Space junk. We talk about visual pollution from satellites and constellations of satellites that move across pictures - unlike the constellations of stars. We talk about space junk like the Chinese Long March 6A rocket that failed a few weeks ago and broke up rather than re-entering whole and breaking up, or the ones that do come down intact. Most people have seen or heard of the movie Gravity, which was based on the idea of space junk causing a chain reaction of collisions that take down the space station.
But we don't talk about the general problem of space junk. Did you know that in November 2021, Russia shot down its own Cosmos 1408 satellite, creating more than 1,000 fragments in orbit. NASA's International Space Station still has to dodge this debris to this day.
A startup company called Privateer Space is trying to address this, work toward tools to ensure more complete information and keep low Earth orbit (I hate this word) sustainable. You'll probably recognize one of the three founders, the guy in the middle:
That's right, Steve Wozniak, better known as Woz. On the left is
astrodynamicist Moriba Jah, from the University of Texas, Austin, and on the
right is Alex Fielding, who appears to do the "routine CEO" stuff.
Three years ago, Dr. Jah did a TED talk about the space junk problem that's a good introduction, and today had a long interview published on Ars Technica.
The video is a short intro, and there's more content by far in the Ars interview. Privateer, I assume using his numbers, says that ground-based observers (primarily radar, as far as I know) track a bit over 27,000 pieces of space junk, but to be detected by those radars means they need to be around the size of a softball. Then they say the total number of "dangerous pieces of junk" is well into the millions - their website says 100 million. Further, of the 27,000 pieces of junk they're tracking, only a few thousand are actually working satellites in use.
Other estimates put the number of pieces of orbital debris about the size of a blueberry (which can't be tracked) in the hundreds of thousands of pieces. Given their velocities, these small objects have the kinetic energy of a falling anvil.
Like every other time you hear the word sustainable, there's mention of needing some sort of big governmental organization to coordinate things and set rules. To some extent, this has already been done in the UN, and in an example from the Ars interview, Dr. Jah says that if Russia were to damage a Starlink satellite, for example, the Russian government would be responsible. Likewise if SpaceX were to damage, say, China's space station, SpaceX wouldn't be responsible, the US Government would be. Companies bear no liability; their governments do.
Much of the frameworks that Dr. Jah is calling for already exists; he mostly talks of tweaks and refinements. He also talks about what he sees as likely things in the rest of this decade. I'll leave the last words to him.
This is where I put my realist hat on. I think we are going to lose the ability to use certain orbits because the carrying capacity is going to get saturated by objects and junk. Orbital capacity being saturated means "when our decisions and actions can no longer prevent undesired outcomes from occurring." So if we're trying to minimize having to move out of the way or bumping into each other, and no matter what we do we can't avoid that, that means that for all intents and purposes, that orbit highway is no longer usable.
I predict that that's going to happen. And I also predict that we will see a loss of human life by (1) school-bus sized objects reentering and surviving reentry and hitting a populated area, or (2) people riding on this wave of civil and commercial astronauts basically having their vehicle getting scwhacked by an unpredicted piece of junk. I predict that both those things are going to happen in the next decade.
I guess he doesn't count China dropping boosters on their own small villages. Those boosters were never space junk.
And this is where SpaceX is way ahead of the competition. They plan and execute systems to deorbit all their garbage. Unlike, say, the Russians or Red Chinese.
ReplyDeleteGet rid of or collect all the broken big pieces by either deorbiting or lifting to a specific garbage patch.
How to catch the little stuff? That's the difficult thing. Outfit large satellites and manned platforms with absorbative or sticky armor?
Glad someone is getting serious about it. There's been lots of talk, but very little action.
Like the sometimes absurdity of moving bolders to prepare for laying a home foundation, the stuff is already up there so figure a way to use it. Especially in consideration of the cost to get it up there in the fiest place.
ReplyDeleteDon't bring it back to earf, or blast it to deep space, pile it in a designated orbit to be useful when someone does invent the means to reuse. Stop calling it junk, start calling it not junk.
