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Wednesday, December 27, 2023

Japan's SLIM Lunar Lander in Lunar Orbit

Perhaps you remember the Japanese Aerospace Exploration Agency (JAXA) successfully launching its Smart Lander for Investigating Moon (SLIM) along with its new telescope the X-Ray Imaging and Spectroscopy Mission (XRISM) back on September 6.  The launch was on the Mitsubishi Heavy Industries H-2A. 

The two satellites separated soon after launch with XRISM staying in Earth orbit and SLIM on a low energy trajectory that took the probe several months to get to the moon.  More precisely, SLIM went into lunar orbit early Christmas morning, eastern US time.  

[T]he spacecraft was successfully inserted into lunar orbit at 2:51 a.m. EST (0951 GMT or 4:51 p.m. Japan time) on Monday (Dec. 25).

"SLIM successfully completed main engine injection at 16:51 and successfully entered lunar orbit! Below is an image sent from SLIM near the moon," JAXA officials wrote.

A photo in the source Space.com article, apparently made from two images in a Twitter (X) post by JAXA.  This appears to me to be the same photo of the moon, with the right view rotated counterclockwise around 60 to 80 degrees.  Look at the bigger and smaller craters near the center of the left picture and note the position of that "pointy thing" on the larger crater's wall with respect to the small crater next to it.  Compare that to the picture on the right.  Also, just below the mid-line of the left picture on the right edge is a small shallow crater.  It appears to be above and to the right of the crater pair from the center. 

Note also the orientation of the shadows in  craters that have visible shadows.  On the left image, the shadow lines are practically horizontal while on the right side they're closer to vertical. 

Getting back to the mission, SLIM is set to touch down on the moon on Jan. 20. If successful, it will make Japan the fifth country after the Soviet Union, the U.S., China, and India to achieve a lunar landing.  Since this is a government job, JAXA is roughly equivalent to NASA, its success or lack thereof has no bearing on the "race" between Astrobotic's Peregrine and Intuitive Machines IM-1 Lunar Lander to be the first private company to land on the moon.  

"By creating the SLIM lander, humans will make a qualitative shift towards being able to land where we want and not just where it is easy to land, as had been the case before," the space agency wrote in a mission description. "By achieving this, it will become possible to land on planets even more resource-scarce than the moon."



6 comments:

  1. JAXA is going for landing accuracy. I whish them the best of luck and skill!

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  2. JAXA has done some fantastic work regarding the Moon. And it looks like they'll continue. 3D mapping and some serious photo-recon work.

    Which is kind of funny, as I am watching the anime "Space Brothers," about two brothers who go to space on the ARES/Orion system (anime was in 2012, before The Lightbringer killed the ARES system.

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  3. No word on how much we'll have to pay Japan to keep up the charade and send back doctored photos of our six faked moon landings.

    /sarc

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    1. Yeah, just imagine how to fake all that hardware lying around.

      Has any of you readers pointed a laser at the moon? Shortly after they put the reflectometer on the surface (Apollo 14?) my brother and I fired a 5kW pulse synthetic ruby laser we had built, and we got a return! I tried it again a few years later so I could measure the distance to the moon but didn't have the right optical equipment to get the return to show up on the scope. Hey, that was back in the early 70's and I didn't have access to a lot of good electronics parts so that I could amplify the return signal enough to get a blip on the scope and into my digital counter I designed.
      Ah well, others smarter than me have successfully measured it on their own. No biggie.

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    2. I've never had any hardware that could approach the kW pulse synthetic ruby laser, but ISTRC working with a guy who worked at Grumman as a new grad in the Apollo days, and he talked about doing the experiment. I worked with this guy around 1995, so my memory is hazy on that.

      Do you happen to recall how much spread your laser had at the moon? Basically, how accurately did you need to point it, and did you need a clock drive like the hobbyist astrophotographers use?

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  4. It's clearly the same scene, close in time. Perhaps the orbiter is rolling. Or, of course, perhaps the magazine wanted two pics when they only had one.

    The dust rays from that small recent crater in the center have a slightly different appearance, possibly two exposure settings, so I don't think it's identically the same image despite my lack of respect for magazine publishers.

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