Space.com (May 17, 2010)
"The first hypersonic X-51 scramjet powered long-duration flights to give the Pentagon a new "Prompt Global Strike" capability that ties atmospheric and space propulsion will begin as early as May 25 at Edwards Air Force Base, Calif. The X-vehicle scramjet flight tests are also a key step for the use of air breathing propulsion to launch into space.
"As spectacular as space shuttle flights still are, they are also about the past. Scramjet propulsion is about the future. Unlike rocket engines, scramjets (supersonic combustion ramjets) are air-breathing engines that inhale oxygen from the atmosphere to achieve near rocket engine velocities and altitudes without carrying tons of oxidizer supplies.
"Scramjets should eventually enable flights to hypersonic near-space velocities and altitudes, just like high performance jet engines propelled the Anglo-French Concorde to supersonic speeds in the upper atmosphere..."
(from Pratt & Whitney, via Space.com, used w/o permission)
"The X-51 WaveRider is designed to fly longer hypersonically than all of its predecessors combined. Credit: Pratt & Whitney"
Scramjets have been in development for decades: the science was fairly straightforward, but there was an enormous amount of technology to develop to handle the forces and temperatures involved.
The Space.com article goes into quite a bit of detail about what's been happening with the X-51 project, how scramjets in general and the X-51 in particular are supposed to work, and and military applications of scramjets.
As someone who's been reading about scramjets for decades, it's exciting to see another test - this time of a vehicle that's expected / hoped to fly between 350 and 400 miles.
It's no 'spaceplane,' but it looks like we're coming a lot closer to having something that can take off from an airport, fly to orbit, and return. Just in time to provide passenger service to those orbital hotels and manufacturing plants.
They're not here - yet - but I think it's just a matter of time before the ISS has company.
- "NASA, Collier Trophy, and the International Space Station"
(May 17, 2010)
- "Space Marines: Really"
(April 18, 2010)
- "X-37B / Orbital Test Vehicle Robot Spaceplane Now an Air Force Project"
(April 5, 2010)
- "Hypersonic Transports: Not Yet, But They're Coming"
(March 30, 2010)
- A few modifications, and these could 'fly' to orbit and back
- "X-51 Waverider, Bullet Trains: Change Happens"
(March 11, 2010)
- "Hypersonic Vehicles: Waveriders to Space"
(November 2, 2009)