[Keith_McClary]

Hi Agent R:

Please allow me try to explain this to you using something I bet you are familiar with. Have you ever used a handheld GPS unit? Do you know how they work?
..,
Its a simple fact that the positions of satellites and their velocities are precisely known, and its a simple fact that models exist that can project their positions for years into the future. Millions of people unwittingly use this technology in their GPS units. Its a simple fact that EVERY single potential close encounter between two satellites is identified years in advance, and the models said this one wasn't even going to be a close encounter.

The positions of the GPS sats are precisely known, but it's not clear how the positions of other sats, especially dead ones and space junk, could be precisely known. They do not have GPS transceivers.

And "models exist that can project their positions for years into the future" but these are no good for low orbits due to variations in the upper atmosphere.

[Plantagenet]

Hi Agent R:

Please allow me try to explain this to you using something I bet you are familiar with. Have you ever used a handheld GPS unit? Do you know how they work?
..,
Its a simple fact that the positions of satellites and their velocities are precisely known, and its a simple fact that models exist that can project their positions for years into the future. Millions of people unwittingly use this technology in their GPS units. Its a simple fact that EVERY single potential close encounter between two satellites is identified years in advance, and the models said this one wasn't even going to be a close encounter.

The positions of the GPS sats are precisely known, but it's not clear how the positions of other sats, especially dead ones and space junk, could be precisely known. They do not have GPS transceivers.

And "models exist that can project their positions for years into the future" but these are no good for low orbits due to variations in the upper atmosphere.

The positions of GPS satellites aren't known because there is a little man inside pushing the button on a GPS. They are known because they are forward calculated using orbital models. The GPS satellites do indeed recheck their positions internally using GPS technology, but the position calculated by your hand-held unit is done based on the mathematical model.

Their position (and the position of thousands of other satellites and pieces of space junk) is also precisely known because the US (and other countries) maintain networks of radar systems that can track everything down to quite small sizes. The satellites are being monitored to avoid collisions. The Russian and US satellites were not tiny....they were both huge.... close to a metric ton in weight....and both were being tracked and their positions were known and their orbital paths had been modeled for years into the future. These satellites weren't even expected to be close to one-another on the day the collision occurred.

[Plantagenet]

The Canadians have just released a report that Russia sent a nuclear-bomb capable bomber on a mission to fly across the Arctic Ocean towards Canada to coincide with Obama's state visit to Canada a couple of weeks ago.

Yet another not so subtle poke-in-the-chest from Russia.

[Plantagenet]

it's not clear how the positions of other sats, especially dead ones and space junk, could be precisely known. They do not have GPS transceivers..

There is this marvellous technology called "radar". Its been in use for about 70 years now. Using "radar" from ground stations the US can track satellites very accurately.

Here's what we know about the limits of the tracking capabilities..." the limitations of the US space tracking system—it can only reliably track debris particles greater than 5 to 10cm (2 to 4 inches)."


The tracking is used to test and calibrate the orbital models. Based on the "radar" calibrated orbital models, the Russian satellite wasn't where it was supposed to be when the collision occurred......

[TheDude]

Orbiting space junk heightens risk of satellite catastrophes - Ars Technica

Since 1991, there have been 8 major satellite collisions, not including China's ASAT test. This would lend credence to the number I calculated: given the number of active and inactive satellites, the chance of collisions are small, but non-zero.

This collision happened to occur in a particularly bad area, as mentioned previously. The altitudes where this collision occurred are already so congested with space debris that they are referred to as supercritical. That means debris is being generated through collisions at a faster rate than atmospheric drag can remove the existing debris from orbit.

He calculates that a major collision is a once in 44 years event. Also notes that US tracking radar can only follow objects larger than ca. 2 inches - leaving out the majority of debris, like that paint fleck that cracked a Shuttle windshield back in the 90s.

[Plantagenet]

Orbiting space junk heightens risk of satellite catastrophes - Ars Technica

Since 1991, there have been 8 major satellite collisions

This is potentially confusing since every piece of junk in orbit is technically referred to as a satellite. None of these prior collisions involved two huge satellites....they typically involved two small pieces of junk, such a piece of a rocket and a shard of debris a few centimeters across, and the collisions were only detectable because radar tracking of the orbits of the pieces of junk showed changes AFTER the collision.

http://www.spaceref.com/news/viewsr.html?pid=16201

The difference in the Iridium case is that the orbit of the Russian satellite must have changed PRIOR to the collision, because orbital models showed it passing no closer then a km to the Iridium satellite.

