Apollo-Sigma uses the Saturn 1B, which is capable of delivering 21,000 kg to LEO. The payload is a Centaur D-1T kick stage with a 10-foot hemispherical capsule for a two man crew. The mass of the Centaur D-1T is 15,320 kg (1,830 kg inert + 13,490 kg propellant) and the mass of the capsule is 5,200 kg. The Apollo-Sigma vehicle only requires potable water, oxygen, food, and electrical power for seven days. Once reaching the Cynthia station at Earth-Moon L1 the ship is placed on standby and the crew transfers to the station to use the station’s life support. Total initial mass in LEO is 20,070 kg (well within Saturn 1B’s capacity). Total final mass is 6,680 kg (capsule + dry Centaur). Centaur specific impulse is 444 seconds. Mission delta-v is about 4,800 m/s. Margin for error is about 350 m/s at Cynthia arrival.