VIRGIN GALACTIC’S SPACESHIPTWO FOR ‘EDGE OF SPACE TOURISTS’ EXITS THE ATMOSPHERE AT G-FORCE 3, AND RE-ENTERS AT ABOUT TWICE THAT LEVEL. A high-level roller coaster typically pulls up to 5 g. And fighter pilots will routinely experience even more.
Sierra Nevada Corporation’s Dream Chaser spacecraft doesn’t perform quite as dramatically, but it is a most impressive flying machine nevertheless. Designed for both crewed and unmanned low-Earth orbit missions, it will pull no more than 1.5 g throughout its flight profile. This makes it an ideal vehicle for transporting sensitive payloads, or returning injured or end-of-mission crew members from space.
With its use of all non-toxic consumables, including propellants, it is also designed to operate on a variety of landing infrastructure, as long as there’s 3,000 km (10,000 ft) of runway. SNC is in the process of trying to gain FAA approval for commercial missions to land Dream Chaser at commercial airports and existing spaceports.
This is key to fulfilling a memorandum of understanding signed with the United Nations Office of Outer Space Affairs (UNOOSA) to pursue extended microgravity missions for UN member states. The idea is to assist smaller and developing countries in developing space flight capabilities.
Eligible countries will pay a portion of mission costs, as will major sponsors. Payloads will be selected in 2018 and the launch is scheduled for 2021. UNOOSA sees it as a way to “promote international cooperation in the peaceful use of outer space”. Perhaps, if mankind avoids replicating its history on Earth, there may be a chance of achieving just that.