Purpose of a rocket-launched spaceplane

[Jestersage]

Aside from SSTO and designs based on NASA Space Shuttles, the other kinds of spaceplanes I see are plane launched, plane-on-a-stick (rocket), and Buran based.

In KSP, we know why we do the latter designs: They are much easier to design and fly.

But IRL, the plane-on-a-stick (ESA Hermes) and the Buran type made be wonder why they even bothered with a plane at all. Until Space-X (and a one-off Energia Block II design), boosters are not reusable, making the cost much higher. In the meantime, they need to figure out the technology to land the plane safely... meanwhile, the Soviets have the nice space capsules already.

I know there are arguments, even by Popular Mechanics, that state the Buran are better. Aside from its automatic landing system, I am not sure how correct that argument is. So can someone explain why would Plane-on-a-stick and Buran be better than using space capsules, possible with cargo fairing beneath the capsule (which is one of the plan for Energia usage)?

[steuben]

The automagic landing was probably more of a testing feature than a full feature in the production model. But it would have been left in... just in case.

It is a set of trades. You are trading complexity of design, candle -> Buran (of increasing complexity) for recovered equipment candle -> Buran (increasing recovery ratio).

This set of trades is the same in game as IRL. 

 

[Frybert]

Moved to science and spaceflight.

[softweir]

One major requirement for both Shuttle and Buran was that they could fly "crossrange", that is, after reentry they could aim at a touchdown point well to one side of their reentry trajectory. This was a military requirement, enabling them to be used to launch spy satellites or even weapons systems during a conflict, reenter within one orbit, and still reach a safe landing point without coming under enemy attack. Hence the requirement for a reentry vehicle with wings, which could use those wings to glide to a touchdown.

In the case of the Buran, they made the orbiter/reentry vehicle a great deal cheaper and lighter (and hence more capable) by not having massive launch engines on it. The expendable rocket part was more expensive as a result, but still cheap enough that the cost seemed affordable - disposable rockets can be quite cheap compared to reusable ones. It also saved fuel - the Shuttle had to waste a lot of Orbital Maneuvering Engine fuel hauling those huge launch engines while performing final circularisation! The buran, on the other hand - left the huge engines to drop back into the atmosphere.

Having said all that, it is arguable whether any kind of "spaceplane" can be justified for civilian use. If you don't need the extreme crossrange capability of the Shuttle or Buran then the huge additional costs of a flying, reusable orbiter no longer make sense. SpaceX has proven that vertical landings are achievable, and though I wouldn't trust my cheeks in one yet it is quite probable that with enough development and experience that sort of system could be made to work. (OK, Skylon might, just, perhaps, one day get off the ground.)

[DerekL1963]

1 hour ago, softweir said:

One major requirement for both Shuttle and Buran was that they could fly "crossrange", that is, after reentry they could aim at a touchdown point well to one side of their reentry trajectory. This was a military requirement, enabling them to be used to launch spy satellites or even weapons systems during a conflict, reenter within one orbit, and still reach a safe landing point without coming under enemy attack. Hence the requirement for a reentry vehicle with wings, which could use those wings to glide to a touchdown.

Partly truth, partly nonsense.  Even before the DoD came onboard, they were  examining Shuttle designs with with lift (and therefore crossrange) capabilities - because it turns out that crossrange is a very handy thing to have.  Crossrange increases abort capability and widens recovery windows (sometimes even creating a window where one wouldn't have existed otherwise).
 

1 hour ago, softweir said:

SpaceX has proven that vertical landings are achievable

Assuming you have a landing site available within it's rather narrow (along-track as well as cross-track) landing ellipse.

[Norcalplanner]

Shuttle was a lot of ideas that looked great on paper, but didn't quite pan out in reality. And history showed quite emphatically that placing a spaceplane on the side of a rocket is a really bad idea.

Cheaper than an expendable rocket? Nope.

Safer than an expendable rocket? Nope.

More utility than an expendable rocket? Kinda/sorta if you focus on a narrow set of criteria, otherwise nope.

Cheaper recovery? Yep - no naval task force waiting around.

The major advantage of the shuttle touted during its design was the ability to capture a satellite, bring it back to earth, and then launch it again. Unfortunately for the shuttle program, economics and technology continued their forward march during its development, making this mission impractical and a money loser by the time the shuttle came online. It seems to me that if a more cost-effective recovery method had been instituted for whatever followed Apollo, with some greater level of cross-range capability (but still less than that of the shuttle) then there wouldn't have been any advantages in the shuttle's corner.

