I N D E X - G E R M A N

From the beginning I preferred a solar sail craft with a second driving force besides photonic thrust, which could provide steerage and the possibility to move were the solar sail canīt.

State of the art are ion thrusters. They could be fabricated pretty small and light and contrary to chemical thrusters can fire with high speeds, (about 30 km/sec.)

But even that light this thrusters could be made, didnīt the use of thrusters with the additional fuel add too much weight to the solar sail? After all I wanted to design a craft light like a butterfly!

I found the answer as I realized that weight is surely important, but even more important is the size. It was important to get a construction of high solidness when building something really big and this is in my opinion best possible with a frame around. So an outer ring from pipes (but lightweight) was my choice to reach this goal.

The frame is also bracket for the thrusters. Two of them located opposite each other fired in opposite directions move a very long lever as bigger the craft is. When You compare the lever of an self employing square sail with a steering thruster unit mounted on a short boom with the lever of a large STS with a radius of say 1000 m you get the picture. I guess it is more complicated to fine tune the STS-Thrusters than to give them enough power to turn the ring.

Under current assumptions (Solar Sailing, Colin R. McInnes, Springer page 22) the biggest possible square sail with an area of 2 km x 2 km and a mass of 19200 kg could handle a payload of 32000 kg.

Therefore besides asking, how we could fabricate parts as light as possible we should also ask how can we get the craft as big as possible. For this I found the answer. You can also find the answer on transporting and mounting this in space on my web site.

The solutions are the Ring Skeleton Structure (RSS), a Spacecraft Building System, able to build large space ring structures of pipe segments in a fast and simple way and the Launcher Transport Head (LTH) a head for the launcher tip similar to the ASAP ring for the Ariane V rocket which makes it possible to transport the pipe-segments into space outside of the launcher - (were they are needed when mounted).

Those large structures would be the ideal To get some benefit (maybe) out of my work I decided to ask for patents in Germany before publishing my thoughts onto the Internet. The German "Patentamt" is now working on my applications. I didnīt ask for patents in other countries.

I N D E X - G E R M A N