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
Artificial satellites in retrograde orbit Artificial satellites in retrograde orbit Artificial satellites are rarely placed in retrograde orbit. This is partly due to the extra velocity (and fuel) required to launch into orbit against the direction of the Earth's rotation. Most commercial Earth-observing satellites use retrograde sun-synchronous orbits to ensure that observations are performed at the same local time each pass of any given location, while almost all communication satellites use prograde orbits. Israel has successfully launched seven Ofeq satellites in retrograde orbit aboard a Shavit launcher. These reconnaissance satellites complete one Earth orbit every 90 minutes and initially make about six daylight passes per