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A first for Japan.
The Japanese SLIM / Smart Lander for Investigating Moon landed successfully within only 55 metres from the intended spot on Friday 19th January 2024. Software akin to face recognition software, from very high resolution images supplied by NASA's Lunar Reconnaissance Orbiter & ISRO's Chandrayaan 2 orbiter were loaded onto SLIM to attempt a super accurate landing. The navigation was all but perfect. Worked extremely well.
News is that the SLIM Moon Sniper did reawaken during the lunar afternoon. A new observation of the tiny rock Toy Poodle, barely three CM tall and wide with a ten filter spectral observation resulting in an image that reveals Olivine, aka Peridot., a volcanic rock, magnesium iron silicate.
The landing site was chosen because the tiny 270 metre wide Shioli Crater, is on impact ejecta from the 100 KM wide, 4.2 KM deep Theophilus Crater impact. The tiny impact that formed Shioli Crater excavated ancient ejecta, unaltered by sunlight and micrometeoriod impacts.
Previous spectral analysis of this area suggested that the Theophilus Crater impact bought up material from the lunar mantle. SLIM Spacecraft was sent here to investigate.
The image is not exciting as it covers a tiny area, less than the size of a postage stamp. However the information oit holds is scientifically extremely interesting and important.
SLIM was launched on: Wednesday 6th September 2023 as a rideshare payload alongside the primary payload, the X-Ray space telescope XRISM / X-Ray Imaging and Spectroscopy Mission, a joint JAXA, ESA and NASA mission.
On Christmas Day 2023, the tiny SLIM spacecraft (only about two metres long) successfully entered Low Moon Orbit after a slow weak stability boundary trajectory (after launch and entering Low Earth Orbit, SLIM used it's engines to slowly spiral out to meet the Moon).
Shortly before landing, two small 'rovers' where ejected and both L.E.V 1 / Lunar Excursion Vehicle & hopper bot and L.E.V 2 named SORA-Q a baseball sized instrument laden sphere were both successfully activated. SORA-Q communicates to Earth via L.E.V 1. L.E.V 1 also has two cameras, an inclinometer (measures tilting) and a UHF link to Earth.
L.E.V 2 or SORA-Q can change it's shape slightly and uses this to roll. L.E.V 2 has a high resolution colour camera.
The main SLIM craft named Moon Sniper soon after landing a problem was detected. The solar array was not generating power. SORA-Q returned an image that showed the problem. Moon Sniper although landed safely, had tipped forward with the solar array facing away from the Sun. The array ended up facing west when it should had been facing up and the nose of the craft facing downward towards the lunar regolith. The onboard battery went down to 12% and the Moon Sniper shut down. Later on during the 14 day long lunar daytime, the Sun shone on the solar array during the lunar afternoon and the craft did reawaken. It appears that one engine bell 'fell off' the spacecraft just seconds before landing. Perhaps related to the release of the mini bots?
Landing location confirmed as 25.2 East & 13.3 South, on the northwest outer slope of the tiny 270 metre wide Shioli Crater, within Mare Nectaris / Sea of Nectar.
Also a new image just returned shows the scene again that was obtained just after landing, during the lunar morning, this time under a very low Sun in the late lunar afternoon. I have posted both morning and late afternoon views.
What is ironic is that if SLIM Moon Sniper landed correctly, the late afternoon observation may not have been possible as the solar arrays would have been facing straight up and the Sun at this time would be very low. However westward facing in a 'face plant' in the lunar regolith had enabled extended observations till almost sunset on the Moon.
However, unlike the faceplant that caused the power issues, the lunar night will certainly end the mission. The surface temperature will drop to about minus 180 Celsius / minus 292 Fahrenheit & SLIM Moon Sniper was not designed to survive for a fourteen day long lunar night.
Text: Andrew R Brown.
JAXA | Japan Aerospace Exploration Agency. SLIM / Moon Sniper.