[Azothius]

Another Black Swan just waiting to hatch...

Two Dead Satellites May Collide Tonight. That's Really, Really Bad.
https://www.yahoo.com/finance/news/two- ... 00690.html

An incident such as this also has the potential to contribute to the sudden collapse of modern civilization:

According to the company's latest calculations, the objects are expected to come within 80 feet of each other (±59 feet). The probability of a collision is greater than 10 percent. If the satellites collide, the impact could spread a network of debris throughout low-Earth Orbit.

This exact scenario is one that spaceflight experts have been warning about for decades. Earth is shrouded in a web of space junk, with pieces ranging in size from flecks of paint to spent rocket stages. The United States Space Surveillance Network is currently monitoring roughly 200,000 objects between 0.4 and 4 inches, 14,000 objects larger than 4 inches, and thousands of larger objects.

In 1978, NASA scientist Donald Kessler published a landmark paper on the potential impacts of space junk collisions in Earth's orbit. He predicted a grim future in which a chain of collisions could send an impenetrable wave of debris out across low-Earth orbit, rendering the rest of the universe out of reach to humanity for decades.

[REAL Green]

Another Black Swan just waiting to hatch...

Two Dead Satellites May Collide Tonight. That's Really, Really Bad.
https://www.yahoo.com/finance/news/two- ... 00690.html

An incident such as this also has the potential to contribute to the sudden collapse of modern civilization:

More evidence of diminishing returns to technology. This phenomenon is starting to go nonlinear in some areas.

[AdamB]

Another Black Swan just waiting to hatch...

Two Dead Satellites May Collide Tonight. That's Really, Really Bad.
https://www.yahoo.com/finance/news/two- ... 00690.html

An incident such as this also has the potential to contribute to the sudden collapse of modern civilization:

Boy, you'll fall for just about anything, won't you?

There is Azothius, sitting in his/her residence, and their cable goes out because a satellite gets knocked out. "OMG!!!!" he/she says, this is the collapse of modern civilization!!

[Outcast_Searcher]

Another Black Swan just waiting to hatch...

Two Dead Satellites May Collide Tonight. That's Really, Really Bad.
https://www.yahoo.com/finance/news/two- ... 00690.html

An incident such as this also has the potential to contribute to the sudden collapse of modern civilization:

Greatly overstated, as usual by the doomers on this site.

I had read the story on a scientific site days ago, including the figures, odds, problems, etc.

First, it didn't happen this time.

Second, there are companies working on solutions, including sending up small satellites with heavy duty foam to catch LOTS of the small stuff. When they accumulate enough, their orbit decays due to the additional weight (but no additional velocity), and they burn up on re-entry.

A horrendous and expensive way to deal with just part (the small stuff) of the mess, but an example of how the issue is not at all hopeless (the way fast crash doomers try to portray nearly every issue, at EVERY turn, which is what makes them completely lack credibility).

Also, losing most access to space for years would be HIGHLY inconvenient and expensive. It would NOT mean collapse of modern civilization or anything close to that, even if satellite maintenance became very difficult for awhile.

As usual with MANY modern problems, it's sad and very stupid that we WAIT to DO anything meaningful about it until the threat is HUGE, but if nothing else, humans as large groups are FANTASTIC about procrastination, instead arguing about or ignoring serious issues.

So as usual, continuing to stumble along, mostly stupidly, is a FAR more likely scenario for the next decade or three (or many many more) than swift doom from man-made issue X.

[Outcast_Searcher]

Another Black Swan just waiting to hatch...

Two Dead Satellites May Collide Tonight. That's Really, Really Bad.
https://www.yahoo.com/finance/news/two- ... 00690.html

An incident such as this also has the potential to contribute to the sudden collapse of modern civilization:

Greatly overstated, as usual by the doomers on this site.

I had read the story on a scientific site days ago, including the figures, odds, problems, etc.

First, it didn't happen this time.

Second, there are companies working on solutions, including sending up small satellites with heavy duty foam to catch LOTS of the small stuff. When they accumulate enough, their orbit decays due to the additional weight (but no additional velocity), and they burn up on re-entry.

