Which is more effective, disposable capsules or reusable spaceplanes?

[Pipcard]

Capsules cost less to build, but they are single-use.

Spaceplanes can be reused, but the development and maintenance costs are higher.

 

[Cras]

Reusable space planes.

 

[Ark]

Spaceplanes have the potential to be more affordable, but in the short term, IMO capsules are better. The Shuttle was supposed to be cheap and reusable, but SpaceX could probably build and fly half a dozen Dragons for the cost of one Shuttle flight plus turnaround.

 

[PhantomCruiser]

@ Cras - I agree, up to a point.
If the Shuttle had ever moved beyond the prototype stage and we'd actually made it re-usable rather than very nearly re-buildable, it would have definitely been more effective than it was. If we could ever truly develop a reuseable space plane then we'd be in Fat City.
I do understand the need for everything to be perfect if human are going to fly on it though. 99.9% ain't good enough if people are on board.
Another plus for spaceplaces is the down-mass ability. Dragon will have some capability, but not a lot. Not like Shuttle.
I think SpaceX might have the best of both worlds if they can refurbish and re-fly the Dragon like they want. It'll take a lot of NDI to prove that a capsule can make more than one trip. Of course, money will be the driving factor.

 

[Cras]

@ Cras - I agree, up to a point.
If the Shuttle had ever moved beyond the prototype stage and we'd actually made it re-usable rather than very nearly re-buildable, it would have definitely been more effective than it was. If we could ever truly develop a reuseable space plane then we'd be in Fat City.
I do understand the need for everything to be perfect if human are going to fly on it though. 99.9% ain't good enough if people are on board.
Another plus for spaceplaces is the down-mass ability. Dragon will have some capability, but not a lot. Not like Shuttle.
I think SpaceX might have the best of both worlds if they can refurbish and re-fly the Dragon like they want. It'll take a lot of NDI to prove that a capsule can make more than one trip. Of course, money will be the driving factor.

I think you nailed it right on the head PhantomCruiser. The Shuttle, despite being the only real life example of a manned space plane, is really not the ideal. Why? Beacuse it was the first. Idealy, we would have built upon it. Come out with a 2nd Gen Shuttle, then a 3rd, push further and further to greater, safer, and cheaper reusability. As it stands now, we had the Shuttle, was more re-buildable than re-usable, I get that conecpt. Long and costly turnaround, risky launches, and it was then left and never built upon. We never got a 2nd Gen Shuttle.

Long term, as someone who wants to see space travel become as common place as a airplane ride to Cleveland, I see one time use capsules as a non-starter, it cannot possible be a solution toward this goal. Granted, this goal is not something that is going to occur in the next 10 years, or maybe even 20, but it wont come at all if we dont at least start to walk down the path.

SpaceX seems to understand the fact that reusability not only being advantageous, but rather a requirement for successful progression of mankind into space. They are not going to go for reusability via a Space Plane, but reusable nonetheless.

 

[TMac3000]

Space planes take big one-time cost out of the program, but will be cheaper in the long run.

 

[Columbia42]

I agree with Cras and Phantom Cruiser that in the long run non-reusable capsules are a non-starter and in the future reusable spaceplanes could revolutionize space travel, especially if they don't need an entire non-reusable rocket to be built for each launch. Although capsules are a solution in the short term, they are not viable in the long run and I would rather see ten or even twenty years without a single launch while we develop a good spacecraft than ten or twenty years of one-off, dead end programs that are funded because they're cheap and to make it look like politicians are doing something.

 

[NovaSilisko]

Reusable Capsules. Simpler vehicles, simpler mechanics involved.

 

[Hlynkacg]

99.9% ain't good enough if people are on board.

I suspect that it puts me in the minority I'm going to have to disagree with you on this.

There is no need for a spacecraft to have a %99.9 percent safety margin If those who fly it are willing to accept the risk.

 

[C3PO]

99.9% ain't good enough if people are on board.

All manned space craft so far have had a reliability that's significantly lower than that.

NASA's current risk assessment model upped the STS from 1/250 to 1/50 (Loss of crew and mission). The same model put Saturn V at 1/6. Orion was planned to score 1/1250.

 

[Jarvitä]

Reusable capsules. It's the simplest re-entry vehicle and the most mass-effective, not to mention there's much less moving parts to maintain and repair to make it reusable than a spaceplane.

