In the vacuum chamber, no one can hear you scream

PicSat is back in the thermal vacuum chamber SimEnOm! After having cycled the payload electronic board v1.00, the payload electronic board v1.10, and the full engineering model, we are now cycling the flight model of PicSat! We have just removed the telescope so that our very talented optical team can continue working on the alignment. But there is no star in SimEnOm anyway, so that’s fine.

We are cycling the satellite from -20°C to +30°C. These are not extreme temperatures, but they are representative of the range we expect to have in space.

Installing PicSat in the chamber took quite a bit a time, as we had to be extremely careful not to damage anything, or deploy the solar panels by mistake. Oh, and yeah, we somehow found a way to forgot to put the latest version of the code on the payload board when integrating it into the satellite, so we also had to unscrew one side of the satellite to plug in the JTAG connector and (unsuccessfully) try to update it…

(management banned the picture here)

Uh? But wait a minute, haven’t we developed, wrote and tested a bootloader for this board, allowing updates to be performed remotely by radio? Yeah, but we kinda messed up with the versions here too…

ANYWAY, the main computer receives and replies to all our TCs (aka telecommands) smoothly; it tirelessly emits its beacon every 10 s; and we see all those sweet TM (telemetry) packets with our constantly changing, ever-evolving ground segment software! Plus, the faulty payload bootloader still accept/reply to some commands, so evreything is fine. There is even a beacon on the old payload app! So, really, what more could we ask for? Better version control / software quality management, maybe? Meh! Who needs that?

The main objective was to check the full communication chain at different temperatures, and thus the test campaign was unanimously considered a SUCCESS.

Next: vibrations!

Sylvestre is installing PicSat into the testPOD. Worry not: he was very well supervized during this operation.


Ground Segment Software Release

The Ground Segment Software specifically developed for PicSat is finally released!

Here are some of its features:

  • Pure-python (compatible 2.7 and 3.5)
  • OS-independent (ran on windows, Linux and raspberry PI)
  • Remote-controlling enabled (through ssh)
  • TeleCommand and TeleMetries APIs (Application Programming Interfaces) for scripting commands
  • Data-frames based on CCSDS standard, packing/unpacking fully parameterizable to meet specific needs
  • Real-time storage of unpacked frames in database (up to ~1 Mbytes/sec), and on disk
  • Cryptographic signature to secure TCs
  • AX25-KISS aware
  • Antenna listening & writing from-to any port (serial, usb, tcp/ip, etc)
  • Possibility of interfacing third-party applications for additional real-time visualization and tweaks

It is released under the GPL Licence, see for details.

News from the secondary mirror

Sorry for the recent lack of news. We were busy: after all the stress tests, the secondary mirror gave signs of cracking. We had to expertise it, and understand where it was coming from.

Conclusion, we have now a brand new coating: Silver (we are rich). Thanks to Optics Fichou for saving us!

Here is new version of M2, next to the old. Next task is the integration of the telescope into the flight model.

By the way, we have a cool new picture of the satellite (the payload is not yet inside):

Deployment successful!

To provide the required 5W of electrical power, the PicSat satellite encompass 2 deployable solar panels of 2U length each. It gives a total of 50cmx10cm of surface exposed to the Sun.

Because the solar panels deploy on two opposite sides (for redundancy), the VHF/UHF antennas deploy on the other two faces. They are on opposite edges to maximise transmission, and decrease the risk of interference.

Here is how the satellite looks, once fully deployed

Flight model update

Some news on PicSat !

We just receive the mechanical parts of the Payload, the next step is the coating to avoid lights reflection inside the telescope.
The avionics is also now integrated in the structure with body mounted solar panels, assembly of the deployables ones will occur soon !