Build a better Shuttle

[magnemoe]

7 hours ago, Zeiss Ikon said:

Venture Star was to have a linear aerospike main engine, so wouldn't need vacuum optimization.  And there were a bunch of smart people who thought they could make it fly to orbit on its own, though they admitted it wouldn't have much in the way of payload fraction.

I know, aerospikes are nice if pressure changes during trajectory, problem is the high fuel fraction required for an ssto makes it very unpractical. 
And if you get it to work you has to push the envelope very far so you end up with an hangar queen who require lots of maintenance 
With dual stage you escape this issue, 

 

[Bill Phil]

7 hours ago, Capt. Hunt said:

My understanding is the extra large payload bay was more or less a side effect of the fuselage being stretched to accommodate larger wings to increase the crossrange capability. 

I suspect that the boosters on your design are more expensive then the entire orbiter, in which case it does become economical to recover them.  The real shuttle SRBs were just made "reusable" so that NASA could claim that "most" of the craft was reusable, in reality, since they were basically stacked steel tubes filled with solid fuel, they were one of the cheaper components.  The SSMEs on the other hand, were among the most expensive components.

The cargo bay was made bigger to accommodate the future reconnaissance satellites that the USAF had planned. The the USAF developed smaller/better satellites... The original payload design was ten tonnes, if I recall. The USAF needed a few things: more payload, more payload space, more cross range, and polar orbit capability.

[DDE]

7 hours ago, kerbiloid said:

Or this way.

  Hide contents

 

https://translate.google.ru/translate?sl=ru&tl=en&js=y&prev=_t&hl=ru&ie=UTF-8&u=http%3A%2F%2Fwww.buran.ru%2Fhtm%2Fcliper05.htm&edit-text=

To spare the ugly translation: this is a proposed upgraded version of the TKS spacecraft and its return vehicle. It has a hatch right through the heatshield, like the Blue Gemini.

Just a broad variety of trunks and main propulsion units; the front mounts a combination of a regular LES mast and a retrorocket and extra life support package.

[kerbiloid]

Main idea is: a single-use service module behind, rather than ugly sphere on the nose.

P.S.
Is at all the service part (docking node, toilet, etc) to be reusable?

If the ship spends several months docked to the station, in vacuum, +/-100 kelvins every turn, etc.
Remember the first American EVA when the airlock door spring got welded after 20 minutes being opened.

Stressing the node by its 15-20 t body. Using the toilet instead of a station toilet. Using all the service module like a trash can.
Engines and RCS, used instead of the station own engines, spending their lifetime.

FGB+VA looks much more realistic design. TKS/Big Gemini.

P.P.S.
This sketch is very fictional. The artist mixed parts of TKS and TKS-based modules.

Edited May 10, 2017 by kerbiloid

[KAL 9000]

I'm surprised no one's mentioned nuclear thermal turbojets. The use literally no fuel in-atmo, and are incredibly efficient in vacuum. You could easily build a reusable SSTO spaceplane with them, even in the real world. 

The technology is mostly there. The only problem is the public is unreasonably terrified of anything with the word "nuclear" in it.

[DDE]

19 minutes ago, KAL 9000 said:

I'm surprised no one's mentioned nuclear thermal turbojets. The use literally no fuel in-atmo, and are incredibly efficient in vacuum. You could easily build a reusable SSTO spaceplane with them, even in the real world. 

The technology is mostly there. The only problem is the public is unreasonably terrified of anything with the word "nuclear" in it.

I haven't ever heard of an actual design that combined an airbreather an a NERVA, though.

[_Augustus_]

1 hour ago, KAL 9000 said:

The only problem is the public is unreasonably terrified of anything with the word "nuclear" in it.

This also holds back NERVA, Orion/Medusa, and nuclear power plants....

