US Naval Academy PCSAT

As has been reported in the RSGB News, the PCSAT spacecraft was launched September 30, 2001 and has, due to an on-board power system issue, started to transmit APRS again on 144.390 MHz.

Although this is the correct frequency for APRS operation in IARU Region 2, it is not compatible with our Region 1 bandplan which has this part of the band designated for weak signal and particularly Meteor Scatter operation.

The orbit of this spacecraft means that sometimes it is in full sunlight and, at other times, it is eclipsed for a major percentage of the orbit. As the on-board batteries have lost their ability to hold a charge, the problem can only occur when it is in sunlight.

Various methods of mitigate this problem are presently under active consideration but in the meantime it is important that no amateur in Region 1 should attempt to digipeat through this spacecraft. Additionally those amateurs on the east coast of the American continent are also requested not to attempt to activate the spacecraft when it can be “seen” from Europe.

At IARU level, further work is being undertaken to reduce the risk from future spacecraft potentially causing similar problems. Such problems could result from developers not following the globally agreed bandplans for amateur satellite operations. In particular the IARU Satellite Coordinator has been requested to make urgent contact with the team responsible for XW-2(CAS-3) mission of nine satellites from China. Some of the proposed frequencies do not respect the internationally agreed Region 1 Bandplan for 2 metres.

Interference from PC-Sat reported July 28, 2002 http://home.hccnet.nl/uffe.noucha/pcsat