UWE-3 News

UWE-3 News: Status report

On 21st of May 2016 UWE-3 celebrated 2.5 years in space without any significant failures. Batteries, EPS, OBC and ADCS are fine, nevertheless we were confronted with a minor problem with one of the radios UWE-3 autonomously recovered from. Since then UWE-3 is in a very stable condition again.

Some weeks ago we have re-initiated operations with UWE-3 on an interim basis. The goal is to test new magnetic control algorithms in space. Therefore we operate the satellite on the 436.395200 MHz frequency and perform data downloads from time to time. In the figure below the satellite’s rotation rate w is shown for one of the experiments. The goal was to establish a rotation about the satellite’s X-axis (blue) at 10 deg/s while the Y/Z-axes should be at 0 deg/s. In general the desired rotation rate could be achieved but with major deviations from the setpoint. With the intention of optimizing the relevant control laws we will continue with these experiments within the next days and weeks.

UWE-3-news-23-05-2016

During our experiments we received an outstanding support from the radio community from all over the world we are very thankful for. The received packets were instantaneous injected into our algorithms and delivered an important contribution to our research work. We would like to express our special thanks to DK3WN, PE0SAT, DL8MCO, EU1XX, ON4HF, Rainer, JA5BLZ, JA6PL, CU2JX, LU4EOU, JA1GDE, SP7THR, G7GQW, YC3BVG, JF1EUY, JE9PEL, JE1CVL, JO1PTD, ZL4JL, EA7ADI, K4KDR, JA0CAW, JH4XSY, PA2EON, SM0TGU. THANK YOU!

Yours sincerely,

UWE-3 Team.

UWE-3 Mission Logo

Achieving Science with CubeSats

Achieving Science with CubeSats: Thinking Inside the Box

A great presentation by Thomas Zurbuchen on Cubesats and where we are today.

Thomas Zurbuchen holds a PhD in Astrophysics from the University of Bern, Switzerland and was a recipient of a Swiss National Science Foundation award before coming to the University of Michigan in 1998. Since then, he has received numerous awards, including the prestigious U.S. Presidential Early Career Award, which represents the highest honor bestowed by the U.S. government on scientists and engineers beginning their independent careers. A specialist in the robotic exploration of space, Zurbuchen served as team leader for the development of NASA’s Fast Imaging Plasma Spectrometer, an instrument aboard the Messenger spacecraft, which made its first Mercury flyby in 2008. Professor Zurbuchen is also part of several committees of the National Academy of Sciences and NASA.

Es’Hail-2 satellite frequencies

Amsat-DL has announced the P4-A Frequencies for Narrow (NB) and Wideband (WB) transponder on Es’Hail-2 geostationary satellite. It will be launched in December 2016. Latest launch information is Q1/2017.

X-Band Downlink:

  • 89 cm dishes in rainy areas at EOC like Brazil or Thailand
  • 60 cm around coverage peak
  • 75 cm dishes at peak -2dB
  • NB: linear vertical polarisation
  • WB: linear horizontal polarisation

S-Band NB-Uplink:

  • narrow band modes like SSB, CW
  • 5W nominal Uplink power (22.5 dBi antenna gain, 75cm dish)
  • RHCP polarisation

S-Band WB-Uplink (DATV):

  • wide band modes, DVB-S2
  • peak EIRP of 53 dBW (2.4m dish and 100W) required
  • RHCP polarisation

EsHail-2 Operating Frequencies

Credits: Amsat-DL

Lonestar-2 Launched

Lonestar-2 (AggieSAT-4 and BEVO-2) Launched from the International Space Station.

AggieSAT-4-Launched-29012016

AggieSAT-4-after-launch

Source: Tim Peak on Flickr

It was only on the fifth pass that I could receive signals from AggieSAT-4 on 436.250 MHz. Data is send with 9600 baud FSK and decoded with the help of UZ7HO HS sound-modem software.

AggieSAT4-TLM-RX

   1 > C0 00 57 48 32 58 47 4E 6C 09 00 00 24 0E D8 0E DB DC 00 DB 
  21 > DC 00 02 00 03 00 6A 02 02 00 01 00 02 00 00 00 00 00 00 00 
  41 > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
  61 > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
  81 > 00 00 00 00 00 00 00 00 00 00 08 20 80 3A 00 00 00 00 00 00 
 101 > DB DC 7F 00 00 DB DC 7F 00 00 DB DC 7F 37 0D 01 07 13 00 00 
 121 > 00 68 68 68 68 DE 45 C0 
 WH2XGN

At the moment if you want to receive AggieSAT-4, you can use the TLE data from ISS. The coming days a NORAD ID will be announced and this object will get his own TLE data.

0 LONESTAR
1 41313U 98067HP  16030.33672022 -.00000484  00000-0  00000+0 0  9993
2 41313  51.6476  30.4721 0005403  89.0857 271.0404 15.54324811    90

More information on AggieSAT-4 and the Texas A&M University can be found at the following URL: AggieSAT Lab

Decoding MXL Cubesats

Decoding MXL Cubesats with a SDR and Sound-Modem software.

The Michigan Exploration Laboratory (MXL) ground-station software by default wants to connect to a physical TNC. For this connection they use a python based daemon that connects the RS232 TNC interface via a tcp socket on port 12500 to there final ground-station client. This solutions is used with: MCubed, MCubed-2 and GRIFEX.

Many radio amateurs such like myself use a SDR receiver and no longer make use of a  physical TNC and therefor I was looking for an alternative way to use there ground-station software. Well the python part can be swapped with another kiss server like the one that comes with the UZ7HO Sound-Modem or Direwolf (that also runs on Linux) solution.

Below a block diagram with the two different ways to connect the ground-station software.

sound-modem-mxl

For this to work with a SDR solution, one has to do the following:

Alter the MXL ground-station software configuration file

<path>\MCubed2_GS_Client\config.props

radio.1.name=Radio
radio.1.address=localhost
radio.1.port=8100
radio.1.type=KISS
radio.1.tncport=1
client.callsign=(call)
client.id=(call)_GS
server.address=mxlab.engin.umich.edu
server.port=12805

UZ7HO-KissServerUZ7HO, enable the kiss server option and select a ground-station software corresponding port. Select Settings -> Devices -> Server setup. In this example I used port 9100, default is 8100.

After this you can start your favorite SDR program, redirect the audio to the sound-modem software and start the MXL ground-station JAR (Java Archive) for example mcubed2_gs_client.jar when you want to decode MCubed-2.

This information can also be found at the website from JE9PEL: 9k6 decoding

Credits: UZ7HO, VB-Cable, SDR# and MXL