Sunday, November 23, 2008
These are some recently uploaded videos of the LES (emergency escape rocket) designed to pull the manned Orion capsule (with 4 men) off of the Areas I rocket in the event of an abort. I think this will be used from the pad, or low speed flight (maybe to 100 KM or so). This is very high thrust for a short period of time, it has to pull a large object clear. The lower bound of the impulse is set by the need to carry the men high enough to give the recovery system time to act all the same. I expect several thousand feet is the target. G forced experienced on ejection could hit or pass 10 Gs. This is within limits, but probably pretty painful and dangerous all the same. As pilots know, ejection is a last resort. This will probably still be far safer and more gentle than a jet ejection. There is a Praxis (large line of great space books) book coming out on emergency and abort systems for space flight. But not yet, some day it will be out. If anyone wants to buy it and donate to me, leave a comment.
This is how it is expected to work. Please comment if youtube videos are not working for you. From time to time, I seem to have problems with them on my own pages. Is that the page? Or the video? Or my computer? Hard to figure out.
Here are some specs on the system:
"On ignition, the abort motor fired for 5.5 seconds. The high impulse motor was developed to expend the majority of its propellant in the first three seconds, delivering the half million pounds of thrust needed to pull the capsule away from its launch vehicle in an emergency abort.
While similar to the Apollo Program's launch abort motor, Orion's abort motor incorporates today's technology into a more robust design. The launch abort motor uses a composite case and an exhaust turn-flow technology instead of a tower, which results in weight savings, improved performance and improved success in crew survival during an abort. Instead of the rocket plume exiting a rear nozzle, the manifold is placed at the forward end of the motor. The rocket thrust enters the manifold and is turned 155 degrees and forced out the four nozzles, creating a forward-pulling force."