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 is divided among the seven payloads as follows: In 2022, a robotic rover was proposed to be launched to Mars in order to scout a landing site for the 2027 lander and a site for the Mars One colony. At the same time, a communication satellite would be launched, enabling continuous communication with the future landed assets. In 2024, six cargo missions were proposed to be in close succession, consisting of two living units, two life-support units, and two supply units. A spacecraft transporting four astronauts was proposed to meet a transit vehicle bound for Mars. In 2025, the landing