We need gravity: It anchors us. But the gravity we experience on Earth is very different from the gravity on the moon, and both, it turns out, can fluctuate due to a number of things!
NASA/GODDARD SPACE FLIGHT CENTER/DLR/ASU
The initiatives are part of an evolving space exploration strategy that relies on indigenous resources, primarily to make rocket fuel for the return trip home.
Studies show the most viable options for future human expeditions to Mars -- as well as Mars sample return missions -- require what is known as “in-situ resource utilization,” or IRSU, to save the enormous costs of launching everything from Earth.
“Every pound that you don’t have to launch from the Earth of dumb mass -- things like water and air and propellant -- means that you can add a pound of intelligent mass -- an experiment, a computer, something designed to accomplish some job or give us some capability,” lunar geologist Paul Spudis, with the Lunar and Planetary Institute in Houston, told Discovery News.
“Doing ISRU gives you incredible leverage because you’re changing the fraction of intelligent-to-dumb mass on your spacecraft in favor of the intelligent part,” he said.
The first in-space ISRU test is targeted for 2018. NASA plans to launch a mission called Resource Prospector that includes a rover with instruments to scout for telltale hydrogen, drill out samples, heat them and scan for water vapor and other volatiles on the moon.
Vapor also could be re-condensed to form a drop of water.
“A lot of the technologies have broader use than just lunar ... it’s just a convenient location to be testing the ISRU technology,” said Jason Crusan, director of Advanced Exploration Systems at NASA headquarters in Washington DC.
A second ISRU experiment is due to be aboard NASA’s next Mars rover, which is slated for launch in 2020. The device, which has yet to be selected, would pull carbon dioxide from the planet’s atmosphere, filter out dust and other particles and prepare the gas for chemical processing into oxygen.
The demonstration also could include actual oxygen production.
“It’s basic chemistry,” Spudis said. “The real issues are not the basic process. The issues are what are the unforeseen things about the environment, about being in space, being on the moon, being on Mars, that we don’t know or we don’t anticipate that are going to impact that production.”
If successful, scientists hope ISRU technologies will evolve past demonstrations and into operational missions.
“There’s an inherent risk of putting ISRU in the critical path of mission success, so it’s been stated that you need to do demonstrations. That said, a lot of times funding is associated only with things that are in the critical path for human missions. So we’ve been kind of in a catch-22,” said Gerald Sanders, who oversees ISRU programs at NASA’s Johnson Space Center in Houston.
“The important of a mission like Resource Prospector or the Mars 2020 (ISRU demonstration) is that it kind of breaks that cycle, the paradigm,” he said. “If it pans out, you can start seriously thinking about how you would change your exploration approach.”