Veddy interestink you'd post this after posting Space X's launch schedule. While reading that, it was all I thought of; accumulation of space junk.
ReplyDeleteAfter working for GEODSS in '03 to '04, I know we were tracking 8000-plus objects in orbit. With the Chinese throwing their crap all over the place, it's MUCH worse now! And I'm pretty sure they blew up that booster to cause the debris field to interfere/collide with Starlink birds.
ReplyDeleteOrbital Roomba, and then programmed junk bundle dumps on a course to burn up over uninhabited ocean. First guy that does that, owns space, and/or the fees he can collect to clean it up. You could shake down every nation with liability and/or vulnerability, and you'd make a profit before you even launched. Full salvage rights on anything useful, as either an artifact, or actually useful. Charge by the gram.
ReplyDeleteSpace-X sub-corp. in 3, 2, ...
If Elon needs a project manager, I'm available.
Mega Maid from Spaceballs. "The vacuum of space."
DeleteDo note that, when you are unable to "USE" an orbit, you are also likely to be unable to LAUNCH through that same orbit.
ReplyDeleteIf it's dense enough, debris could be like a shell. I'm surprised he didn't talk about that aspect.
DeleteBeans. That makes sense, but I think that very large solar mirrors like those in John Ringo's "Troy Rising" would work, but I'm holding out for a large, spherical, self propelled space station that would use a single beam of destruction.
ReplyDeleteOn the other hand, as others said, you put a large amount of effort into getting those items into orbit and stowing them in a space junkyard makes more sense.
And, just in time to start confronting this problem, they discover better ways to make armor. It is possible that molecular engineering like this will result in a light skin that can be used to resist penetration by most of the small orbital debris:
ReplyDeletenewatlas(dot)com/materials/protein-based-armor-material-withstand-supersonic-impacts/
If nothing else, it might aid in building "nets" to herd the debris into a junk orbit.
I always get a little uncomfortable when I hear someone like Dr. Jah (in the video) talking about a screw or piece of metal junk moving at 18,000 mph. Yeah, they are, but it's the relative velocity that matters, and in any given orbit, the junk is moving at the same general speed and direction - or else they'd be moving into a different orbit. If the screw is moving 18,000 and you're moving 18,002, no big deal. If you're moving at 18,000 and it was somehow moving at you at 18,000, giving a relative difference of 36,000, that's rather different.
DeleteI think polar orbits intersecting non-polar orbits would be worst case, but I'd have to SWAG some trig off the top of my head to throw some numbers around.
In the case of a protein-based armor, what about momentum transfer? That's still going to be there.
As you say, the energy transfer is the problem. I don't know how much heat protein molecules can withstand. That said, there is a LOT of room for creative engineering here. If I were 30 years younger, I'd jump all over it.
Deleteand that's the way to solve it. Put a pile of money (potential market) on the table and let a bunch of engineers at the problem. Not a bunch of government regulators.
DeleteSiG, most people don't understand relative motion, nor do they understand Orbital Mechanics. Those of us who do, however, shudder when we hear retrograde orbit.
ReplyDeleteI shudder when I hear the old "paint chip traveling at 18,000 mph" line. The guy (Dr. Jah) is an "astrodynamicist" and that sure sounds like dynamics.
DeleteI wanted to say that if the satellites and the debris are going the same velocity, both magnitude and direction, that's called "flying in formation." It's the stuff moving in from another direction that's the problem. If they hit each other with a velocity difference of "a few" - mph or degrees - that's probably not a big deal.
Exactly. Just like the astronaut and his coffee are flying in formation. And the Earth and it's atmosphere are flying in formation around the sun.
DeleteAnd the gangbanger and his target are flying in formation down the Los Angeles freeway.
But most people cannot grasp vectors, let alone vector arithmetic. That shocked me when I figured that out. No wonder engineers get paid the big bucks...