NASA 'Hyper-X' Series Scramjets

swight1701 writes "Sciencedaily.com is reporting that NASA has revealed its plans for developing Hypersonic aircraft within 2 decades. These plans include planes that could routinely go Mach 5+ and capable of taking off from an airport and visiting the IIS, or for you earthbound folk, from one airport to any other within 2 hours. And you thought your luggage gets lost NOW.:)" NASA's release includes some graphics showing what the test vehicles look like.

Comments

Re:How do they see?

[TamMan2000]

I am going out on a limb here, but I think they have to use remote sensing because of the aerodynamics involved.

Any useful window has to have a large area projected to a plane perpendicular to the direction of travel. This would mean an extremely large window because of the wedge angle at the front of the plane. And this angle is required to be very small to keep the losses associated with the bow shock from becoming astronomical. The faster you are going (relative to the speed of sound) the smaller that angle must be to keep the shock attached and oblique.

The really interesting stuff on this craft is the engine inlets, the entire plane is designed to minimize engine inlet losses, due to shocks. Cool stuff

PULSEJET: Combines Air Breathing and Rocket

[justanyone]

Pulse jets (like the WWII German V-1 "cruise missle") could transition between air-scoop and rocket. Features:

• using atmospheric oxygen as oxidizer at low altitude & speed
• use onboard oxygen as oxidizer at higher altitudes and speeds;
• climb to 50-60 K feet altitude and refuel conventionally (subsonic of course);
• change air scoop / inlet geometry with increasing speed / air density (model this in wind tunnel);
• Add oxidizer as needed to optimize fuel efficiency;
• Fuel/oxidizer drop-tanks if necessary (cheap, conventional);
• pulsejets are non-continuous burn, can shut them down easeier than turbine / rocket engines;
• Can use variable-sweep wings for different mach numbers and to optimize wing loading;

Just some ideas.

ALSO: How come we don't see postings on Nasa websites with "what we've considered and why it didn't work" so outside engineers can solve their problems for them...