Moons of Mars formed a large moon. Gravitational interactions between this moon and the outer ring formed Phobos and Deimos. Later, the large moon crashed into Mars, but the two small moons remained in orbit. This theory agrees with the fine-grained surface of the moons and their high porosity. The outer disk would create fine-grained material. While many Martian probes provided images and other data about Phobos and Deimos, only few were dedicated to these satellites and intended to perform a flyby or landing on the surface. Two probes under the Soviet Phobos program were successfully launched in 1988, but neither conducted the
Mars One for public viewing. Mars One initially estimated a one-way trip, excluding the cost of maintaining four astronauts on Mars until they die, at 6 billion USD. Lansdorp has declined questions regarding the cost estimate. A proposed global reality-TV show was intended to provide funds to finance the expedition, however, no such television show has emerged and no contracts have been signed. The astronaut selection process (with some public participation) was to be televised and continue on through the first years of living on Mars. Discussions between Endemol started in June 2014, producers of the "Big Brother" series, and Mars One