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

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...