That is an interesting thought. The re-entry stuctures we are considering could be made very large without much weight and so could bring a first stage down quite gentally.We have already done a drop test to look at stability, and the thermal requirements we understand and can handle.Until we mine the Moon and asteroids only small amounts of cargo need returning to the Earth.There may be a market for returning to the Earth the upper stages of launch vehicles going to low Earth orbit (LEO). Currently it is cheaper to buy new upper stages and crash the used ones back than fit heat shields, including the cost of reduced payload.Spaceships repeatedly flying between LEO and say the Earth-Moon Lagrange points could use a low cost way of slowing down on the return journey. Lifting the propellant to perform the 3.77 km/s delta-v is normally considered too expensive, so currently spacecraft reenter.http://en.wikipedia.org/wiki/Aerocapture
The main question now is how much cargo is there to return from orbit?Paul
Quote from: Paul Adams on 03/02/2010 10:27 amThe main question now is how much cargo is there to return from orbit?PaulMy uninformed opinion: Not just how much, but how often and what size when you do.I am guessing that usually we dont need to return much intact (apart from crew) but sometimes we want to return a fairly large object. For example even if you are not reusing an upper stage it must be useful to be able to examine one in detail after real use occasionally.This idea of an inflatable re-entry vehicle seems very worthwhile because it could let you occasionally return large objects when really needed while not paying for this ability even in missions where it is not required, as with the shuttle.
FYI: The Goodyear "InflatoPlane" structural concept was explored by Goodyear for several other possible uses including commercial aircraft, light-aircraft flyers market AND a concept for a Reentry vehicle. Unfortunatly not a lot of documentation for ANY of the concepts let alone the construction and manufacturing for the Inflatiplane have been found.Randy
I thought as an inflatable or telescopic wing might make sense for landing on Mars.Landing heavy vehicles on Mars is difficult to do without massive rockets so any lightweight solution would be great.If we can slow down in the atmosphere and then convert the speed into lift we can then use maybe rockets for the last few feet. Parachutes have the problem that you hit the planet fast before getting to a sensible speed.
Quote from: colbourne on 03/06/2010 03:18 amI thought as an inflatable or telescopic wing might make sense for landing on Mars.Landing heavy vehicles on Mars is difficult to do without massive rockets so any lightweight solution would be great.If we can slow down in the atmosphere and then convert the speed into lift we can then use maybe rockets for the last few feet. Parachutes have the problem that you hit the planet fast before getting to a sensible speed.No, you just don't get it. The atmosphere is too thin. Like we have said to you many times, rockets are needed for more than a few feet. The wings would be enormous and instead of a vertical speed then is now a high horizontal speed.
1. Now I realize that the Cube Root law would have a MAJOR effect here, possibly invalidating this idea, but to come in like gang busters and say that "you just don't get it" seems to me to be a bit rude. 2. I mean, if it weren't possible, why would NASA bother with parachutes for their Mars probes? And why did VonBraun want to land a Flying Wing manned craft on Mars in the first place? Prior to settling on the Giant Apollo Capsule design for some of the early baseline missions, NASA was actively considering a Lifting Body design for the Martain Landing. In fact, some of the later Cargo Lander designs proposed by people like Boeing and Lockheed Marten, were suggesting use of lifting bodys, along with parachutes and rockets "For the last few hundred feet". Now, maybe these systems wouldn't have worked for some reason that I don't know or comprehend, but the "Big Boys" thought they would.
Quote from: JasonAW3 on 03/06/2010 01:36 pm 1. Now I realize that the Cube Root law would have a MAJOR effect here, possibly invalidating this idea, but to come in like gang busters and say that "you just don't get it" seems to me to be a bit rude. 2. I mean, if it weren't possible, why would NASA bother with parachutes for their Mars probes? And why did VonBraun want to land a Flying Wing manned craft on Mars in the first place? Prior to settling on the Giant Apollo Capsule design for some of the early baseline missions, NASA was actively considering a Lifting Body design for the Martain Landing. In fact, some of the later Cargo Lander designs proposed by people like Boeing and Lockheed Marten, were suggesting use of lifting bodys, along with parachutes and rockets "For the last few hundred feet". Now, maybe these systems wouldn't have worked for some reason that I don't know or comprehend, but the "Big Boys" thought they would.We talking landing and not flying.1. this is a continuation of this threadhttp://forum.nasaspaceflight.com/index.php?topic=17798.0colbourne doesn't understand how thin the atmosphere is.2. Parachutes are used for deceleration and not landing. Lifting bodies are for control during entry and not landing.