Of course, hindsight is usually clearer than foresight. 

[magnemoe]

4 hours ago, Jestersage said:

Aside from SSTO and designs based on NASA Space Shuttles, the other kinds of spaceplanes I see are plane launched, plane-on-a-stick (rocket), and Buran based.

In KSP, we know why we do the latter designs: They are much easier to design and fly.

But IRL, the plane-on-a-stick (ESA Hermes) and the Buran type made be wonder why they even bothered with a plane at all. Until Space-X (and a one-off Energia Block II design), boosters are not reusable, making the cost much higher. In the meantime, they need to figure out the technology to land the plane safely... meanwhile, the Soviets have the nice space capsules already.

I know there are arguments, even by Popular Mechanics, that state the Buran are better. Aside from its automatic landing system, I am not sure how correct that argument is. So can someone explain why would Plane-on-a-stick and Buran be better than using space capsules, possible with cargo fairing beneath the capsule (which is one of the plan for Energia usage)?

Hermes and the other upper stage spaceplanes has the benefit of lower g forces during reentry, you also have cross range and an controlled landing on an runway. 
Downside is that its heavier than an capsule and much more complex with things who can go wrong catastrophically as its not aerodynamic stable during decent 
An capsule is as simple as you can make something, heat shield is simple and its protected by service module / inter stage until decent. 

Spaceplanes is an old idea for recovery dating back to the 1950 Von Braun plans with staged spaceplanes taking off vertically and landing as planes. Few had thought of doing and powered landing of the first stage, combination of an unusual approach and that you need good control software to do it. 

 

[KamenRiderzero1]

When you really think about it, the beauty of the concept of the Shuttle and Buran was not so much what they could bring up, but what they could bring back down.

[kerbiloid]

1. Spaceplane is a kind of return vehicle that can maneuver and precisely land on any airdrome with enough long runway. So, many positions for safe landing without need in escape procedures.
2. Spaceplane airbrakes with 2-3 g, while capsule with 3-5 g and greater. Crew health is less critical , you don't have to sort out a clever but weak specialist.
3 Same as p.2. You can return fragile or dangerous cargo (say, nukes).
As none of these points are not still really required, no spaceplanes (except Sh. and B.).
4. Originally, spaceplanes were the spaceships. Capsules were being considered as unsafe and less capable.

upd.
I.e. the question is not phrased correctly.
Not "why use rocket to launch a spaceplane"?
But "why use wing to return the return vehicle launched doesn't matter how"

Edited October 25, 2016 by kerbiloid

[hugix]

Landing a plane is way softer than landing in a capsule. even with the parachutes and the braking rockets a soyuz landing is most commonly described as a controlled car crash. And that's just for a capsule with 3 persons inside it.  A winged vehicle can haul a whole lot of fragile down payload from space to Earth. 

[Bill Phil]

Space Capsules > Buran > Shuttle

Here's why:

Space Capsules are the safest and the lightest for a given mission. Buran and the Shuttle are extremely similar, but, not only can Buran fly unmanned, but it's attached to the Energia booster, which can launch other payloads besides Buran. Capsules are better because they don't have wings and heavy landing gear and associated systems.

3 hours ago, hugix said:

Landing a plane is way softer than landing in a capsule. even with the parachutes and the braking rockets a soyuz landing is most commonly described as a controlled car crash. And that's just for a capsule with 3 persons inside it.  A winged vehicle can haul a whole lot of fragile down payload from space to Earth. 

Oh, yes. But that's only the case for the capsule designs that have been flown. NASA (or the USAF) had an idea to put "wings" on a Gemini capsule. And another one to make it a paraglider.

[DerekL1963]

3 hours ago, Bill Phil said:

Space Capsules > Buran > Shuttle

Here's why:

Space Capsules are the safest and the lightest for a given mission. Buran and the Shuttle are extremely similar, but, not only can Buran fly unmanned, but it's attached to the Energia booster, which can launch other payloads besides Buran. Capsules are better because they don't have wings and heavy landing gear and associated systems.

Translation:  Capsules are better only so long as I don't actually discuss or compare relative capabilities.

[Bill Phil]

Just now, DerekL1963 said:

Translation:  Capsules are better only so long as I don't actually discuss or compare relative capabilities.

? Whatever.

