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Virgin Galactic spacecraft performs the first powered flight since fatal 2014 crash
Richard Branson's fledgling space tourism company Virgin Galactic performed a powered flight of its spacecraft today, the first since a fatal crash in 2014.
Virgin's spacecraft is unlike others because it is launched mid-flight by a larger plane called White Knight Two. This particular version of the spacecraft, dubbed SpaceShipTwo VSS Unity, has performed seven glide tests since it was built in 2016. Like those previous tests, it was carried high above the Mojave Desert by White Knight Two and released at 46,000 feet. But today, pilots Mark Stucky and Dave Mackay fired Unity's engine and continued skyward.
The spaceplane's engine burned for 30 seconds, pushing the Unity supersonic to Mach 1.87 before the engines cut off. It coasted to 84,000 feet before gliding down again for a safe landing at the company's spaceport back in Mojave. White Knight Two safely touched down roughly 30 minutes later.
(Score: 3, Informative) by bzipitidoo on Saturday April 07 2018, @12:25AM (2 children)
Several problems. I suspect people can't take 10G for 70 seconds. The longer the duration, the less Gs a person can take. 6G may be the limit for over 1 minute. In that case a = 60. Then, to reach 7 km/s, S must be 408.3 km.
But, moving anything at such speeds in the lower atmosphere will generate a lot of heat. Near sea level, shells fired at speeds of 6 km/s tend to burn up in the air before they reach their target. I don't know how much difference 6000m of elevation makes, but I doubt that's high enough to avoid this problem.
No, I had in mind that the railgun would assist, rather than provide all the momentum. Anyway, while workable, it's probably too costly.
(Score: 1, Interesting) by Anonymous Coward on Saturday April 07 2018, @01:10PM
Yeah, I worked out a long time ago that the optimum was probably about 60 km of rail with an exit velocity of about 3 km/s on top of a mountain. That's fast enough to let you use a reasonably robust and cheap single-stage-to-orbit vehicle without absolutely insane engineering on either the railgun or the launch vehicle.
If they ever get that hypersonic scramjet working, you could go back to two stages with an airbreathing first stage and put a bigger load into orbit with the same launch mass.
(Score: 2) by corey on Thursday April 12 2018, @09:40PM
Do it.
Come up with a proposal and get some venture funding.
This concept is good but engineering is a challenge. Just like the hyperloop.
Hundreds of km is just too much but you could expect to get to Mach 1 on a rail launcher.
It'd be interesting to design, build and test a vehicle that would withstand up to 10G for that period too.