space debris Archives

June 21, 2017January 16, 2018 by Matt Williams

Let’s Clean up the Space Junk with Magnetic Space Tugs

In the future, derelict satellites could be grappled and removed from key orbits around Earth with a space tug using magnetic forces. Credit: Philippe Ogaki

After 50 years of sending rockets, satellites, and payloads into orbit, humanity has created something of a “space junk” problem. Recent estimates indicate that there are more than 170 million pieces of debris up there, ranging in size from less than 1 cm (0.4 in) to a few meters in diameter. Not only does this junk threaten spacecraft and the ISS, but collisions between bits of debris can cause more to form, a phenomena known as the Kessler Effect.

And thanks to the growth of the commercial aerospace industry and the development of small satellites, things are not likely to get any less cluttered up there anytime soon. Hence why multiple strategies are being explored to clean up the space lanes, ranging from robotic arms and nets to harpoons. But in what may be the most ambitious plan to date, the ESA has proposed creating space tugs with powerful magnets to yank debris out of orbit.

The concept comes from Emilien Fabacher, a researcher from the Institut Supérieur de l’Aéronautique et de l’Espace at the University of Toulouse, France. His concept for a magnetic tug seeks to address one type of space debris in particular – inoperable satellites. These uncontrolled, rapidly spinning objects often weigh up to several tons, and are therefore one of the most significant collision hazards there is.

*Illustration showing the problem of space debris. Credit: ESA*

When applied to the problem of orbital debris, magnetic attraction is an attractive solutions for the safe deorbiting of spent satellites. For starters, it relies on technology that is standard issue aboard many low-orbiting satellites, which is known as magnetorquers. These electromagnets allow satellites to adjust their orientation using the Earth’s magnetic field. Hence, debris-chasing satellites would not need to be specially equipped in advance.

What’s more, this same magnetic attraction or repulsion technology is being considered as a safe method for allowing multiple satellites to maintain close formations in space. Such satellites – like NASA’s Magnetospheric Multiscale mission (MMS), the Landsat 7 and the Earth Observing-1 satellites, and the ESA’s upcoming LISA mission – are either operational or soon will be around Earth.

Because of this, this kind of magnetic attraction technology presents a safe and effective alternative for deorbiting space junk. As Fabacher explained in a recent ESA press release:

“With a satellite you want to deorbit, it’s much better if you can stay at a safe distance, without needing to come into direct contact and risking damage to both chaser and target satellites. So the idea I’m investigating is to apply magnetic forces either to attract or repel the target satellite, to shift its orbit or deorbit it entirely.”

*Artist’s impression of the ESA’s proposed Darwin mission, six formation-flying satellites that would look for exoplanets. Credit: ESA/Medialab*

The concept emerged out of a conversation Fabacher had with experts from the ESA’s technical center in the Netherlands. As part of his PhD research, he was looking into how magnetic guidance, navigation and control techniques would work in practice. This led to a discussion about how similar technology could allow swarms of satellites to attract and remove debris from orbit.

After making some calculations that combined a rendezvous simulator with magnetic interaction models, and also taking account the ever-changing state of Earth’s own magnetosphere, Fabacher and his colleagues realized they had a working concept. “The first surprise was that it was indeed possible, theoretically – initially we couldn’t be sure, but it turns out that the physics works fine,” he said.

To break it down, the chaser satellites would generate a strong magnetic field using superconducting wires that are cooled to cryogenic temperatures. These satellites would also rely on magnetic fields to maintain precise flying formations, thus allowing a swarm of chaser satellites the ability to deal with multiple pieces of debris, or to coordinate and guide debris to a specific location.

According to Finn Ankersen – an ESA expert in rendezvous and docking and formation flight – these magnetic tugs would also be able to remove space debris with a very high level of precision. “This kind of contactless magnetic influence would work from about 10–15 meters out, offering positioning precision within 10 cm with attitude precision [of] 1 – 2º,” he said.

*Why Space Debris Mitigation is needed. Click for animation. Credit: ESA*

The concept is being developed with support provided by the ESA’s Networking/Partnering Initiative, a program that offers support to universities and research institutes for the sake of developing space-related technologies. And it comes at a time when the issue of space debris is becoming increasingly worrisome.

