[I]via: [/I]BBC
[QUOTE]Two spacecraft are about to begin an unusual orbital dance above the Pacific Ocean to try to evade the interference from a third, failed satellite.
Control was lost of Intelsat's Galaxy-15 platform in April. It will not take commands from the ground and is in a drift towards neighbouring spacecraft.
The nearest, AMC-11, will now be eased out of its path, and some of its TV channels moved to a partner platform.
The pair's operator, SES World Skies, says customers should be unaffected.
The intricacy of the space choreography that is about to take place is thought to be unprecedented in the commercial telecommunications sector.
"We have to do slight manoeuvres with our spacecraft pretty regularly, but a manoeuvre of this nature and complexity - no, I'm not aware of anyone having done this before," said Alan Young, chief technology officer with SES World Skies.
"We need to make sure Americans can continue to watch their television. They love their TV and it's important," he told BBC News.
'Zombie' nickname Galaxy-15 was launched in 2005 to re-distribute TV services to cable companies across North and Central America, and also to send navigation data to aeroplanes to improve the accuracy of their GPS receivers.
On 5 April, it experienced a major fault and its services were switched to a back-up spacecraft. Engineers have not yet established the cause, but damage from a solar storm is one possibility being investigated.
Although Intelsat cannot talk to Galaxy-15, its electronics payload remains fully functional, and it is capable of re-transmitting on full power any signal it receives.
This means that if Galaxy-15 were to get too close to other telecommunications spacecraft, it could start re-transmitting their signals and seriously interfering with their services.
This "dead-but-alive" condition has earned the Intelsat platform the unfortunate nick-name of "zombie-sat" in some quarters.
Normally positioned at 133 degrees West, and some 36,000km above the Pacific, the satellite is now drifting east into the slot occupied by AMC-11, a satellite operated by competitor SES World Skies.
To ensure its TV customers experience no loss or degradation of service, SES plans on Tuesday to initiate a drift in AMC-11 to match that of Galaxy-15. It has also already commanded a second satellite, SES-1, to come in behind the damaged platform.
Services will then be juggled between the two SES satellites until Galaxy-15 passes through the orbital slot and AMC-11 can return to its normal position and duties.
"We've moved customers on AMC-11 on to a very large uplink antenna," explained Mr Young.
"This means we can very finely discriminate between the two spacecraft so that we can direct all of the energy into AMC-11 and as little energy as possible into Galaxy-15. If you don't put anything into Galaxy-15, you won't get anything out."
Intelsat told BBC News its engineers would continue to try to regain control of Galaxy-15, whilst co-operating fully with other operators to minimise disruption.
Collisions with other satellites are highly unlikely. As it passes through other orbital slots, Galaxy-15 should still be separated from nearby spacecraft by many kilometres.
Ultimately, it is expected that the Intelsat platform will lose the ability to point its solar panels at the Sun and experience total power failure. This could take some months.
It should end its days in one of the gravity "sweetspots", or libration points, where orbital debris has a tendency to aggregate.
[/QUOTE]Source and Video: [URL]http://news.bbc.co.uk/2/hi/science_and_environment/10150614.stm[/URL]
Couldn't they just turn off AMC-11's transmitter and use Galaxy 15 to retransmit their signals while it passes their slot? ( While it may be uncontrollable it can still transmit.)
[QUOTE=winsanity;22174658]Couldn't they just turn off AMC-11's transmitter and use Galaxy 15 to retransmit their signals while it passes their slot? ( While it may be uncontrollable it can still transmit.)[/QUOTE]
I'm sure they haven't thought of that.
That's provided Galaxy 15 is still facing the right way.
automerge broke
I think it's time we call China and ask them to blow up another satellite.
The last thing we want is another KLA incident.
[QUOTE=pentium;22174801]I think it's time we call China and ask them to blow up another satellite.
The last thing we want is another KLA incident.[/QUOTE]
Oh god.
The VERY last thing.
The Palin satellite strikes again.
[QUOTE=Lambeth;22174896]The Palin satellite strikes again.[/QUOTE]
"I can see the whole world from my house!"
So I am guessing the satellite will be [I]risen[/I]?
[editline]03:04PM[/editline]
Badum-tish...
[QUOTE=Vinze;22175225]So I am guessing the satellite will be [I]risen[/I]?
