This wacky guy, the MAKS (Многоцелевая авиационно-космическая система – Multi-purpose aerospace system)
was a project proposed in 1988, but cancelled in 1991. It would have been launched from an An-225 strategic airlifter, much like the NASA X-15 or Orbital ATK Pegasus, and included a crew of between two and six. The launch configuration would be similar to the Shuttle Carrier Aircraft, where the orbiter (and in the case of MAKS, the fuel tank) would be strapped to the top of the An-225 and launched from there.
Had the program developed into an actual spacecraft, it would’ve weighted 275 metric tons, and would be capable of carrying 7 metric ton payloads into Low Earth Orbit. There would have been three varients: the MAKS-OS, the standard configuration; MAKS-T, with upgraded payload capacity (18 tons); and MAKS-M, a version that included the fuel tank inside the orbiter itself.
Russia has considered reviving the MAKS program since January 2010, but nothing more has developed since space.com reported that in June of 2010.