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.
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!
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.
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.
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
narrow band modes like SSB, CW
5W nominal Uplink power (22.5 dBi antenna gain, 75cm dish)
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.
For this to work with a SDR solution, one has to do the following:
Alter the MXL ground-station software configuration file
UZ7HO, 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