During my Xmas-break I had all kinds of dreams at night related to possible designs of the Copenhagen Suborbitals DIY space capsule Tycho Deep Space II.

The last couple of months I have presented a variety of ideas and solutions but I haven’t really nailed it yet. It’s a huge puzzle and getting it all to work is hard. There seems to be too much mass in the top of the capsule to get the uprighting to work, forcing me to change the interior design and so much else that doesn’t really add up, so far.

Since I am still working basic design ideas, there is still time to sketch even the craziest ideas and I just had such one, a couple of days ago.

What if the capsule doesn’t hold any systems in the top but in the bottom instead, changing the center of mass leading to a correct attitude in water, post splashdown?

What if the capsule doesn’t hold any parachutes at all, but only a drogue for maintaining a correct descent attitude and the bottom is equipped with a solid propellant retro-burner for a final change in velocity?

What if the bottom geometry, holding the retro-burner and RCS, was shaped for enhancing capsule water-carving making even a high speed landing feel like landing in candy-floss?

It may seem far fetched. But nevertheless it does solve a lot of the issues I have encountered so far and I don’t really know if I trust three homemade main-parachutes more than a homemade solid rocket retro-booster.

Tycho Deep Space II end-burner configuration and possible flight path. Image: Kristian von Bengtson Tycho Deep Space II end-burner configuration and possible flight path. Image: Kristian von Bengtson

Right now calculations are being made to estimate terminal velocity, engine power, burn-time and engine-ignition altitude. A rocket too powerful will pose dangers for the astronaut and must be ignited just above the water line unless you want to capsule to gain speed once again, due to gravity. A low-powered engine will be wasting fuel against the will of gravity. So, there is a fine balance somewhere in between.

So far, it’s just a crazy idea I like very much and it may die soon. But so far there seems to be support inside Copenhagen Suborbitals and we might take this many steps further, even with scaled testing at sea.

Needless to say, this idea was inspired by SpaceX who intend to land a capsule with no parachutes at all (not even a drogue). This is beyond our skills. But a combination with of both worlds might be the answer…

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Kristian von Bengtson