Last week, Maxwell Technologies Inc. announced that Northrop Grumman Space Technology selected its SCS750 single board computer for spacecraft control and payload data management for the National Polar-orbiting Operational Environmental Satellite System (NPOESS) and is hoping that this contract will give the company enough credibility to compete effectively for future commercial contracts.

This particular contract, with a $6 million base value and $14 million total value if all options are exercised, is important to Maxwell because the company was able to beat out its competition with a product that has thus far never left the ground.

“The space market is very conservative and heritage makes a big difference,” Larry Longden, senior director of marketing and technology, told Satellite News. “We do not have flight heritage yet, so being selected by one of the biggest satellite manufacturers in the United States provides a lot of credibility and other people are already looking at [the SCS750] and are deciding to follow suit.” Longden did not disclose any other commercial contracts for the SCS750, but he noted that the first single board computer should reach orbit in early 2007, about two years before the first of six NPOESS satellites is launched in 2009.

The Evolution of SCS750

The story of the SCS750 goes back about three years when Maxwell began its work addressing a need in the spacecraft electronics market, namely getting the most current technology available at the time of manufacture onto a spacecraft.

“Traditionally, the way the market has dealt with this is we developed radiation-hardened electronics,” Longden said. “Those are done at the semiconductor level where we actually design very specific circuits that are intended to be used in a radiation-hardened environment. They are manufactured following a specific set of processes that we know will guarantee radiation hardness. It is a very expensive process. It takes many years to design a radiation-hardened integrated circuit, and by the time it gets into production, it is five to 10 years behind in technology.”

Longden explained that the radiation-hardening process is important because of radiation’s effects on a satellite’s electronics. Radiation causes the electronics to degrade to the point of being taken out of commission, more commonly, creating upsets that would force an operator to have to reboot onboard computer systems.

And while radiation hardening would protect a spacecraft’s computer circuits, Maxwell took a different approach that potentially could translate into future savings on cost of manufacturing a satellite. The company uses commercially available power processing chips (PC) commonly found in today’s desktop and laptop computers and uses them without any radiation hardening in its SCS750.

“At Maxwell, we do not have a fabrication facility for semiconductors, but we do manufacture finished product,” Longden said. “What we do is take commercial semiconductors and evaluate their performance in a radiation environment, fully understand how they operate, what problems they have, then we integrate them with a variety of radiation mitigation technologies that we have developed throughout the years and basically prevent those radiation effects from impacting the system.”

Longden added the company has been working on the SCS750 for the past three years and funded the development of the single board computer with its own money. The result of that development is a computer that Longden said offers a greater reliability than its current competitors on the market.

“We take commercial power PCs that we know will have an upset problem in space and we put three of them on the board and run them in a two-out-of-three voting scheme called triple modular redundancy,” Longden said. “Basically, you will always get the correct answer because two of them always will have the right answer. In addition, on a periodic basis, maybe once a second or minute or hour depending on where the satellite is flying in space, we do a process called automatic resynchronization, which forces all three power PCs to the same state so that they are always performing the same function at the same time. That way, we can provide error free operations during the entire life of the mission.”

Longden added that Maxwell is looking to go head-to-head in the marketplace with the two major suppliers of radiation-hardened computers in the United States, with a primary focus on taking away marketshare from industry leader BAE Systems. “The NPOESS award is a significant step in that direction,” Longden said.

–Gregory Twachtman

(Larry Longden, Maxwell, 858/503-3399)