SUNSAT Status Day 45-53 (9-17 April 1999)

This last week has been frustrating.  With the week end passes spent uploading new code to OBC1's RAM we had to disable magnetic control for some time and lost gravity gradient lock again.

We have thus had to re-boot OBC1 with its old code (in flash RAM) to activate the ADCS controller. While doing this we have been trying to upload the new OBC1 code, but are in a catch-22 situation with the uncertain satellite attitude hampering communications.

To add to our misfortune, we had our first winter rains this week, and probably just to spite us, the elevation actuator on our tracking dish failed (water or just plain cussed?), with some colateral damage. We don't have a compatible replacement and are busy with a machine shop job to effect a running repair using a different actuator.

Some weeks ago we attached one of our antennas on the side of the dish to prevent our uplink transmitter interfering with the downink receiver (which is on a separate tracking mount.) Since we can't easily elevate the dish, we have to put up with TX/RX interference or a misaligned antenna for a few days.

To add to the confusion, the hard disk one of our ground station PC's failed. Unfortunately, it is rather critically set up to handle the real-time communications and networks and took time to get restored to full operation.

All in all, this week will largely have to be written off as far as planned progress is concerned. We are working some night passes over the week end of 17 April to try and catch up.

Plans for the coming week are to get the new OBC1 code uploaded, get the tracking antennas functional, and get back to our planned testing of the S-Band link and the updated software.

We would like to activate the VHF/UHF amateur transponder during night passes over South Africa and possibly over some other continents in the coming week. We will coordinate with SA-AMSAT if this becomes possible, and put an announcement out via the amateur networks and on this web site.

We greatly appreciate the good wishes many people have been sending to us in various ways. We are trying our best within our resources to get the amateur communications operating and to get our first images, or pieces of image down.

73's


© Electronic Systems Laboratory 1999
by Buchan Milne
WWW:sunsat.ee.sun.ac.za