Transportation concepts for Mars exploration

The transportation aspects of astronaut travel to Mars are discussed. Alternative types of propulsion are examined, including mainline and ancillary chemical propulsion, electric propulsion, and nuclear thermal rocket propulsion. The possibility of remote propellant production is presented, focusing on the use of lunar liquid oxygen, Phobos propellants and Mars propellant production. Also, the way in which habitat models may be derived from Space Station modules or from other designs capitalizing on larger diameter payload envelopes for heavy-lift launch vehicles is considered.