The version that ended up in Australia was not orbit capable. It was an aerodynamic test vehicle used as a landing trainer. It was equipped with
four jet engines at the tail so that pilots could make touch-and-go landings to practice landing the orbiter.
"The program also included six full-scale mock-ups used to test a variety of manufacturing, assembly, and flying quality characteristics as well as
handling procedures. Among these was a piloted flight test vehicle
fitted with four jet engines and capable of taking off under its own power. The "analog Buran," as it was known, was used to make repeated landings
and collect data needed to develop an autopilot and automated landing system. This vehicle was later put on display for over a year in Sydney,
Australia, for the 2000 Olympics. The owners actually attempted to auction it off for $6 million through a Los Angeles radio station, but no buyers
were found, and it is believed that the vehicle still remains in Australia."
You can learn more about it here:
www.meniscus.net...
www.aerospaceweb.org...
The one on display is Gorkiy Park in Moscow was a full-scale mock-up. It was a structural test article used to evaluate the loads on the airframe.
Additional information on its fate can be found here:
aeroweb.lucia.it...
As far as space-worthy craft go, a total of five were planned. The first two were named Buran and Ptichka. Buran made the only trip into space but
was damaged on re-entry. Rumors say that it could not be repaired and was no longer flyable. It was placed in storage at Baikonur and was probably
the one lost in the collapse of the hangar in 2002.
Ptichka was the second craft and was due to make an unmanned flight in 1991 but never did so. It was eventually to be upgraded to carry a human crew,
but I don't believe it was completed. It was also stored at Baikonur, but I have been unable to determine its ultimate fate.
The third unnamed vehicle was due to be the first to make a manned flight, but I believe only the external shell was built and the interior was never
completed. It was also put into storage, perhaps in Moscow, but I haven't found any conclusive information.
The fourth and fifth vehicles were under construction but stopped in the late 80s or early 90s. The incomplete vehicles were scrapped at the
production site.