Bye bye PicSat (for now)

On the afternoon (in Paris) of Tuesday 20 March 2018 PicSat suddenly fell silent, after two successful morning passes over Europe. Attempts to re-establish contact have failed, nothing has been heard from the satellite, no sign of life. There was a short-lived hope that PicSat was heard on Friday 30 March by a team at the Morehead State University, but it radio amateur W2RTV was the first to manage to decode the faint signal and turned out to be another satellite (TIGRISAT). Today, Thursday 5 April 2018, the team decided to call mission-closed. A “pot” (French for party / drink) was organised at noon at the Paris Observatory in Meudon. Sylvestre Lacour did a short speech. Four radio amateurs who have been PicSat fans and great supporters joined in via a dedicated Google Hangout. A short video can be seen here. The team will continue to try to understand what went awry, while plans for new projects are being made. PicSat was operational for over 10 weeks. From a technological point of view it has been a success for the LESIA laboratory of the Paris Observatory – PSL, for whom PicSat has been the very first nano-satellite complete built and opereated in-house. This experience will open doors for new nano-satellite projects in the (near) future.

 

PicSat suddenly silent

Yesterday 20 March PicSat has suddenly fallen silent, stopping to emit telemetry data.

The mission has been going really well, in spite of a problem with the Attitude Determination and Control System, the solution of which is well under way. 80 radio amateurs from around the globe have been contributing to the mission by receiving and sending the decoded telemetry to the PicSat Data Base. This has proven extremely useful for the team!

The cause of the sudden silence is not known at this point. The last beacon was received from Brazil by Roland Zurmely, PY4ZBZ, yesterday at 13:17:37UTC. If nothing happens in the 72 hours following the last communication, yesterday at 11:20 UTC, then the Watch Dog should be kick starting the satellite and get everything back operational again. Everybody waits and hopes to see this coming Friday 23rd March. In the mean time, the team tries to find out more about what could have caused the sudden stop of communication.

SiDS now open

How hard can it be? I mean, creating an SiDS server and making it available to anyone wishing to send frames in real time? That’s just about parsing an HTTP request, and saving stuff in the database. Piece of cake, really. After all, SiDS just means “Simple Downlink Share”, doesn’t it?

And yet… Bad request forwarding, slow server response time, access right issues, database collisions, we got them all! So, no, it wasn’t easy. And I can’t guarantee that there won’t be a few bugs left out here and there. But so far it seems to be working well enough.

I am glad to announce that the SiDS server for PicSat is now open and ready to process your telemetry frames!

In order to use it, you will need to go under your “profile” tab (don’t have an account on this website? Create one here!), and open your SiDS access by clicking on the button. You can also find the “source” that you should use when sending data. This should be your callsign if you have one, or your user name if not.

More info here: https://picsat.obspm.fr/sids/index?locale=en

A big thank to Mike DK3WN and Viljo ES5PC for their help in debugging that stuff!

P.S.: Sylvain F4GKR’s PicSat decoder PicTalk now allows for automatic forwarding of the data frames to the SiDS server!

P.P.S.: Telemetry forwarder also added to D3KWN’s PicSat Telemetry Decoder and Forwarder.

 

The launch is near!

PicSat has been in India at the ISRO Sriharikota launch base since last month, and PicSat team members Mathias Lowak and Lester David have been on site to make sure that all is OK.

The launch is foreseen to happen on Friday 12 January at 4h48m AM Paris local time (9h28m local time in Shriharikota). It will happen on the PSLV (Polar Satellite Launch Vehicle) mission C40, together with a collection of other CubeSats and the larger Cartosat mission. After the ignition of the rocket, it should be about 20 minutes to reach the altitude of 505km where PicSat it to be released from its launch pod. The initialisation sequence is then automatically started, and 30 minutes later the antennas will deploy.

Then somewhere between 8 and 10 in the morning local time, we expect to receive a signal from PicSat as it passes of the Paris region.

We are all very excited with the prospect of having our satellite finally up in Low Earth Orbit soon!

 

PicSat en français !

Nous y voilà ! Le site PicSat est désormais disponible en français, pour ceux qui préfèrent la langue de Molière à celle de Shakespeare !

Les News, quant à elles, seront tantôt en Anglais, tantôt en Français, selon l’humeur de l’auteur… Au pire, il y a toujours Google traduction !

Pour accéder à cette version, il suffit de cliquer sur le drapeau tricolore situé en haut à droite de la page.

Back online!

After a short appearance during the week-end of December 2 – December 3, 2017, our brand new PicSat website is finally coming back online !

This website describes the mission and its objective, and it will be used throughout the mission to provide a way for all radioamateurs listening to the satellite to upload the data they received, and collaborate to our mission.

Retrieving all the the photometry of Beta Pictoris 24/7 to detect an exoplanet or some exocomets passing in front of it will be hard. And we know that. But we hope that with the support of the community, we will be able to do just that!

We are in the final stage of our pre-launch activities in Meudon. PicSat is still on the ground, but it will soon fly to India and start its journey to space. In the meantime, we will connect this website to our “engineering model” (a spare copy of the satellite that we keep on ground), so that you can have an idea of what our data look like. Some maintenance has to be expected during the next few days.

But we promise: as soon as PicSat is in space, this website will show the true uncorrected raw data coming directly from it! We hope you’ll enjoy this opportunity to see how a space mission is operated, and to get an idea of the sparsity of data we have to deal with on a day-to-day basis…

Don’t forget to check our Twitter account IamPicSat for the latest news!

Fit check OK

Yesterday we performed a fit check of PicSat in the QuadPack CubeSat dispenser (on the right).

The dispenser and PicSat will be ship separatly to India where we will put PicSat in the dispenser before the integration on the launch vehicle.
This test allows to avoid discomfiture on the launch pad in case of an external modification of the satellite which may block it in the deployer. For this test, PicSat was almost in flight configuration with a development detector which will be modified in the next days.

 

Space is hard: PSLV-C39 launch failure

Building and testing a satellite is an Herculean task. Making reliable software is exceptionally time-consuming and requires a lot of hard work. Building a working ground station and making sure that it can track a satellite moving at  8km/s above our head is tough. Making sure that the science instrument can reach the level of precision required for detecting the transit of Beta Pic b, and creating a database reliable and efficient enough to store all the data is a challenge all by itself. And today, we are recalled that launching a satellite into orbit — the only thing we were taking for granted so far — is also terribly complex and difficult…

The Indian rocket PSLV-C39, which lifted-off on schedule from Sriharikota, suffered from some sort of malfunction (apparently, the fairing did not separate), leading to the failure of the mission. More can be read on Space News or the Times of India.

PicSat is supposed to be launched on the next PSLV (codenamed PSLV-C40). At that time, we have no real info on what will happen to C40. But it would not really be a surprise if it suffers some delay due to the failure of C39…

Yeah, space IS hard.

Underperformance of the PSLV in late phase of the launch (upper plot is velocity relative to Earth vs time, and lower plot is altitude vs time; nominal expected curves and real data are shown). Credits: DD national.

 

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.