AO-51
|
|
| Operator | AMSAT-NA |
|---|---|
| Satellite of | Earth |
| Launch date | June 29, 2004 |
| Launch vehicle | Dnepr rocket |
| Launch site | Baikonur Cosmodrome |
| COSPAR ID | 2004-025K |
| Homepage | [1] |
| Mass | 11.14kg |
| Orbital elements | |
| Semimajor axis | 7,134.3 km |
| Inclination | 98.1 degrees |
| Apoapsis | 823.7 km |
| Periapsis | 702.9 km |
| Orbital period | 100.0 min |
| Transponders | |
| Transponders |
Uplink 145.880MHz 145.920MHz 1268.7MHz Downlink 435.150MHz 435.300MHz 2401.2MHz |
AO-51 is the in-orbit name designation of a LEO amateur radio satellite of the OSCAR series; formerly known as ECHO, built by AMSAT. It was launched on June 29, 2004 from Baikonur Cosmodrome, Kazakhstan on a Dnepr launch vehicle. It is in sun synchronous low Earth orbit.
AO-51 contains an FM repeater with both 144 MHz (V band) and 1.2 GHz (L band) uplinks and 435 MHz (U band) and 2.4 GHz (S band) downlinks. It also contains a digital subsystem that transmits telemetry on 70 cm and provides a complete PACSAT BBS that can be configured on both V band and S band uplinks. As well, there is a 10 meter PSK uplink.
AO-51 has four VHF receivers, two UHF transmitters, six modems, and 56 channels of telemetry. The two UHF transmitters are connected to four phased antennas, yielding right-hand circular polarization for the 435.300 downlink and left-hand circular polarization for the 435.150 downlink.
The AO-51 FM satellite is easily workable with an amateur radio VHF dual band hand-held radio, as long as you know when the satellite's footprint is within reach. Transatlantic contacts have been made without much effort, as long as the satellite is approximately mid-Atlantic so that the edge of the satellites footprint is within reach on either continent.
It's always good practice to check the AO-51 Schedule before trying to transmit during a satellite pass to ensure that the sat is in the correct mode and not being tasked for emergency comms.
As of May 2011 the satellite has problems with the battery. By September, a work around for the battery issue was found, bringing the repeater back in use. On November 29, 2011, the AO-51 Command Team announced that AO-51 has ceased transmission and is not responding to commands.[1]
[edit] Two-Line Element Set (TLE)
1 28375U 04025K 10319.48348090 .00000056 00000-0 29545-4 0 8243 2 28375 098.0749 304.4752 0084701 358.8875 001.2111 14.40709462335298
[edit] External links
- AMSAT's ECHO Project page
- AO-51 Control Team News
- Satellite summary
- AO-51 Archive (Text-Only)
- AMSAT news about AMSAT 2006 Space Symposium
- ARRL Web Kid's Day Rules
- How to Work AO-51 with Your HT
- ANS-126 AMSAT News Service Special Bulletin - AO-51 Batteries Failing
[edit] References
 |
This article related to amateur radio is a stub. You can help Wikipedia by expanding it. |
 |
This article about one or more spacecraft of the United States is a stub. You can help Wikipedia by expanding it. |