[editline]03:04PM[/editline]
Badum-tish...[/QUOTE]
:golfclap:
So it's possible many months from now that this zombie satellite will eventually die out. But notice they stopped there.
Never mentioned it would;
A: Float away from Earth.
B: Go through the atmosphere and burn up.
C: Do A, collide with an asteroid and become space debris.
I don't understand why they don't send a shuttle up there, grab ahold of this renegade satellite, and bring it down to Earth for repairs.
It would be expensive for one.
[QUOTE=Benie;22175407]So it's possible many months from now that this zombie satellite will eventually die out. But notice they stopped there.
Never mentioned it would;
A: Float away from Earth.
B: Go through the atmosphere and burn up.
C: Do A, collide with an asteroid and become space debris.
I don't understand why they don't send a shuttle up there, grab ahold of this renegade satellite, and bring it down to Earth for repairs.[/QUOTE]
Way too expensive, hell shooting that thing down with a missle is more cost effective.
[editline]09:54PM[/editline]
Ninja'd
Shooting it down with a missile just seems risky. The debris may head towards the atmosphere. Some of it may not get burned up and come crashing down to the planet surface.
[QUOTE=Benie;22175562]Shooting it down with a missile just seems risky. The debris may head towards the atmosphere. Some of it may not get burned up and come crashing down to the planet surface.[/QUOTE]
and the problem is? it's not going to hit anything. They'll send out word to whoever happens to live nearby, if on the offchance something survives the fall, it'll just hit the ground, or, more likely, the ocean.
The problem with blasting a satellite is that it sends out tons of debris orbiting the earth, which can rip apart other satellites etc.
China was being a dick when they shot down theirs
inb4 Dancing with the Stars
I came in here expecting Zombies and Satellites. But what ever.
[QUOTE=Benie;22175562]Shooting it down with a missile just seems risky. The debris may head towards the atmosphere. Some of it may not get burned up and come crashing down to the planet surface.[/QUOTE]
Impossible. At orbital speed (They have to move VERY VERY fast so they don't dive straight into Earth) they will just burn entirely.
[editline]03:40AM[/editline]
[QUOTE=Benie;22175407]So it's possible many months from now that this zombie satellite will eventually die out. But notice they stopped there.
Never mentioned it would;
A: Float away from Earth.
B: Go through the atmosphere and burn up.
C: Do A, collide with an asteroid and become space debris.
I don't understand why they don't send a shuttle up there, grab ahold of this renegade satellite, and bring it down to Earth for repairs.[/QUOTE]
It costs way too much to send stuff into space, especially a human crew just to pick up a satellite among others.
The Space Shuttle was terribly inefficient and expensive, but it was the best NASA had after Nixon cut it's budget, plus it's cool. Future stuff like Spaceplanes and such will make space access cheaper, and picking up a satellite won't be much of a situation. The problem is catching up with the satellite, which requires a shitload of DeltaV, that is, how much fuel you have left.
[QUOTE=Eudoxia;22185303]Impossible. At orbital speed (They have to move VERY VERY fast so they don't dive straight into Earth) they will just burn entirely.
[editline]03:40AM[/editline]
It costs way too much to send stuff into space, especially a human crew just to pick up a satellite among others.
The Space Shuttle was terribly inefficient and expensive, but it was the best NASA had after Nixon cut it's budget, plus it's cool. Future stuff like Spaceplanes and such will make space access cheaper, and picking up a satellite won't be much of a situation. The problem is catching up with the satellite, which requires a shitload of DeltaV, that is, how much fuel you have left.[/QUOTE]
They could have waited to retire the shuttle fleet until a viable alternative/successor was ready for service at least.
How many satellites are in orbit? I've always wondered that.
[QUOTE=Benie;22175562]Shooting it down with a missile just seems risky. The debris may head towards the atmosphere. Some of it may not get burned up and come crashing down to the planet surface.[/QUOTE]
The satellite is the size of a small bus, if it were to be shot down the pieces would burn up in the upper atmosphere, way before they would be a threat to anything on earth. However those pieces would pose a threat to other satellites in orbit, they move at a speed fast enough to rip apart any satellite in their path.
[editline]09:29PM[/editline]
[QUOTE=zerglingv2;22187404]How many satellites are in orbit? I've always wondered that.[/QUOTE]
Here you go (needs java)
[url]http://science.nasa.gov/realtime/jtrack/3d/jtrack3d.html[/url]
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