Cosmic correction: Booster headed for moon came from China, not SpaceX

Remember that old rocket booster we told you about, the one that is expected to crash into the moon on March 4?

It still is, but Elon Musk isn’t the one to blame.

What scientists originally thought was part of a Falcon 9 rocket launched in 2015 by Musk’s SpaceX company is now believed to be a Chinese booster launched in 2014 as part of that country’s recent series of robotic missions to the moon.

Over the weekend, Bill Gray, the astronomer credited with tracking the wayward booster, posted a lengthy correction on his website at https://www.projectpluto.com/temp/correct.htm.

Gray said a question from an engineer at NASA’s Jet Propulsion Laboratory prompted him to reexamine his original calculations. He said the available evidence now shows that what he thought was the second stage of a Falcon 9 is really the rocket booster used to send China’s Chang’e 5-T1 mission to the moon in October 2014.

Researchers at the University of Arizona’s Lunar and Planetary Laboratory have since confirmed Gray’s new findings, using data gathered when the booster tumbled past Earth — and through the sky above Tucson — in January and again early last week.

“We took a spectrum, which can reveal the material makeup of an object, and compared it with Chinese and SpaceX rockets of similar types, and it matches the Chinese rocket,” said UA associate professor Vishnu Reddy, who co-leads the UA’s Space Domain Awareness lab with engineering professor Roberto Furfaro. “This is the best match, and we have the best possible evidence at this point.”

Reddy and a team of his students have been tracking the chunk of space debris and sharing their observations with the Jet Propulsion Laboratory to help pinpoint where the booster will crash down.

The object is still expected to hit the moon at approximately 5:25 a.m. Tucson time on March 4, but don’t bother going outside to watch the show. The booster is not visible with the naked eye, and its impact site will be somewhere in or near the Hertzsprung crater on the far side of the moon, permanently out of sight to us earthlings.

Plans are in the works to have NASA’s Lunar Reconnaissance Orbiter verify the crash site next month and collect some before and after pictures.

Arizona is the only public university with a dedicated academic program for Space Domain Awareness. Reddy said their work helps the U.S. Air Force track satellites and space junk, and Gray is a “close collaborator” for that effort.

In his explanation on the web, Gray said “high-altitude junk” like the Chang’e 5-T1 rocket or the SpaceX booster isn’t actively tracked by the U.S. Space Force or anyone else, because it is too far out to pose a risk to the satelites and space stations orbiting closer to the Earth.

“Strange as it seems (to me, anyway), orbits are computed for objects of this sort only by me, in my spare time,” he writes.

But Gray thinks it is time for the international community to rethink its approach to tracking and minimizing space junk, in light of this mix up and the overall increase in high-orbit missions.

He is advocating for a publicly available, central clearinghouse for launch vectors for high-orbit missions and observational data on any space junk they might create.

Soon, “such junk will no longer be merely an annoyance to a small group of astronomers,” he writes. “Basically, I’m asking for somebody to take over the job.”

So if this isn’t it, just where is that SpaceX rocket booster from 2015 that carried the National Oceanic and Atmospheric Administration’s Deep Space Climate Observatory into space?

“That’s a good question,” Gray writes. “I wish I had a good answer. But I strongly suspect that nobody does.”

His best guess is that the second stage of the Falcon 9 flew along with NOAA’s early-warning satellite for solar storms until the spacecraft maneuvered itself into position about 1 million miles from Earth. At that point, Elon Musk’s rocket booster sailed on by, eventually settling into its own distant orbit around the sun.