Cosmopolis XXI

"Explorer (space plane)" redirects here. For the Johnson/KSC NASA full sized mock-up, see Space Shuttle Explorer. For the fictional orbiter Explorer in the 2013 film, see Gravity (2013 film). For the fictional orbiter Independence in the 1998 film, see Armageddon (1998 film).

Cosmopolis XXI was a late 2000s Russian concept launch vehicle billed as a space tourism vehicle, similar to Mojave Aerospace's Tier One program. Designed and built by the Myasishchev Design Bureau, it would use the M-55X launch aircraft (derived from Myasishchev M-55), and the proposed C-21 spaceplane or its successor the Explorer. It would be a TSTSO (Two-Stage to SubOrbit) launch platform.

The Explorer spaceplane is a suborbital tourist spaceplane based on the C-21 design. The plane was being developed by Space Adventures with the Russian Federal Space Agency and was intended to carry 3 passengers. It is to be air-launched by carrier aircraft from a Space Adventures spaceport. Space Adventures abandoned the Explorer project in 2010 because "it got too expensive."^[1] It is unclear if Russia continues its development.