Actually, the Ariane 5
was designed to accomodate a European space shuttle called
Hermes. Hermes would have been much smaller than the U.S. shuttle; although the Hermes design
went through a number of iterations before finally being cancelled, elements common to all designs include accomodation for a crew of anywhere from 3
to 6 and a payload in the region of ~4500 kg. There was no open-to-space payload bay as in the U.S. shuttle. Hermes would have been launched on the
top of an Ariane 5, a system which would have made Hermes immune to the foam-strike problems inherent to the parallel-payload system we see on the
STS.
Funding for the Hermes program was approved by the ESA in 1987, but the program ultimately petered out in 1992. Design changes made after the
Challenger accident had upped the weight of the shuttle, and Hermes would have needed an uprated version of the already over-budget Ariane 5 to get to
orbit. The expense, as well as an inability on the part of France, Germany, and Italy to agree on ESA priorities, doomed Hermes. The Ariane 5
program continued much as before, and the legacy requirement of being able to loft Hermes to orbit is why the Ariane 5 has as much payload potential
as it does.
Which is too bad - it would have been a nifty little shuttle, in my opinion, something like what NASA wanted the U.S. shuttle to be before the Air
Force got involved with outrageous payload and crossrange demands.
It is also worth noting that other concepts for ESA manned space access were considered, including a
British design from 1987 called the Multi-Role Recovery Capsule that would have flown on a
variant of the Ariane 4.
As far as American programs go, after the Challenger incident NASA started to look for an alternative to the shuttle, in case the shuttle were
grounded or if the program had to be abandoned. What they came up with was a lifting body design called the
HL-20, which would have launched on the Titan IV at the time - if the program had continued
beyond the design stage, it could also presumably be launched today by a Delta IV Heavy, but that's heavy speculation. The truth is that NASA is
tied to the Shuttle both ideologically and - more importantly in my opinion - politically.
With private space flight all the rage today, there's plenty of activity on this front. Lockheed and Bigelow Aerospace are teaming to bring the
Atlas V up to
man-rated status, and the ESA will start launching Soyuz rockets from
Kourou
in the latter half of 2008. The Soyuz pad at Kourou is
being prepared to allow it to be easily modified to allow for manned launches, if that should occur at some later date.