Space/Science — HabitableZone

Space/Science » in reply to Not exactly

Re: Not exactly

Not quite. You'd still have to decelerate the mass of the fuel. That takes fuel. It takes propellant to accelerate (or decelerate) propellant, even if you're not lifting it directly. You'd also need a much bigger propellant tank than you can carry in the orbiter.

An orbiter in space has a velocity on the order of 17,500 MPH. To slow it down enough where aerodynamic braking isn't needed or where the aerodynamic heating isn't a factor, you'd need to chop something like 16,000 MPH. Any way you want to look at it, it'd take a hell of a lot of propellant to do that.

By way of comparison and from numbers I recall reading several years ago, the OMS system carries somewhere around 20,000 pounds of hypergolic propellant at liftoff. That propellant is used to do the final insertion burn, all orbital maneuvers and attitude changes, and the deorbit burn. All together, the system has a delta-v (change in velocity) capability of 1,000 feet per second, or about 600 MPH. Those numbers may be off a bit. Kim Keller would certainly know them better than I do.

Log in or register to post.

The whole thread (20 posts)