A horrendous and expensive way to deal with just part (the small stuff) of the mess, but an example of how the issue is not at all hopeless (the way fast crash doomers try to portray nearly every issue, at EVERY turn, which is what makes them completely lack credibility).

Also, losing most access to space for years would be HIGHLY inconvenient and expensive. It would NOT mean collapse of modern civilization or anything close to that, even if satellite maintenance became very difficult for awhile.

As usual with MANY modern problems, it's sad and very stupid that we WAIT to DO anything meaningful about it until the threat is HUGE, but if nothing else, humans as large groups are FANTASTIC about procrastination, instead arguing about or ignoring serious issues.

So as usual, continuing to stumble along, mostly stupidly, is a FAR more likely scenario for the next decade or three (or many many more) than swift doom from man-made issue X.

Oh, and given the massive projects to put tens of thousands of low orbit WIFI satellites up in coming years to blanket the earth with reliable and high capacity WIFI service everywhere, hopefully there is plenty of financial incentive to actually want to DEAL with the problem -- if nothing else, because it's better than the alternative re keeping such a system(s) running reliably and at massive profits.

[Newfie]

Another Black Swan just waiting to hatch...

Two Dead Satellites May Collide Tonight. That's Really, Really Bad.
https://www.yahoo.com/finance/news/two- ... 00690.html

An incident such as this also has the potential to contribute to the sudden collapse of modern civilization:

Boy, you'll fall for just about anything, won't you?

There is Azothius, sitting in his/her residence, and their cable goes out because a satellite gets knocked out. "OMG!!!!" he/she says, this is the collapse of modern civilization!!

Adam,

You need to lighten up a good bit.

This post post could easily be classified as a purely personal attack and be deleted.

[Subjectivist]

Another Black Swan just waiting to hatch...

Two Dead Satellites May Collide Tonight. That's Really, Really Bad.
https://www.yahoo.com/finance/news/two- ... 00690.html

An incident such as this also has the potential to contribute to the sudden collapse of modern civilization:

Greatly overstated, as usual by the doomers on this site.

I had read the story on a scientific site days ago, including the figures, odds, problems, etc.

First, it didn't happen this time.

Second, there are companies working on solutions, including sending up small satellites with heavy duty foam to catch LOTS of the small stuff. When they accumulate enough, their orbit decays due to the additional weight (but no additional velocity), and they burn up on re-entry.

A horrendous and expensive way to deal with just part (the small stuff) of the mess, but an example of how the issue is not at all hopeless (the way fast crash doomers try to portray nearly every issue, at EVERY turn, which is what makes them completely lack credibility).

Also, losing most access to space for years would be HIGHLY inconvenient and expensive. It would NOT mean collapse of modern civilization or anything close to that, even if satellite maintenance became very difficult for awhile.

As usual with MANY modern problems, it's sad and very stupid that we WAIT to DO anything meaningful about it until the threat is HUGE, but if nothing else, humans as large groups are FANTASTIC about procrastination, instead arguing about or ignoring serious issues.

So as usual, continuing to stumble along, mostly stupidly, is a FAR more likely scenario for the next decade or three (or many many more) than swift doom from man-made issue X.

Oh, and given the massive projects to put tens of thousands of low orbit WIFI satellites up in coming years to blanket the earth with reliable and high capacity WIFI service everywhere, hopefully there is plenty of financial incentive to actually want to DEAL with the problem -- if nothing else, because it's better than the alternative re keeping such a system(s) running reliably and at massive profits.

I don't think it is an immediate problem, however this is an issue that has been growing since at least the 1970's. In more recent times most countries require that the upper stages of launch vehicles be put into a rapidly decaying orbit so that they don't become more uncontrolled space junk in orbit, but in the earlier days this was not a consideration. As a result the USAF-Space Force tracks hund5reds or orbiting upper stages from launches that are completely uncontrolled and orbiting at (obviously) great speed. They constantly update the orbital data so that new vehicles and existing satellites can avoid the uncontrolled junk and for the most part this is successful. However they only track stuff about 10cm(4 inches) in size and up so paint flecks, nuts, bolts and other objects that fall apart are not tracked. It is estimated these now number in the tens of thousands of objects. If you don't believe a bolt weighing half an ounce can destroy a satellite if they hit one another in opposing orbits then you do not understand how much of a shooting gallery things are becoming. A simple bolt even if made of aircraft grade aluminum in an opposing orbit impacts with a closing speed of 34,000 mph which is 20 times the speed of a bullet as it leaves the muzzle of a hunting rifle. It doesn't pierce through the satellite, it vaporizes on impact. The resulting lance of plasma sprays through the satellite the same way an anti-tank RPG does by using a shaped charge to convert is copper payload into a plasma lance of copper. The results are catastrophic to say the least, especially if the plasma goes through any of the fuel tanks for the attitude and control thrusters.

