Purpose of a rocket-launched spaceplane

[kerbiloid]

7 hours ago, DerekL1963 said:

I can buy a dozen economy sedans for the cost of a single full size pickup truck - but everyone would rightfully look at me as a fool if I tried to use the former for the latter, or confused the two.

Especially when your full size pickup truck needs a trailer several times heavier than itself to move. (110 t for 30 t cargo)

[78stonewobble]

Well now I'm curious... Suppose we go into orbital manufacturing in zero-G or asteroid mining and we do need to bring back from orbit sizeable quantities. Or just for the mental exercise of it...

How would we best bring back somewhat sizeable and heavy loads repeatedly?

Can you make a simple winged or lifting body reentry vehicle that is single use as opposed to a possibly too advanced multiple use one?  

Possible reuse underlying structure and control surfaces and landing wheels, but the heat resistant parts are all one time use (like putting a shoe on)?

[monophonic]

5 hours ago, 78stonewobble said:

Well now I'm curious... Suppose we go into orbital manufacturing in zero-G or asteroid mining and we do need to bring back from orbit sizeable quantities. Or just for the mental exercise of it...

How would we best bring back somewhat sizeable and heavy loads repeatedly?

Can you make a simple winged or lifting body reentry vehicle that is single use as opposed to a possibly too advanced multiple use one?  

Possible reuse underlying structure and control surfaces and landing wheels, but the heat resistant parts are all one time use (like putting a shoe on)?

Cheapest in the near future? We build the re-entry vehicles from the most common elements found in those asteroids. The rarer elements are the payload that pays for the enterprise. Most critical parts, like guidance computers, RCS motors and/or parachutes might be brought from Earth as long as they constitute only a small fraction of the full mass. Even a perfectly reusable launcher cannot match the cost of mass you don't have to launch in the first place.

[78stonewobble]

2 hours ago, monophonic said:

Cheapest in the near future? We build the re-entry vehicles from the most common elements found in those asteroids. The rarer elements are the payload that pays for the enterprise. Most critical parts, like guidance computers, RCS motors and/or parachutes might be brought from Earth as long as they constitute only a small fraction of the full mass. Even a perfectly reusable launcher cannot match the cost of mass you don't have to launch in the first place.

That's kinda what im curious about... Capsule like shape or lifting body with or without wings ... for breaking and returning materials.

[kerbiloid]

19 hours ago, 78stonewobble said:

asteroid mining and we do need to bring back from orbit sizeable quantities

Deep lake and good insurance

(The first - to catch, the second - if oops)

Edited October 28, 2016 by kerbiloid

[Jestersage]

On a sidenote: About how much smaller is the Shuttle DC-3 compared to the One we ended up having? All I got is that the DC-3 have 5.7 ton payload and diameter of 5m, compared to 24.4 ton and diameter of 8.7m of STS

[monophonic]

17 hours ago, 78stonewobble said:

That's kinda what im curious about... Capsule like shape or lifting body with or without wings ... for breaking and returning materials.

Landing (not really returning when the stuff is mined off-world) dense stuff. I am imagining something that can provide decent lift at atmospheric entry to give sufficient time to slow down but is aerodynamically stable so it stays in the correct attitude without active control. Maybe something like a flat capsule or a fat lifting body, basically a blend between the two. It might not even need an ablative heat shield, the cargo probably isn't terribly picky about the temperature and provides plenty of mass for sinking heat into.

This does feel like one of the simpler problems in asteroid mining.

[78stonewobble]

6 hours ago, kerbiloid said:

Deep lake and good insurance

(The first - to catch, the second - if oops)

I presume that would create a waterhammer of sizeable proportions and embed the payload underwater... Wouldn't a desert be better?  

45 minutes ago, monophonic said:

Landing (not really returning when the stuff is mined off-world) dense stuff. I am imagining something that can provide decent lift at atmospheric entry to give sufficient time to slow down but is aerodynamically stable so it stays in the correct attitude without active control. Maybe something like a flat capsule or a fat lifting body, basically a blend between the two. It might not even need an ablative heat shield, the cargo probably isn't terribly picky about the temperature and provides plenty of mass for sinking heat into.

This does feel like one of the simpler problems in asteroid mining.

Can't ablate asymmetrically tho can? Still leaves the problem of eg. finished goods and returning those properly.

[monophonic]

2 hours ago, 78stonewobble said:

Can't ablate asymmetrically tho can? Still leaves the problem of eg. finished goods and returning those properly.

I don't know how symmetrically Apollo capsules' heat shields ablated, but those capsules did have an offset center of mass to re-enter at a slight angle. The reason was to use a bit of body lift to lessen the g forces during the re-entry. As of today Soyuz and I presume Shenzhou too do the same thing.

Varying the thickness of the ablative layer won't be a problem for most materials, if there is need to do so. Pretty much anything in production today uses variable thickness parts if only because it saves the tiniest bit of material and thus cost.

Personally I don't think bringing finished goods down from deep space will ever be really competitive. By the time we are extracting enough resources from space to support whole production chains we will have plenty of low g settlements to consume those products without the need to bring them into a gravity well raising the cost.

Edited October 28, 2016 by monophonic
Added note for Soyuz and Shenzhou