Super Flower Blood Lunar Eclipse this month will leave the spacecraft in the dark. The first total lunar eclipse in 2022 means no sun for solar-powered probes operated by NASA, India and China. The Super Flower Blood Moon lunar eclipse will take place tonight (May 15) and may be a fascinating spectacle for Earth-bound viewers, but it's more of a stumbling block for spacecraft on the Moon.
That's because the three currently active lunar spacecraft - NASA's Lunar Reconnaissance Orbiter (LRO), India's Chandrayaan-2 orbiter, and China's Yutu-2 rover - are all solar powered. Since the moon will experience a total lunar eclipse on May 15 until the morning of May 16, as the moon enters Earth's shadow, the half of the moon that receives all sunlight will darken and the spacecraft will not be able to charge its batteries.
Fortunately, it's not the spacecraft's first experience with a total lunar eclipse. You can watch the lunar eclipse online in a series of webcasts starting around 9:30am EDT (0130 GMT). The eclipse will end at 2:50 am edt (0650 GMT).
Since LRO began its mission in lunar orbit in September 2009, the spacecraft has experienced 11 total lunar eclipses, so its team knows exactly how to prepare for the 85-minute total or total darkness period of this eclipse – that is, by powering it.
“When LRO goes through long eclipses, any drain on our battery is not ideal, so we wait until the battery is fully charged before turning the instruments off and on again,” LRO Project Scientist Noah Petro told Space.com. “We're also going to heat the spacecraft so that we're in the shadow of the Earth, so it doesn't get too cold and we don't get into a position where the spacecraft and instruments are too cold. We've done this several times, so it's a well-rehearsed set of procedures."
In fact, the preparations started a few weeks ago. “We did a small burn-in of our engines to slightly adjust our trajectory, thus minimizing time in the dark. “This burn and subsequent maneuvers put the LRO in the best position to minimize time in the dark and prepare us for Sunday night/Monday morning,” he said.
Chandrayaan—2 was launched on July 22, 2019—11 years after Apollo 50's moon landing—and was placed in lunar orbit on August 19, 2019. There was a total lunar eclipse on May 26, 2021.
Like the LRO, it is powered by solar arrays, meaning it will likely shut down during the eclipse.
But Yutu-2 will escape the wrath of a total lunar eclipse, just as it did on May 26, 2021. While LRO and Chandrayaan-2 are in orbit, Yutu-2 is a rover that landed on the far side of the moon in January 4 as part of China's Chang'e 2019 mission.
He has been exploring the Von Kármán crater ever since.
Being on the moon's surface means that Yutu-2 is subject to lunar days and nights, each lasting approximately 14.5 days at the rover's location. As a solar powered vehicle, the Yutu-2 cannot operate on lunar nights and therefore shuts down for more than two weeks at a time. Given that total lunar eclipses occur only at full moons when the far side of the moon is in complete darkness, the rover will be in the middle of the lunar night on May 15 and will already be closed.
Whatever procedures the lunar spacecraft will take during this lunar eclipse, they will soon have to repeat them—the next total lunar eclipse will occur in the morning hours of November. 8, 2022.