Very impressive.  Are you also doing the software for this? 

Thanks, I used SafeRTOS because it supports IEC 61508-3 SIL 3 and ISO 26262 ASIL D.

I configured 2 watchdog tasks. 

One task keeps on feeding a heartbeat signal to the external hardware watchdog.

The other task checks for the completion of critical tasks and if a task fails it will terminate the task or do a cold reboot.

Does GPS work in space? Most of the modules I found these days are limited both on speed and  altitude.

GPS can be used in orbit. Not just any old GPS will work though. ITAR for example is a regulation of GPS use in these scenario's that comes into play as well.

If your satellite is below the GPS satellites, then it will work without any problems.

Consumer grade GPS will not work because there are speed regulations set by ITAR.

You need to have a special GPS that has the speed regulations disabled

Alternatively, you can use magnetometers and star trackers to get your absolute position. Every location on Earth has a unique magnetic field strength and you can use it to determine absolute position. Also, star trackers are good because you can just track which stars you can see and compare it to a star map to get the absolute position.

specs ?

since 2017 ?

I posted the Schematics and Altium Projec FIles