Cosmopolis XXI is a planned Russian vehicle that is 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 is being developed by Space Adventures with the Russian Federal Space Agency and is designed to carry 5 passengers. It is to be air-launched by carrier aircraft from a Space Adventures spaceport. The spaceport for the Explorer is being developed with Prodea (the company of Anousheh and Amir Ansari, who funded the Ansari X-Prize) in the United Arab Emirates, the Ras Al Khaimah spaceport.