Left unchecked, space debris is likely to become a very serious hazard in the coming years and decades. Already, it is estimated that the small satellite market will grow by $5.3 billion in the next decade (according to Space Works and Eurostat) and many private companies are looking to provide regular launch services to accommodate that growth.

If we intend to begin making a return to the Moon and mounting missions to Mars, we need to make sure the space lanes are clear! And given the importance of the International Space Station to scientific research and international collaboration, and with companies like Bigelow Aerospace looking to establish space habitats in orbit, something has to be done about this problem before it gets completely out of control!

Who knows? Maybe a small fleet or magnetic tugs is just what we need to clean up this mess!

Further Reading: ESA

January 6, 2017December 3, 2018 by Matt Williams

What is Low Earth Orbit?

Artist's impression of debris in low Earth orbit. Credit: ESA

Beginning in the 1950s with the Sputnik, Vostok and Mercury programs, human beings began to “slip the surly bonds of Earth”. And for a time, all of our missions were what is known as Low-Earth Orbit (LEO). Over time, with the Apollo missions and deep space missions involving robotic spacecraft (like the Voyager missions), we began to venture beyond, reaching the Moon and other planets of the Solar System.

But by and large, the vast majority of missions to space over the years – be they crewed or uncrewed – have been to Low-Earth Orbit. It is here that the Earth’s vast array of communications, navigation and military satellites reside. And it is here that the International Space Station (ISS) conducts its operations, which is also where the majority of crewed missions today go. So just what is LEO and why are we so intent on sending things there? Continue reading “What is Low Earth Orbit?”

April 19, 2016May 5, 2016 by Matt Williams

NASA Invests In Radical Game-Changing Concepts For Exploration

Artist's concept of some of the Phase I winners of the 2016 NIAC program. Credit: NASA

Every year, the NASA Innovative Advanced Concepts (NIAC) program puts out the call to the general public, hoping to find better or entirely new aerospace architectures, systems, or mission ideas. As part of the Space Technology Mission Directorate, this program has been in operation since 1998, serving as a high-level entry point to entrepreneurs, innovators and researchers who want to contribute to human space exploration.

This year, thirteen concepts were chosen for Phase I of the NIAC program, ranging from reprogrammed microorganisms for Mars, a two-dimensional spacecraft that could de-orbit space debris, an analog rover for extreme environments, a robot that turn asteroids into spacecraft, and a next-generation exoplanet hunter. These proposals were awarded $100,000 each for a nine month period to assess the feasibility of their concept.

Continue reading “NASA Invests In Radical Game-Changing Concepts For Exploration”

July 2, 2015February 27, 2017 by Fraser Cain

How Do Astronauts Avoid Debris?

So, just how do we keep our space stations, ships and astronauts from being riddled with holes from all of the space junk in orbit around Earth?

We revel in the terror grab bag of all the magical ways to get snuffed in space. Almost as much as we celebrate the giant brass backbones of the people who travel there.

We’ve already talked about all the scary ways that astronauts can die in space. My personal recurring “Hail Mary full of grace, please don’t let me die in space” nightmare is orbital debris.

We’re talking about a vast collection of spent rockets, dead satellites, flotsam, jetsam, lagan and derelict. It’s not a short list. NASA figures there are 21,000 bits of junk bigger than 10 cm, 500,000 particles between 1 and 10 cm, and more than 100 million smaller than 1 cm. Sound familiar, humans? This is our high tech, sci fi great Pacific garbage patch.

Sure, a tiny rivet or piece of scrap foil doesn’t sound very dangerous, but consider the fact that astronauts are orbiting the Earth at a velocity of about 28,000 km/h. And the Tang packets, uneaten dehydrated ice cream, and astronaut poops are also traveling at 28,000 km/h. Then think about what happens when they collide. Yikes… or yuck.

Here’s the International Space Station’s solar array. See that tiny hole? Embiggen and clarinosticate! That’s a tiny puncture hole made in the array by a piece of orbital crap.

The whole station is pummeled by tiny pieces of space program junk drawer contents. Back when the Space Shuttle was flying, NASA had to constantly replace their windows because of the damage they were experiencing from the orbital equivalent of Dennis the Menace hurling paint chips, fingernail clippings, and frozen scabs.

