Monday, February 28, 2011

NASA wants spacecraft designed for Mars return trip

Getting home might prove to be as difficult. NASA today selected three companies -- Alliant Techsystems, Lockheed Martin and Northrop Grumman - to being the task of defining the spacecraft that will leave Mars, presumably at first loaded with red planet rock samples, then later possibly humans - for a safe trip back to Earth.
The engineering challenges those three companies face are immense.
From a NASA whitepaper on the challenges of a return trip from Mars: "Lifting geology samples off of Mars is both a daunting technical problem for propulsion experts and a cultural challenge for the entire community that plans and implements planetary science missions. The vast majority of science spacecraft require propulsive maneuvers that are similar to what is done routinely with communication satellites, so most needs have been met by adapting hardware and methods from the satellite industry. While it is even possible to reach Earth from the surface of the moon using such traditional technology, ascending from the surface of Mars is beyond proven capability for either solid or liquid propellant rocket technology. Miniature rocket stages for a Mars ascent vehicle would need to be over 80 percent propellant by mass. It is argued that the planetary community faces a steep learning curve toward nontraditional propulsion expertise, in order to successfully accomplish a Mars sample return mission. A cultural shift may be needed to accommodate more technical risk acceptance during the technology development phase. Achieving a small size and mass for the Mars Ascent Vehicle (MAV) is critical to mission affordability, because program budgets have been 1-2 million dollars per kilogram of useful mass landed on Mars."
NASA said of the MAV in the past, "of particular interest is a MAV design/architecture or supporting technologies that reduces the system mass as compared to the previous studies. Technologies should be applicable for, but are not limited to either a two-stage solid (primary interest) or a liquid propulsion system with three-axis stabilization."

Read More

No comments: