Buran was born dead, because it was so expensive, eats all money from programs it could launch.
Examples, Soviets planning space telescope like Hubble; martian sample return; long-duration heavy Venus rover.
Unfortunately, Soviet non-market economy was about 4-5 times smaller than US, so US have money for Shuttle payloads, but Soviets don't have.
BTW, Buran was by design much more expensive than Shuttle.
Because non-reusable parts of Shuttle where cheap SRB's and fuel tank, but expensive LOH-LOX engines saved.
On each launch of Buran sacrificed equivalent to three Zenith rockets (essentially, Energia was unificated with Zenith, side boosters where very similar to Zenith 1st stage, and central block was Hydrogen, but costs similar).
Examples, Soviets planning space telescope like Hubble; martian sample return; long-duration heavy Venus rover.
Unfortunately, Soviet non-market economy was about 4-5 times smaller than US, so US have money for Shuttle payloads, but Soviets don't have.
BTW, Buran was by design much more expensive than Shuttle.
Because non-reusable parts of Shuttle where cheap SRB's and fuel tank, but expensive LOH-LOX engines saved. On each launch of Buran sacrificed equivalent to three Zenith rockets (essentially, Energia was unificated with Zenith, side boosters where very similar to Zenith 1st stage, and central block was Hydrogen, but costs similar).