Bimodal NTR Mars mission (2001) Part One In the BNTR DRM, two unpiloted spacecraft would leave Earth for Mars during the 2011 low-energy Mars-Earth transfer opportunity, and a third, bearing the crew, would depart for Mars in 2014. Components for the three spacecraft would reach Earth orbit on six Shuttle-Derived Heavy-Lift Launch Vehicles (SDHLVs), each capable of launching 80 tons into 220-mile-high assembly orbit, and in the payload bay of a Space Shuttle orbiter which would also deliver the Mars crew. SDHLV 1 would launch Bimodal Nuclear Thermal Rocket (BNTR) stage 1. Each BNTR DRM mission would need three 28-meter-long, 7.4-meter-diameter BNTR stages. BNTR stage 1 would carry 47 tons of liquid hydrogen (LH2) propellant. The BNTR stages would each include three 15,000-pound-thrust BNTR engines developed as part of a joint U.S./Russian project in 1992-1993. SDHLV 2 would boost the unpiloted 62.2-ton cargo lander into assembly orbit. The lander would include a Mars aerobrake and entry shield, landing parachutes, a descent stage, a 25.8-ton Mars surface payload including an in-situ resource utilization (ISRU) propellant plant, and an unfueled Mars Ascent Vehicle (MAV) made up of a conical Earth Crew Return Vehicle (ECRV) capsule and an ascent stage. SDHLV launch 3, identical to SDHLV launch 1, would place into assembly orbit BNTR stage 2 containing 46 tons of LH2 propellant. SDHLV launch 4 would place the unpiloted 60.5-ton Habitat lander into assembly orbit. It would include a Mars aerobrake/entry shield identical to that of the cargo lander, parachutes, a descent stage, and a 32.7-ton payload including the crew's Mars surface living quarters. The BNTR stage forward section would include chemical thrusters for attitude control and for maneuvering capability for docking the stages with the Habitat and cargo landers in assembly orbit. The BNTR 1/cargo lander combination would have a mass of 133.7 tons, while the BNTR 2/Habitat lander combination would have a mass of 131 tons. Both combinations would measure 57.5 meters long. As the launch window for Mars opened, the BNTR stages would fire their engines to depart assembly orbit for Mars. Following Earth-orbit departure, the BNTR engine nuclear reactors would switch to electricity-generation mode. They would heat a working fluid to drive three turbine generators providing a total of 50 kilowatts of electricity. Fifteen kilowatts of this would power a refrigeration system in the BNTR stage for minimizing LH2 boil-off. As Mars loomed large ahead, the power generators would charge the lander batteries. The BNTR stages would then separate and fire their engines to miss Mars and enter disposal orbit around the Sun. The landers would aerobrake in Mars's upper atmosphere. The Habitat lander would capture into Mars orbit and extend twin solar arrays to generate electricity. The cargo lander would capture into orbit, then fire its deorbit engines to enter the atmosphere a second time. After casting off its aero-shell/heat-shield, it would deploy three parachutes. Descent engines would fire, then landing legs would deploy just before touchdown. The Engineers opted for a horizontal landing configuration; this would, they explained, prevent tipping and provide the astronauts with easy access to the lander's cargo. After cargo lander touchdown, a teleoperated cart bearing a nuclear power source would lower to the ground and trundle away to a safe distance trailing a power cable. This would power the lander's ISRU propellant plant, which over several months would react four tons of "seed" hydrogen brought from Earth with martian atmospheric carbon dioxide to produce 39.5 tons of liquid methane and liquid oxygen propellants for the MAV's ascent engines.

What could have been...

Excellent work! NASA's mod of Zubrin's plan. Same people who say then need seven years to build a a launcher out of shuttle parts....

Fantastic modeling! Corrie

grand stuff, as always, bud!

Xcellent presentation!

Very convincing! If only, if only...!

fantastic model!!

Fantastic work, this is some great stuff! I remember reading "The Case for Mars" and being inspired by it so many years ago. Great job!

Great work!