International Space Station program with on-orbit refurbishment in mind. According to the Outer Space Treaty the United States is legally responsible for all modules it has launched. In ISS planning, NASA examined options including returning the station to Earth via shuttle missions (deemed too expensive, as the station(USOS) is not designed for disassembly and this would require at least 27 shuttle missions), natural orbital decay with random reentry similar to Skylab, boosting the station to a higher altitude (which would simply delay reentry) and a controlled targeted de-orbit to a remote ocean area. The technical feasibility of a controlled targeted deorbit into a remote
Scientific research on the International Space Station Much like NASA and JAXA, ESA also conducted numerous experiments on the International Space Station. In May 2011, Space Shuttle Endeavour mission STS-134 carried 13 Lego kits to the ISS, where astronauts built models and saw how they reacted in microgravity, as part of the Lego Bricks in Space program. The results were shared with schools as part of an educational project. Scientific research on the International Space Station Scientific research on the International Space Station is a collection of experiments that require one or more of the unusual conditions present in low Earth orbit. The primary fields of research