That’s just little pieces of paint. What can NASA do to keep Sandra Bullock safe from the larger, more dangerous chunks that could tear the station a new entry hatch?

For starters, NASA and the US Department of Defense are constantly tracking as much of the orbital debris that they can. They know the position of every piece of debris larger than a softball. Which I think, as far as careers go, would be grossly underestimated for its coolness and complexity at a cocktail party.

“What do you do for a living?”
“Me, oh, I’m part of the program which tracks orbital debris to keep astronauts safe.”
“So…you track our space garbage?”
“Uh, actually, never mind, I’m an accountant.”

Furthermore, they’re tracking everything in low Earth orbit – where the astronauts fly – down to a size of 5 cm. That’s 21,000 discrete objects.

NASA then compares the movements of all these objects and compares it to the position of the Space Station. If there’s any risk of a collision, NASA takes preventative measures and moves the Space Station to avoid the debris.

The ISS has thrusters of its own, but it can also use the assistance of spacecraft which are docked to it at the time, such as a Russian Soyuz capsule.

NASA is ready to make these maneuvers at a moment’s notice if necessary, but often they’ll have a few days notice, and give the astronauts time to prepare. Plus, who doesn’t love a close call?

For example, in some alerts, the astronauts have gotten into their Soyuz escape craft, ready to abandon the Station if there’s a catastrophic impact. And if they have even less warning, the astronauts have to just hunker down in some of the Station’s more sturdy regions and wait out the debris flyby.

The Iridium constellation - a robust satellite network (Iridium) — The Iridium constellation – a robust satellite network (Iridium)

This isn’t speculation and overcautious nannying on NASA’s part. In 2009 an Iridium communications satellite was smashed by a dead Russian Kosmos-2251 military satellite. The collision destroyed both satellites instantly. As icing on this whirling, screaming metallic orbital-terror-cake, it added 2,000 new chunks of debris to the growing collection.

Most material was in a fairly low orbit, and much of it has already been slowed down by the Earth’s atmosphere and burned up.

This wasn’t the first time two star-crossed satellites with a love that could-not-be had a shrapnel fountain suicide pact, and I promise it won’t be the last. Each collision adds to the total amount of debris in orbit, and increases the risk of a run-away cascade of orbital collisions.

We should never underestimate the bravery and commitment of astronauts. They strap themselves to massive explosion tubes and weather the metal squalls of earth orbit in tiny steel life-rafts. So, would you be willing to risk all that debris for a chance to fly in orbit? Tell us in the comments below.

April 10, 2014December 23, 2015 by Elizabeth Howell

European Satellite Dodged Space Debris Hours After Reaching Orbit

Artist's conception of Sentinel-1, an environment-monitoring satellite from the European Space Agency. Credit: ESA/ATG medialab

Yesterday, the European Space Agency disclosed a serious problem early in the Sentinel-1A mission, which lifted off April 3 on a mission to observe the Earth. The spacecraft — which reportedly cost 280 million Euros ($384 million) to launch — came close to a collision in orbit.

“At the end of the first day after the launch (4 April): all deployments have been executed during the night and completed early in the morning at the beginning of the first ‘day shift’,” read a blog post from the Sentinel-1A team on the European Space Agency’s website.

“As the first day shift nears its end, a serious alert is received: there is a danger of a collision with a NASA satellite called ACRIMSAT, which has run out of fuel and can no longer be maneuvered. Not much information at the beginning, we are waiting for more information, but a collision avoidance maneuver may be needed. ‘Are you kidding? A collision avoidance maneuver during LEOP [launch and early orbit phase]? This has never been done before, this has not been simulated!’ ”

Worse, as controllers looked at the data they realized there was not one, but two possible points of collision. Cue the inevitable Gravity reference, and then a solution: to essentially move the satellite out of the way. The maneuver took about 39 seconds, and safely skirted Sentinel-1A out of danger.

You can read more about the situation in the blog post. ESA’s main Twitter feed and the ESA Operations Twitter feed also first reported the near-collision yesterday, nearly a week after it occurred. It should also be noted that the Europeans (among many other space agencies) are looking at ways to reduce space debris.

