NASA engineers are dusting off a 20-year-old science instrument for a series of upcoming Moon landing missions.
NASA has contracted with two private companies so far to build landers for a series of uncrewed science missions to the Moon, with the first launches planned for 2021. The uncrewed lander missions are the first phase of NASA’s Artemis program, with the ambitious eventual goals of crewed Moon landings, an orbital lunar outpost, and lunar mining. To that end, several of the instruments are focused on better understanding where and how to look for hydrogen, water, and other important chemical compounds on the Moon.
NASA Has A SEAL Team
From left to right, Astrobiotic's Peregrine lander model, Intuitive Machines' Nova-C lander model, ... [+]
One of those instruments is Surface and Exosphere Alterations by Landers (or SEAL to its friends and its human operators, who can now call themselves the SEAL team). SEAL will use a mass spectrometer to measure the lander’s exhaust gas (insert your own joke here) while the lander enters lunar orbit, during its descent through the very thin lunar exosphere to the surface, and while the lander sits around on the surface doing science.
The SEAL team is interested in how spacecraft exhaust spreads compounds like water and carbon dioxide across the lunar surface – and how future missions can tell the difference between actual deposits of volatile compounds and lingering traces of spacecraft exhaust. NASA estimates that even a relatively small lander like China’s Chang’e 3 can scatter more than 300kg (660 pounds) of water and other compounds over several kilometers of the lunar surface. That’s part of why the Apollo astronauts hiked (and later, drove) so far from their landing sites to collect samples.
Now the agency wants to know how much of that exhaust sticks around in the regolith and how much of it drifts through the exosphere (which is much, much too thin for people to breathe but still capable of mitransporting gases from place to place) to eventually settle at the poles or on other parts of the lunar surface. SEAL will also help researchers understand how temperature affects easily-evaporated compounds like water and carbon dioxide on the Moon, and how stable water ice deposits in the lunar soil might be. That information will be important for future exploration on the Moon, especially for efforts to mine water ice, hydrogen, or other materials from the Moon’s surface.
The Mission That Never Was
Nozomi was supposed to study how the upper atmosphere of Mars interacts with the charged particles ... [+]
That’s a pretty cool mission for an instrument that spent the last 20 years in storage at NASA’s Goddard Space Flight Center. Engineers built SEAL in 1998 as a practice mockup for an instrument aboard Japan’s Nozomi mission. Nozomi was supposed to orbit Mars and study the planet’s upper atmosphere; the original mission plan called for an eccentric orbit that would carry Nozomi 17,000 km (10,500 miles) away from Mars before swooping in to just 300km above the Martian surface to gather data on the upper layers of the planet’s atmosphere.
On its way to Mars, Nozomi flew past the Moon twice and Earth three times, borrowing a nudge from our planet’s gravity to boost the spacecraft into the right orbit around the Sun so it could rendezvous with Mars. But on the final Earth flyby in December 2003, Murphy’s Law reared its ugly head. The main thruster failed to fire during an orientation maneuver, so the mission team couldn’t get Nozomi into the right orbit – and couldn’t guarantee that the spacecraft wouldn’t crash into Mars, potentially scattering Earth bacteria all over the potentially habitable Martian surface.
To avoid the risk of accidentally seeding Mars with terrestrial life – which would spell disaster for any native life on Mars, not to mention confusing the daylights out of future astrobiologists – Nozomi had to be sacrificed. The spacecraft got only a brief look at Mars during a single, 1,000 km (620 mile) distance flyby, and then flew out of the history books on a two-year orbit around the Sun, which would eventually end the way all heliocentric orbits must.
From Mothballs To A Moon Mission
SEAL spent the last 20 years in this warehouse at NASA Goddard.
Nozomi’s spectrometer training mockup went into storage, until NASA planetary scientist Mehdi Benna and his colleagues decided to give it a makeover and a second chance. “It’s a comeback story,” Benna said in a recent NASA press release. “SEAL is like the Rocky Balboa of space travel.”
Bringing SEAL back to life meant a solid week of rummaging through a warehouse full of discarded spacecraft, instruments, and components at NASA Goddard to unearth all of the instrument’s hardware and technical documentation. Then came the process of restoring and repairing SEAL’s electronic systems and upgrading the spectrometer with some updated technology.
“We need these kinds of measurements at multiple sites across the lunar surface to build our understanding of the three-dimensional, natural lunar exosphere and how it responds to perturbations such as rocket exhaust,” explained NASA planetary scientist Barbara Cohen, principle investigator for another instrument called the PROSPECT Ion-Trap Mass Spectrometer, in a recent NASA press release.
The PROSPECT Ion-Trap Mass Spectrometer will study whether concentrations of volatile chemicals like carbon dioxide, carbon monoxide, methane, nitrogen, and water change during the course of the lunar day as the surface temperature rises and falls. In particular, the PROSPECT team wants to know whether the lunar surface, as it heats up during the day, could release water and other molecules into the exosphere – and whether those molecules might then drift across the lunar surface to settle in the cold, dark bottoms of craters near the poles, where they could form deposits big enough to be worth mining.
Big Plans At NASA
Cohen and her colleagues (Sarah Valencia on the right and Natalie Curran on the left) are pictured ... [+]
In all, NASA has selected two dozen payloads for its commercial landers so far: 12 from NASA science teams and 12 from universities and companies. They’re a mixture of technology demonstrators, experiments, and instruments.
The lander contracts are part of NASA’s Commercial Lunar Payload Services under which the agency selected nine companies to bid on contracts for various aspects of transporting science payloads to and from the Moon, from launch vehicles to landers – and even vehicles that can take off from the lunar surface and return samples and instruments to Earth. (In case you’re wondering how the process works, NASA put out a request for proposals in September 2018, and in November 2018 it announced its initial pool of nine companies. Those nine companies can now bid on contracts for vehicles and systems.)
Pittsburgh-based Astrobiotic Technology and Houston-based Intuitive Machines hold the first two lander contracts, awarded in May 2019, for two strikingly different-looking designs (a third company, OrbitBeyond, received a contract but later backed out). NASA awarded Astrobotic $79.5 million for its proposal to fly as many as 14 payloads to Lacus Mortis, a large crater on the near side of the Moon, by July 2021. The agency awarded Intuitive Machines $77 million for its proposal to fly up to five payloads to Ocean Procellarum, a dark area of the lunar surface that's of interest to geologists, by July 2021.
https://www.forbes.com/sites/kionasmith/2019/09/30/nasa-engineers-revived-a-discarded-decades-old-instrument-for-a-2020s-moon-mission/
2019-09-30 08:04:34Z
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