Re:B-52 - X15 comparison (Score 2, Interesting)

Rutan has always been one of thos engineers who thinks outside of the box and has quite a few successes and here is another one. The current approach and basically unchanged since rocketry's infancy has been to avoid drag as much as possible in hopes of fuel economy and vehicle efficiency. Conventional wisdom has always said," go straight up and pass through the least amount of atmosphere and get to were you want to be as fast as possible and you will save the most fuel". The current wisdom has always treated drag as an enemy which it is but drag also has a sibling called lift. Now in a rocket going straight up, lift from an airfoil is to be avoided since the lift vector is in an axis perpendicular to the main direction of travel and all it will do is cause extra drag. Rutan's approach, way out of the box when it comes to rockets, is to use an effecient airfoil which will give minimal drag and maximum lift and travel to a high altitude with a minimum amount of fuel. By doing this he is: 1. Drastically reducing the fuel requirements just to get were the air is thin for the high speed portion of the launch. 2.Reducing the size of the launch vehicle system drastically just by not having to carry all that extra fuel. 3.Using smaller propulsion units because of decreased launch vehicle mass. These not only will weigh less but be cheaper to manufacture and be more durable. 4.By using smaller and more conventional propulsion units, he is also gaining a significant level of safety. A moderate sized jet or rocket engine is much easier to control technically. You can always just turn off the fuel and the fire goes out. One of the big safety issuse with the shuttle program has been the solid fuel booster engines. Once they are lit, there is no turning them off until they are consumed. Also because a rocket has no lift, there are limited options of launch abortal in the early moments of launch. Actually as the launch proceeds and gains altitude, the emergency procedure options increase dramatically with conventional launches. By using a quasi-conventional aircraft design, the complete launch vehicle will always have the ability to do an engine out glide return to earth up to vehicle seperation and actual high altitude launch sequence begins. Even this will be at a very great altitude giving many emergency options and this space vehicle is also a lifting body so it will be capable of gliding also. Rutan has had a huge influence on winged aviation for the military and civilian side. It appears that he is leaving his mark on the space program also. As a side note, Rutan and Nasa and the Air Force are on very friendly terms. It wouldn't surprise me if they have not been helping fund some of this research. I can't waqit to see this actually fly and reach orbit.