Long March 5B Stage Reenters North of Maldives as NASA Administrator Nelson Criticizes Chinese Actions as Irresponsible
by Douglas Messier
Managing Editor
A Chinese Long March 5B reentered the Earth atmosphere on Sunday over the Indian Ocean north of the Maldives, ending more than a week of global anxiety that the massive booster could spread debris over a populated area.
The 18th Space Control Squadron confirmed the 21-metric ton stage reentered the atmosphere and fell into the ocean north of the island chain at latitude 22.2, longitude 50.0 on Sunday, May 9 at 0214 UTC. There have been no reports of injuries.
While most of the booster was expected to burn up, some parts of the rocket were expect to reach the Earth’s surface. A Long March 5B first stage scattered debris over the Ivory Coast in May 2020.
The stage had been in orbit for about 10 days after it launched the Tianhe core module of China’s first permanent space station on April 29.
In Washington, NASA Administrator Bill Nelson issued a statement on Saturday criticizing China’s handling of the matter.
“Spacefaring nations must minimize the risks to people and property on Earth of re-entries of space objects and maximize transparency regarding those operations.
“It is clear that China is failing to meet responsible standards regarding their space debris.
“It is critical that China and all spacefaring nations and commercial entities act responsibly and transparently in space to ensure the safety, stability, security, and long-term sustainability of outer space activities.”
Chinese officials downplayed the risk to life and property as the booster tumbled out of control. But, they said little else as governments around the world scrambled to determine when and where the stage would reenter the atmosphere.
It’s not known whether Chinese controllers attempted to deorbit the rocket over a remote part of the ocean before they lost contact with it. It’s not even clear whether Long March 5B has a controlled de-orbit capability.
A Long March 5B stage orbited the Earth last year before making a similar uncontrolled reentry over Africa. Ivory Coast residents reported flashes, a sonic boom and pieces of metal falling from the sky. There were no reports of injuries.
The Long March 5B is part of China’s most powerful booster family. The variant is capable of launching about 25 metric tons into low Earth orbit.
In early April, one of Falcon 9’s much smaller second stages that SpaceX was unable to deorbit reentered in a spectacular nighttime display over Oregon and Washington. A helium tank was subsequently recovered from a Washington farm.
22 responses to “Long March 5B Stage Reenters North of Maldives as NASA Administrator Nelson Criticizes Chinese Actions as Irresponsible”
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Best get use to it as they have several more launches planned in the near future.
Yeah…just like the good old days when I was a kid trying to dodge Russian nukes. This will probably be a more useful strategy for dodging Chinese rockets.
https://uploads.disquscdn.c…
From what I can tell, the risk to property was fairly low and the risk or injury far less. Has anyone run the numbers to see if it hit the <10^6* risk for FAA launches? While agreeing that it appears seriously irresponsible, I wonder how much actual risk is involved
*as I recall.
Probably not much.
It’s estimated 3 percent of the land surface area of the Earth is urbanized while crops are planted regularly on 20% of the land surface. An urban area has a population of greater than 500 people per square mile, while land with crops would have less than 500 people per square mile but more that 5 people per square mile. About 29% of the Earth is land while the rest is ocean, so the odds of it landing on an urban area is .0087 while on farmland it’s .0580, while it’s .71 probable it will land in the ocean as this one did.
However these rough numbers are low estimates as they include the polar regions which are mostly empty of inhabitants and NOT under the flight path of the second stages falling to Earth so the actual numbers would be much higher, perhaps by 60% or so.
Your numbers would indicate a considerably higher risk probability than I had guessed.
Hence the fuel tank from a Falcon landing on a farm in Washington state.
I have my skylab falling hat
That’s a keeper.
“It’s not even clear whether Long March 5B has a controlled de-orbit capability.”
Lockheed was not instructed to assist them with that part of the program.
I was surprised at how inaccurate the predicted reentry footprints are. I’d have thought modern radar and telescopic video images would have allowed for a very accurate numerical integration to place the reentry corridor to at least the size of a continent. From Jonathan McDowell’s twitter page the tumble was still going strong as it passed over Israel, but was no longer tumbling by the time it was shedding parts and leaving a visible ionization/debris trail over Oman.
