data transmission. CAMBR Principal Investigator Gary Maki recently delivered two new chips to NASA Goddard. One is the High Rate Base Band Modulator (HRBM) chip. The HRBM processes about 1.5 billion bits of information per second (Gbps) and automatically changes modulation schemes to find the most effective radio bandwidth for transmitting data. According to NASA engineers Wai Fong and Victor Sank, the HRBM provides a hardware efficient method to produce Radio Frequency (RF) digital signal transmissions, called modulations. It can be programmed to a variety of different signaling schemes, and provides very tight RF power spectrum response or bandwidth occupation through the use of simple digital processing that emulates complex RF analog filtering. The chip replaces bulky and massive analog components, saving on-board physical space, power consumption and weight. “The voices and music that we listen to on AM and FM bands is information added to the radio frequency wave by modulating the wave,” explained CAMBR scientist Sterling Whitaker. “Each modulation mode has advantages and disadvantages. NASA uses several types of modulation to add information to radio waves sent to earth from spacecraft. The HRBM modulator chip designed by CAMBR allows NASA scientists to choose the most appropriate modulation mode from 20 preprogrammed modulation schemes, and also allows them to program in new modulation schemes.” The CAMBR’s HRBM contains more than 2 million transistors designed to allow transmission of more than 300 million bits of information per second (Mbps). Recent NASA testing has shown the CAMBR technology has a 50 percent higher throughput, or a 450 Mbps data rate. Maki also delivered the CAMBR team’s Low Density Parity Check (LDPC) encoder chip to NASA Goddard. It serves as a companion chip for the HRBM. The LDPC appends – or encodes – a data stream with redundant information at a data rate over 1 Gbps – a process known as channel coding. The LDCP decodes noise-corrupted information, resulting in near error-free data. Like the CAMBR technology employed on New Horizons, the LDPC is all about maintaining the integrity of data gathered in space. “Information can be lost during transmission to earth in much the same way that static can cause the listener to miss parts of a sentence spoken by a D.J. on AM radio,” explained Whitaker. “The LDPC encoder chip enables ground receivers to correct errors and recover the exact data sent from the space craft.” The LPDC uses more than 350,000 transistors to compute and produce the additional error correcting information. The code and chip are part of the next generation international space communication standards authorized by the International Consulting Committee on Space Data Systems (CCSDS). The CAMBR technologies are being tested by NASA for use in the new Crew Exploration Vehicle (CEV), which will replace the shuttle. The new CEV communication electronics will provide links between Earth and the CEV when it orbits Earth, the moon or Mars; CEV communication electronics also will provide a direct communications link with astronauts working in space, on the surface of the moon, or Mars. NASA also is testing them for use in several weather and Earth sensing satellites. CAMBR scientists currently are working to incorporate both Reed-Solomon and LPDC capabilities into a single chip, which will give NASA scientists the ability to dynamically select the appropriate code for each use. “Direct communication with astronauts may use Reed-Solomon, whereas data communication with the CEV likely will be implemented with LDPC processors,” said Maki. “Direct communication with astronauts must not incur transmission delays found in the LDPC processors due to the nature of human communication. LDPC decoders may experience an unacceptable latency delay when the communication link experiences a large amount of noise due to natural or artificial means.” As that hybrid technology is developed, CAMBR scientists are in discussion with engineers at the Johnson Space Center in Houston, and with Lockheed Martin, the company that is engineering the CEV communication system. CAMBR scientists were the first to produce the CCDS Reed-Solomon processor, currently used in more than 90 percent of NASA Goddard satellites. They now are the first to produce the LPDC code for use in government satellites and other space applications. The CAMBR has attracted more than $19 million in grants and contracts since returning to the University of Idaho in 2002. CAMBR has been awarded grants and contracts from: the U.S. Department of Agriculture, Cooperative State Research, Education and Extension Services; USDA-Hatch Act ; NASA Headquarters; NASA Goddard Space Flight Center; American Semiconductor; U.S. Department of Health and Human Services, Center for Disease Control and Prevention; Office of Naval Research, U.S. Department of Housing and Urban Development; Sandia National Laboratory; Concise Logic, Inc.; National Science Foundation/University of California, Davis ITR/SI; Massachusetts Institute of Technology, Lincoln Laboratory/ Defense Advanced Research Projects Agency; University of Michigan, Jet Propulsion Laboratory; and the Mayo Clinic. CAMBR works in partnership with: Cornell University, Nanoscale Fabrication Facility; JHUAPL; NASA Johnson Space Center; University of Idaho, chemistry department.; Washington State University; Oregon State University; Micron; National Science Foundation; the IDeA Network for Biomedical Research Excellence; Center of Biomedical Research Excellence; Defense Advanced Research Projects Agency, International Business Machines Corporation; Northrop Grumman; National Institute of Health; Taiwan Semiconductor/TSMC; SPARWAR/Navy; AMI Semiconductor; Hewlett Packard; Aeroflex; Lockheed Martin; Intel Research; and General Dynamics. For more information, contact Maki at www.maki@cambr.uidaho.edu # # # About the University of Idaho Founded in 1889, the University of Idaho is the state’s flagship higher-education institution and its principal graduate education and research university, bringing insight and innovation to the state, the nation and the world. University researchers attract nearly $100 million in research grants and contracts each year; the University of Idaho is the only institution in the state to earn the prestigious Carnegie Foundation ranking for high research activity. The university’s student population includes first-generation college students and ethnically diverse scholars. Offering more than 150 degree options in 10 colleges, the university combines the strengths of a large university with the intimacy of small learning communities. For information, visit www.uidaho.edu Contact: Tania Thompson, University of Idaho Communications, (208) 885-6567, www.taniat@uidaho.edu DE-1/9/08-CAMBR
About the University of Idaho
The University of Idaho helps students to succeed and become leaders. Its land-grant mission furthers innovative scholarly and creative research to grow Idaho's economy and serve a statewide community. From its main campus in Moscow, Idaho, to 70 research and academic locations statewide, U-Idaho emphasizes real-world application as part of its student experience. U-Idaho combines the strength of a large university with the intimacy of small learning communities. It is home to the Vandals. For information, visit www.uidaho.edu.