Oct 15, 2009

For all you out there here is an update on our week and flight:

  • This was one of the most challenging weeks of our lives!
  • Every day we would make excellent progress, only for something else critical to occur, have to be identified and solved: thermal issues, bail breaking, FISH ADC soldering, MAIN Payload short circuit, our batteries critically discharging during tests (even though we mostlly checked them very regularly) and consequently the ordering and refitting of a new type of batteries, interference from EBASS, interference to NAVIS, so on and so forth. This resulted in us getting between 1-3 hours sleep per night for the whole week. We learned so much about fault and failure diagnosis and worked hard and effectively as a team to solve these system level issues.
  • About 2 days before the actual flight we were fully functional according to all of our testing and indeed were 'ready for flight'! (A Great Achievement!) and received a round of applause from the other bexus members. Although we weren't as ready as most of the other teams, we were congratulated for 'never giving up' and being fighters to solving our hugely complex system.
  • The morning of the flight was very nerve wracking with us always worrying we would lose communications with the FISH. We did lose it for about 10 minutes while on the ground during our comprehensive prelaunch checklist, but it came back again. Later we found this may have been a ELINK problem. We also found a small bug which meant the high data rate worked on the FISH but not the MAIN Payload, meaning that we would receive data from the FISH up until the drop to the ground station, but during and after the drop it would be on the FISH.
  • The flight seemed to work magnificently - a beautiful lift-off with our psychadelic orange FISH visible for quite some time during ascent. Our IP camera pointing downwards towards Earth has video and audio for the whole flight until ELINK cut-off during the float down after cut-off from the balloon (this will be put on the Youtube channel REXUSBEXUS soon).
  • We had a huge crowd around our 'tv' view of the IP camera the whole time, particularly 10minutes into float when we were given the all clear to begin our drop sequence.
  • The line guide auto-unreeling worked awesomely, and then when we reeled up the line a bit to double check it was undone it all went really well.
  • We began the drop sequence and everything worked for the drop - a great achievement considering the complexity in our system required for this to occur: Positioning the bail correctly, lining up the servo and opening the bail, turning the bail with the motor, having the reel hit a slab of metal to friction-force the bail with enough motor force to do so.
  • The FISH dropped away from the camera, but unfortunately kept dropping out of sight. The audio file demonstrated a series of loud clicking sounds a couple of seconds after the drop, which we were trying to diagnose.
  • We took down the time and notified Esrange of a lost FISH. We plan to identify the position of the FISH and hopefully are able to find it (although this is very difficult) as the FISH contains excellent data of a drop and also the entire acceleration profile of the atmosphere - with great scientific value! Not to mention the sensors on board.
  • After the flight and the return of the gondola we began our diagnosis.

After viewing the payload, it seems that all should have been fully functional, but the line was snapped in TWO places - where it was connected to the reel and at the end of the line! Very strange! We are not sure exactly how this occurred and diagnostics are ongoing. It may have been an unforeseen snag in the line or sharp ice forming on the edge of part of our system, or hitting an antenna hanging below from another experiment. More diagnostics are required and are ongoing (for example reeling the line off the reel and measuring at what point it snapped).
Despite that we weren't fully functional, all of you should be extremely proud of the efforts of yourselves and the team as a whole. We had an 8 month slog that was challenging and expensive in so many ways, and we pulled through to the end and never gave up, with full-functionality achieved in this complex system in the days before flight. I know that I learned so much and it is an experience I will never forget and will take so much of it with me for future projects.

The FISH was dropped at 13h.17m.16s and we have just received the EBASS data of BEXUS-9 (GPS positions, velocities etc of the gondola), which I will forward to you all in a separate email. This change in vertical speed due to the dropping of the FISH should be reflected also in the EBASS flight data, identifying a corresponding GPS coordinate and horizontal speed as is required to calculate the most likely ground GPS of the FISH landing. Campbell's parachute height was set about 400 pressure units above the ground level at kiruna that day and this can be used to calculate the height of parachute deployment, which combine with wind profiles and the terminal velocity of the parachute helps in pin-pointing the landing area. As I understand it, Jan and Waen may go to the likely landing location of the FISH. It would be so fantastic if it were found! As it is, a 'return to esrange' sticker is on the FISH, including a reward. So it may be returned to us in the coming months if they are not able to locate it.

Thanks, and so long to the FISH!

SpaceMaster Robotics Team

We want to specially thank our sponsors
for their financial support!

SpaceMaster Robotics Team Members

SpaceMaster Robotics Team

A student team consisting of members formerly studying in the Joint European Master in Space Science & Technology (SpaceMaster) programme. It is currently spread all over Europe.

The team consists for this project of the following 9 team members: Katherine Bennell, Mark 'Fitts' Fittock, Mikulas Jandak, Juxi Leitner, David Leal Martínez, Waen Nawarat, Campbell Pegg, Mikael Persson, and Jan Speidel


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