From: NASA HQ
Posted: Saturday, April 22, 2006
In less than a month after launch, the ST5 team has checked out the ST5 spacecraft and successfully activated all technologies. All three spacecraft are performing nominally, including attitude, thermal and power profiles. Data are being collected on the performance of the spacecraft and their advanced technologies, including demonstration science data from the magnetometers.
Miniaturized components and technologies are integrated into each of the ST5 micro-satellites. Each micro-satellite weighs approximately 25 kilograms (55 pounds). These micro-sats are being tested in space in order to validate the performance of these new technologies for future science missions.
"We are extremely pleased with the performance of our onboard technologies and the ST5 mission is already a major success," said Art Azarbarzin, ST5 Project Manger at NASA's Goddard Space Flight Center, Greenbelt, Md.
"We have begun demonstrating all of the New Millennium Program technologies, including the low-voltage power system, X-band transponder for space-to-ground communications, Cold Gas Micro-Thruster for spacecraft maneuvering and attitude control, CMOS Ultra Low Power Radiation Tolerant logic (CULPRiT) and Variable Emittance Coating thermal technologies, as well as some of our ground system automation. We have also demonstrated the capability of our micro-satellites' miniature magnetometers, sun sensors, nutation dampers, magnetometer booms and launch vehicle deployment system."
During the first week, the spacecraft went through a Lunar Eclipse and all three behaved as expected. The batteries went through a discharge/recharge cycle and this was the first time a battery discharge on all three spacecraft had been observed since launch. Without any eclipse, solar arrays are able to keep up with the power demand and charge the battery at the same time.
The ST5 mission operations team has begun commanding the spacecraft to perform maneuvers that will position the spacecraft in a constellation formation. The spacecraft will be aligned in a "string of pearls" so that the spacecraft are approximately 100-200 km (60-124 miles) apart. The spacecraft were initially separating at a rate of 25-200 km (15-124 miles) per day, so the maneuver strategy was designed to "stop" their separation and then move the spacecraft closer together, using ST5's new technology micro-thruster.
The constellation formation will allow the three spacecraft to be positioned simultaneously within a single "current sheet" within the Earth's auroral region. Using the resulting magnetometer data, the ST5 science team will demonstrate the benefits of a group of small low-cost spacecraft taking scientific measurements at the same time in different locations.
The ST5 project was built and tested at Goddard for NASA's Science Mission Directorate. It is part of the New Millennium Program, which develops and tests critical and revolutionary technologies needed to enable future endeavors in space. For information about the ST5 project and mission on the Web, visit:
Information on the New Millennium Program can be viewed on the Web at:
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