The successful liftoff of Sentinel-1A in April 2014. Credit: ESA-S.Corvaja, 2014

February 21, 2014April 26, 2016 by Elizabeth Howell

How We Will Retrieve Dead Satellites In The Future? Hint: It Likely Won’t Be Using Astronauts

NASA astronaut Dale Gardner captures the malfunctioning WESTAR-VI satellite in 1984. Gardner was using the Manned Maneuvering Unit, a sort of space backpack that was discontinued for astronaut use after the Challenger explosion of 1986. Credit: NASA

I’ll admit it: I’m too young to remember 1984. I wish I did, however, because it was a banner year for the Manned Maneuvering Unit. NASA astronaut Dale Gardner, for example, used this jet backpack to retrieve malfunctioning satellites, as you can see above. (FYI, Gardner died Wednesday (Feb. 19) of a brain aneurysm at the age of 65.)

After three shuttle flights, however, NASA discontinued use of the backpack in space for several reasons — most famously, safety considerations following the shuttle Challenger explosion of 1986. But thirty years on, the problem of dead satellites is growing. There are now thousands of pieces whipping around our planet, occasionally causing collisions and generally causing headaches for people wanting to launch stuff into orbit safely.

Space agencies such as NASA and the European Space Agency have been working hard on reducing debris during launches, but there’s still stuff from decades before. And when a satellite goes dead, if it’s in the wrong orbit it could be circling up there for decades before burning up. How do you fix that?

Robotics has come a long way in 30 years, so space agencies are looking to use those instead to pick up derelict satellites since that would pose far less danger to astronauts. One example is the e.DeOrbit mission recently talked about by ESA, which would pick up debris in polar orbits of altitudes between 800 and 1,000 kilometers (about 500 to 620 miles).

One design idea for the e.DeOrbit mission, which would retrieve dead satellites from orbit. Credit: European Space Agency

The mission would use autonomous control and image sensors to get up close to the drifting satellite, and then capture it in some way. Several ideas are being considered, ESA added. A big enough net could easily nab the satellite, or perhaps one could clamp on using tentacles or grab it with a harpoon or robotic arm. Here’s a 2013 proposal with more information on e.DeOrbit. ESA noted there is a symposium coming up May 6 to discuss this in more detail.

e.DeOrbit is one of just several proposals to pick satellites up. A Swiss idea called CleanSpace One appears to use a sort of pincer claw to grab satellites for retrieval. The Phoenix program (proposed by Defense Advanced Research Projects Agency) would take useable parts off of broken satellites for use in new satellites, and in past years DARPA had some ideas to remove satellites from orbit as well. Another option is satellite refueling to make these machines useable again, a possibility that NASA, Canada and many others are taking seriously.

What do you think is the best solution? Leave your thoughts in the comments.

August 14, 2013December 23, 2015 by David Dickinson

The USAF’s ‘Space Fence’ Surveillance System: Another Victim of Sequestration

Times are getting tougher in the battle to track space debris. A key asset in the fight to follow and monitor space junk is getting the axe on October 1st of this year. United States Air Force General and commander of Air Force Space Command William Shelton has ordered that the Air Force Space Surveillance System, informally known as Space Fence will be deactivated. The General also directed all related sites across the southern United States to prepare for closure.

This shutdown will be automatically triggered due to the U.S. Air Force electing not to renew its fifth year contract with Five Rivers Services, the Colorado Springs-based LLC that was awarded the contract for the day-to-day management of the Space Fence surveillance system in 2009.

To be sure, the Space Fence system was an aging one and is overdue for an upgrade and replacement.

The Space Fence system was first brought on line in the early days of the Space Age in the 1961. Space Fence was originally known as the Naval Space Surveillance (NAVSPASUR) system until passing into the custody of the U.S. Air Force’s 20^th Space Control Squadron in late 2004. Space Fence is a series of multi-static VHF receiving and transmitting sites strung out across the continental United States at latitude 33° north ranging from California to Georgia.

The Worldwide Space Surveillance Network, including Space Fence across the southern United States. (Credit: the U.S. Department of Defense).

Space Fence is part of the greater Space Surveillance Network, and comprises about 40% of the overall observations of space debris and hardware in orbit carried out by the U.S. Air Force. Space Fence is also a unique asset in the battle to track space junk and dangerous debris, as it gives users an “uncued” tracking ability. This means that it’s constantly “on” and tracking objects that pass overhead without being specifically assigned to do so.

