Born: 20 April 1963, Moscow, Russia
Group: Energia Engineer Group 14 Supplemental (1999)
Kostenko is CEO of Russian based Orbital Technologies, which is working with Space Adventures (based in Virginia, USA) and the Russian Space Agency in hopes of building a commercial "space hotel". Kostenko is also Moscow VP of Space Adventures.
Kostenko served as the backup to American Gregory Olsen, at Olsen's request. He may best described as Russia's reluctant cosmonaut, really hoping that Olsen would fly. He is more comfortable in the business environment, although he says the training experience would prove valuable in future business dealings.