Space Shuttle V2 Thought Experiment

[Nibb31]

38 minutes ago, Emperor of the Titan Squid said:

Why does everyone give up on spaceplanes?Also, i say no external tanks, remember the space shuttle? 

Because you don't need wings in space. In fact, you only need the wings for the last few minutes of the mission, and with those wings come landing gear, control surfaces, hydraulics, and super large area to protect with a TPS. And there goes your payload fraction...

I don't understand the fascination that some people have for winged space ships.

[SpaceplaneAddict]

We should just strap a newer, larger shuttle to the back of another, larger fuel tank, and the SRB's be replaced with Falcon Heavy boosters. The fuel tank is discarded, the shuttle oes on to perform orbital stuff, and the Falcon Heavy rockets fly back to base.

10 minutes ago, Nibb31 said:

I don't understand the fascination that some people have for winged space ships

They're a billion billion billion percent cooler. And are easy to recover.

[Nibb31]

 

2 minutes ago, SpaceplaneAddict said:

We should just strap a newer, larger shuttle to the back of another, larger fuel tank, and the SRB's be replaced with Falcon Heavy boosters. The fuel tank is discarded, the shuttle oes on to perform orbital stuff, and the Falcon Heavy rockets fly back to base.

How does that help with all the huge design flaws of a side-mounted spaceplane ?

Edited February 7, 2016 by Nibb31

[fredinno]

3 hours ago, shynung said:

11 hours ago, fredinno said:

rk?

This is probably one of the cheaper approaches: reuse old tech. We still have the designs, we just have to recreate the tooling to make them. Still a lot of work there, but it's got a decent headstart compared to all-new designs.

That was actually intended to be for another thread, discussing the feasability of such a design.

Nowadays, you'd skip that entirely and just attach a Shuttle to SLS+ F-1 LRBs. But yeah, it has a pretty decent headstart.... if it was made in the 70s.

3 hours ago, shynung said:

Not exactly a problem. Mishmash rockets are fine.

The thing is, the Shuttle could carry 90T to LEO- if you removed the shuttle, added an engine pod, and added an upper stage on  top of it. https://en.wikipedia.org/wiki/Shuttle-Derived_Heavy_Lift_Launch_Vehicle

So, yes, it kind of IS cheating.

[Nibb31]

1 hour ago, SpaceplaneAddict said:

They're a billion billion billion percent cooler. And are easy to recover.

Vertical landing is a billion billion billion percent cooler, and more elegant engineering. Look at the effort that went into making the Shuttle recoverable, compared to the effort that went into making the F9 recoverable.

[tater]

1 hour ago, fredinno said:

The thing is, the Shuttle could carry 90T to LEO- if you removed the shuttle, added an engine pod, and added an upper stage on  top of it. https://en.wikipedia.org/wiki/Shuttle-Derived_Heavy_Lift_Launch_Vehicle

So, yes, it kind of IS cheating.

The shuttle loaded was ~90T-100T(max), it could carry only 25T. So 75% of the payload was "spaceplane." Because spaceplane.

As a small, crew vehicle (Sierra Nevada) it can make sense assuming multiple possible landing sites worldwide for emergencies. As a giant pig of a thing like Shuttle... no. For HLVs that are reusable, some of the old VTVL ideas looked at decades ago might make more sense. That's assuming you have some use for an HLV in the first place.

[Bill Phil]

34 minutes ago, Nibb31 said:

Vertical landing is a billion billion billion percent cooler, and more elegant engineering. Look at the effort that went into making the Shuttle recoverable, compared to the effort that went into making the F9 recoverable.

I wouldn't say it's more elegant. It's harder. 

But it is cooler, since almost every sci fi show/movie has it.

2 hours ago, Nibb31 said:

Because you don't need wings in space. In fact, you only need the wings for the last few minutes of the mission, and with those wings come landing gear, control surfaces, hydraulics, and super large area to protect with a TPS. And there goes your payload fraction...

I don't understand the fascination that some people have for winged space ships.

The wings are still useful for surface area. If you wanted to maximize power, you could put a bunch of solar panels in them, or radiators to have better cooling. But more components is still more complex.

[Nothalogh]

>STS v2.0

Its a bad idea, majority of cargo transport is one way. 

Would be useful as a passenger transport though

[billbobjebkirk]

13 hours ago, fredinno said:

Except you know, SLS Block I.

The SLS is over 70 TTO, I was talking about under 70.

