The ECHO flight computer connected to a logic analyzer during initial integration. [Mike Kingery, KE4AZN, Photo]
The ECHO flight computer connected to a logic analyzer during initial integration. [Mike Kingery, KE4AZN, Photo] |
NEWINGTON, CT, Jan 20, 2004--The AMSAT-OCSCAR ECHO satellite project edged a bit closer to being ready for launch. An initial integration effort recently determined that 90 percent of the hardware onboard the new satellite tested out successfully, AMSAT-NA reports. AO-ECHO is set to go into space this spring. During the next six weeks or so, the development team will resolve various outstanding issues, and final integration will be scheduled.
"The launch window opens in late March, so the satellite is coming together on plan," said AMSAT Marketing Manager Jim Jarvis, N2EA. He says there's still time for satellite enthusiasts who donate to the ECHO project to have their names placed in orbit aboard the new satellite. "The names of all contributors will be placed inside the ECHO satellite," he said. AMSAT-NA has not yet reached its $110,000 goal to pay for the AO-ECHO launch.
Jim White, WD0E, and Mike Kingery, KE4AZN, headed the integration team assembled in December at SpaceQuest in Fairfax, Virginia. In addition to hardware testing, the integration team also wrapped up telemetry calibration for the new bird. AMSAT says that even the experimental L-band receiver and S-band transmitter functioned well during their first tests.
 The ECHO battery "tray." When fully integrated, the satellite will resemble a stack of trays, each housing various onboard systems. [Mike Kingery, KE4AZN, Photo] |
AO-ECHO's planned sun-synchronous orbit will be approximately 800 km above Earth. Up to 10 satellites--including AO-ECHO and the primary payload, the Demeter satellite--will ride into orbit during the scheduled March 31 launch from Baikonur Cosmodrome in Kazakhstan. A Russian Dnepr LV rocket--a converted SS-18 intercontinental ballistic missile--will carry the approximately 10-inch-square ECHO satellite and its companions into space.
Among other capabilities, AO-ECHO will allow satellite voice communication using handheld FM transceivers. ECHO will feature V/U, L/S and HF/U operational configurations, with V/S, L/U and HF/S also possible. FM voice and various digital modes--including PSK31 on a 10-meter SSB uplink--also will be available.
Tom Clark, W3IWI--who has been involved with microsat development since the early years--says one of the most exciting innovations in AO-ECHO is a programmable attitude control magnet. "In the past microsats, gross attitude control has been achieved with fixed bar magnets," Clark explains in a posting to the AMSAT-BB reflector. "In ECHO, a soft iron rod will be 'pulsed' to change the direction of the magnetic field."
Clark says the pulser works much like a photo-flash unit, charging a large capacitor, then discharging it as a high current pulse through the magnet coil. "Both the strength and polarity of the charging pulse can be varied by uplink command," he notes.
Visit the AMSAT
AO-ECHO Web page for additional details.
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