Comparing capsules to spaceplanes isn't going to get us anywhere, anyways. Comparing the two has little use. One is a dedicated spacecraft designed to deliver people to orbit and back with a small payload, the other is trying to be a generalized spacecraft that can carry anything within the constraints of its payload bay and up mass ability. It'd be much more effective to compare launch vehicles. Sadly, the Space Shuttle fits in more as a launch vehicle than as a spacecraft. The Orbiter is an upper stage. It has wings, a cargo bay, and a crew added to it. The Soyuz rocket can lift more than the Soyuz or Progress capsules. It can lift space probes, satellites, and unmanned vehicles, all for a lower cost and higher payload mass percentage than the Shuttle. The real question here is: Is the Shuttle indicative of other spaceplanes? I would say so. Mainly due to an inherent design quirk: A spaceplane has unavoidable mass, which hurts payload capability.

 

But, even not considering that, we could've done all of the things the Shuttle did with capsules, save be reused. But how many capsules could you buy with the cost of refurbishing the Shuttle? Could put the same payloads on a launch vehicle behind a small space capsule, and then the crew of the capsule could operate said payload. Spacelab? Could've been a capsule mission. Building the ISS? The Russians built a station sans Shuttle. Studying things with instruments that need to be returned? Wouldn't be easy to do, but could be done (although at high gees). Again, the real question here is whether or not the Shuttle is indicative of other space planes.

 

So, it'd read likes this:

Translation: Capsules are great for their mission, spaceplanes aren't really good for their mission.

[razark]

37 minutes ago, Bill Phil said:

we could've done all of the things the Shuttle did with capsules, save be reused.

Capture and return a satellite from orbit?

 

37 minutes ago, Bill Phil said:

Spacelab? Could've been a capsule mission.

Shuttle brought the Spacelab back, so they didn't have to build a completely new one for each flight.

Edited October 26, 2016 by razark

[Eklykti]

On 25.10.2016 at 3:40 AM, softweir said:

OK, Skylon might, just, perhaps, one day get off the ground.

Given it's complexity it may be possible that just it's engines will be more expensive than the entire ITS complex, which will lift about 300 tons to LEO (and even more if they will made a specialized cargo version) instead of only 12 available to Skylon.

[kerbiloid]

7 hours ago, Bill Phil said:

Space Capsules > Buran > Shuttle

> Space Capsules again

2 hours ago, razark said:

Shuttle brought the Spacelab back, so they didn't have to build a completely new one for each flight.

= every 10 years?

[razark]

3 hours ago, kerbiloid said:

= every 10 years?

No.  Thirty-two times over twenty years.

[kerbiloid]

43 minutes ago, razark said:

No.  Thirty-two times over twenty years.

I mean: Salyut-6, -7, Mir, Skylab, ISS.  5 long-term stations per 40 years.
15-20 t module count = 1 + 1 + 6 + 1 (but large) + ~10 (counting small ones as 3:1).
So ~ 20 Almaz-sized modules total. Formally single-use, but every "single use" lasts for 5..20 years.

So, looks cheaper to leave modules on orbit, rather than carry them there and back for 10-20 days.

[razark]

38 minutes ago, kerbiloid said:

So, looks cheaper to leave modules on orbit, rather than carry them there and back for 10-20 days.

While true, it wasn't the point I was addressing.

The assertion was that a pod mission could do anything the Shuttle could do.

[Jestersage]

19 hours ago, Bill Phil said:

Space Capsules > Buran > Shuttle

Here's why:

Space Capsules are the safest and the lightest for a given mission. Buran and the Shuttle are extremely similar, but, not only can Buran fly unmanned, but it's attached to the Energia booster, which can launch other payloads besides Buran. Capsules are better because they don't have wings and heavy landing gear and associated systems.

Oh, yes. But that's only the case for the capsule designs that have been flown. NASA (or the USAF) had an idea to put "wings" on a Gemini capsule. And another one to make it a paraglider.

I am not going to disagree on Energia being better rocket, but in terms of the alleged purpose of a spaceplane / shuttle-- more reuse-- is it better? Block 2 energia-buran is definitely better by being reusable, but what about Block I, where an expensive rocket have to be discarded everytime?

7 hours ago, razark said:

While true, it wasn't the point I was addressing.

The assertion was that a pod mission could do anything the Shuttle could do.

If we are going straightly-pod-to-shuttle: As soon as shuttle use ISS instead of the skylab, yes, pod is cheaper. especially if they managed to make pod reusable (which wasn't true with Apollo or soyuz, but yes for Orion). Shuttle is only cheaper if based on the alleged plan of reusing its booster (and the orange fuel tank IS cheap), but apparently it's not.

As for carrying a experiment capsule, Shenzhou's Orbital Module would like to say ni'hao.