[DerekL1963]

1 hour ago, Nibb31 said:

Vertical landing is a billion billion billion percent cooler, and more elegant engineering. Look at the effort that went into making the Shuttle recoverable, compared to the effort that went into making the F9 recoverable.

If the F9 was recoverable - that would be a valid question.   But it's not.   Only the first stage is recoverable, from much lower speeds and altitudes, and carrying zero payload or passengers.   You're trying to compare apples and the thing least like apples you can possibly imagine.

[tater]

The actual cost per kg for Shuttle (actual payload, not counting the Orbiter) was ~$60,000. (total cost of program over total carried payload mass)

If the job of shuttle had just been to shuttle crew someplace, it would've looked more like Dream Chaser (which is a more sensible spaceplane design).

[shynung]

3 hours ago, fredinno said:

The thing is, the Shuttle could carry 90T to LEO- if you removed the shuttle, added an engine pod, and added an upper stage on  top of it. https://en.wikipedia.org/wiki/Shuttle-Derived_Heavy_Lift_Launch_Vehicle

So, yes, it kind of IS cheating.

Except the SD-HLLV is a non-reusable design. All the components - SRBs, external tank, and the SSMEs - are disposed of like a regular rocket. Since we're looking for something that's mostly reusable, that really IS cheating.

If we approach by redesigning the HLLV, there's plenty of extra mass available. The goal was a 60-ton-to-LEO rocket, and this can lift 90. I'd say sparing 10 tons on reusability-related equipment could go a long way.

So I think it could go like this: Space Shuttle External Tank with a detachable engine mount on the bottom, with SSMEs bolted on them, aided by Baikal-style flyback boosters that glide back to the runway after it's spent (so all propellant is available to lift the payload, instead of being used for propulsive landing), topped by either a cheap hypergolic upper stage, or a reusable nuclear thermal rocket. At first stage MECO, the engine mounts detach from the tank, deploy an inflatable heat shield, and reenter, and lands on parachutes.

Edited February 7, 2016 by shynung

[tater]

The point should not be to design a vehicle of a certain type, but to have a mission that requires a certain total mass be delivered wherever, then figure out what the best way to do that is.

Say the mission is landing a habitat, rover, and crew lander on the Moon, and returning them to earth after a few months of work on the lunar surface. Then you figure out what the best way to do that is. If the goal is just LEO, what is that LEO goal? Sending crew to ISS, or payloads? The solutions are entirely different.

 

[shynung]

The mission is a simple cargo run. Here is the OP:

On 5/12/2015 at 2:05 AM, shynung said:

Suppose that in the near-future, a space launch service agency/corporation wants to construct a high-capacity semi-(or fully)reusable space launch system, with the following design requirements:

-60 tons to LEO payload.

-Staging permitted.

-No more than 20% of hardware by mass is discarded in each mission. 80% must be recovered.

-Any discarded hardware must be of low value (spent SRBs, empty fuel tanks sans engine, fairings).

-Capable of precision landing. Either runways or landing pads are acceptable. Maximum reentry G-loads capped at 4G.

-Cargo bay large enough for 2 standard 40-foot intermodal containers.

-Crew optional. LES required, ejects only the crew cabin.

-Propellant primarily LH2/kerosene-LOX, other (hypergolic/exotic fuels, nuclear) propulsion systems acceptable above 100km.

-Price-per-kilogram must be comparable to currently-available launch vehicles.

-Post-landing maintenance costs must be cheaper than building costs for a single unit.

A single vehicle is expected to launch 4-5 mission per year (about one launch every 3 months), and to last at least 20 flights (4 year's worth of use).

[SpaceplaneAddict]

3 hours ago, Nibb31 said:

Vertical landing is a billion billion billion percent cooler, and more elegant engineering. Look at the effort that went into making the Shuttle recoverable, compared to the effort that went into making the F9 recoverable.

Making the shuttle more fulfilling, and plus, flying in from orbit. You can't get cooler than that.

[tater]

The Shuttle Orbiter cost about 4% of the total program cost, so the post-landing costs hugely exceeded the cost of a single vehicle.

Note that for 60T to LEO, you'd need 3 Shuttle launches, so that's 4.5 billion. A slightly spiffed Delta 4 Heavy would do that in 2 at 1/4 the price.