When the two objects impacting are larger like two dead satellites in crossing orbits the section of mass on both where the silhouettes overlap in the collision are converted into highly energetic plasma and the mass outside the overlap is thrown away in all directions as if a very large chemical bomb had been set off in the middle of a junk car. This happened about a decade ago and the resulting junk is still up there like twin shotgun blasts of debris that is still following in tracks roughly aligned to the two original orbits.

As for the proposed plastic catchers mitt arrangement to start clearing out the orbital junk, they sound great. Unfortunately nobody has actually launched them even as a proof of concept and if they work as advertised they will be very expensive when you count the number of junk collectors that will have to be launched to clean up the mess we have left behind in orbit. And before anyone says it, yes atmospheric drag will eventually knock everything back down that is in orbit now, but the higher the orbit the longer it takes. For stuff in the same orbits used by the ISS you are talking a decade or two. For stuff in intermediate orbits like the leftover parts from Apollo tests of the 1960's you are talking about up to a century, and for Geosynchronous orbits where the cable satellite and other communications birds orbit you are talking millennia. Every year there are more nations launching stuff into orbit and truthfully hardly a day goes by now that someone somewhere isn't launching something.

http://www.spacesafetymagazine.com/spac ... -syndrome/

https://youtu.be/iEAp_6Jo5O4

https://www.youtube.com/watch?v=4iIO4t2dRAw

[Azothius]

Another Black Swan just waiting to hatch...

Two Dead Satellites May Collide Tonight. That's Really, Really Bad.
https://www.yahoo.com/finance/news/two- ... 00690.html

An incident such as this also has the potential to contribute to the sudden collapse of modern civilization:

Boy, you'll fall for just about anything, won't you?

There is Azothius, sitting in his/her residence, and their cable goes out because a satellite gets knocked out. "OMG!!!!" he/she says, this is the collapse of modern civilization!!

LOL!

Luckily, I don't have cable so I won't be startled quite so easily.

[Tanada]

China, which has been quietly but steadily entering the space business over the last two decades, has just demonstrated a new capability. Some "Blame China for everything" types are freaking out because this capability could be used to mess with other nations satellites.

I however see this as China demonstrating both that they have a capability nobody else has to this point deployed and they are willing to use it to keep their portion of the extremely valuable Geosynchronous space uncluttered by dead and therefore troublesome satellites.

For those who are unaware Geosynchronous orbits are at a precise altitude so that they circle the earth at the equator exactly once each day. When these satellites are "retired" deliberately they are boosted to a higher drift orbit if possible to get them out of the way but this part of orbit has at least 12 and possibly as many as 120 dead satellites or satellites out of fuel and disabled that require each new bird to be 'slotted in' between other objects. China could earn quite a but for themselves clearing the dead junk out of the way in some of the more crowded spaces like those used by the USA for cable TV and Telephone relay signals. We have some dead satellites up there dating back to the mid 1960's that it would be convenient to get out of the way. If we pay China to do it that is great diplomacy, if they do it without permission it is an act of piracy and could lead to bad things happening.

A Chinese Satellite Just Grappled Another And Pulled It Out Of Geosynchronous Orbit

A Chinese satellite was observed grabbing another satellite and pulling it out of its normal geosynchronous orbit and into a “super-graveyard drift orbit.” The maneuver raises questions about the potential applications of these types of satellites designed to maneuver close to other satellites for inspection or manipulation and adds to growing concerns about China's space program overall.

On January 22, China’s Shijian-21 satellite, or SJ-21, disappeared from its regular position in orbit during daylight hours when observations were difficult to make with optical telescopes. SJ-21 was then observed executing a “large maneuver” to bring it closely alongside another satellite, a dead BeiDou Navigation System satellite. SJ-21 then pulled the dead satellite out of its normal geosynchronous orbit and placed it a few hundred miles away in what is known as a graveyard orbit. These distant orbits are designated for defunct satellites at the end of their lives and are intended to reduce the risk of collision with operational assets.

