Request to add CTIM to Satnogs DB

Hey all,

I’m an instrument engineer at the Laboratory for Atmospheric and Space Physics (LASP) at the University of Colorado Boulder (CU). I’m part of the team that built up and tested the Compact Total Irradiance Monitor (CTIM) 6U cubesat. CTIM is demonstrating next-generation technology for monitoring total solar irradiance. The instrument uses silicon-substrate room temperature vertically aligned carbon nanotube (VACNT) bolometers to measure the total irradiance of the sun with an accuracy <0.1%.

We are scheduled to launch no earlier than June 29 (late next month) on Virgin Galactic’s LauncherOne. We do not have a preliminary TLE for this launch, but I believe we should have an update to the TLE within 45 minutes after launch.

I have developed support to add CTIM to gr-satellites and will be contacting the developer to integrate this support into the software package. Like CUTE from LASP, we will need a temporary NORAD ID assigned to CTIM by SatNOGs in order to do so. I created an issue report on the SatNOGS issue tracker requesting a NORAD ID a while ago, but haven’t yet heard a response.

I have also written a kaitai struct parser that I will be pushing to satnogs-decoders github repo. The ax.25 framing of our satellite is slightly “quirky” (a software bug in the framing was found at too late of a stage to update prior to launch), but the ksy parser as written has worked on our beacon packets. My understanding is that once I push the .ksy parser to the repo the work can start on the dashboard, is that right?

Thanks!
Adalyn Fyhrie

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Update: I created a merge request to add the ksy parser here: https://gitlab.com/librespacefoundation/satnogs/satnogs-decoders/-/merge_requests/239

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The satellite is now created with temporary NORAD ID 99402. Feel free to edit and suggest any details.

Transmitters will be added soon, or you can suggest them too in transmitters tab.

About the TLE maybe if we have some data we can calculate preliminary TLE set before launch.

@afyhrie feel free you or other member of your team to join our chat channels where there is more direct communication, this will be very useful especially near the launch date. More details on how to join check Get In Touch - SatNOGS Wiki

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IARU CTIM details IARU Sat Coordinator This on the other hand already looks to be from a long time ago, @afyhrie can you explain?

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Hey @PE0SAT , our team completed the frequency coordination and licensing extremely early on in the cubesat build process. This was done out of an abundance of caution.
Unfortunately the radio we intended to use (transmission at 437.325 MHz) does not function with the power system of our cubesat – we ended up having to use a flight spare that transmits at 437.25 MHz. I will ensure our team contacts the IARU to update the frequency coordination.

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… is the frequency not programmable? If not, it seems to kind of defeat the purpose of frequency coordination…

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Hey @vk5qi , the radio that we have (Spacequest TRX-U) is delivered with a frequency set. There is a command available enabling a force-feed of the transceiver registers (enabling a frequency change), but there are a few issues with changing our frequency now:

  1. the command is not persistent through a radio power cycle, and we have observed many spacecraft resets on orbit for our other cubesats on orbit. To have this command issued automatically on a spacecraft reboot would require a flight software change (program management is opposed to this)
  2. the command is not recommended for anything but diagnostics or experiments, which I would argue being on-orbit doesn’t qualify as one of those two use cases
  3. the issue with the power board and intended flight radio was discovered somewhat late in the game. At this point the spacecraft is being delivered to the launch provider on Friday and no further testing is possible.

This gives me no joy, especially when we are already out of alignment with the amateur community with our AX.25 header issues. We have someone working on contacting the IARU to have a discussion with them, and hopefully we can come to an understanding before we launch.

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Update for those interested: the launch window is 30-Jun 0500GMT to 30-Jun 0900GMT with a drop at 0600GMT and s/c sep at 06:55GMT !

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