If FH costs are as claimed, it would take a single FH, plus a regular F9 launch, a ~29X savings. Even using the per launch figures for shuttle that ignore most of the actual costs, shuttle would still cost more. Any Shuttle V2 would need to be an order of magnitude cheaper to operate than the original to be even in the same ballpark.

[shynung]

Yes, it does. I'm wondering out loud what kind of design would suit that purpose well.

Also, even though I'm using the word 'Shuttle', I'm not implying a winged return vehicle. The thing doesn't have to come back in one giant vehicle. Stuff like fairings and fuel tanks can be thrown away - the returning parts are engines, crew cabins, the expensive stuff. Costs are down to maintaining the engines and manufacturing new tanks and fairings.

[tater]

Yeah, there can certainly be possible savings, though equipment savings need to include refurbishment and testing costs.

Aircraft are checked about every month of flight time (so every few months calendar time) in a check that takes just overnight. Every 1.5 years they get a check that might take a few weeks---the type of thing that might in fact be very short by the standards of Shuttle. If your launch pace is such that your ground crew is just "full time employed" busy 100% of the year, and the time to refurbish is low enough, then reuse starts showing real benefit.

Again to use Shuttle as an example, a single orbiter cost ~1.7 billion, and over the entire program launches ended up averaging 1.5 billion each.

[Nibb31]

1 hour ago, SpaceplaneAddict said:

Making the shuttle more fulfilling, and plus, flying in from orbit. You can't get cooler than that.

"Fulfilling" and "cool" are not relevant requirements for a national space program.

[Emperor of the Titan Squid]

What if we pack the wings with fuel? Also, Just FYI, my definition of spaceplane is horizontal take off.I understand your point though.I now know why spaceplanes aren't AS good.Still,SERV MURP is a good design.Consider it.

6 hours ago, Nibb31 said:

Because you don't need wings in space. In fact, you only need the wings for the last few minutes of the mission, and with those wings come landing gear, control surfaces, hydraulics, and super large area to protect with a TPS. And there goes your payload fraction...

I don't understand the fascination that some people have for winged space ships.

 

35 minutes ago, shynung said:

Yes, it does. I'm wondering out loud what kind of design would suit that purpose well.

Also, even though I'm using the word 'Shuttle', I'm not implying a winged return vehicle. The thing doesn't have to come back in one giant vehicle. Stuff like fairings and fuel tanks can be thrown away - the returning parts are engines, crew cabins, the expensive stuff. Costs are down to maintaining the engines and manufacturing new tanks and fairings.

Fuel tanks are too expensive to through away.(big ones,that is.)

[SpaceplaneAddict]

13 minutes ago, Nibb31 said:

"Fulfilling" and "cool" are not relevant requirements for a national space program.

When the public see's something they like, they support it. Support = Funds.

[Bill Phil]

7 minutes ago, SpaceplaneAddict said:

When the public see's something they like, they support it. Support = Funds.

And yet public support for the space program is pretty high. Higher than during the Apollo Era, in fact...

[SpaceplaneAddict]

2 minutes ago, Bill Phil said:

And yet public support for the space program is pretty high. Higher than during the Apollo Era, in fact...

Higher is better.

[fredinno]

 

4 hours ago, tater said:

The shuttle loaded was ~90T-100T(max), it could carry only 25T. So 75% of the payload was "spaceplane." Because spaceplane.

As a small, crew vehicle (Sierra Nevada) it can make sense assuming multiple possible landing sites worldwide for emergencies. As a giant pig of a thing like Shuttle... no. For HLVs that are reusable, some of the old VTVL ideas looked at decades ago might make more sense. That's assuming you have some use for an HLV in the first place.

Shuttles are actually useful if you can pull off reusability really well- then you can return satellites for repair on Earth, make reusable recoverable satellites, and return things like old space tugs and satellites that can no longer be used back to Earth for recycling/a museum home, which would in theory, reduce costs. The enormous downmass capacity would also be useful for space mining and manufacturing. And tourists tend to love spaceplanes.

 

The Shuttle's original designs, and the concept of a 2-stage reusable shuttle isn't really fundamentally flawed- NASA just pursued the idea 100 years too early. Only when you have a true space economy and very economical reuse does something like that make sense.

3 hours ago, DerekL1963 said:

If the F9 was recoverable - that would be a valid question.   But it's not.   Only the first stage is recoverable, from much lower speeds and altitudes, and carrying zero payload or passengers.   You're trying to compare apples and the thing least like apples you can possibly imagine.

