Tomáš Svoboda, Tomáš Svítek, Jiří Vackář, Jiří Bárta, Karel Vítek, Michal Kirschner, Milan Urban

“ To keep the price of the Perun Space Station as low as possible we have made effort to utilize in the design plenty of offshelf hardware which has been developed for earlier space projects. In fact even the tank itself is a piece of offshelf hardware. A number of subsystems is used from Skylab and Spacelab projects, some from the Space Shuttle. More details will be given in the appropriate parts of this report.
Launching the Tank It is possible to launch the tank fully fuelled and use its internal volume for habitation by the crew. ”

“ The LH2 enclosure has the shape of two half-ellipsoids. Both of these enclosures are connected by a tunnel passing through the intertank through existing manholes used normally for ground servicing of the tank. The total living volume in the tank is 212 m3. On the top of ET a passive Apollo docking port should be installed, protected by the ET Nose Cap. After jettisoning the Nose Cap in orbit a Skylab Multiple Docking Adapter should be connected to the docking system. The two docking ports of the Docking Adapter would be used one for Orbiter docking and the other one for Spacelab berthing. ”

“ Four more Shuttle launches are required to bring to Perun 4 Spacelab modules carrying materials for rebuilding the tank. These include plug-in equipment mounted in 78 Spacelab type small racks, 60 prefabricated panels 1OO by 250 cm to serve as partitions, excercise equipment etc. The initialization period of rebuilding should take about 5 weeks for an initial crew of k. Then regular operation may start. The crew for Perun is 8 persons. This crew size has the advantage of potential rescue by a single Orbiter (providing that no mission specialist is present) . ”

“ In our project we have arrived at a Space Station carrying a permanent crew of 8 people, orbiting the Earth at an altitude of 390 km, resupplied by STS once in 80 days.
Keywords Space Station, Space Transportation System, Space Shuttle, Space Shuttle External Tank, Spacelab, Permanent, Universal.
Introduction The Space Shuttle External Tank (ET) is the only part of the Space Transportation System which is designed as expendable. It will carry liquid hydrogen and oxygen to power the Space Shuttle Main Engines during launch. ET is 48.4 m long and has a diameter of 8.4 m. ”

“ The frontal area to mass ratio for Perun is about 4 times greater than for Skylab. This justifies the quicker downfall of Perun. A Propulsion System is necessary for cancellation of the atmospheric drag to keep the station at a stable altitude. This system is described in the next section.
To achieve a stable orbital altitude trajectory corrections should take place approximately every 10 days. ”

“ The habitation floor is used by the crew for eating and leisure It also holds much subsystem equipment mounted in racks surrounding the tank walls. The racks in all parts of Perun are identical with those used on Spacelab. It would therefore be possible to transport most of the onboard equipment for Perun in Spacelab modules mounted directly in the Spacelab racks. ”

“ For purposes of math modelling we have broken the structure down to 240 nodes. Every node has been assigned a thermal capacity, heat input (from Sun, Earth and internal sources) , radiating areas to the interior and exterior and thermal conductivity toward the adjacent nodes. ”

“ The Environmental Control System can be composed mostly of Spacelab hardware.
Berthing Port scheme Detail of the Probe-Drogue Unit The Berthing System is very specific for this project. We believe that in the near future any Space Station will need a means of berthing dedicated modules. There are indications that a berthing port for this purpose is already under development in the USSR. Existing docking systems are not suitable.for this purpose bacause of their high mass and insufficient dimensions of passage tunnels. ”

“ In this version the tank is launched from Earth fully fuelled. The crew then occupies the volume which was used previously for propellant storage. In this version the whole LOX tank is inhabited but not the LH2. This gives a total volume of 552 m3 - that is 1.7 times as much as on Skylab. Several Spacelab modules should be connected by special berthing ports to the LOX cylindrical section. Electrical installations, plumbing and a mechanical secondary structure should be built in prior to launch. ”