[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[jamsat-news:952] SEDSAT 1 In Orbit!
SEDSAT 1 is in orbit and appears to be performing well. It
launched as a secondary payload with NASA's Deep Space 1, on a Delta 2, at
12:08:00.502 UTC. Our ground station crew at the University of Arizona in
Tucson had a number of problems the first pass, and the satellite team in
Florida had audio confirmation of telemetry sometime later in the duration
of they're pass (we're about 5 minutes apart).
On the second orbit we were able to verify the audio of the SEDSAT
heartbeat, but weren't able to decode the digital telemetry other than the
following packets similar to the following (the first packet received and
Uptime is 000/01:48:01
By this time, the team in Florida no longer had radio access (they
can explain) and Chris Bond suggested a mode change to KISS on our TNC,
and on the third pass we successfully received the full heartbeat and
decoded it to reveal that the satellite is operating at a nominal main
voltage, reasonable temperatures, sucessfull bootups of various processes,
but slightly more power drained than expected. I don't understand the
technical details of the satellite, so I'll leave it to Chris Bond to
explain once he has a full telemetry set in his hands.
We have a short fourth pass here in about 20 minutes, and I will
take a snapshot of the telemetry visualization program and post it on the
web site for all to see. After that, its nap time until the passes later
this evening. We may be performing a test of the uplink on one of this
We at Arizona are also developing the "SEDSAT Database" which will be
accessible over the internet and you will be able to search the telemetry
online (and eventually add your own downlinks to it). This may be online
as early as tonight, but may take longer, as we're students with student's
Here is the TLE set that I've used since the second pass (we're
approach #4 now). At the moment, it appears to be off by about 40-50
seconds (the satellite comes up over the horizon before its predicted to,
and stops early). I don't think this is an epoch problem, but it could be
a number of things, as these numbers are a from a conglomerate of times
along the mission. Hopefully we'll have more "official" ones soon. (I've
guessed at some of the non-orbital designator numbers, so those are
subject to change)
1 25507U 9860B 98297.56693868 .00000215 00000-0 00000-0 0 32
2 25507 31.4370 33.8868 0360000 250.2325 171.5630 14.23776070 14
The downlink frequency that we've been using is 437.910, and
although the Huntsville crew reports that they've had better experience
slightly below that number, it works well for us in Arizona.
Please let the team know about your monitoring of the satellite's
telemetry. Software to decode it may be available soon.
There is an email list for SEDSAT which is email@example.com.
Subscribe by sending a "subscribe sedsat" message to firstname.lastname@example.org
Also, the SEDSAT web page can be perused at http://www.seds.org/sedsat
We'll try to put more info up there regarding telemetry, tracking, etc as
the week goes on.
I'm a busy guy and don't have time to read Amsat-BB, so if you must ask me
questions, please respond directly (I can't guarantee a quick response, as
I have three midterms next week)
Christopher A. Lewicki KC7NYV 520.977.0758 Maintainer of SEDS.LPL.Arizona.EDU
Program Manager, University of Arizona Student Satellite Project
Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org