The unusual maneuver was observed by telescopes belonging to commercial space awareness firm Exoanalytic Solutions. During a webinar hosted by the Center for Strategic and International Studies (CSIS) this week, Exoanalytic Solutions’ Brien Flewelling said the SJ-21 satellite “appears to be functioning as a space tug.” Space Command did not respond to a request for comment, Breaking Defense reports.

Space Force has been increasingly turning to commercial space companies to provide a variety of data and services to boost its situational awareness, and to that end, Joint Task Force-Space Defense awarded Exoanalytic Solutions a contract in 2021 to provide space domain data. “Comms, data relay, remote sensing, and even ISR and some other things — [these] capabilities are increasingly available in the commercial market,” Space Force deputy Lt. Gen. David Thompson said last year.

SJ-21, or Shijian-21, was launched in October 2021 atop a Long March-3B rocket. The satellite is officially designated as an On-Orbit Servicing, Assembly, and Manufacturing, or OSAM satellite, a broad class of satellites designed with capabilities to get close to and interact with other satellites. Such systems could enable a wide range of applications including extending the life of existing satellites, assembling satellites in orbit, or performing other maintenance and repairs. According to Chinese state news outlets, SJ-21 was designed to “test and verify space debris mitigation technologies.”

SJ-21’s recent maneuver raises questions and concerns about these types of satellites and their potential for military use. Todd Harrison, director of CSIS’s Aerospace Project, told Breaking Defense that SJ-21’s actions present “more questions than answers,” adding that while we can observe the satellite’s actions, “the intent behind it and what China plans to do with this technology is a more subjective assessment.”

This isn’t the first time SJ-21 has made headlines with its questionable behavior. In November 2021, just a month after its launch, an unknown object was seen orbiting alongside SJ-21. At the time, Space Force designated the unidentified object as a spent apogee kick motor, but it was also reported that it might have been an experimental payload designed to test SJ-21’s ability to perform remote operations and manipulate other satellites.

The United States Air Force’s China Aerospace Studies Institute (CASI) published a report on Shijian-21 last year shortly after its unknown companion appeared. The report notes that “Even Chinese media, academics, and bloggers agree with Western analysts that remote proximity operation capabilities and robotic arm technologies are dual-use,” meaning they have potential military applications in addition to scientific or utility ones. The report mentions unverified claims that SJ-21 might have some form of net used to capture space debris, claims which have also appeared on social media.

Analyzing the potential applications of these dual-use satellites is difficult. As CASI notes, while SJ-21’s previous behaviors demonstrate “technology to potentially enable weapons or reconnaissance capabilities,” they are also perfectly in line with China’s peaceful economic and scientific goals in space, particularly related to debris removal.

Still, if SJ-21 can grab a dead satellite and move it out of orbit, there is likely little stopping it from doing the same thing to an operational one the American military depends upon. It’s important to note that the United States is also exploring on-orbit servicing capabilities that will likely prompt similar concerns from America's competitors. Northrop Grumman is developing a satellite featuring a DARPA-made robotic arm for a planned launch in 2024 that is capable of “detailed inspections, relocations of client vehicles or simple repairs such as releasing a solar array that is stuck or an antenna that doesn’t deploy properly.”
Artwork for NASA's OSAM-1, a robotic spacecraft equipped with the ability to grasp and relocate satellites., NASA

The fact that China has these capabilities in orbit now underscores concerns the Pentagon has been voicing in recent years about China’s rapidly advancing space capabilities. James Dickinson, commander of United States Space Command, told Congress last year that Chinese satellites like SJ-21 and others “could be used in a future system for grappling other satellites.” As early as 2013, there have been reports of Chinese satellites using robotic arms to grab other satellites. A robotic arm launched aboard the Tianhe module of China’s Tiangong space station has displayed similar capabilities.

