Copenhagen Suborbital's HEAT 1X has serious combustion instability problems - video | Miscellaneous | Forum

This is an unfortunate surprise!  Although, I seem to recall seeing a much less severe example of this phenomenon in another test?  I hope they can get this sorted easily enough, however.  If CS manage to complete their project successfully it will give open source amateur space exploration a huge boost in credibility.  Instead of being something that is instinctively laughed at, it will be something which has been proven workable, at least in its simplest form (suborbital flight).

Nick said:

I would love to see the thrust curve for that test.

You should go ahead and ask them for it.  In my experience, if you send an email to Copenhagen Suborbitals, one of two things happens:

1. You hear nothing back at all.
2. You get a very friendly reply with detailed and helpful responses to all of your questions.

When number 2 happens, it's great – I've previously got numerical details not on their website in replies, discussions of the process by which they cast their fuel grains, etc.  It certainly can't hurt to ask for a thrust curve.