US, Russian satellites collide in space

[CougarKing]

Considering the number of satellites up there, this makes me wonder if this really is the first collision of satellites in orbit ever.

2 big satellites collide 500 miles over Siberia
Updated February 12, 2009 08:00 AM 

CAPE CANAVERAL (AP) – Two big communications satellites collided in the first-ever crash of two intact spacecraft in orbit, shooting out a pair of massive debris clouds and posing a slight risk to the international space station.

NASA said it will take weeks to determine the full magnitude of the crash, which occurred nearly 500 miles over Siberia on Tuesday.

"We knew this was going to happen eventually," said Mark Matney, an orbital debris scientist at Johnson Space Center in Houston.

NASA believes any risk to the space station and its three astronauts should be low. It orbits about 270 miles below the collision course. There also should be no danger to the space shuttle set to launch with seven astronauts on Feb. 22, officials said, but that will be re-evaluated in the coming days.

The collision involved an Iridium commercial satellite, which was launched in 1997, and a Russian satellite launched in 1993 and believed to be nonfunctioning. The Russian satellite was out of control, Matney said.

The Iridium craft weighed 1,235 pounds, and the Russian craft nearly a ton.

No one has any idea yet how many pieces were generated or how big they might be.

"Right now, they're definitely counting dozens," Matney said. "I would suspect that they'll be counting hundreds when the counting is done."

As for pieces the size of micrometers, the count will likely be in the thousands, he added.

There have been four other cases in which space objects have collided accidentally in orbit, NASA said. But those were considered minor and involved parts of spent rockets or small satellites.

As of Wednesday, there were 9,831 pieces of manmade debris — not counting anything from Tuesday's collision — orbiting Earth. The items, at least 4 inches in size, are being tracked by the U.S. Space Surveillance Network, which is operated by the military. The network detected the two debris clouds created Tuesday.

Litter in orbit has increased in recent years, in part because of the deliberate breakups of old satellites. It's gotten so bad that orbital debris is now the biggest threat to a space shuttle in flight, surpassing the dangers of liftoff and return to Earth. NASA is in regular touch with the Space Surveillance Network, to keep the space station a safe distance from any encroaching objects, and shuttles, too, when they're flying.

"The collisions are going to be becoming more and more important in the coming decades," Matney said.

Iridium Holdings LLC has a system of 65 active satellites which relay calls from portable phones that are about twice the size of a regular mobile phone. It has more than 300,000 subscribers. The US Department of Defense is one of its largest customers.

The company has spare satellites, and it is unclear whether the collision caused an outage. An Iridium spokeswoman had no immediate comment.

Initially launched by Motorola Inc. in the 1990s, Iridium plunged into bankruptcy in 1999. Private investors relaunched service in 2001.

Iridium satellites are unusual because their orbit is so low and they move so fast. Most communications satellites are in much higher orbits and don't move relative to each other, which means collisions are rare.

Iridium Holdings LLC, is owned by New York-based investment firm Greenhill & Co. through a subsidiary, GHL Acquisition Corp., which is listed on the American Stock Exchange. The shares closed Wednesday down 3 cents at $9.28.

 

[a_majoor]

The Law od Space:

http://www.popularmechanics.com/science/air_space/4303567.html

The Law of Space Collisions: International Rule Above the Earth

When two satellites collided on Wednesday nearly 500 miles over Siberia, the first thought for NASA scientists was to assess the effects space debris would have on the International Space Station. Now that the ISS has been deemed out of harm's way, damages are being assessed. The question now turns to who pays for damages in space. Space law expert Glenn Reynolds explains the rules that apply far above Earth.

By Glenn H. Reynolds
Published on: February 13, 2009

The collision of a dead Russian satellite with an Iridium communications satellite left a cloud of debris and a number of questions. But, contrary to some people's impressions, it didn't occur outside the law. Outer space is not a lawless region; it is governed by international law (and, in the case of U.S. spacecraft, or the U.S. parts of the International Space Station, by American law).

In fact, damage to and by spacecraft is covered by the 1972 Convention on International Liability for Damage Caused by Space Objects. Under that treaty, liability for damage caused to people or property on the ground is "absolute"—meaning that the country that launched the spacecraft is liable for damages even if there was no negligence. The same is true if a crashing space object strikes an aircraft. It does not matter how the accident happened: If your spacecraft does damage, you pay. This rule was made to protect people on the ground: Expecting everyone to be on guard against crashing satellites is asking a bit much.