Those concerns aren’t unfounded. In another direct example of this potential threat, an American spy satellite was shadowed closely in 2020 by a Russian “space apparatus inspector” believed to have capabilities similar to SJ-21. Maneuvering one satellite close to another in orbit is a technologically complex proposition, and there is always the possibility of an unintentional collision occurring during one of these operations. There are also concerns about adversary satellites with more destructive capabilities such as high-powered microwaves or the ability to launch projectiles. Any satellite that has the ability to maneuver in close proximity to another could potentially carry out a variety of attacks on it such as jamming its transmissions, blinding its sensors, spraying aerosols on its solar panels and optics, physically manipulating it, or moving it out of orbit as in the case of Shijian-21's recent operation.
An infographic from the Defense Intelligence Agency depicting a number of ways in which one satellite might attack another, including by acting as a kinetic kill vehicle., DIA

With all of these developments, it’s no wonder Space Force recently expanded its Geosynchronous Space Situational Awareness Program aimed at keeping an eye on other satellites in the same orbit as SJ-21 where many of America’s critical early warning and spy satellites reside. Some Pentagon leadership have also argued that declassification of America’s space-based capabilities could help serve as a deterrent and boost support for Space Force.

As Shijian-21’s recent actions demonstrate, there is a pressing need for the United States to be able to defend its assets in distant orbit. It’s likely we could see similar shows of force in the near term as Space Force responds to other nations’ demonstrations of “killer” satellite capabilities.

LINK

[Subjectivist]

China, which has been quietly but steadily entering the space business over the last two decades, has just demonstrated a new capability. Some "Blame China for everything" types are freaking out because this capability could be used to mess with other nations satellites.

I however see this as China demonstrating both that they have a capability nobody else has to this point deployed and they are willing to use it to keep their portion of the extremely valuable Geosynchronous space uncluttered by dead and therefore troublesome satellites.

For those who are unaware Geosynchronous orbits are at a precise altitude so that they circle the earth at the equator exactly once each day. When these satellites are "retired" deliberately they are boosted to a higher drift orbit if possible to get them out of the way but this part of orbit has at least 12 and possibly as many as 120 dead satellites or satellites out of fuel and disabled that require each new bird to be 'slotted in' between other objects. China could earn quite a but for themselves clearing the dead junk out of the way in some of the more crowded spaces like those used by the USA for cable TV and Telephone relay signals. We have some dead satellites up there dating back to the mid 1960's that it would be convenient to get out of the way. If we pay China to do it that is great diplomacy, if they do it without permission it is an act of piracy and could lead to bad things happening.

The fact that China went from essentially no space program in 1992 to having capabilities the USA/NASA/ESA still lacks is IMO a very sad commentary on the space programs of both NASA and the ESA. So long as the ISS is in orbit with a handful of astronauts perpetually circling the earth the western politicians appear to be happy to not do anything useful. The concerns about junk in space causing crowding and occasional collisions is not remotely a new issue, it was first pointed out as a potential problem in the early 1970's!

Heck they even made a movie about what a potential disaster it is a few years ago starring Sandra Bullock! Ironically the movie Gravity came out two years after the Space Shuttle was permanently grounded yet it stars the Space Shuttle, the ISS and a Chinese space station. https://www.imdb.com/title/tt1454468/?ref_=nv_sr_srsg_0

[Tanada]

Getting space junk under control may require an attitude shift



This NASA graphic depicts the amount of space junk orbiting Earth. The debris field is based on data from NASA's Orbital Debris Program Office. Image released on May 1, 2013. (Image credit: NASA's Goddard Space Flight Center/JSC)

There's a lot of discussion these days about the best way to deal with our growing space debris problem.

No single answer will likely serve as a silver bullet, partly because the issue is a global one. Indeed, space junk experts have characterized it as a "tragedy of the commons."

Exacerbating this state of affairs is the rise of worldwide launch rates, which is driven to a significant extent by the assembly of satellite megaconstellations like SpaceX's Starlink broadband network.

https://www.space.com/kessler-syndrome-space-debris

Then there's the associated clutter of dead or dying spacecraft, spent rocket stages and myriad other pieces of human-made leftovers, from effluents belched out by solid rocket motors to stray nuts and bolts to paint chips to droplets bubbling out of spacecraft coolant systems, some of them radioactive. And toss in, for good measure, shards of satellites blasted apart during anti-satellite tests.

In short, it's a heavenly mess — with long-term consequences.

"With nearly 5,000 operational satellites and over 30,000 pieces of trackable debris, the ability to operate safely in space is growing increasingly challenging," Paul Bate, chief executive of the U.K. Space Agency, said in a statement (opens in new tab) last month.
Lofty ambition

For many years, multiple ideas have been put forth to clean up the space environment, including fishing-like nets, harpoons, laser blasts, de-orbiting tethers, solar sails and grappling by spacecraft outfitted with robotic arms.

