199th Carnival of Space is hosted this week by Weirdwarp. There are some really cool posts this week, but I was especially intrigued by the mysterious black Skylon space plane, which was reported by Next Big Future. This unpiloted SSTO (single stage to orbit) vehicle has been proposed by a UK company, Reaction Engines, Ltd. (Skylon press release here, PDF). The news is that an ESA report commissioned by the UK Space Agency concluded "no impediments or critical items have been identified for either the SKYLON vehicle or the SABRE engine that are a block to further developments."
This is exciting stuff, the key to its possible feasibility being the SABRE hybrid air-breathing/rocket engine that would allow Skylon to operate like a jet airplane while within the denser part of the atmosphere, leading to an enormous reduction in the amount of oxidizer that must be carried. The report states that the current design has a gross take off weight of 275 metric tonnes, of which 220 tonnes are propellent, with the ability to place 12 tonnes into an equatorial low Earth orbit. This is something like 4.4% of the total which is pretty good, especially with a fully-reusable vehicle (the calculation for the soon-to-retire space shuttle is about 1.4%, not including the orbiter itself).
The Reaction Engines site says that Skylon is in the "proof of concept" stage, with development estimated at 10 years. There are obviously a few technical issues to overcome (materials, for one, I would imagine), but it's great that ESA at least sees no fundamental showstoppers in the Skylon proposal. Now to get it funded! Reaction Engines estimates development costs of about $10 billion (this seems pretty cheap, even for an unpiloted vehicle).
Bonus: finally a rocket ship that looks like one of Wernher von Braun and Chesley Bonestell's classic Colliers Magazine rocket ships from the 1950's! More or less. Check out the Skylon mission animation video.