[Bill Phil]

2 hours ago, KAL 9000 said:

I'm surprised no one's mentioned nuclear thermal turbojets. The use literally no fuel in-atmo, and are incredibly efficient in vacuum. You could easily build a reusable SSTO spaceplane with them, even in the real world. 

The technology is mostly there. The only problem is the public is unreasonably terrified of anything with the word "nuclear" in it.

Power to weight of the atmo engines are generally far too low. This isn't a big issue it's planes, of course.

LANTR, however...

[KAL 9000]

22 hours ago, Bill Phil said:

Power to weight of the atmo engines are generally far too low. This isn't a big issue it's planes, of course.

LANTR, however...

Exactly! Plane takeoff and landing! 

[DDE]

On ‎10‎.‎05‎.‎2017 at 11:09 PM, Bill Phil said:

Power to weight of the atmo engines are generally far too low. This isn't a big issue it's planes, of course.

LANTR, however...

NERVA is significantly constrained by its design. There may be hotter equivalents that might achieve a TWR of 4.

[shynung]

1 hour ago, DDE said:

NERVA is significantly constrained by its design

Not if you can pulse it like a TRIGA reactor.

No, I'm not talking about the infamous Orion.

[53miner53]

Similar main launch craft to the Shuttle IIc concept: crew cabin at the front with LES, cargo bay behind it. I would also have some fuel for the main engines on board for higher altitude aborts, and be able to glide to various runways if need be. Main engines can be placed in cargo bay and jet engines mounted in their place to facilitate orbiter transportation. Lunar rated heat shielding so it can launch things directly to the Moon or bring people directly to the Moon

Cargo shuttle with higher cargo capacity and no crew for when you need to bring a heavy payload. 

Also, fully reusable, main engine switching between tanks and shuttles for shorter turnaround time while being able to overhaul main engines between flights, and no SRBs.

[wumpus]

On 5/12/2017 at 1:35 PM, shynung said:

Not if you can pulse it like a TRIGA reactor.

No, I'm not talking about the infamous Orion.

Interesting (and a long, long, way from space).  I suspect the ability to quickly quench the reaction (assuming it can, I only did a quick read through and lack the nuclear physics to know) would be the most valuable feature (compared to other nuclear rockets).  Note that hydrogen's wonderfullness as a fuel tends to decrease after escaping Earth's gravity well.  That stuff simply doesn't like staying in the fuel tank.

[DDE]

On ‎12‎.‎05‎.‎2017 at 8:35 PM, shynung said:

Not if you can pulse it like a TRIGA reactor.

No, I'm not talking about the infamous Orion.

I know that one and it's not what I mean. NERVA was constrained by the choice of pressure vessel and fuel assembly design and materials; even within the constraints of a solid-core design higher Isp and thermal output (thrust) could be achieved.

[sevenperforce]

If you're talking about airbreathing NERVAs, there's always Project Pluto.

[tater]

I would imagine the regulatory issues around nukes for a LV would be... non-trivial. That's even with fracturing no longer an issue.

Edited May 14, 2017 by tater

[Nothalogh]

On 4/23/2017 at 11:08 PM, sevenperforce said:

how would you go about it?

Eliminate the cargo bay

[Matuchkin]

Well idk. I think our "shuttle mk2" needs:

a) Maximal usage of efficiency (anything it takes to be more efficient)

b) Full recoverability (no orange tanks here)

c) No payload jettison (payload will have to be dropped into ocean and refurbished under huge costs)

d) Crew space and a cargo bay

I think a sort of lift utilising vehicle (plane?) is useful here, as it can fit a bay, cockpit, and can land fairly easily. Here's a vague idea:

- Vehicle has the form factor of a hypersonic aircraft.

- Vehicle has moving wings in order to utilise as much lift as possible at all speeds.

- Cockpit+crew section in front, cargo bay in rear.

- extra utilities (solar panels/generators, etc) ingrained into wing base.

Main engines: rocket powered, gas generator cycle. Initial TWR below 1.

OMS: hypergolic.

