This article is from the source 'bbc' and was first published or seen on . It will not be checked again for changes.
You can find the current article at its original source at http://news.bbc.co.uk/go/rss/-/1/hi/sci/tech/7885750.stm
The article has changed 14 times. There is an RSS feed of changes available.
Version 0 | Version 1 |
---|---|
Sat collision highlights growing threat | Sat collision highlights growing threat |
(about 1 hour later) | |
By Paul Rincon Science reporter, BBC News There are some 17,000 man-made objects orbiting our planet | By Paul Rincon Science reporter, BBC News There are some 17,000 man-made objects orbiting our planet |
The collision between a US and Russian satellite in space highlights the growing importance of monitoring objects in orbit. | The collision between a US and Russian satellite in space highlights the growing importance of monitoring objects in orbit. |
It also shows that there are still major capability gaps in current systems set up for this task. | It also shows that there are still major capability gaps in current systems set up for this task. |
There are about 17,000 man-made objects above 10cm in size that orbit Earth - and the tally is constantly increasing. This in turn raises the risk of collisions between objects. | There are about 17,000 man-made objects above 10cm in size that orbit Earth - and the tally is constantly increasing. This in turn raises the risk of collisions between objects. |
Nevertheless, experts say the incident was extremely unusual. The vastness of space means the probability of two spacecraft colliding is very low indeed. | Nevertheless, experts say the incident was extremely unusual. The vastness of space means the probability of two spacecraft colliding is very low indeed. |
Intact satellites share Earth's orbit with everything from spent rocket stages and spacecraft wreckage to paint flakes and dust. | Intact satellites share Earth's orbit with everything from spent rocket stages and spacecraft wreckage to paint flakes and dust. |
Tracking facilities | |
The diffuse mist of junk around our planet is the legacy of 51 years of human activity in space. | The diffuse mist of junk around our planet is the legacy of 51 years of human activity in space. |
At orbital velocities, even small pieces of space debris can cause serious damage to spacecraft. | At orbital velocities, even small pieces of space debris can cause serious damage to spacecraft. |
And both the Americans and Russians have networks of tracking stations to monitor objects. | And both the Americans and Russians have networks of tracking stations to monitor objects. |
The US military operates 25 centres around the world involved in space surveillance, including one at RAF Fylingdales in the UK. | The US military operates 25 centres around the world involved in space surveillance, including one at RAF Fylingdales in the UK. |
Russia's space surveillance facilities include an "Okno" optical tracking system near Nurek, Tajikistan, and a "Krona" long-range radar and optical tracking centre at Storozhevaya in south-west Russia. | Russia's space surveillance facilities include an "Okno" optical tracking system near Nurek, Tajikistan, and a "Krona" long-range radar and optical tracking centre at Storozhevaya in south-west Russia. |
Radars are generally used to track objects in low-Earth orbit, while optical telescopes are often used to observe objects further away from the Earth. | Radars are generally used to track objects in low-Earth orbit, while optical telescopes are often used to observe objects further away from the Earth. |
Radio frequency technology - a form of electronic surveillance - can be used to assess whether or not satellites are active. | Radio frequency technology - a form of electronic surveillance - can be used to assess whether or not satellites are active. |
China and the European Space Agency (Esa) are developing their own systems. | China and the European Space Agency (Esa) are developing their own systems. |
An advanced ability to monitor space debris, satellites, near-Earth objects and solar activity is known as Space Situational Awareness (SSA). Many experts see this as a step to space traffic control. | An advanced ability to monitor space debris, satellites, near-Earth objects and solar activity is known as Space Situational Awareness (SSA). Many experts see this as a step to space traffic control. |
Although there have been some near-misses and a few minor collisions, this is the first time two intact satellites have crashed into each other. | Although there have been some near-misses and a few minor collisions, this is the first time two intact satellites have crashed into each other. |
The latest incident has produced the worst field of space debris since China destroyed a defunct Fengyun satellite with a missile in January 2007. | The latest incident has produced the worst field of space debris since China destroyed a defunct Fengyun satellite with a missile in January 2007. |
That incident, designed to test an anti-satellite weapon system, produced more than 2,000 separate fragments of debris. | That incident, designed to test an anti-satellite weapon system, produced more than 2,000 separate fragments of debris. |
On Christmas Eve, the US Air Force notified Esa that a European weather satellite called Metop might be threatened by a piece of debris from the Chinese A-Sat test. | On Christmas Eve, the US Air Force notified Esa that a European weather satellite called Metop might be threatened by a piece of debris from the Chinese A-Sat test. |
Ultimately, no action was taken. But the event highlighted Europe's near-total reliance on the US military for knowing what is going on in space. | Ultimately, no action was taken. But the event highlighted Europe's near-total reliance on the US military for knowing what is going on in space. |
Nasa has said it considers the threat to the International Space Station to be low, but that the orbiting outpost could carry out a collision avoidance manoeuvre if necessary. | Nasa has said it considers the threat to the International Space Station to be low, but that the orbiting outpost could carry out a collision avoidance manoeuvre if necessary. |
The ISS flies at an altitude of about 350km (220 miles), well below the point, some 790 km (490 miles) up, where the Russian and US satellites collided. | The ISS flies at an altitude of about 350km (220 miles), well below the point, some 790 km (490 miles) up, where the Russian and US satellites collided. |
Paul.Rincon-INTERNET@bbc.co.uk | Paul.Rincon-INTERNET@bbc.co.uk |