[amsat-bb] PSAT Status (day 4)

Robert Bruninga bruninga at usna.edu
Sun May 24 16:57:52 UTC 2015

PSAT  PSK31 435.350 MHz FM downlink is full quieting with 6 bars using a
decent UHF Yagi.

But we have not seen any users other than those using the 28.120 PSK
channel on HF normally.  We welcome people to experiment with it.
Everyone within the 28.120 to 28.123 MHz ten meter passband will be
uplinked and heard on the 435.350 MHz downlink.

The Naval Academy's PSAT seems healthy with plenty of power (we are
keeping the APRS digipeater off to allow max power for PSK31).

PSAT 's radio and packet system are a simple $250 APRS tracker
http://www.byonics.com/mtt4b sent to space.  The PSK31 transponder is a
single 3.4" square circuit board made by Brno Universtiy in the Czech
Republic.  The CPU for controlling bulletins and timing is a simple
Parallax Basic Stamp.

PSAT is actually only about a 1U cubesat but in a 1.5U package since the
flight was available and it gave us more power for our NON-SPACE solar
cells.  We are using standard silicon that are only half as efficient as
multi-junction cells, but only cost 1% as much.

PSAT has a single 21" VHF  and 72" long HF whip.  It has two UHF 6"
orthogonal monopoles, all of very thin Nitinol wire.

More details will eventually follow as the page will be  updated over the
coming weeks.  http://aprs.org/psat.html

* PSAT packet telemetry is OK, Digipeater will be off (secondary mission)
* PSAT PSK31 transponder is ON with 28.120 MHz uplink! (primary mission)
* WOD data fixed.  Spin data now available.  Right now it is at 3 RPM with
+Z pointing 45 deg off Sun
* Launch TLE elements (below) are still very good
* http://PCSAT.APRS.ORG  web page is now capturing PSAT telelmetry that
users inject into the APRS-IS
* BRICSAT telemetry has been heard but is cycling OFF due to low power
* BRICSAT PSK31 downlink (also FM) has also been heard barely (when ON)
* USS Langley not heard


PSAT:       145.825 - 1200 baud AX.25 telemetry - digi off
PSAT PSK31-5:  435.350 FM down, 28.120 SSB PK31 uplink - Brno University

BRICsat:  437.975 - 9600 baud telemetry evry 20s
BRICsat PSK31-6 - same as PSAT but PSK TLM on 375 Hz (PSAT on 315 Hz)

USS Langley - 437.475  9600 baud telemetry   <== CORRECTION

ULTRASat3  <these are still tracking well>
1 99993U          15140.67013889  .00040043  00000-0  10235-2 0 00009
2 99993 055.0004 339.9238 0251027 182.3314 074.3075 15.12517086000014


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