My Hypothetical Launch Vehicle - TAL/CUS

[GigaG]

TAL/CUS stands for "Transatlantic Landing/Centaur Upper Stage" and is my concept for a partially reusable launch vehicle. It is probably idiotic, uneconomical and dangerous, but it might just be crazy enough to work.

The first stage (TAL stage) resembles a giant Shuttle orbiter. Rather than a cargo bay, it has a fuel tank inside - a tank a bit smaller than an ET to power a 3-engine cluster of SSMEs to a ballistic trajectory. Because this is not an ultra-heavy launch vehicle, we don't have any SRBs, or we use smaller SRBs that can be attached over the wings, as this is essentially a linear launch vehicle and we don't have anything under the wings to attach large Shuttle-type SRBs to.) The front end of the TAL stage is a nosecone, which is concealed inside the interstage fairing. Above this is a widened, shortened Centaur upper stage, and above this is the payload.

The rocket would work like any other, but the first stage would have an unusual return path. After MECO, the stage would remotely re-enter and land in Spain or another coastal area in Europe, with the intention that it can be loaded onto a barge and be brought back to KSC. Essentially, it would perform a Transoceanic Abort Landing (in this context, it is a Trans-Atlantic Landing, as this is not an abort - it is normal operation.) The Centaur is expendable, as Centaurs are.

Issues-

-Costs of moving a giant, precise rocket stage across stormy seas. The stage would be too big to use a Shuttle Carrier aircraft, and the SCA can't fly that far with a piggybacked payload anyways.

-Need suitable, long landing strip with boat access.

-Re-entry should not pass any populated areas. Zaragoza is pretty far inland. The TAL landing strips were not expected to be regularly used in the Shuttle era, but these will.

-The diplomatic issues of landing giant empty rocket stages on foreign territory.

Benefits-

-Reusability. particularly of the SSMEs

-The payload of a medium-sized Atlas V without the current controversial Russian engines.

-Can fly longer on the first stage than a "flyback" design.

Just a little thought experiment. Has this ever been proposed?

[Bill Phil]

So, kind if like the DC-3 shuttle concept? Except with an expendable upper stage?

[sgt_flyer]

One of the problems with this kind of launch, is that you'll be limited to launches to specific orbital angles (you won't be able to do a polar launch for example, because you need to stay lined up with your landing strip.)

Returning the thing by barge would be costly and lenghty (most reusable designs can only achieve rentability by having a high turnaround rate, so you'll almost be faster to partially refuel the first stage and launch it back to it's starting point. Nevertheless, you'll have to maintain several additionnal landing zones in other countries to be able to cover various launch angles (which would veery expensive - having classic 'airports' prepped for the shuttle's emergency transoceanic abort mode on each flight was already costly , you'll have to add to that a full logistic chain if you plan to do it on each launch)

You'll also need a correct weather on both ends at each launch.

Besides, the SSME's would be severely underperforming for this kind of mission :

They are built to sustain a very long burn in near vaccuum conditions (which is not the kind of conditions experienced by a first stage - so you'll have to make new nozzles adapted for it.)

And they don't have that mich thrust at sea level, compared to other LH2/LOX engines (so you'll need SRB's anyway)

The 3 SSME's, with their 1860kN of thrust at sea level each, would have a TWR < 1 if they where trying to only lift a fully fuelled external tank (625 tons) - without any upper stage or orbiter

(For comparison, a single RS-68A has more than 3000kN of thrust at sea level for a delta-IV rocket)

So, for your kind of first stage, i think it would be easier to start directly from a delta-IV rocket 1st stage and make it reusable instead of starting from the Space Shuttle subsystems

Now, if your first stage has a similar size and shape to a space shuttle, maybe you'll be able to use boeing's shuttle carrier plane to transport it

Edited December 27, 2014 by sgt_flyer

[Kryten]

There's already a design for a Delta IV first stage combined with a shortened Centaur, though. It's called 'Delta IV'.

[GigaG]

I was thinking that, about TWR. I just love SSMEs, I guess. Such a great engine. I guess I think of them as ground engines because of how they ignite, even though they do spend most of their burn time in vacuum or extremely thin air.

[moogoob]

I love that we're still using Centaurs. Workhorses, they are.

[MikeFox1]

I made this in KSP. Try it for yourself! CLICK / IMAGE