Discussion LKS inspired shuttle concept.

[Loru]

For some time I've been playing around with various spaceplane concepts I'd like to use in orbiter for "daily use". I put "Starchaser" on hold because I want crew shuttle first. I played around with various concepts and I ended up returning to Chelomei's LKS.

There something in that thing that draws me in.

Basically I want something in XR-2 class of complexity however current/near tech. That's why I ditched kero/lox/air jet-rocket hybrid engines, limited dV to 500m/s and came up with this. Basically it's slightly smaller LKS capable with crew of 2 + 6 passengers.

Here's what I've done today (airbrakes deployed):

Now question: Original LKS was intended to be lifted by Proton. Do you think it's viable to use inline configuration or safer would be to put it in some form of sidemount launch vehicle?

Any suggestions apriciated.

 

[Urwumpe]

The shape looks like it can be launched by an inline booster... but if you want to reach Orbit, you should better use something else than a Proton.

 

[ISProgram]

Now question: Original LKS was intended to be lifted by Proton. Do you think it's viable to use inline configuration or safer would be to put it in some form of sidemount launch vehicle?

Sidemount, Viable: YES, Safe: NO

Inline, Viable: YES, Safe: Safer than sidemount, at the very least.

 

[Loru]

The shape looks like it can be launched by an inline booster... but if you want to reach Orbit, you should better use something else than a Proton.

No Proton but question still stands. LKS concept had folding wings and I'm worried lift generated by wings far from COG during the launch could easilly tip rocket over or break it.

---------- Post added at 10:32 PM ---------- Previous post was at 10:23 PM ----------

Sidemount, Viable: YES, Safe: NO

Inline, Viable: YES, Safe: Safer than sidemount, at the very least.

Why do you think inline is safer than sidemount? Sidemount doesn't nescessary include SRBs.

 

[MaverickSawyer]

No Proton but question still stands. LKS concept had folding wings and I'm worried lift generated by wings far from COG during the launch could easilly tip rocket over or break it.

---------- Post added at 10:32 PM ---------- Previous post was at 10:23 PM ----------



Why do you think inline is safer than sidemount? Sidemount doesn't nescessary include SRBs.

Abort is simpler. The system that woo482 used for his shuttle atop the earlier Themis version is a good example of how easy it would be. Foldi g wings, though, would be mandatory for stability.

 

[K_Jameson]

In my understanding, and after intense discussions at the old times of the Eridanus development, sidemount is by far preferable if your spaceplane has large fixed wings.
Obviously in this configuration, safety is a heavy concern if you haven't a launch abort system, because your orbiter's cockpit is pretty close to the propellant tanks.

 

[Loru]

That rules out SRBs I think. Ideally I'd like fully Kero/LOX LV however I may end up with Energia like solution (Kero/LOX boosters + LH2/LOX core).

 

[Urwumpe]

The only big advantage of sidemounting payloads is the high of the stack. The Space Shuttle did not really have any advantage in safety by being a sidemount, quite contrary in its actual implementation. But from the ground operations perspective, sidemount was perfect. The payload bay was only 20 meters above ground, inline it would have been 50 meters higher. Also, most important connections had been very close together (at the aft end), which greatly simplified the launch operations.

Since this vehicle is significant smaller than the Shuttle and has no large payload bay to use, mounting it inline is not coming with huge ground operation problems.

Of course, if you care about how to get the rocket assembled and moved to the launch pad, side-mount might still make things a lot easier.

 

[PhantomCruiser]

I thought the LKS wings were in a folded condition when launched. I have a picture somewhere with LKS and MAKS side-by-side, with both craft using an in-line launch configuration they both had their wings folded.

I'm a bigger fan of the Mira airlaunching MAKS, but mainly just for the John Wayne factor.

 

[ISProgram]

Why do you think inline is safer than sidemount? Sidemount doesn't nescessary include SRBs.

When I said that inline is safer than sidemount, I was alluding to the fact that for a spaceplane, sidemount seems riskier than inline architectures.

STS-107 is the obvious example. A sidemount capsule seems like it would be safer.

 

[MaverickSawyer]

When I said that inline is safer than sidemount, I was alluding to the fact that for a spaceplane, sidemount seems riskier than inline architectures.

STS-107 is the obvious example. A sidemount capsule seems like it would be safer.

Eridanus has a two-pronged approach to fix the sidemount issues, if memory serves: A conformal shield that protects the TPS from debris strikes, and a detachable crew compartment attached to a LES tower.

 

[fred18]

I think the other advantage for the space shuttle was that the SSMEs were recoverable and of course the only way to have this was to have it sidemounted.

Anyway, as other said, from a safety point of view surely inline is safer.

 

[Loru]

I thought the LKS wings were in a folded condition when launched.

Yes but it's LKS inspired shuttle not LKS itself. I ditched folding wings to reduce craft's complexity. Without folding wigs or fairing there will be tremendous forces acting on the rocket.

STS-107 is the obvious example. A sidemount capsule seems like it would be safer.

Foam strikes were mostly caused I think by vibrations induced by SRBs. Since I plan all liquid fuel LV, risk is greatly reduced.

 

[N_Molson]

mounting it inline is not coming with huge ground operation problems.

Especially given that Russians assemble their rockets horizontally, then put the whole thing on an erector (that was even true for the N1).

I'd try a multi-core version of Angara as a launcher.

 

[ISProgram]

Foam strikes were mostly caused I think by vibrations induced by SRBs. Since I plan all liquid fuel LV, risk is greatly reduced.

From what I was aware, the ET foam was in fact weakened by thermal flexing during propellant filling, creating cracks. Though the vibration environment from the SRBs almost certainly contributed. Ice breaking off the vehicle during liftoff is also still an issue.


The Atlas V might be a decent launch vehicle, though without SRBs, the triple-core configuration becomes necessary.

 

[Loru]

Made a quick test in silverbird's calculation and I ended up with LH2/LOX core with ~1MN engine along with 2 RD170 powered boosters.

Here are numbers and tank size visualisation.

 

[Urwumpe]

Sounds like an Energia-M to me, which was two RD-170 boosters and a single RD-0120M engine (2MN thrust).

http://www.astronautix.com/lvs/energiam.htm

But your empty masses are pretty low in comparison.

 

[K_Jameson]

Loru, wh you can't size your orbiter for already existing rockets of your inventory instead of making new rockets every time?

 

[Urwumpe]

Loru, wh you can't size your orbiter for already existing rockets of your inventory instead of making new rockets every time?

Because it would be only half as much fun? :lol:

 

[K_Jameson]

Sure, but it would be more realistic.