cosmic rays

[Torofamily Profile]

something to look forward to

maybe a little radiation poisening




Could cosmic rays affect electronics here on Earth? Yes, absolutely. Could cosmic rays be what's causing the mysterious accelerator problems in Toyota cars? Maybe. That's one of the reasons why a NASA engineering team has been called in to assist in a federal investigation.

Electrical consultant Antony Anderson holds up an electronic chip from an
acceleration pedal assembly during a news conference at the National Press Club
in Washington to discuss Toyota's sudden acceleration problems.

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The team - drawn from the NASA Engineering and Safety Center, or NESC - serves as the space agency's rapid-response unit for engineering expertise. It was set up in the wake of the 2003 Columbia tragedy, in response to investigators' concerns that NASA didn't have an independent safety watchdog.

Since its formation seven years ago, NESC has taken on more than 100 engineering and safety assessments, said Keith Henry, a spokesman at NASA's Langley Research Center in Virginia. "They range all the way from the shuttle and the International Space Station to interplanetary missions, Hubble, earth satellites and aviation questions," he told me.

However, the Toyota investigation apparently represents a new frontier: "To our knowledge, this is the first time the NESC has done anything related to automobiles," Henry said.

Nowadays, that's not as big a leap as you might think. Automobiles are relying more heavily on electronics for control systems. Just as the aviation industry adopted fly-by-wire systems, the automotive industry is moving toward drive-by-wire. "There isn't that much difference anymore between spacecraft, aircraft and modern automobiles," Henry observed.

Some suspect Toyota's troubles are the result of electronic glitches, and those are issues that will get close attention from the NASA engineers. Glitches could be caused by electromagnetic incompatibilities, or corrosion, or metal stress effects such as "tin whiskers," or elusive single-event effects such as cosmic-ray hits.

The cosmic-ray connection
Cosmic rays? Hitting cars? The connection made headlines last month when the Detroit Free Press reported that subatomic particles from outer space were being considered as a potential cause of the accelerator glitches. The report cited an anonymous memo sent to the National Highway Transportation Safety Board, complaining that "the automotive industry has yet to truly anticipate" the effects of cosmic radiation.

Earth's atmosphere stops most of the dangerous cosmic rays that zoom in from outer space, but some particles get through nevertheless. If those particles hit electronic chips, they can spark unpredictable little jolts of energy in the circuitry, potentially flipping bits out of their proper state. In space, cosmic rays can scramble the brains of a Mars orbiter. At high altitudes, they could bring an airplane to the brink of disaster. And on the ground, they can crash computers and reset routers.

Engineers try to make sure that the circuits they design are robust enough to weather cosmic rays, and Toyota insists its electronics are not at fault. But experts say that as the circuitry in our cars gets more sophisticated, cosmic rays become more of a concern.

"Modern electronics are more and more susceptilble to the phenomenon," said Dave Walsh, principal member of technical staff at Sandia National Laboratories in New Mexico. "The smaller and more integrated the circuits are, the more likely you are to find it, unless you design around it."

Lloyd Massengill, director of engineering at Vanderbilt University's Institute for Space and Defense Electronics, agreed. "The single-event problem tends to get worse with scaling, that's for sure," he told me.

Two years ago, Intel senior scientist Eric Hannah said it was just a matter of time before the cosmic-ray problem started affecting cars. "It's strange, but this is the reality we're moving into as we get smaller and smaller circuits," he told the BBC.

Has that time now arrived? It's too early to say for sure, but NASA's engineers may well help provide an answer. "Right now what they're doing, besides getting the team together, is designing the testing program and getting parts from Toyota," Henry told me. The testing program will almost surely include blasting electronic components in a particle accelerator. That's a standard method for measuring vulnerability to cosmic rays.

The Toyota accelerator investigation, led by the NHTSA, is due to be completed by late summer. The National Academy of Sciences' Transportation Research Board will also be studying the issues surrounding automotive electronics on an industrywide basis over the course of the next 15 months.

The cost of the two studies combined is expected to amount to $3 million, according to the Department of Transportation. Henry said NASA's contribution will be equivalent to the time of nine full-time employees over a period of six months, although more than nine people will be involved. The DOT will reimburse the space agency for its costs, which are budgeted at $1 million.

NASA behind the wheel
This may well be NESC's first foray into automotive engineering, but NASA has delved into the field before. The space agency's wind tunnels have been used to improve the aerodynamics of race cars and semitrailer-trucks. One recent study, conducted in cooperation with other research groups, came up with more efficient designs for semis that could saves billions of dollars a year in fuel costs.

NASA engineers also have played supporting roles in developing technologies to clear the air in automobiles, produce better batteries for electric vehicles and build cars more efficiently with robots.

Then there's the "child presence sensor." Engineers at Langley adapted a sensor system originally used on the space center's research aircraft to go into a child's car seat. The sensor can tell when a child is sitting in the seat, and transmit a coded signal to a pocket-sized alarm hanging from the driver's key chain. If the driver leaves the child in the seat and wanders too far away from the car, the key-chain alarm sounds a warning.

"We have demonstrated the technology, and it's out there if someone wants to license it," Henry said.