SpaceShipTwo Tests Its Rocket Engine and Goes Supersonic

ehartwell writes "It's official. This morning, after WhiteKnightTwo released SpaceShipTwo at an altitude of around 50,000 feet, pilots Mark Stucky and Mike Alsbury ignited the engine for a roughly 16-second blast. After the engine cutoff, the plane coasted back to its landing back at the Mojave airport. Virgin Galactic tweeted that the pilots confirmed 'SpaceShipTwo exceeded the speed of sound on today's flight!' Its predecessor, SpaceShipOne, first went supersonic December 17, 2003."

Re:Terribly Exciting - 10 years ago

[0123456]

SpaceX charge rather more than $200,000 per seat to fly into space. And there's a big difference between NASA 'man rating' and being safe enough to routinely fly tourists; if SS2 flew daily and was as 'man rated' as the shuttle, they'd kill everyone on board every two months.

Re:regression

[bkmoore]

Nope, no X-plane ever made it into orbit. They were very-high-altitude rocket planes, and were much too small to contain enough fuel to reach orbit. More fuel would necessitate a bigger plane to contain it, and hence a bigger motor to propel it, and hence more fuel to run the bigger motor, etc... That's why rockets get around this problem with multiple stages. They jettison excess mass on the way to orbit. A true "space plane" that lands and takes off on a runway and doesn't dump stages along the way would need to be Single-Stage-To-Orbit (SSTO). So far, there are no true SSTO vehicles, even rockets. A space plane would need to haul along landing gear, wings, conventional engines, etc, and would be much more difficult to do than a simple SSTO rocket.

Re:These flights have nothing to do really with sp

[wagnerrp]

There is a vast difference between SSO, or even SST, and what you propose. SSO and SST just go straight up and straight back down. There is very little ground track in their flight envelope. In order to get to orbit, you need to go straight up, and then go about double that to really get out of the atmosphere, and then tack on around 8km/s velocity. You're looking at a few dozen times more energy, and around a hundred times more fuel. A sub-orbital transcontinental flight won't need quite that much, but you're still way up there in comparison. Add in the fact that you're actually going to need a real thermal protection system for re-entry. They're not even in the ballpark.

Re:Not So Sure

[confused one]

It's not a jet turbine burning kerosene with oxygen, it is a hybrid rocket motor. It is burning a solid composite material with a nitrous oxide oxidizer. It will never be a "clean looking" burn; expect something closer to what the solid boosters on the shuttle produced.

Re:These flights have nothing to do really with sp

[wagnerrp]

I think you're understating the difficulty of more d-V. Six times the d-V doesn't simply mean six times the fuel. Energy is proportional to velocity squared, so you immediately need thirty-six times the energy. When you factor in the exponential behavior of the rocket equation, and the fact that you need yet more fuel just to take up the additional fuel needed to accelerate the spacecraft itself, your fuel consumption balloons fast.