APOD: Concept Plane: Supersonic Green Machine (2017 Oct 01)

[rstevenson]

...cassini space probe should have been recovered and returned to the earth for recycling
or
held in saturn orbit until such recovery would have been made possible ...

Held? How? By magic? Cassini had almost run out of fuel for maintaining its orbit, and used the last of it to set up its plunge into a safe spot, Saturn. And don't try to suggest it could find a stable orbit and just wait for someone to come get it. The value of its recovered alloys wouldn't amount to even 1% of the cost of such a mission.

Rob (who will now try to figure out what this silly complaint had to do with the thread it is in)

[ArtGarf]

My big bright green pleasure machine...

[gordonrogers]

The mention of the Supersonic Green Machine makes me wonder if NASA has heard of Reaction Engines and the engine expected to run for the first time in 2020 that will power an aircraft from London to Sydney in about four hours? Being built at Westcott, close to where I live, and part funded by the UK government to the tune of £60m, it all hinges on heat exchangers that will take air at 1,000 C and reduce the temperature to minus 100c in 100th of a second. In doing this hydrogen, helium and oxygen are extracted from the atmosphere so that the engine is self-fuelling. In addition they are working on an unmanned machine, Skylon, that when in the upper atmosphere will proceed into space by rocket power, launch its payload into orbit and return to earth as an aircraft. Because it has no need for re-entry fuel and has no crew it will be light enough for re-entry without heat shielding tiles. I managed to find this out by wangling an invitation to a rocket scientists' reunion at Westcott. Gordon Rogers - near Oxford