Ariane Reusable (Ariane X) VTVL rocket proposed in 1981

[Pipcard]

Michel Van mentioned this seemingly obscure proposal from Messerschmitt-Bölkow-Blohm for a reusable VTVL Ariane rocket on this forum (Flightglobal archive) and secretprojects.co.uk.

Notice that it shares several features with a Falcon 9, but differs in other key aspects:
- Two-stage with engine commonality, a cluster of 9 engines on first stage (but with hydrolox)
- Common propellant tank diameters on both stages (but not for the outer mold line, and using clustered tanks on the first stage)
- Ballistic re-entry and apparent "hoverslam" of the first stage

Considering that ArianeGroup is currently researching VTVL reusability in the form of Callisto/Themis/Ariane Next in response to Falcon 9, why wasn't this adopted before? They saw STS (and tried to emulate it in the form of Hermes) before thinking that any reusable launch system wasn't worth it?

[libra]

They saw STS and thought any reusable launch system wasn't worth it?

It's a complicated story... yes, they saw STS, and their opinion of it was mixed even before Challenger. Just like the Soviet with Energiya Buran, the sceptics were only partially heard, and some kind of answer was still needed. It was kind of "You never know: NASA is so enthusiastic and confident with the Shuttle, better to develop some symmetrical answer just in case it succeeds... even if there are serious doubts over the viability of the whole thing."

Europe went the following way.

First, as far as the Shuttle orbiter go, early sketches of Hermes looked like miniature clones of it, to absurd level. I have a 1981 picture somewhere on my HD (thanks to Michel Van a loong time ago on another forum)  Hermes really looks like a subscale Columbia.

Now Ariane 5... http://www.capcomespace.net/dossiers/espace_europeen/ariane/index.htm

There were three major concepts by 1983.
-The 5-P (= Poudre = solid fuel)
- the 5-C (100% cryogenic like an early Delta IV)
- and the 5-R (Reference: to Ariane 44L)

You can see them there.


And in the end, the 5P concept carried the day and become the familiar Ariane 5. Note that an Ariane 5 with an Hermes on top has basically all the major elements of a Shuttle stack, except assembled a little differently
- SSME = Vulcain
- two big SRBs
- a big cryogenic core (more or less the External tank)
- an orbiter (Hermes)

That's was CNES / ESA most immediate answer to the Shuttle.

In 1997 they did tried to recover Ariane 5 SRB at sea, Shuttle style, but were only partially successfull; then Ariane 5 very troubled childhood until 2003 sunk the idea.

The studies shown here tried to tackle the only non-recoverable bit of the Ariane 5 - Hermes stack: the EPC, Etage Principal Cryogénique. Hermes was recoverable, so were the big SRBs, on paper at least.

So there were varied studies trying to turn the EPC (and the Vulcain) powering it into a reusable booster - either flyback, or vertical landing style.
Now the lure of hydrolox, and the difficulty in creating the Vulcain in the first place, were already tricky enough. Trying to make a flyback booster with a reusable Vulcain would have been quite complicated for Europe back then, plus all the doubts over the Shuttle... the studies were made, but only at very low level.