Moons of Mars attention when Houston's claim was repeated in earnest by a Soviet scientist, Iosif Shklovsky, who, based on a later-disproven density estimate, suggested Phobos was a hollow metal shell. Searches have been conducted for additional satellites. In 2003, Scott S. Sheppard and David C. Jewitt surveyed nearly the entire Hill sphere of Mars for irregular satellites. However scattered light from Mars prevented them from searching the inner few arcminutes where the satellites Phobos and Deimos reside. No new satellites were found to an apparent limiting red magnitude of 23.5, which corresponds to radii of about 0.09 km using an albedo of
Mars One from any money earned from guest appearances (which would amount to a minimal portion of the estimated $6 billion required for the mission). Finally, despite being one of 100 finalists, Roche himself has never spoken to any Mars One employee or representative in person, and instead of psychological or psychometric testing as is normal for astronaut candidates (especially for a lengthy, one-way mission), his interview process consisted of a 10-minute Skype conversation. In April 2015, Mars One's CEO Bas Lansdorp admitted that their 12-year plan for landing humans on Mars by 2027 is mostly fiction. Robert Zubrin, advocate for crewed