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 developing the technology needed, it is unclear what the astronauts would be training for. Mars One has stated that the teams selected will be undergoing a battery of training, ranging from psycho-social skills to engineering and scientific observation. Mars One funding comes from astronaut application fees, donations, undisclosed private investment, intellectual property (IP) rights, and mostly, the potential sale of future broadcasting rights. Over three quarters of the funds would reportedly go to concept design studies. Mars One states that "income from donations and merchandise have not been used to pay salaries". To date, no financial records have been released