 

[Codz]

Capsules. They're cheap, easy to build, and relatively safe.

 

[Spacethingy]

I don't suppose there's such a thing as a reusable capsule? Now that would be cool.

 

[Jarvitä]

I don't suppose there's such a thing as a reusable capsule? Now that would be cool.

Orion and Dragon are both supposed to be reusable.

 

[Urwumpe]

The main problem with capsules are wind-sensitivity and landing accuracy, otherwise they would be pretty fine. a capsule that could do powered landing would be better there, but then, the landing system weights already more than comparable wings for bigger vehicles.

Space planes would have the tiny advantage of being capable of using any runways that are long enough and can land intact - while capsules would always need to jettison parts, and even if this part is just a parachute bag.

Capsules have less constraints on aerodynamics, but lack cross-range, making them unable to reach special landing sites if they are too far away from their orbit ground track. While no problem for landing successfully, the recovery after landing can be complicated.

If it would be just about manned flights with small crews and minimal payload to be landed, I would say capsules are better. If you want bigger crews or return a larger payload, wings will be your better choice.

 

[Unstung]

Not everything on the shuttle was reusable, specifically the external fuel tank. A SSTO like Skylon may greatly reduce costs for various reasons.

 

[GoForPDI]

It all depends on what you want to do though. Space Planes can be very useful in carrying and retrieving large payloads (as the Shuttle demonstrated) from LEO, while capsules are the simplest and safest method of returning people from high velocities from further afield.

It's like an 18 wheeler big rig vs Audi's Le Mans winning R18.

 

[FADEC]

Spaceplanes are only useful, in my point of view, for low earth orbit transportation and operation like the Space Shuttle was useful for. Especially returning payloads home. On the other hand: the Shuttle did not very often return payloads home. So I am questioning that kind of use. The only rational argument of using spaceplanes, in my point of view, is for ballistic/very high altitude intercontinental flights in the wide future. Transportation from A to B in a very short period of time.

I personally would always prefer capsules for manned space exploration and transportation. They are handy, cheap, reliable and can be reusable if designed for.

I'm convinced that the age of spaceplanes, in terms of national manned space flight programs (not future aviation technology and transportation), started and ended with the Space Shuttle. It's simply too costly since there is no big marked for something like the Shuttle. There are far more effective launch vehicles for putting stuff into low earth orbit.

 

[Urwumpe]

On the other hand: the Shuttle did not very often return payloads home.

There had been really few missions in which the shuttle returned empty, and in all such cases, in which the Shuttle returned payloads, it returned much more payload than what existing or proposed capsules can return. Even for smaller experiments hosted in the Mid-deck, the capability to return the experiments completely was very important - because it permits you to do much more complex research including research on the experiment hardware after the mission.

Payload is not just the payload bay - but even then it was more often returning cargo, than returning empty.

The key problem was, that the decision makers in the USA had been really short-sighted and not following the vision of NASA that they had when designing the Shuttle. Instead of looking at the whole complex, they just looked at a single spacecraft.

 

[zerofay32]

Spaceplanes are only useful, in my point of view, for low earth orbit transportation and operation like the Space Shuttle was useful for. Especially returning payloads home. On the other hand: the Shuttle did not very often return payloads home.

One situation when the shuttle did bring a lot of payload home was the MLPMs. The station crew put a lot of equipment and gear in those for the return home. As cluttered as the station is now, it would be (and will get) a lot worse in the coming years.

EDIT: Urwumpe sort-of beat me to the punch.

And bringing back satellites was never fully explored. Most of that type of mission would require an Orbital Maneuvering Vehicle to retrieve the payload and bring it down to the shuttle's working altitudes. No OMV was ever approved and STS-51-L caused Congress to nix the shuttle's satellite work. So up until the station era, only a handful of missions bought back payloads that the shuttle didn't already take up with it.

To the topic at hand: My feeling is that space planes would be better suited for large cargo, or large # of crew, types of missions. The problem with the later is that there is no destination for 30+ passengers. perhaps in the future. But for smaller crews, crewed missions would be best carried out with capsules. But my belief is that capsules can be (at least partially) reusable (at least as 'reusable' as the shuttles were, though for not as many flights).