 to an “isolation half-module” added to the Space Station in 1998. The samples would enable scientists to identify any hazards in Mars’s surface materials and would aid engineers in the design of spacecraft, rovers, habitats, space suits, and tools.
Phase I would also include biomedical research on board the Space Station, which would reach Permanent Manned Configuration (PMC) in 1994. Almost immediately after it achieved PMC, NASA would add a Life Science Module. A six-person crew would then conduct a Mars mission simulation on board the Station that would last for the planned piloted sprint mission duration.
If the astronauts remained healthy after the simulation, then in 1996 NASA would begin development of a Mars sprint spacecraft lacking any provision for artificial gravity (that is, no part of it would rotate to create acceleration which the crew would feel as gravity). A module for housing Mars spacecraft assembly crews would join the Station in 2002, kicking off Phase II of SAIC’s Mars program. The cargo spacecraft for the first split/sprint mission would depart LEO during the 2003 low-energy Earth-Mars transfer opportunity.
If, on the other hand, biomedical researchers determined that the simulation crew had suffered harm, then NASA would add a “variable-gravity module” to the Station in 2001. Crews would conduct simulations in the spinning module to determine the minimum level of artificial gravity required to safeguard astronaut health. Development of an artificial-gravity sprint spacecraft would not commence until after the simulations ended in 2004. If the artificial-gravity sprint spacecraft needed as much development time as its no-gravity counterpart, then the first piloted Mars mission might not leave Earth until 2013. SAIC largely ignored this possibility.
Launching parts and propellants from Earth’s surface for the 238.5-metric-ton cargo spacecraft and its single 349.6-metric-ton reusable Orbital Transfer Vehicle (OTV) would require seven heavy-lift rocket launches. The cargo spacecraft would carry at the center of its 28-meter-diameter bowl-shaped Mars Orbit Insertion (MOI) aerobrake heat shield the mission’s two-stage, 60-metric-ton Mars Lander. Spherical tanks surrounding the Lander would hold the 82.5 tons of cryogenic liquid hydrogen and liquid oxygen propellants the piloted sprint spacecraft would need for return to Earth. The cargo spacecraft would also carry 4.2 metric tons of propellants for correcting its course during flight from Earth to Mars and 16.4 metric tons of propellants for circularizing its orbit after it aerobraked in Mars’s atmosphere. A 9.1-metric-ton cooling system would prevent the propellants from boiling and escaping.
On 9 June 2003, the 30.5-meter-long cargo spacecraft/OTV stack would move away from the Space Station. The OTV would then ignite its engines to push the cargo spacecraft out of LEO. After sending the cargo spacecraft on its way, the OTV would separate, fire its engines to slow itself, aerobrake in Earth’s upper atmosphere, and return to the Station for refurbishment, refueling, and reuse.
The cargo spacecraft would intersect Mars on 29 December 2003. It would aerobrake in Mars’s upper atmosphere to slow itself so that the planet’s gravity could capture it. The cargo spacecraft would rise to its apoapsis (orbit high point), then fire its rocket engines to raise its periapsis (orbit low point) out of the atmosphere and circularize its orbit. Flight controllers would then begin careful checkout and monitoring of the cargo spacecraft and its cargo, paying special attention to the propellants the piloted sprint spacecraft would need for return to Earth.
SAIC offered a piloted spacecraft design with Station-derived pressurized crew modules connected in “race track” formation; that is, in a square with each module linked by short tunnels to the modules on either side of it. A pair of 4.4-meter-diameter, 12.2-meter-long habitat modules, each with a mass of 15.5 metric tons, would form two sides of the square; a 4.4-meter-diameter, 12.2-meter-long, 10.8-metric-ton logis