UPRA - MATeF POC Probe and Flights

[bgoczan]

Quick Update on our progress.

We started to populate the Flight Model PCB-s. As soon as all components are in place we will run smoke test on all cards and start the integration of the flight system.

[RandomAerospace]

Great to see folk making stuff themselves - rather than relying on off the shelf solutions. There is so much more to be leant that way.

[bgoczan]

Thank you!

We are very proud of that we have developed the flight computer ourselves. I hope it will be reliable enough to support third party experiments from university research groups.

[bgoczan]

We have a launch date: 2018. March. 31. 10:00 (UTC+2).

This will be a shakedown test of the system before our GSBC flight. Right now we are doing the final integration and inspections before flight.

Our plan is that the flight could be followed live on our website.

[dgerson]

Good luck! Can't wait to hear more

[bgoczan]

T-9h40m and counting

We have the probe fully integrated. Checked and packed all the launch equipment.

[bgoczan]

Successful launch and recovery. We will start processing the flight data soon and publish a post-flight analysis like last time.

[dgerson]

Well done! Looking forward to the summary

[bgoczan]

We have analysed the flight data and compared with the local meteorological station's radiosonde data. Their flight was performed two hours after our launch and most of the data were very similar to ours.
Also the simulations we performed in our thermal chamber were matched with the actual flight data, which is a very promising result for further test campaigns.

Some of our team members have begun the development of a live landing predictor software component which we will use during flights to help the recovery team. They will also study the ascent and descent phases of the flight and how the payload train behaves during these periods.

We have made some minor firmware changes for the next flight to improve the APRS tracking.

Our next flight which will also be our GSBC flight will take place on April 18 on the XV. Simonyi Conference (for Hungarian speakers), where I will give a presentation about the development and testing of the last 18 month.
I will also have a poster presentation at the 2nd ESA SSA Symposium in the same subject next week.

Due to the tight schedule the detailed Post-flight Report of the March 31 flight will be published after the Simonyi Conference.

[dgerson]

Good luck with the flight and presentation!

[bgoczan]

We've had a successful flight on April 18. We proved that our team can prepare and launch the same flight system in less than three weeks. We've also tested our in-house developed GPS-GSM backup tracker prototype. Unfortunately our camera was shut down in the early phase of the flight, which we suspect caused by some EMC disturbance.

We are starting to analyse the flight data today and publish the report together with our March 31 flight. Until then a nice video clip of the launch:

The photo album of the preparation:
https://spot.sch.bme.hu/photo/2018/20180418_matef_3/

And the photo album of the previous flight (March 31):
https://www.facebook.com/pg/UPRA.team/photos/?tab=album&album_id=1620820477986542

[dgerson]

Very cool! Awesome that the in house tracker worked - that isn't always easy, so you should be proud of yourselves!

[ProyectoK]

I am very impressed by not only the design of this probe, but also, the testing procedure and system integration. Good luck! wish you the best!

[bgoczan]

We have finished the post flight analysis of our last two flights. It took a bit more time than I suspected which was due to the academic occupation of most of the team members. Unfortunately we couldn't make it until the GSBC report deadline, but we are very proud we could perform a successful flight in the GSBC launch window which is our primary launch window for the last three years.

The first flight (MATeF-2) was the shakedown test of the service module and in the second flight (MATeF-3) our GPS-GSM Backup Tracker prototype was added as a payload. In MATeF-3 mission the camera was a last minute addition, and unfortunately we couldn't test it completely thus the camera was shut down right before launch. The cause of the shut down was some EMC disturbance generated by our Backup Tracker prototype.

We've had a 'Lessons Learned' meeting and analysed the data gathered by the on-board computer and compared to our simulations. We use these information to develop our live, in-flight predictor which could generate trajectory according to actual flight data during flight. The beta version is under testing right now and we will integrate it to our control station software.

You can read our complete flight report below:
MATeF-2 Flight Report
MATeF-3 Flight Report

[bgoczan]

MATeF - 4 Flight

On November 3rd the last flight of our MATeF POC programme took place.

The configuration was similar to the last two flights (MATeF-2 and MATeF-3):
- We used the MATeF POC services module, with our UPRA flight computer.
- There wan an additional capsule for an offlilne camera
- And there was an other additional capsule for the Backup GPS Tracker

The camera was set to movie recording mode and it was a cheap action camera (an SJ4000 knock off). The lens of the camera has no infra red filter which led to major discoloration as the probe reached the thin cloud layers.

The flight was kind of successful. We have found most of the payload train. Yeah...most of it...
During ascent the different capsules of the payload train had major rotation issues. There was no resting point and the rotation was continuous as it could be seen on the video feed.
At 12000m (40000ft) of altitude the line between the camera pod and the parachute snapped due to the continuous torsion forces. At this point it is possible we had already lost the Backup GPS tracker too.
The remains of the payload train (Service Module and Camera Pod) reached the surface in free fall in about 7 minutes. During descent the rotation of the payload train probably generated larger forces than 4G since the service module lost GPS signal.

After hard landing all the remaining devices were operational. We had radio signal from our main radio, on board data logging shows that every subsystem was in good health. Only major damage in the service module electronics was the broken APRS antenna connector, which could be avoided with an angled connector instead of straight one.

Currently we are processing the video feed. Due to the rotation we decided to use the data to create still pictures, panoramas and short videos.
We are also processing the on-board and ground station data. So far despite the rotation and line snap incident we are confident that our system is ready to host third party payload. We have plans of minor modifications to prevent dangerous rotation which only affect the payload train harness and not the individual hardware components.

We are also planning that on the next GSBC event we will open our platform for university students to fly their experiments.

And here are some processed image data from the first few minutes of the flight:

We upload the processed images to this facebook album as we proceed.

[dgerson]

Sorry to hear about the rotational issues, but glad you were able to recover most of the payload train- and those pictures you have still look fantastic!

Do you have ideas for countering the rotation in future flights?

[bgoczan]

We used a single line between the payload-train components. This was generated no problem with one capsule. But with multiple capsules the rotation started. Probably because of the center of mass of each capsule.
In the future we still planning to use multiple capsules in the payload train so our solution right now is to use double, parallel harness (like suspenders) to connect the payload-train components.

We saw this technique in large balloons like ESA's BeXUS balloon. And according to their video footage it works.

This solution may also decrease the length of our payload train if we could use some clever arrangements.