In space, however, things aren't so straightforward. When one spacecraft collides with another, there's only liability if the spacecraft operator is at fault—that is, negligent in some way. But what's negligence in the context of Wednesday's crash? That's not so clear. Operating a spacecraft in a way that poses a foreseeable risk to others is probably negligent, but in this case the Russian Kosmos military satellite was described as "defunct," meaning that it had either broken down, or run out of maneuvering fuel. There are lots of such satellites in orbit, and although good practice calls for their operators to either de-orbit them, or to boost them into harmless parking orbits, this is not always possible, and it would be hard to argue that failure to do so constitutes negligence. While we may develop standards of practice ("rules of the road" for space) someday, such standards would require space operators to ensure that satellites don't remain in high-traffic orbits at the end of their lives. Failing to do so would give rise to damages. Space law is not yet this forward-looking.

Worse yet, while intact satellites can be traced back to their countries of origin, debris fragments—which because of the tremendous velocities involved can be enough to wreck a spacecraft even when they're as small as a golf ball—will often be from unidentifiable sources. Some scholars have proposed an international regime that would "tax" countries for debris cleanup based on the amount of material left in orbit, but such proposals remain purely academic.

Finally, current space law doesn't allow another solution to the space-junk problem: Salvage. Under the 1967 Outer Space Treaty, nations retain "jurisdiction and control" over their spacecraft even when they are inoperable, meaning that a salvage operator wouldn't be able to take title or claim an award for recovering a defunct craft as is done on earth. Space lawyers (yes, there are space lawyers) have been arguing for years that the proliferation of space junk makes some sort of salvage law necessary, but up to now there has been little progress. The technology for recovering defunct satellites is there, though cleaning up smaller debris fragments would be much, much harder. That's a reason to try to get a handle on the problem sooner, rather than later. A space salvage law might even give a shot in the arm to commercial space efforts, by providing yet another money-making option. Will this collision focus attention on the problem? Let's hope.

Glenn Reynolds, a contributing editor to Popular Mechanics, is co-author (with Robert P. Merges) of Outer Space: Problems of Law and Policy. He teaches space law at the University of Tennessee.

 

[Yrys]

Same subject, another article :

Russian and US satellites collide


US and Russian communications satellites have collided in space in what is thought
to be the biggest incident of its kind to date. The US commercial Iridium spacecraft
hit a defunct Russian satellite at an altitude of about 800km (500 miles) over Siberia
on Tuesday, Nasa said.

The risk to the International Space Station and a shuttle launch planned for later this
month is said to be low. The impact produced a cloud of debris, which will be tracked
into the future.

Since the Soviets launched Sputnik in 1957, it is estimated about 6,000 satellites have
been put in orbit. Satellite operators are all too aware that the chances of a collision
are increasing.The Americans are now following the debris path from the impact. It is
hoped that most of it will fall to Earth and burn up in the atmosphere.

Shuttle launch

The concern is whether the debris will spread and pose any risk to the ISS, which is
orbiting the Earth some 435km below the course of the collision.

According to the Washington Post, a Nasa memo said officials determined the risk to
be "elevated" but have estimated it as "very small and within acceptable limits". Nasa
spokesman John Yembrick said the ISS had the "capability of doing a debris-avoidance
manoeuvre if necessary". He said this had happened on just eight previous occasions
during the course of its 60,000-plus orbits.

Officials said there were no plans to delay the launch of Nasa's space shuttle Discovery
later this month, although that would be re-evaluated in coming days. Nicholas Johnson,
an orbital debris expert at the Johnson Space Center in Houston, was quoted by the
Associated Press as saying that the Hubble Space Telescope and Earth-observing satellites
at higher orbits and closer to the collision site were at greater risk of damage.

'Extremely unusual'

Communications firm Iridium, based in Bethesda, Maryland, said it "lost an operational
satellite" after it was struck on Tuesday by the Russian satellite. It said its clients may
experience some brief outages until it had temporarily fixed the problem by Friday.
Iridium said it hoped to replace the 560kg satellite, launched in 1997, with one of its
in-orbit spares within the next 30 days. The firm described it as an "extremely unusual,
very low-probability event", stressing that it was not caused by any fault on its part.