Indeed, the rocket would likely have a 4-5m first stage diameter if 2nd stage reuse was pursued.

2 hours ago, shynung said:

Except the SD-HLLV is a non-reusable design. All the components - SRBs, external tank, and the SSMEs - are disposed of like a regular rocket. Since we're looking for something that's mostly reusable, that really IS cheating.

If we approach by redesigning the HLLV, there's plenty of extra mass available. The goal was a 60-ton-to-LEO rocket, and this can lift 90. I'd say sparing 10 tons on reusability-related equipment could go a long way.

So I think it could go like this: Space Shuttle External Tank with a detachable engine mount on the bottom, with SSMEs bolted on them, aided by Baikal-style flyback boosters that glide back to the runway after it's spent (so all propellant is available to lift the payload, instead of being used for propulsive landing), topped by either a cheap hypergolic upper stage, or a reusable nuclear thermal rocket. At first stage MECO, the engine mounts detach from the tank, deploy an inflatable heat shield, and reenter, and lands on parachutes.

I was responding to your statement that Energia could carry 100T to LEO. I responded that it could only do that when expendable, and with a upper stage, so it was cheating. It was not supposed to be reusable.

And what you propose would basically be a reusable SLS with a hypergol upper stage. BTW, Hypergols are not cheap anymore due to enivronmental and handling costs. And any design that needs NTRs is a unrealistic dream. I know KSPers love NTR, but still...

Today, you'd just use a SLS w/o upper stage (IUS would be used for MEO, GEO, and planetary robotic missions, while Exploration Upper Stage is used for manned lunar and asteroid missions.) with 2x F-1C Dynetics-esque boosters. These would land vertically via smaller landing engines (which can also serve as booster verniers). The SSMEs would be reused Vulcan-style, with helicopter recovery, while the core would be expendable. Even then, since Dynetics + SLS Block I could launch 120T to LEO, you would have a lot of payload capacity left over. So much, you might be able to just put a massive inflatable heat shield on the core, then return both the tanks and the engines via parafoil and horizontal landing on a runway. The deorbit burn would be done by disposable small solid motors. The boosters can't be reused like this since you would need jet engines to do so, and those would increase the complexity enormously.

1 hour ago, tater said:

The Shuttle Orbiter cost about 4% of the total program cost, so the post-landing costs hugely exceeded the cost of a single vehicle.

Note that for 60T to LEO, you'd need 3 Shuttle launches, so that's 4.5 billion. A slightly spiffed Delta 4 Heavy would do that in 2 at 1/4 the price.

If FH costs are as claimed, it would take a single FH, plus a regular F9 launch, a ~29X savings. Even using the per launch figures for shuttle that ignore most of the actual costs, shuttle would still cost more. Any Shuttle V2 would need to be an order of magnitude cheaper to operate than the original to be even in the same ballpark.

Actually, FH is only capable of ~50T to LEO disposable, and the payload fairing is too small and the upper stage engine with too low of a TWR for sending 50T to LEO in practice. Realistically, you'd need 2 FH-R for 60T to LEO.

52 minutes ago, shynung said:

Yes, it does. I'm wondering out loud what kind of design would suit that purpose well.

Also, even though I'm using the word 'Shuttle', I'm not implying a winged return vehicle. The thing doesn't have to come back in one giant vehicle. Stuff like fairings and fuel tanks can be thrown away - the returning parts are engines, crew cabins, the expensive stuff. Costs are down to maintaining the engines and manufacturing new tanks and fairings.

Actually, fuel tanks are about 45% of cost (excluding avionics). They are cheap in terms of mass-to cost ratio, but not in actual cost. However, disposing tanks are a good way of getting the most payload out of a RLV, while keeping costs down as much as possible.

16 minutes ago, Emperor of the Titan Squid said:

What if we pack the wings with fuel? Also, Just FYI, my definition of spaceplane is horizontal take off.I understand your point though.I now know why spaceplanes aren't AS good.Still,SERV MURP is a good design.Consider it.

 

Fuel tanks are too expensive to through away.(big ones,that is.)

Packing the wings with fuel adds a whole new level of complexity it's better not to bother.

[tater]

1 hour ago, Nibb31 said:

"Fulfilling" and "cool" are not relevant requirements for a national space program.

I could not disagree more. They are in fact the only requirements for manned flight, anyway.

For probes science is the purpose, but as a national program in a democratic society, both must secure funding.