 

Flight plans?

1. Vehicle is launched under an aircraft (presumably a fast, high altitude military aircraft like the B1 Lancer).

2. After sufficient altitude and speed is reached, aircraft is released.

3. Main engines ignite. As TWR approaches 1, aircraft does not pitch up (focus on gaining speed/momentum for the fling into orbit).

4. TWR passes 1. Aircraft pitches up according to most efficient planned flight path.

5. Apoapsis reaches somewhere around 200km. Aircraft starts slowly leveling out.

6. MECO. Aircraft instantly ignites OMS to finish burn to orbit.

7. Low orbit established. Orbital operations commence and end.

8. Aircraft reenters atmosphere at sufficient angle. Reentry/landing procedure similar to that of space shuttle.

9. Landing on runway.

 

This will be a very frantic, precision-based launch. It will also manage to barely get the vehicle to LEO. However, in the end it will be in orbit, from which it will have more freedom. Plus, we will have a system that is completely, 100% reusable.

[magnemoe]

1 hour ago, Matuchkin said:

Well idk. I think our "shuttle mk2" needs:

a) Maximal usage of efficiency (anything it takes to be more efficient)

b) Full recoverability (no orange tanks here)

c) No payload jettison (payload will have to be dropped into ocean and refurbished under huge costs)

d) Crew space and a cargo bay

I think a sort of lift utilising vehicle (plane?) is useful here, as it can fit a bay, cockpit, and can land fairly easily. Here's a vague idea:

- Vehicle has the form factor of a hypersonic aircraft.

- Vehicle has moving wings in order to utilise as much lift as possible at all speeds.

- Cockpit+crew section in front, cargo bay in rear.

- extra utilities (solar panels/generators, etc) ingrained into wing base.

Main engines: rocket powered, gas generator cycle. Initial TWR below 1.

OMS: hypergolic.

 

Flight plans?

1. Vehicle is launched under an aircraft (presumably a fast, high altitude military aircraft like the B1 Lancer).

2. After sufficient altitude and speed is reached, aircraft is released.

3. Main engines ignite. As TWR approaches 1, aircraft does not pitch up (focus on gaining speed/momentum for the fling into orbit).

4. TWR passes 1. Aircraft pitches up according to most efficient planned flight path.

5. Apoapsis reaches somewhere around 200km. Aircraft starts slowly leveling out.

6. MECO. Aircraft instantly ignites OMS to finish burn to orbit.

7. Low orbit established. Orbital operations commence and end.

8. Aircraft reenters atmosphere at sufficient angle. Reentry/landing procedure similar to that of space shuttle.

9. Landing on runway.

 

This will be a very frantic, precision-based launch. It will also manage to barely get the vehicle to LEO. However, in the end it will be in orbit, from which it will have more freedom. Plus, we will have a system that is completely, 100% reusable.

Plane launch is an old idea, it has some issues, as said in other treads main benefit is that you can start with an vacuum optimized engine. 
Exception is if you have an very fast carrier plane, B1 don't have high cargo capacity and is hardly supersonic
Now how slower the first stage is how larger does the shuttle has to be. 
Think you have to reach above 4.000 km/h for this to make sense. 
Problem is that supersonic / hypersonic separation is hard.
Building an large high supersonic/ hypersonic plane is also very expensive, you could probably save some having an rocket engine on plane taking you from mach 3 to 5-6 and edge of space, here separation is easier. 

Still using an recoverable first stage like falcon9 will be far cheaper to develop. Was another tread about this, You would probably also want storable propellant for orbital use if you want to stay up some time. I would also reduce the cargo bay and cargo capacity as its an overkill. Optionally having an unmanned version for larger loads. 
 

[DDE]

On ‎20‎.‎05‎.‎2017 at 4:05 PM, Matuchkin said:

- Vehicle has moving wings in order to utilise as much lift as possible at all speeds.

