Scivillage.com Casual Discussion Science Forum

It's a group of some 55 unpaid volunteers in Denmark called Copenhagen Suborbitals, all working part-time, all with day-jobs, funded entirely by crowd-sourcing. They have already completed and flown some very sophisticated amateur rockets, built and tested some liquid fueled rocket engines, and now are hoping to perfect a much larger rocket (it looks similar in size to the first stage of Rocketlab's Electron) that they will build themselves to send a human into space on a suborbital flight. Their launches take place off the Danish island of Bornholm in the Baltic sea. They are serious and are already doing some cutting-edge research with controlling ballutes, which they hope to use for reentry. They are also researching other supersonic parachute ideas.

I like these guys.

https://copenhagensuborbitals.com/

https://copenhagensuborbitals.com/missions/spica/

A video tour of what they are doing --



Copenhagen Suborbitals image --



Danish European Space Agency astronaut Andreas Mogensen with with a Copenhagen Suborbitals graphic in the Space Station cupola.

2018 video of them testing a small liquid fueled rocket engine that they designed and built themselves. Interesting engineering discussion midway about things like changing the water content in their rocket fuel and what that does to the heat flux on the steel engine structure, which they would prefer not to melt.



And here's a 2020 video of the design for their big rocket engine for their manned suborbital rocket. It's kind of a weird mix of very simple and very sophisticated. It's a pressure-fed rocket engine with a very low chamber pressure, hence not very efficient compared to something like SpaceX's much larger Merlin. While it's not suitable for getting to orbit, it should work fine to get above the Karman line at 100km. It has a burner (not exactly a preburner) but no turbopumps to pump fuel. Instead it's pressure fed and relies on pressure in the fuel tanks to force fuel into the engine while it's running. It uses exhaust from the burner for autogeneous pressurization of the fuel tanks.

They admit that part of the reason why it's so unusual in rocket engine terms is that they are crowd-funded and don't have any money for harder to manufacture custom rocket components. That being said, these people may be a bunch of amateurs, but there's a lot of engineering R&D in what they do.

Copenhagen Suborbitals are building fuel tank pressure domes for Spica, their do-it-yourself manned spacecraft.

(Copenhagen Suborbitals photo)



Not quite as large as the ones in Boca. Of course SpaceX is currently valued at something like $36 billion, and Copenhagen Suborbitals is crowd-funded.

(SpaceX photo)