But the head of the Russian space agency, Yuri Koptev, said it was discussing candidates to become the next space tourist with the owner of the Soyuz spacecrafts, Interfax reported.

CNN: Russia 'plans more space tourism'

Effects stemming from the Earth's atmosphere, from ocean tides and from the solar wind of charged particles were all found to be too small to explain the spacecrafts' extra velocity.

ECONOMIST: Physics

In addition to his interest in neuroscience, Bezos has long funded a secretive aerospace company called Blue Origin, which made headlines in August when one of their unmanned spacecrafts blew up during a test flight.

FORBES: Bezos Donates $15 Million For Princeton Neuroscience Center

In 1999, CNN news anchor Lou Dobbs joined the ranks of hungry tech entrepreneurs by launching Space.com--an advertising-supported, newsy Web outfit aimed at space fanatics with a taste for Pathfinder spacecrafts and photos of Mars.

FORBES: Magazine Article