There’s been a lot of talk lately about human beings going to Mars. But the engineering challenges for getting to the red planet are as great as the goal itself. We paid a visit to spacecraft and plasmadynamics specialist Ben Longmier to discuss the obstacles and moral implications of sending colonists to the red planet.
ABOUT THE PROFESSOR: Ben Longmier is an Assistant Professor of Aerospace Engineering at the University of Michigan College of Engineering. He is developing the next generation of advanced thrusters from 10W to 200kW to enable wide access to remote destinations within the solar system. To enable this, his research in the U-M Plasmadynamics and Electric Propulsion Lab (PEPL) interests center on electric propulsion, spacecraft and aerostat design, basic plasma physics, plasma materials interaction, and plasma diagnostics.
I’m a bit confused by this video. Ben says that it would take 20-40 Saturn V rockets just to launch enough fuel to get to Mars. The Saturn V could put 120,000kg of payload into LEO, which makes 1.2 – 2.4MILLION kg of fuel to send a rocket to Mars. What sort of mission profile does he have in mind that would require such an enormous amount of fuel? Mars Curiosity is roaming the surface of Mars right now and needed no such expenditure of fuel. Inspiration Mars has plotted out a manned flyby mission that will need only the soon-to-be available lift of a Falcon Heavy booster, which is only 53,000kg to LEO. Please elaborate.
The main difference between Curiosity or the fly-by mission and an actual human landing on Mars is the need to return. Not only would we need to send the people and their equipment, life support systems and consumables, but we would also need to send with them a separate launch system and enough fuel to get them back off of Mars. When sending a rover, the only ultimate payload we need to send is the rover itself, since we don’t feel the need to get it back again. The flyby mission is similar in that it would likely remain in a free-return trajectory, which would need much less fuel to perform the return journey.
Respectfully, I think Dr Longmier didn’t do the research on chemically fueled mission architectures. It can be done in a manner similar to Zubrin’s Mars Direct where the return fuel is generated on the surface. (I think you want it to to be quite a bit bigger than Zubrin’s proposal but that’s my personal preference).
As part of President Kennedy’s man-to-the-moon mission there was also an active follow on project for a man-to-mars-return mission. I worked on it, as a nuclear and aeronautical engineer, on the NERVA nucler rocket propulsion system – which run successfully. This after-atmosphere upperstage makes a large difference in transit time between Earth and Mars. Dr.James Burnett (Michigan).