Russia's space forces confirmed the collision with the defunct 950kg (2,094lb) satellite.
"A collision occurred between an Iridium 33 satellite and a Russian Kosmos 2251 military
satellite," Major General Alexander Yakushin said. The satellite was launched in 1993 and
ceased to function two years later, he said according to the AFP news agency. Russia has
not commented on claims the satellite was out of control.

Littered orbit

Space debris experts say the chances of such collisions have been rising. Litter in orbit -
caused in part by the break-ups of old satellites - has increased to such an extent that it is
now the biggest threat to a space shuttle in flight. Mr Johnson said that at the beginning
of this year about 17,000 manmade pieces of debris were orbiting Earth.

The items, some as small as 10cm (four inches), are tracked by the US Space Surveillance
Network - sending information to help spacecraft operators avoid the debris. Of the 6,000
satellites sent into orbit since 1957, about 3,000 remain in operation, according to Nasa.

Europe has just initiated its own space surveillance programme. One of its main weather
satellites had a near miss in December with a Chinese object. The Europeans knew nothing
about the threat until the Americans contacted the European Space Agency to inform it of the
danger.

 

[a_majoor]

A long article in the Space Review. Read it all here

http://www.thespacereview.com/article/1314/1

Billiards in space
by Brian Weeden
Monday, February 23, 2009
Comments (5)
For the third time in three years, a major event in space has both created public consternation and changed how many look at the issue of space security. The first event of this ominous trio was the Chinese anti-satellite test in January 2007, followed a year later by the destruction of an ailing spy satellite by the United States in February 2008. The most recent event was the first-ever accidental collision between two satellites in Earth orbit, which took place on February 10, 2009.

All three of these events generated an incredible amount of interest with both the media and the public. And all three events brought with them a torrent of hype, misinformation, gossip, paranoia, and conspiracy theories along with the facts and the real issues. The goal of this article is to elucidate how two satellites operated by the biggest space powers on the planet could collide, and along the way separate the facts from the fiction, put some perspective on why this event happened, and present some potential solutions to prevent similar events in the future.

***

Separating fact from fiction
The facts known about this collision are as follows. On February 10 at 1156 EST, Iridium lost contact with one of its satellites, Iridium 33. They contacted the JSpOC at Vandenberg requesting help with resolving the anomaly. Using their network of radars, the JSpOC confirmed that there were two breakups, one corresponding to the inclination of Iridium 33 and another in a different inclination, later discovered to be that of Cosmos 2251.

While the two satellites were in relatively close inclinations, 86° for the Iridium and 74° for the Cosmos, the difference in their right ascension meant that their orbits intersected at almost a 90° angle close to the North Pole. So even though each object was traveling at around 7.5 kilometers per sec, the combined velocity at the moment of impact was around 10 kilometers per second.

What is unknown is how much overlap there was between the two objects at the moment of contact. This is extremely important for determining how much debris was created. If only a few protruding pieces were in contact, then the debris generated from this event is likely to be relatively low (on the order of tens to a few hundred trackable pieces). If a significant amount of the bodies of the two satellites were in contact, then it is likely that a couple thousand pieces of trackable debris were generated. It is unlikely that the event generated debris on the order of the Chinese ASAT test because of the extremely low probability of 100% overlap between the two satellites and the comparatively low collision velocity.

Some pundits have put forth the notion that Iridium had maneuvered to avoid another object and wandered into the path of Cosmos 2251. Others have speculated that a tiny anti-satellite pushed Cosmos 2251 into Iridium 33’s path. There is no factual basis for either of these scenarios, and in fact inquiring minds can verify this by checking the last several positions for each object published in the Space Track catalog. Doing so will show no appreciable changes in position of either object before the collision. This can be further verified by analyzing the velocity distribution of all the post-event pieces of debris and calculating the position and velocity of the parent objects at the moment of impact.

Both of these conjectures seem to stem from the false assumption that the US military has perfect knowledge about the objects in Earth orbit and is looking at every one for possible collisions. Therefore, a sudden orbital change at the last minute would be the only way to escape their vigilance. As I will explain later in this article, this is assumption is not true.

Others have speculated that the US military is concentrating its tracking efforts on only the smaller pieces of debris and thus wasn’t paying close enough attention to the big pieces. Again, that does not hold up to scrutiny. If anything, it is more important to track the big pieces because their larger surface area means they are more likely to be collision candidates and would create a much bigger debris cloud if they indeed hit. They are also much easier to track and it would be criminal not to expend the rather low amount of resources to keep their positions updated.

