Working meetings

From time to time, Face to Face (F2F) meetings are held involving the technical designers. The pages on the menu offer a flavour of what the meetings looked like. It surprising how quickly a bare room can be turned into an electronics/RF lab when you have several car loads of test equipment, and some passionate engineers. Of course, in general terms, the meetings provided good ‘targets’ for team members to aim for various stages in completing their designs, and were also excellent team building events. Above all they were FUN!!

Below is a list of the meetings that have taken place, and some short notes about each of them.

1. 10/11 Apr 2010. The “FlatSat” meeting held in London at the offices of Allgood plc, near Euston Station. This was our first F2F meeting, and at this meeting we successfully decoded the proposed FEC BPSK downlink signals for the very first time. There was much cheering and back slapping when this was done. It proved one of our important concepts; no more AX-25, rather BPSK with FEC, and a signal that could be distinguished fairly easily by ear.

2. 19/20 June 2010. Also held in London, the aim was to build the component prototype PCBs into a ‘stack’ (ie one on top of the other). In the event this did not prove possible as the RF board was not advanced sufficiently in its construction. However, the two members of the team living in Holland were able to bring with them a test rig (“AntS simulator”) which simulated the interface of the antennas deployment system with the main sat I2C bus, and we showed that the Processor board (CCT Board) was able to control it.

3. 13/14 Nov 2010. This meeting was held at BT Martlesham which is a good location for several reasons. Most of the software team are BT Martlesham employees and live in the area, and the developers who live in Holland can travel quite conveniently from Hook of Holland to nearby Harwich on the overnight ferry. The aims for this meeting, which were generally met, were to test the transponder, ensure that the satellite would respond to commands, check we could receive and decode the telemetry, and load and receive fitter messages. The prototype satellite was constructed as a stack, as opposed to a “FlatSat”.

4. 19/20 Mar 2011. Again held at Martlesham, this was the first meeting when the signals were received and decoded by a “FUNcube Dongle”. We had a much improved version of the flight software. and also the first version of the “Engineering Dashboard” (software running on a PC, which displays the decoded telemetry information). We were also able to check that the MSE experiment sensors actually worked.

5. 18-26 July 2011. Thermo-vacuum and vibration tests conducted at RAL Space in Harwell. These were performed on our Engineering model PCBs. A test pod was very kindly loaned to us by ISIS. We are very grateful to both organisations for their support.

6. 12/13 Nov 2011. A Crtical Design Review (CDR) meeting was held at BT Martleshm. The aim of this meeting was to gather all the developers together, and very carefully examine each of the staellite’s components, ie CCT, RF and PA pcbs) and their interfaces to those elements to be provided from elswhere, eg the EPS. This meeting did determine some adjustments that were needed, eg to the AGC circuit in the onboard receiver, and also to the flight software.

7. 17/18 Feb 2012. This meeting was held in Delft, and did not include members of the software team. It was mainly to test and adjust the interface and tuning components on the RF and PA pcbs.

8. 20-22 April 2011. This was the first of several software testing sessions held at Martlesham. The aim was to completely exerecise all the functions provided by the flight software, eg command decoding, controlling the deployment of the antenna system after separating from the POD, collecting WOD, Real time data, etc. Although largely successful, some errors and omissions were found.

9. 28 May – 1 Jun 2011. Meeting at Delft to do further testing and analysis work on the RF and PA boards

10. 5 – 8 June 2011. A further meeting at Martlesham was held for software testing. We were able to demonstrate automatic switching between Eclipse (low power tlm and transponder) mode to Sunlight (full power tlm only, “Educational”) Mode.

11. 16-18 July 2011 Further software testing at Martlesham. After this meeting, it was decided that the software tested was probably good enough to fly with, and it was named, “Flight Version Candidate 1”. A good milestone!

12. 21 – 18 July 2011. An RF meeting at Delft was held to verify the RF board design step by step. Performance was enhanced by a number of relatively small component value changes. After this meeting it was considered that we had sufficient confidence in the design such that we could formally authorise the completion of the Flight Models (one each for FC-1 and FC-2).

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