However we're able to do it, "taking out the trash" in orbit would guide us toward space sustainability — the ability of all spacefaring nations to continue to use outer space for the benefit of all.

That's a lofty ambition, yes, but it's one that's addressed by the Orbital Sustainability Act of 2022 (opens in new tab) (ORBITS Act), which was introduced in the U.S. Senate on Sept. 12. The bipartisan bill seeks to "establish a demonstration program for the active remediation of orbital debris" and "require the development of uniform orbital debris standard practices in order to support a safe and sustainable orbital environment."

Then there's the U.S. Federal Communications Commission (FCC) action to shape new rules to reduce the risks caused by orbital debris, by shrinking the time that defunct satellites stay aloft. The FCC recently voted favorably to dispose of low-Earth orbit satellites within five years, not within 25 years as previously recommended to satellite operators.

"The changes being made seem to be in the right direction," said Don Kessler, a now-retired NASA senior scientist who has done pioneering orbital debris research. Indeed, the Kessler Syndrome — a feared cascade of space debris collisions that would generate ever more orbital clutter — is named after him.

"The FCC could become the regulatory agency that ensures NASA guidelines are followed," Kessler told Space.com. "Shortening the '25-year Rule' to five years would be a significant improvement, given the large number of operators of constellations in low Earth orbit who said they could easily meet a five-year rule. The FCC will need NASA's debris models to predict the outcome of any proposed changes."

Breakups in Earth orbit have been recorded since 1961. Most have been caused by explosions of satellites and rocket upper stages, rather than collisions between objects. (Image credit: ESA/ID&Sense/ONiRiXEL, CC BY-SA 3.0 IGO)
Come clean on the situation

The FCC adopting a five-year rule to get things out of orbit would be "a step in the right direction," said T.S. Kelso, senior research astrodynamicist for Analytical Graphics, Inc. and lead space debris authority for the Center for Space Standards and Innovation in Colorado Springs and Wailuku, Hawaii. However, he added, "it quite simply isn't enough."

"We need to change people's attitudes about the space environment," Kelso told Space.com. "While it seems a somewhat ambiguous goal, we can't really effect change without getting people to change their fundamental view of what should be done. Not how it could be done."

It is one thing to recognize that pollution of the near-Earth space environment is bad, Kelso said, but it is quite another to accept that we should change our behavior.

"Specifically, people — both in and out of the space community — should acknowledge that we should not leave things in orbit once their mission is complete," he said. "So, a rocket that is used to launch a satellite should be removed once it has delivered its payload to orbit. The same is true for a satellite that has reached its planned end of life. Get it out of orbit while it still has fuel and is controllable."
Competitive phase

It's important to take action against space junk now, many experts say, because low Earth orbit (LEO) is only going to get more and more crowded in the future.

"The LEO constellation market is in the early stages of growth, with all indications that it will evolve into a vibrant market," said Brad King, CEO of Orbion Space Technology in Houghton, Michigan.

"The benefits of LEO constellations are now undeniable. Early entrants, such as Planet and SpaceX, have shown that it is possible to deploy large constellations and that the satellites can provide disruptive and valuable benefit to the global economy and society," King told Space.com. "Once the planet becomes accustomed to these services from space, we will incorporate them into our life, and we will come to expect them and take them for granted."

The market is now transitioning into a competitive phase, King said, in which multiple companies will look for the right business model and will learn from each other's successes and failures.

"After this phase will come consolidation, where the successful companies merge and/or absorb less successful competitors and then, finally, stabilization to a less-dynamic list of companies that will become the long-term space providers," he said.

At the moment, the biggest risks to space sustainability are orbital debris and traffic congestion, King said. "Both can lead to collisions, which amplifies the problem," he said. Orbion's propulsion systems, he added, allow each satellite to maneuver during their mission and also to safely dispose of themselves when their time is up.

Those two capabilities are important in preventing space collisions, along with knowing where space objects are and sharing that information with other operators, King said.

The cost of doing nothing

How should dying spacecraft bring themselves down? There are multiple options, each of which has costs associated with it, Kelso said.

Using a high-thrust de-orbiting method would require extra fuel and the added weight of a larger engine but would remove an object more quickly and likely in a controlled fashion, Kelso said. Using a low-thrust method, he continued, may cost less up front, but it leaves the object up longer and presents an increased risk of collision, and the ability to control where reentry occurs is diminished, increasing risk of damage on the Earth's surface.