Read the rest.

 

[KingKikapu]

WHAT!?!?!

 

[a_majoor]

How we can avoid these problems in the future:

http://news.bbc.co.uk/2/hi/science/nature/8029899.stm

How satellites could 'sail' home 
By Jonathan Amos
Science reporter, BBC News 

The booms can be inflated with gas but need then to be made rigid
Satellites and spent rocket stages could soon deploy "sails" to guide them back to Earth much faster than they would otherwise fall out of the sky.

With space becoming ever more crowded, there is a need to remove redundant objects that could pose a collision threat to operational missions.

Extending a sail on an old spacecraft would increase drag and pull it into the Earth's atmosphere to burn up.

Major European space firm EADS Astrium says the scheme has great potential.

"It is an interesting solution, especially for the satellite that has no propulsion system at the end of its life," Brice Santerre told BBC News.

Santerre and colleague Max Cerf have been working on the Innovative DEorbiting Aerobrake System (IDEAS).

The concept involves extending booms and sheeting from spacecraft to increase the amount of drag they experience from the residual air molecules still present at altitudes up to even 750km (470 miles)

"The principle of aerobraking is to increase the surface over mass ratio of an orbital object, to accelerate the fall-out by increasing the drag on the system," Mr Santerre said.

"To do that, we need to deploy a very light structure. That's why we chose to use 'gossamer structures'. These are composed of booms and very thin membranes."


Microscope will investigate the behaviour of free-falling objects
Astrium has been developing an aerobraking sail concept for the forthcoming French Microscope satellite.

Microscope is a science mission that will investigate the force of gravity and the behaviour of free-falling objects in a test of what has become known as the equivalence principle.

The satellite will take about a year to make its measurements and will then have no further purpose.

Ideally, such a spacecraft would be removed from orbit, especially since it will be circling at an altitude where many important Earth observation satellites also operate.

"Microscope has no propulsion system so it cannot de-orbit by itself. If we were to do nothing, the fall-out duration would be between 50 and 100 years," said Mr Santerre.

By erecting their boom and membrane mechanism, Santerre and Serf believe Microscope could be brought out of the sky in less than 25 years, which meets international orbital junk mitigation guidelines.

Astrium is now investigating how the IDEAS concept could be applied to spent rocket stages.

The company leads the production of Europe's premier launcher, the Ariane 5.


The concept developed for Microscope would bring it back inside 25 years
Much of the Ariane's structure - its main core stage and solid boosters - fall rapidly out of the sky at the end of a flight; but the upper-stage is much longer lived in orbit.

Once it has ejected its satellite payload, the stage continues to circle the Earth in a large ellipse, running out to more than 35,000km from the Earth and coming as close as about 250km.

It may take 100 years before an upper-stage falls naturally from the sky.

"Our study shows that if we want to apply the aerobraking concept to an Ariane-class upper-stage then we need a system with booms, or masts, of about 12m and a deployed surface of about 250 sq m.

"This is possible with our current technologies. We need now to check that this is the best solution. We are also thinking whether this type of system can be applied to other launchers as well."

One alternative, of course, is to give the Ariane 5 upper-stage the capability to take a powered dive into the Earth's atmosphere.


The Ariane 5 upper-stage continues to circle the Earth for decades
This was done for the first time last year at the end of the launch of the Jules Verne space station freighter. This was considered essential because of the number of manned missions that routinely follow the station's orbit.

Once Jules Verne was released from the rocket, the upper-stage reignited its engine to make a controlled burn-up over the Pacific.

The advantages of de-orbiting in this way are clear, but the extra fuel requirements and complexity of re-ignitable engines add cost to what is already a very expensive endeavour.

Aerobraking sails, on the other hand, are lightweight and extremely simple. Their operation could even be controlled by a pre-set timer, fixed to deploy a certain number of minutes after the end of a flight.

This means that even an upper-stage that is out of control can still be guaranteed to return to Earth in a timely fashion.

Santerre and Serf presented their latest research at the recent European Conference on Space Debris in Darmstadt, Germany.

The meeting closed with a statement from its organisers saying that effective measures to clean up space debris needed to be devised and implemented.