Space Fence also has the unique capability to track objects down to 10 centimeters in size out to a distance of 30,000 kilometres. For contrast, the average CubeSat is 10 centimetres on a side, and the tracking capability is out to about 67% of the distance to geosynchronous orbit.

Exact capabilities of the Space Fence have always been classified, but the master transmitter based at Lake Kickapoo, Texas is believed to be the most powerful continuous wave facility in the world, projecting at 768 kilowatts on a frequency of 216.97927 MHz. The original design plans may have called for a setup twice as powerful.

A replacement for Space Fence that will utilize a new and upgraded S-Band radar system is in the works, but ironically, that too is being held up pending review due to the sequestration. Right now, the Department of Defense is preparing for various scenarios that may see its budget slashed by 150 to 500 billion dollars over the next 10 years.

The control center display of the prototype for the next generation Space Fence. (Credit: Lockheed Martin).

The U.S. Air Force has already spent $500 million to design the next generation Space Fence, and awarded contracts to Raytheon, Northrop Grumman and Lockheed Martin in 2009 for its eventual construction.

The eventual $3 billion dollar construction contract is on hold, like so many DoD programs, pending assessment by the Strategic Choices and Management Review, ordered by Secretary of Defense Chuck Hagel earlier this year.

“The AFSSS is much less capable than the space fence radar planned for Kwajalein Island in the Republic of the Marshall Islands,” stated General Shelton in a recent U.S. Air Force press release. “In fact, it’s apples and oranges in trying to compare the two systems.”

One thing’s for certain. There will be a definite capability gap when it comes to tracking space debris starting on October 1^st until the next generation Space Fence comes online, which may be years in the future.

In the near term, Air Force Space Command officials have stated that a “solid space situational awareness” will be maintained by utilizing the space surveillance radar at Eglin Air Force Base in the Florida panhandle and the Perimeter Acquisition Radar Characterization System at Cavalier Air Force Station in North Dakota.

We’ve written about the mounting hazards posed by space debris before. Just earlier this year, two satellites were partially damaged due to space debris. Space junk poses a grave risk to the residents of the International Space Station, which must perform periodic Debris Avoidance Maneuvers (DAMs) to avoid collisions. Astronauts have spotted damage on solar arrays and handrails on the ISS due to micro-meteoroids and space junk. And on more than one occasion, the ISS crew has sat out a debris conjunction that was too close to call in their Soyuz spacecraft, ready to evacuate if necessary.

In 2009, a collision between Iridium 33 and the defunct Cosmos 2251 satellite spread debris across low Earth orbit. In 2007, a Chinese anti-satellite missile test also showered low Earth orbit with more of the same. Ironically, Space Fence was crucial in characterizing both events.

Satellites, such as NanoSail-D2, have demonstrated the capability to use solar sails to hasten reentry at the end of a satellites’ useful life, but we’re a long ways from seeing this capability standard on every satellite.

Amateurs will be affected by the closure of Space Fence as well. Space Weather Radio relies on ham radio operators, who listen for the “pings” generated by the Space Fence radar off of meteors, satellites and spacecraft.

“When combined with the new Joint Space Operations Center’s high-performance computing environment, the new fence will truly represent a quantum leap forward in space situational awareness for the nation,” General Shelton said.

But for now, it’s a brave and uncertain world, as Congress searches for the funds to bring this new resource online. Perhaps the old system will be rescued at the 11^th hour, or perhaps the hazards of space junk will expedite the implementation of the new system. Should we pass the hat around to “Save Space Fence?”

July 23, 2013December 23, 2015 by David Dickinson

Space Debris: A Tale of Two Satellites

Artist's concept of a GOES spacecraft in orbit. (Credit: NOAA.gov).

It’s sometimes tough being a satellite in Earth orbit these days.

An interesting commentary came our way recently via NASA’s Orbital Debris Program Office’s Orbital Debris Quarterly News. The article, entitled High-Speed Particle Impacts Suspected in Two Spacecraft Anomalies, highlights a growing trend in the local space environment.

