Spaceflight Now: Breaking News

Experiments to study failures on small satellite

Posted: February 13, 2001

Artist's impression of the STRV 1C and 1D spacecraft in orbit. Photo: DERA
NASA experiments on a small British satellite are studying the effects of radiation on the various systems that make up each experiment. To yield this information, engineers are actually hoping for the components to fail.

The Space Technology Research Vehicle 1D (STRV 1D) is owned and operated by DERA, the British Defence Evaluation and Research Agency, but NASA, the U.S. Department of Defense Ballistic Missile Defense Organization, the U.S. Air Force and DERA contributed to the program in some form.

"It may sound strange, but we're actually hoping electronic components will fail," said Donna Hardage, the project manager of the NASA components on STRV 1D. "That's the best way we can accurately know their limits."

The experiments will help ascertain the effects of radiation on the electronics inside each respective instrument. "Each NASA experiment will monitor the effects of the radiation dose on the components of the experiments themselves," Hardage told Spaceflight Now.

The NASA contribution to the craft is called the Space Radiation Electronics Testbed and includes six experiments. Some of these items include a dosimetry experiment to measure the amount of radiation on the unit and a pulse height analysis experiment to determine the amount of radiation in the spacecraft's surroundings.

Other NASA components will test the effects of radiation on commercially available satellite parts. The commercial off-the-shelf analog experiment will gauge the results of perpetual radiation dosing on commercial analog devices, such as thermometers and voltmeters, while other experiments will monitor the effects of radiation on digital and optocoupler devices.

"We're monitoring and evaluating several commercial off-the-shelf electronic components to determine how they hold up under the severe exposure to radiation," Hardage explained. "In addition to radiation dose, some of the experiments will also monitor the single event effects that may occur during the mission. Single event effects (SEE) are effects in the microelectronics induced by a single particle passing through the part/component," she said.

After the results of the experiments are accumulated, ground engineers will apply the data to the designs of future satellite electronic parts.

"The results from these experiment will definitely help in all types of future missions. Radiation exists throughout the entire region of space, however, the quantity and spectrum of these radiation types vary with location in the solar system. The results from this mission are expected to ultimately provide designers with new technologies that will enable smaller, cheaper, faster, lower power electronics," said Hardage.

The 220-pound STRV 1D was placed in a highly elliptical orbit by an Ariane 5 rocket in November. This orbit allows the craft to pass in and out of the Van Allen Belts -- bands of intense concentrations of radiation around Earth.

"We're pushing these components to their limits. If they survive, that tells us a lot. But if they fail, it tells us even more," she said.