Yes, IMO the landing engines are probably distinct, smaller engines.On Sat, 15 Feb 2003 [EMAIL PROTECTED] wrote:If one assumes that that vertical takeoff, base-first reentry, and vertical landing is the simplest and lightest way to make an SSTO...Note a fine point: you can use separate landing engines. While using the same engines seems attractive, the thrust requirement is very much lower, feed arrangements might want to be different if you've got separate tanks for landing fuel, and the mass penalty for separate engines is not large.
But I would put it the other way, why would you not run them on the way up? It's extra thrust, and at takeoff you need all the thrust you can get; takeoff thrust determines total engine mass. You can shut them down again a few thousand feet up; but I suspect I would rather throttle, then shutdown, the big engines to help with g limiting, and leave the landing engines running.
Henry Spencer
[EMAIL PROTECTED]