The tale begins with GOES 13 located in geostationary orbit over longitude 75° West. Launched on May 24^th, 2006 atop a Delta IV rocket, GOES 13 is an integral part of the U.S. National Oceanic and Atmospheric Administration (NOAA’s) Geostationary Operational Environmental Satellite network.

The problems began when GOES-13 began to suffer an “attitude disturbance of unknown origin” on May 22^nd of this year, causing it to drift about two degrees per hour off of its required nadir (the opposite of zenith) pointing.

The anomaly was similar to a problem encountered by the NOAA 17 spacecraft on November 20^th, 2005. At the time, the anomaly was suspected to be due to a micrometeoroid impact. The Leonid meteors, which peak right around the middle of November, were a chief suspect. However, NOAA 17 suffered a second failure 18 days later, which was later traced down to a hydrazine leak from its errant thrusters.

GOES-13 has weathered hard times before. Back in December of 2006, GOES-13’s Solar X-Ray Imager suffered damage after being struck by a solar flare shortly after initial deployment. GOES-13 also began returning degraded imagery in September 2012, forcing it into backup status for Hurricane Sandy.

GOES-13 was restored to functionality last month. Current thinking is that the satellite was struck by a micrometeorite. No major meteor showers were active at the time.

Loss of a GOES satellite would place a definite strain on our weather monitoring and Earth observing capability. Begun with the launch of GOES-1 in 1975, currently six GOES satellites are in operation, including one used to relay data for PeaceSat (GOES-7) and one used as a communications relay for the South Pole research station (GOES-3).

The GOES program cost NOAA billions in cost overruns to execute. The next GOES launch is GOES-R scheduled in 2015.

But the universe seems to love coincidences.

NEE-01 Pegaso before deployment. (Credit: Wikimedia Commons image in the Public Domain).

Less than 26 hours after the GOES 13 anomaly, Ecuador’s first satellite, NEE-01 Pegaso began to have difficulties keeping a stable attitude. The event happened shortly after passage near an old Soviet rocket booster (NORAD designation 1986-058B) which launched Kosmos 1768 on August 2^nd, 1986. The U.S. Joint Space Operations Center had warned the fledgling Ecuadorian Space Agency that conjunction was imminent, but of course, there’s not much that could’ve been done to save the tiny CubeSat.

Although the main mass passed Pegaso at a safe distance, current thinking is that the discarded booster may have left a cloud of debris in its wake. Researchers have tracked small “debris clouds” around objects it orbit before- the collision of Iridium 33 and the defunct Kosmos 2251 on February 10^th, 2009 left a ring of debris in its wake, and the Chinese anti-satellite test carried out on January 11^th, 2007 showered low-Earth orbit with debris for years to come.

The loss represents a blow to Ecuador and their first bid to become a space-faring nation. Launched less than a month prior atop a Long March 2D rocket, Pegaso was a small 10 centimetre nanosatellite equipped with solar panels and dual infrared and visible Earth imaging systems.

A translation from the Ecuadorian Space Agencies site states that;

“The NEE-01 survived the crash and remains in orbit; however it has entered uncontrolled rotation due to the event.

Due to this rotation, (the satellite) cannot point its antenna correctly and stably to the Earth station and although still transmitting and running, the signal cannot be decoded. The Ecuadorian Civilian Space Agency is working tirelessly to stabilize the NEE-01 and recover the use of their signal.

The PEGASUS aired for 7 days your signal to the world via EarthCam, millions could see the Earth seen from space in real time, many for the first time, the files in those 7 days have been published after transmission.”

Ecuador plans to launch another CubeSat, NEE 02 Krysaor later in 2013. A carrier has not yet been named.

While both events suffered by the GOES-13 and NEE-01 Pegaso satellites were unrelated, they underscore problems with space junk and space environmental hazards that are occurring with a higher frequency.

Gabbard diagram displaying a sample disintegration of a Long March 4 booster in 2000. (Credit: the NASA Orbital Debris Office).

Such is the modern hazardous environment of low Earth orbit that new satellites must face. With a growing amount of debris, impact threats are becoming more common. The International Space Station must perform frequent debris avoidance maneuvers to avoid hazards, and more than once, the crew has waited out a pass in their Soyuz escape modules should immediate evacuation become necessary. Punctures from micro-meteoroids or space junk have even been seen recently on the ISS solar panel arrays.

