During my visit to Google Lunar X PRIZE team Astrobotic at Carnegie Mellon University in Pittsburgh last week, I got team member and CMU mechanical engineering student Charlie Muñoz to explain how the team is solving a major technical challenge.
The lunar night lasts 14 Earth days, during which surface temperature drops below the temperature of liquid nitrogen, to around -233 degrees Celsius, or -387 degrees Fahrenheit. Any moon robot, such as the one team Astrobotic is building, had better not have water or even water vapor in its onboard batteries if it wants to get through those 14 days in deep freeze and have any hope of reviving when the sun again warms its solar panels.
The Soviet Lunokhod rovers of the 1970s solved the problem by keeping warm with radioactive isotopes. That’s not going to be option for a private university-based team since the appropriate isotopes are tightly controlled.
And when the sun does come out again, the temperature on the lunar surface rises well past the boiling point of water, to about 253 degrees Fahrenheit or 123 degrees Celsius. Staying cool enough to prevent electronic circuits from being cooked to death then becomes the major challenge.
What’s a poor lunar robot to do? Watch my video interview with Muñoz for Atrobotic’s solution.