"These risks and the potential consequences must be weighed against the up-front costs. But there is also a cost of doing nothing and, as we are beginning to understand, it will be more expensive to clean things up later than to simply prevent the problem in the first place," said Kelso. "We should have learned this by now from every other environment we have polluted."
Disposal plan

In Kelso's view, each launch should include a disposal plan for all of the objects that it sends to orbit.

"Perhaps there is some incentive program to get satellite operators and launch providers to adhere to their plan, such as a 'security deposit' that is made prior to launch, which is fully refundable if the disposal plan is executed as planned," he said.

The bottom line for Kelso is that, just like air, land and water resources, near-Earth space is not limitless.

"Once people accept that and advocate for a commonsense approach to 'pack out' whatever we 'pack in,' getting launch providers and satellite operators to work toward that goal should just become the right thing to do," he said. "Then industry can innovate to determine how to best achieve those goals."

Leonard David is an award-winning space journalist who has been reporting on space activities for more than 50 years. Currently writing as Space.com's Space Insider Columnist among his other projects, Leonard has authored numerous books on space exploration, Mars missions and more, with his latest being "Moon Rush: The New Space Race" published in 2019 by National Geographic. He also wrote "Mars: Our Future on the Red Planet" released in 2016 by National Geographic. Leonard has served as a correspondent for SpaceNews, Scientific American and Aerospace America for the AIAA. He was received many awards, including the first Ordway Award for Sustained Excellence in Spaceflight History in 2015 at the AAS Wernher von Braun Memorial Symposium. You can find out Leonard's latest project at his website and on Twitter.

Space Junk

[Outcast_Searcher]

satellite up there to within a centimeter at all times.

Please provide a link to an official claiming such a degree of accuracy.

This is the same guy who has repeatedly claimed BEV batteries are dangerous and cause cancer (though we know that non-ionizing radiation is not considered a meaningful cancer risk, re modern science).

He claims much but actually can prove little, generally. It's what his ilk does.

When I do google searches on satellites, I get results in terms of thousandths of a kilometer, AKA meters, AKA 100 times a centimeter. And whether the results they give are estimates or considered guaranteed accurate, even to a meter, is an open question.

[Plantagenet]

When I do google searches on satellites, I get results in terms of thousandths of a kilometer, AKA meters, AKA 100 times a centimeter. And whether the results they give are estimates or considered guaranteed accurate, even to a meter, is an open question.

I'm always happy to help you out, OC, even when you dredge something up from a thread that has been inactive for over a decade.

In this case you are confusing the accuracy that can be achieved using GPS on your cell phone, which is usually about +/- four meters, with the accuracy involved in scientific work using GPS satellites. I've worked on scientific GPS studies myself, and I'm sure you haven't, and perhaps that is why you have misunderstood and misinterpreted this discussion.

Lets start with the GPS accuracy you get on your phone or on a handheld GPS device.....Your phone calculates your position by very quickly and very roughly determining the distance to 3-4 GPS satellites and calculates a position with an accuracy of ca. +/- 4 meters. However, this accuracy can be improved dramatically by continuously measuring the position over the periods of hours. This is the method that surveyors use when they use GPS to precisely locate their "corners" and surveyed points for land surveying.

And scientists take this concept much much farther. My colleagues and I have put multiple GPS receivers in the field here in Alaska for months at a time....and sometimes have installed GPS stations that can operate continuously for a year or even for multiple years (see pic below). Years ago we had to haul multiple car batteries out to the site to power the GPS unit....now we tend to use solar cells to charge the GPS system. The reason the GPS units are left in the field for so long is because when a GPS instrument collects data over very long periods of time, it can achieve truly remarkably precise locations accurate to the centimeter range and even to the millimeter range. We need this kind of accuracy because we are looking in "real time" at like things like volcano deformation or plate motion in real time, which typically amounts to only a few millimeters to a few centimeters PER YEAR.

If you want to learn more, here is a link to video produced by the US National Science Foundation and UNAVCO on the techniques and accuracy that can be obtained by using the GPS techniques I have briefly sketched out for you above.

NSF/UNAVCO GPS and PLATE TECTONICS

I hope this helps you increase your understanding of this very interesting subject.


Typical installation of a long term GPS station similar to those we use here in Alaska

Cheers!