Sunday, February 13, 2022

It's Apparently Not a Falcon 9 That's Going to Hit The Moon

About three weeks ago, a report surfaced that a large chunk of space debris had been predicted to hit the moon in March, and that piece of junk had been identified as the upper stage of a Falcon 9, tracked to a mission in 2015, called DSCOVR, NOAA's Deep Space Climate Observatory.  

For a variety of reasons (I think) the press went gonzo over this story.  As Eric Berger at Ars Technica writes:

This story set off a firestorm of media activity. Much of this coverage criticized SpaceX for failing to properly dispose of the second stage of its Falcon 9 rocket after the launch of NOAA's Deep Space Climate Observatory mission, or DSCOVR, in 2015. The British tabloids, in particular, had a field day. Even the genteel European Space Agency tut-tutted, noting that it takes care to preserve enough fuel to put spent rocket stages into stable orbits around the Sun.

Why did they jump on the story?  In no particular order, the idea that a man-made object, a rocket upper stage in particular, is going to hit the moon and it will "gain one more crater" (as the European Space Agency put it) is dramatic, headline material.  On top of that, it's being considered at least to be a screw-up, and if not that at least "uncool," to have not put the upper stage into an escape orbit so it can't add that crater.  Then there's the matter that it's a SpaceX screw-up, the company in the news regularly, who just happens to be headed by not just one of those yucky, awful, billionaires, but the richest and most famous of them all.  If you're the typical, borderline communist, industrial news media, kind of person (but I repeat myself), this is a story you just can't resist.  

Along the way of the intervening weeks, science worked as it's supposed to.  The guy who made the initial observations, and originally concluded it was that Falcon 9 upper stage, had invited any of the community of astronomers who like to track such things to check his work.  He's Bill Gray at Project Pluto.  Out in the audience was an engineer from JPL named Jon Giorgini, who saw it and thought the ultimately most important thought in all of science research: "that's funny."  Now JPL doesn't track space junk, but they do track objects like the DSCOVR satellite.  He was able to look at its orbit and thought there's no way a rocket putting that satellite into that orbit should leave the rocket where this is being reported.

He wrote to Gray on Saturday morning explaining that the DSCOVR spacecraft's trajectory did not go particularly close to the Moon, and that it would therefore be a little strange if the second stage strayed close enough to strike it. This prompted Gray to dig back into his data, and identify other potential candidates. 

Gray thinks he's found what it really is now, and has posted a correction.  He has concluded it's a Chinese Long March 3C upper stage from the Chang'e 5-T1 mission launched earlier than DSCOVR: in October 2014.  

Bear in mind, this is just as much a case built on "circumstantial evidence" as thinking it was that Falcon 9 stage, but Gray says that based on his work, as well the work of the other people who supplied information, he's more comfortable with this identification than the SpaceX upper stage. 

Whichever it is, it's going to hit the far side of the moon on Mar 4 at 12:25 UTC.  Because of it being on the far side, it won't be visible from Earth, and while there are satellites on the moon that can measure seismic events like that impact, I haven't read of anyone claiming they'll be able to get pictures of video of it.  Gray points out it will be local noon when the object crashes, so it's a pity nothing is there to get good resolution pictures of it.  He posts this image of the location of impact on the far side.  At the green X. 

He also adds this entertaining note (emphasis added):

Quite a bit of data came in between 2022 Feb 5 and 9, as the object came back close to the earth and passed over the earth's night side. As expected, the object was not entirely on the predicted trajectory; as seen in the sky, the difference was roughly the size of a golf ball seen a mile away. However, it was enough to revise the prediction to land a few kilometers east and a few seconds before the above prediction, and a pixel or two to the right of the green 'X' on the map below.

I wonder if the corporate press will jump over to the story most likely being a Chinese Long March upper stage as quickly as they did when they thought it was a SpaceX rocket. 



6 comments:

  1. And just like that, nobody in the media cares about the crashing 2nd stage. Or is willing to say anything about it?

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  2. Of course not. It's "old news" now, and it did it's intended purpose.

    Remember when a journalist would checked with several sources before publishing something like this?

    I sure do.....

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  3. The press likes communism more than they like Musk.

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  4. Meh.

    Point out all the space debris litter that's already in orbit, and get back to us. At least that rocket booster isn't coming down on someone's house.

    If he could have gotten it to impact on the NYTimes or CNN HQ bldg., however, I'd have sent him a nice "thank you" note.

    Which gives him something to work towards for next time.

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  5. China has always been at war with Hertzsprung.

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  6. It’s too bad we don’t have journalists anymore, what we have are hacks repeating anything that fits the narrative. If it doesn’t they ignore it!

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