Plans are on the drawing board to deal with space junk, involving everything from “space nets” to lasers and even more exotic ideas. Probably the most immediate solution that can be implemented is to assure new payloads have a way to “self-terminate” via de-orbit at the end of their life span. Solar sail technologies, such as NanoSailD2 launched in 2010 have already demonstrated this capability.

Expect reentries also pick up as we approach the peak of solar cycle #24 at the end of 2013 and the beginning of 2014. Increased solar activity energizes the upper atmosphere and creates increased drag on low Earth satellites.

It’s a brave new world “up there,” and hazards, both natural and man-made, are something that space faring nations will have to come to terms with.

-Read and subscribe to the latest edition of NASA’s Orbital Debris Quarterly News for free here.

April 28, 2013April 26, 2016 by Elizabeth Howell

Experts Urge Removal of Space Debris From Orbit

Space debris has been identified as a growing risk for satellites and other space infrastructure. Credit: NASA

Action is needed soon to remove the largest pieces of space debris from orbit before the amount of junk destroys massive amounts of critical space infrastructure, according to a panel at the Sixth European Conference on Space Debris.

“Whatever we are going to do, whatever we have to do, is an expensive solution,” said Heiner Klinkrad, head of the European Space Agency space debris office, in a panel this week that was broadcast on ESA’s website.

“We have to compare the costs to solving the problem in an early stage as opposed to losing the infrastructure in orbit in the not-too-distant future.”

The panel estimated that there is $1.3 billion (1 billion Euros) worth of space satellite infrastructure that must be protected. The 200 most crucial satellites identified by the space community have an insured value of $169.5 million (130 million Euros), Klinkrad added.

Critical infrastructure, though not specified exactly by the panel, can include communication satellites and military eyes in the sky. Also at risk is that largest of human outposts in space — the International Space Station.

A view of the International Space Station as seen by the last departing space shuttle crew, STS-135. Credit: NASA

The conference concluded that without further action — even without launching any new rockets — it’s quite possible there could be a runaway effect of collisions producing debris within a few decades. Even a tiny object could act like a hand grenade in orbit if it smashes into a satellite, Klinkrad said.

A recent example of the problem: a piece of Chinese space debris smashed into a Russian satellite in March. It didn’t destroy the satellite, but altered its orbit.

To mitigate the situation, representatives suggested removing 5 to 10 large pieces of debris every year. They added they are uncertain about how soon a large problem would occur, but noted that the number of small objects is definitively increasing annually according to measurements done by the Walter Baade 6.5-meter Magellan Telescope.

“[It’s] something we haven’t know until now. We have been suspecting it is the case … this is a new result which is very important.”

While highlighting the risk, the European representatives of the panel added they are not standing idly by. Already, there are regulatory changes that could slow the problem for future launches — although there still will be cleanup to do from five past decades of space exploration.

Artist's conception of DEOS (German orbital servicing mission). Credit: Astrium — Artist’s conception of DEOS (German orbital servicing mission). Credit: Astrium

A few of the points brought up:

– German officials are working on an in-orbit satellite servicing solution called DEOS. “The DEOS project will for the first time demonstrate technologies for the controlled in-orbit disposal of a defective satellite,” Astrium, the prime contractor for the definition phase, wrote in a press release in 2012. “In addition, DEOS will practice how to complete maintenance tasks – refuelling in particular – that extend the service life of satellites.”

– France’s Parliament passed the Space Operations Act in December 2010. “Its chief objective is to ensure that the technical risks associated with space activities are properly mitigated, without compromising private contractors’ competitiveness,” French space agency CNES wrote on its website. “The government provides a financial guarantee to compensate damages to people, property or the environment.”

– A United Nations subcommittee of the Committee on the Peaceful Uses of Outer Space is working on space sustainability guidelines that will include space debris and space operations practices. More details should be released in June, although Claudio Portelli (a representative from Italy’s space agency) warned he did not expect any debris removal proposals to emerge from this work.

For more technical details on the space debris problem, check out the webcast of the ESA space debris conference.