[razark]

2 minutes ago, Jestersage said:

If we are going straightly-pod-to-shuttle: As soon as shuttle use ISS instead of the skylab, yes, pod is cheaper. especially if they managed to make pod reusable (which wasn't true with Apollo or soyuz, but yes for Orion). Shuttle is only cheaper if based on the alleged plan of reusing its booster (and the orange fuel tank IS cheap), but apparently it's not.

I never addressed the cost.  (I also never claimed one was "better".)  Simply that the shuttles did have a unique capability that no other craft type has yet included.

 

2 minutes ago, Jestersage said:

As for carrying a experiment capsule, Shenzhou's Orbital Module would like to say ni'hao.

Cool.  I didn't know about the reusability/redocking capability of it.  I'm going to have to steal that idea for my game.

However, my point was that the shuttle also brought the lab back, and could also return satellites to Earth.

[Laie]

20 hours ago, Bill Phil said:

 NASA (or the USAF) had an idea to put "wings" on a Gemini capsule. And another one to make it a paraglider.

The idea behind it (as I understand it) was that capsules may be cheap, but the recovery fleet was not. The ability to land on solid ground, preferably an existing base, was supposed to save big money.

[radonek]

On Tuesday October 25, 2016 at 4:19 AM, DerekL1963 said:

Partly truth, partly nonsense.  Even before the DoD came onboard, they were  examining Shuttle designs with with lift (and therefore crossrange) capabilities - because it turns out that crossrange is a very handy thing to have.  Crossrange increases abort capability and widens recovery windows (sometimes even creating a window where one wouldn't have existed otherwise).

Partly truth, partly nonsense :-) Yes, NASA was after winged designs, but these were vastly different and had tens of miles crossrange at most. Final shuttle design with big heavy delta wing is direct result of thousand miles crossrange that was solely DoD requirement.

source: NASA
 

[DerekL1963]

17 hours ago, Bill Phil said:

But, even not considering that, we could've done all of the things the Shuttle did with capsules, save be reused.

Except of course all the things that capsules can't do.   Like supporting and operate an orbital science facility without requiring expensive support equipment as part of the facility, and then return said facility for re-use.  Like operating prototype equipment, and then returning said equipment for modification and re-use.  Like providing a stable support platform for orbital maintenance, and then returning the maintenance equipment for reuse.  Like...  well, I could go one but you see the pattern.  Your statement above is better phrased as "with capsules, we could do practically nothing the Shuttle could do, without throwing away billions of dollars worth of equipment".
 

17 hours ago, Bill Phil said:

Building the ISS? The Russians built a station sans Shuttle.

A station with a fraction of the capability of the ISS.
 

17 hours ago, Bill Phil said:

But how many capsules could you buy with the cost of refurbishing the Shuttle?

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.  Nobody sober and sane would ever confuse the two or try to substitute the former for the latter.  Yet, when it comes to space, such completely ludicrous apples and oranges comparisons occur regularly and apparently without anyone seeing the contradiction.

 

1 hour ago, Jestersage said:

As for carrying a experiment capsule, Shenzhou's Orbital Module would like to say ni'hao.

Unless they've invented some kind of magical time-and-space warping technology...  the capacity of Shenzhou's orbital module, like Soyuz's, is minimal at best.

[Jestersage]

55 minutes ago, DerekL1963 said:

Unless they've invented some kind of magical time-and-space warping technology...  the capacity of Shenzhou's orbital module, like Soyuz's, is minimal at best.

We know even LESS about the Shenzhou, other than that it's based on Soyuz, with bigger (in comparison to Soyuz) Orbital module that carried its own Solar panels, controls, and thrusters and can fly on its own, and it allegedly "provide experimentation capability". The only thing confirmed is that one of the Orbital Module stayed up there by itself for few months for some experiment.

That being said, it's not a improbability, since Gemini MOL is a Spacelab in itself.

55 minutes ago, DerekL1963 said:

A station with a fraction of the capability of the ISS.

If we are tallkign about SpaceLab, it has at most an equivalent capability to Salyut.

If we are talking about ISS building (vs Mir, etc), it's the module itself, which I think is independent of Shuttle.

58 minutes 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.  Nobody sober and sane would ever confuse the two or try to substitute the former for the latter.  Yet, when it comes to space, such completely ludicrous apples and oranges comparisons occur regularly and apparently without anyone seeing the contradiction.

It's not just space program, In some place, you have politician confusing a bike and full-size pickup truck, and people keep voting them in three times. Oh, and some people believe that it's okay to cook with electricity only.