Variable-geometry wings appear to be a dead end. They were popular back before the deployment of fourth-generation fighters with their advanced aerodynamics and fly-by-wire.

On ‎20‎.‎05‎.‎2017 at 4:05 PM, Matuchkin said:

OMS: hypergolic.

I think a lot can be saved by using a kerolox system for boost, OMS and RCS.

It's not unprecedented.

[shynung]

2 hours ago, DDE said:

I think a lot can be saved by using a kerolox system for boost, OMS and RCS.

RCS and OMS generally used hypergolics because the engines that use them can be throttled very far down, and can start and stop nearly instantly, which is critical for controlling spacecraft orientation. Using propellants that need external ignition systems may introduce delays into the operation of the RCS/OMS that degrades the craft's orientation capability.

 

[Matuchkin]

4 hours ago, DDE said:

Variable-geometry wings appear to be a dead end. They were popular back before the deployment of fourth-generation fighters with their advanced aerodynamics and fly-by-wire.

Yeah, but we're not building a fighter. We're creating a shuttle that has to exploit literally all atmosphere and speed conditions. There has to be some malleability in the design for that to happen seamlessly, right?

Edited May 23, 2017 by Matuchkin

[sevenperforce]

3 hours ago, Matuchkin said:

Yeah, but we're not building a fighter. We're creating a shuttle that has to exploit literally all atmosphere and speed conditions. There has to be some malleability in the design for that to happen seamlessly, right?

Not really, I don't think. Compared to a modern fighter, a glide-down shuttle has a very limited range of conditions. There's virtually no variation in descent profile; the only variables are weight (in case you're bringing downmass home) and crossrange path.

Quote

Main engines: rocket powered, gas generator cycle. Initial TWR below 1.

OMS: hypergolic.

Why would you go for a separate OMS system at all? The only reason the Shuttle used OMS was to avoid having to crossfeed the SSMEs from the ET and from an internal tank. If you're already carrying your tank internally, this advantage goes away.

5 hours ago, shynung said:

RCS and OMS generally used hypergolics because the engines that use them can be throttled very far down, and can start and stop nearly instantly, which is critical for controlling spacecraft orientation. Using propellants that need external ignition systems may introduce delays into the operation of the RCS/OMS that degrades the craft's orientation capability.

Catalyzed H2O2/RP-1 is a better combo, imho. High TWR, great throttle range, room-temp, decent ISP, etc.; and storable for reasonably long enough.

You can even use the peroxide as the restartable ignition system for a kerolox engine (booster or otherwise).

Edited May 23, 2017 by sevenperforce

[shynung]

48 minutes ago, sevenperforce said:

Catalyzed H2O2/RP-1 is a better combo, imho. High TWR, great throttle range, room-temp, decent ISP, etc.; and storable for reasonably long enough.

You can even use the peroxide as the restartable ignition system for a kerolox engine (booster or otherwise).

Vouching for this combo too, for the same reasons. Might also upgrade to methane/peroxide if ISRU capability is considered, just need to have a stock of catalysts (2-ethylanthraquinone and palladium) accessible.

[DDE]

3 hours ago, sevenperforce said:

Catalyzed H2O2/RP-1 is a better combo, imho. High TWR, great throttle range, room-temp, decent ISP, etc.; and storable for reasonably long enough.

You can even use the peroxide as the restartable ignition system for a kerolox engine (booster or otherwise).

Or you can have regular liquid oxygen for even slightly higher ISP. 30 days orbital life is good enough for a crew-cargo ferry, and I imagine there are good reasons why HTP as an oxidizer has been largely ditched.

8 hours ago, shynung said:

RCS and OMS generally used hypergolics because the engines that use them can be throttled very far down, and can start and stop nearly instantly, which is critical for controlling spacecraft orientation. Using propellants that need external ignition systems may introduce delays into the operation of the RCS

Looks fast enough.

I'm going to go look for actual tech specs.

And that was apparently regular gasoline.