Even though we are still investigating the results and impact from our previous capsule mission the design process for a new capsule has begun.

Obviously, there is still much to learn from the Launch Espace System test and maybe there will be more tests with this capsule. But the actual process of building and operating Tycho Deep Space 1 (TDS-1) was the biggest learning process. The 10 months development period held hundreds of part-tests and calculations from which future design strategies can be transferred into the next capsule.

One thing is certain. We will continue with a capsule configuration with one person lying down.

Changing the diameter:

TDS-1 had a diameter of 2 m, based upon the idea of a 7 x HEAT-1X cluster engine. This engine configuration might not be relevant anymore (going liquid?) and considering the mass and size of 2 m diameter launcher I offered Peter Madsen a “smallest possible capsule”, which will be 1.6 m. The 40 cm decrease in diameter provides a launcher mass difference of almost 50% which is quite something for a DIY project like this. This idea and sketches actually dates back to January 2012.

Changing the material

So far, all my space capsules have been made from plain carbon steel and in the early prototype development stages mass was a less important issue when simply trying to find the right design.

Plain carbon steel has a lot of advantages such as price, strength, easy production, welding and modification. However, TDS-1 spend almost 60% of the total mass on its basic structure which is absolutely too much in future designs, with much more systems being added on board. Naturally, this could be optimized.

At the moment I am performing basic FEM calculations using aluminum instead. Aluminum is a common, inexpensive and easy accessible material which keeps its appearance (tired of rusty steal!). Aluminum will require a different approach in construction and production but nothing we cannot handle.

I have a powerful sense that the next capsule will be in aluminum (alloy: AlMg3) and there might be less panels and parts which are being welded together. But, who knows?

General configuration

The shrunken diameter will require a change in the overall configuration of the capsule. TDS-1 had a 55 degree side cone which will have to be increased to fit a man inside. The seat will have to be more compact most likely a Kazbek seat used in the Soyuz capsule. We might end up with something like a Mercury-Soyuz bastard.

Compact seat configuration for a 1.6 m capsule inspired by the Kazbek seat. Image: Kristian von Bengtson

1.6 m capsule design sketching. January 2012. Image: Kristian von Bengtson 1.6 m capsule design sketching. January 2012. Image: Kristian von Bengtson

Design Steps

Before going into the construction of this new capsule there are some design steps I will have to go through. These are:

- Compact seating dimensions

- Grasp reach and human operation inside capsule

- Ingress / egress operation and dimension

- Subsystems breakdown with dimensioning

I will not be designing a capsule into which I will try fitting a human being later. I will try fitting the capsule to the needs of a human being and mission requirements. A human-centered design approach.

So, in the weeks to come I will go through the sketching and writing processes of these design steps mentioned above and come up with some kind of plan. You can follow the process here or even chip in with ideas and thoughts, now or during the process.

Ad Astra

Kristian von Bengtson