April 19, 2013December 23, 2015 by David Dickinson

How Micrometeoroid Impacts Pose a Danger for Today’s Spacewalk

Astronauts perform an EVA outside of the ISS during STS-110. (Credt: NASA).

Video streaming by Ustream

Our very own International Space Station is in the cosmic crosshairs.

As cosmonauts are to begin Extra Vehicular Activity (EVA) this morning to perform routine maintenance, an article reminding us of the hazards of such activity came to us via NASA’s Orbital Debris Quarterly Newsletter.

The problem is Micrometeoroid and Orbital Debris (MMOD) impacts. These are nothing new. Pits and tiny cratering has been observed during post-flight inspections of space shuttle orbiters. But this is the first time we’d seen talk of damage caused by tiny impacts on the exterior of the International Space Station.

The handrails are a particularly sensitive area of concern.

The study examined damage incurred on handrails exposed to the environment of space for years on end. These present a hazard to spacewalking astronauts who rely on the handles to move about. These craters often become spalled, presenting a sharp metal rim raised from the surface of the handle.

Close-up of a micro-meteoroid impact on a handrail. (Credit: NASA/JSC Image & Science Analysis Group).

Of course, these razor sharp rims present a problem, especially to space suit gloves. One 34.8 centimeter long handrail returned on the final Space Shuttle mission STS-135 had six impact craters along its length. The handrail had been in service and exposed to the vacuum of space for 8.7 years.

Craters as large as 1.85 millimetres (mm) in diameter with raised lips of 0.33mm have been observed on post-inspection. In studies conducted by NASA engineers, craters with lip heights as little as 0.25mm have been sufficient to snag and tear spacesuit gloves.

There have also been reported incidents of glove tears during EVAs conducted from the ISS over the years. For example, the report cites a tear noticed by astronaut Rick Mastracchio during STS-118 that cut the EVA short.

Analysis of an impact seen on STS-122. (Credit: NASA/JSC Image & Science Analysis Group).

To protect astronauts and cosmonauts during EVAs, the following measures have been instituted:

– Toughening space suit gloves by adding reinforcement to areas exposed to potential MMOD damage.

– Monitoring and analyzing MMOD impacts along handrails and maintaining a database of problem areas.

– Equipping spacewalkers with the ability to cover and/or repair hazardous MMOD areas during spacewalks.

The studies were carried out by the Johnson Space Center Hypervelocity Impact Technology Group in conjunction with a test facility at White Sands, New Mexico. Astronaut Rick Mastracchio can also be seen talking about the hazards of spacewalking on this video.

Today’s 6 hour EVA by cosmonauts Vinogradov & Romanenko begins at 14:06 UT 10:06AM EDT.

This will be the 32^nd Russian EVA from the International Space Station and will use the Pirs hatch on Zvezda.

Tasks include retrieving and installing experiment packages and replacing a defective retro-reflector device on the station’s exterior. The device is a navigational aid necessary for the Albert Einstein ATV-4 mission headed to the ISS on June 5th.

Progress 51P is also scheduled to launch towards the ISS next week on April 24 for docking on April 26th.

Debris in Low Earth Orbit is becoming an increasing concern. The Chinese anti-satellite test in 2007 and the collision of Kosmos 2251 and Iridium 33 in 2009 have increased hazards to the ISS. Many fear that a tipping point, known as an ablation cascade, could eventually occur with one collision showering LEO with debris that in turn trigger many more. The ISS was only finished in 2011, and it would be a tragic loss to see it abandoned due to a catastrophic collision only years after completion.

More than once, ISS crew members have sat out a debris conjunction that was too close to call in their Soyuz life boats, ready to evacuate the station if necessary. DAMs (Debris Avoidance Maneuvers) are now common for the ISS throughout the year.

Several ideas have been proposed to deal with space debris. In the past year, NanoSail-2D demonstrated the ability to deploy a solar sail from a satellite for reentry at the end of a spacecraft’s life span. Such technology may be standard equipment on future satellites.

Expect reentries to increase as we near the solar maximum for cycle #24 in late 2013 & early 2014. This occurs because the exosphere of Earth “puffs out” due to increased solar activity and increases drag on satellites in low Earth orbit.

All food for thought as we watch today’s EVA… space travel is never routine!

The April 2013 edition of the Orbital Debris Quarterly News is available for free online.