Likely, at least Israel, was imaging it and pinging it with radar in its final pass with line of sight. I wold imagine AWACS in the region were probably working the event as well. Diego Garcia was close by for the final plunge, they have the radar and imaging and tracking capabilities. No doubt they had a great show weather permitting.
curious if they were just “dont care” in the design of they have some plan to use the first stage someday in orbit
the US Had an Arliegh burke flight 2 near by
The omission of a minimal RCS to allow a controlled dump into the SW Pacific is a mystery. It’s not asking for much. Even a most basic set of reaction wheels and a set of solid thrusters. It’s the Chinese. We know what they’ll do to their own people. Besides, rules are for sukkaz.
no they really dont care. I should tell sometime my Long March launch experience where they had a hang fire…
but they dump their boosters on their own people and safety is not a big thing there
but they have the people well under control
“reaction wheels and a set of solid thrusters“
No no and no.
The mass of this thing at LEO velocity means it would take several thousand pounds of avionics, momentum wheels and solid rockets for your scheme to work. All that mass would come outta the usable payload delivered.
And for why? The rationale thing is to emulate the Shuttle/ SLS ascent profile, inject the stack into an elliptical orbit with a perigee halfway around the planet ? at ZERO altitude. Then -of course- stage quickly and use the upper stage to circularize the payload’s orbit. As the payload is doing its thing, the huge core, on the other side of the world, (over ocean) runs into -you know…the atmosphere, and proceeds to destructively enter.
Aero breaking is free “propulsion” here, you just stage earlier so it’s not random.
The “upper stage” in this case, is China’s station modules (which Do have propulsion, power & all that good stuff. The performance shortfall from staging earlier, would come outta the delivered mass of the modules and/or their lifetime on orbit (which has to be made up later).
It’s no doubt too late to alter the plans for the first few modules, but eventually, if there’s enough pressure on them, they could alter the ascent profiles for a pre-planned core entry.
Mkay?
addendum: the Chinese planners wouldn’t like this, because after staging they’d be swapping low Isp pressure fed storable prop vs. high Isp H2 for that final push to the initial, circular orbit.
Several thousand lbs ? Really? A 60 m/sec delta v for this stage with solid fuel requires about 800 – 900 lbs of propellant. Guidance? Really? Does that even mass in anymore? The momentum wheels …. You don’t need high torque, you can take hours, heck days to de spin it and roughly align the burn vector. But you’re right, I did not run those numbers. So just use a basic RCS. It’s not a lot.
Probably simplest solution just have the payload circularize the orbit instead of the core stage. The same way the Space Shuttle handled controlled disposal of the External Tank.
SLS delenda est
have the payload circularize the orbit
Which is exactly what I said earlier, but then you say “so what?”
No, that isn’t exactly what you said. That was about 1/3 of the various assertions you made in that post.
I was quite clear about the error I was addressing, since I quoted the specific text with the error.
SLS delenda est
addendum: the Chinese planners wouldn’t like this, because after staging they’d be swapping low Isp pressure fed storable prop vs. high Isp H2 for that final push to the initial, circular orbit.
Yes. But so what? Losing 20+ metric tons of dead weight more than makes up for the loss of the higher ISP.
SLS delenda est
Ummm errrr so…you’re saying it makes more sense (more payload) to stage earlier, jettison all that core structure mass (dead weight), and circularize with the storable propellant? So…therefore…the Chinese INTENTIONALLY sacrificed payload, in order to play this little Russian roulette game with the LM5 core?
If I parse out your response, that’s the conclusion.
Now that you mention it, yes that would be the conclusion. It’s logical.
So the question then must be asked, then why did the Chinese do what they did, with the Long March 5B? I can think of at least a couple possible reasons…
The first reason is increased security for the payload. A small sacrifice in total payload mass to LEO, but security in establishing a circular orbit right off the bat, without depending on the payload to make that critical burn required within 45 minutes of launch. That gives days of wiggle room to save the payload if any problem emerges.
The second reason might be limitations on the Long March 5B guidance protocol? I imagine Long March 5B might also be used to launch payloads without any maneuvering capacity, so it was designed to circularize orbit.
Those aren’t great reasons, but at least they are plausible.
The Chinese space program remains pretty mysterious to me. Often the choices they make seem extremely logical and practical, yet other times they make me go, “why?”
SLS delenda est