general ignorance

[delman]

Just read another post about replacing an old satellite, which made me realise my general ignorance. So I was wondering a few things:-How do they get a new satellite up there? (I am guessing a space rocket) how do they get it to stay in one place? (no guesses) where does the power to run it come from (guessing solar panels or dialythian warp drive crystals) and how does the satellite get the programmes to send to earth?

It does make me realise sometimes that if the vast technological advances the human race has made over the centuries had been down to me, we would still be living in the stone age (or even the age before that!)

[BlackHawk]

Hi
Communication/TV satellites are only relay stations in space. Ground stations uplink to them at 14Ghz and the satellite converts these signal to 11-12GHz and pumps them down to earth (for ku reception).
Yes, the satellite is sent up via rocket. There will be a launch in early May, Analoguesat, I expect will be giving details of that, and how to view the launch.
Solar panels provide the powrr with battery back up.
Station keeping is achieved by small jets of (I think it's called) hydrozeen gas which is carried on the satellite.
Nothing really new just an update of the flashing mirrors or waving flags of many centuries ago .
BH

[Analoguesat]

3rd May 2007 BH

Full transmission details will be put up on the forum as soon as they are released

Station keeping is done by small thrusters powered by hydrazine (N2H4) which is also found in small amounts in tobacco products!

More than you would ever wish to know about hyradzine:

http://en.wikipedia.org/wiki/Hydrazine

[BGonaSTICK]

All good beginner's questions, and I'm glad you asked them

The modern-day commercial TV satellites are all magically affixed to the sky by the mathematics and science that is geosynchronicity

Sometimes satellite rocket-launches turn spectacular, as in the case of NSS8 which exploded on the sea-launch platform back in January

http://www.satellitehelp.co.uk/forum...c,3519.15.html

Worth a read.

[Gav]

Originally Posted by BGonaSTICK

All good beginner's questions, and I'm glad you asked them

The modern-day commercial TV satellites are all magically affixed to the sky by the mathematics and science that is geosynchronicity

Sometimes satellite rocket-launches turn spectacular, as in the case of NSS8 which exploded on the sea-launch platform back in January

http://www.satellitehelp.co.uk/forum...c,3519.15.html

Worth a read.

:REALLY? Some guy told me they were held in place with string????

[Analoguesat]

The best launch coverages are normally the Yanks with the Atlas 5 coverages. We got to ride into space thanks to some incredible onboard pictures when Hotbird 6 was orbited!

The next best are the Ariane 5's -

The Russkie Protons normally have rubbish coverage - on one recent launch they didnt tilt the camera fast enough and the rocket soon got out of sight Nice pictures of a scorched pad though!

Ive only seen one Sea Launch - and that one blew up on the launchpad...... The camera was way too far away for decent pics of the launch if had been successful though.

I do like the Ariane 5's - most impressive as they climb off the pad with all rockets at full power.

The picture shows the Ariane 5 flight that carried Hotbird 7A into orbit

[BGonaSTICK]

Originally Posted by Gav

:REALLY? Some guy told me they were held in place with string????

As long as it wasn't me, that's just fine

[delman]

Thanks for the replies, the wikipedia link was very interesting. Makes you realise that the Earth is rotating on its axis therefore a satellite in geostationary orbit would have to be keeping time with the Earth's orbit. And being as we are turning some 25000 miles in 24 hours, which must mean the Earth and its atmosphere are travelling through space at 1000 miles and hour (woh, where's my crash hat and goggles!) just in its axis rotation, then that must make the job of launching the satellite, to get it 22000 miles up, in just the right place, at just the right altitude, travelling at just the right speed to attain its geostationary orbit, a very clever bit of rocket driving!

[Analoguesat]

Oh yes its all very clever. For dual payload launches it gets even more complicated as they have to drop the first payload off at a suitable point, drop off the mating unit into a safe orbit where its not going to do any damage to anything then drop the second payload in its intended orbit.

If you are interested in such things I strongly suggest you watch the Ariane 5 launch later this week which will orbit Astra 1L & Galaxy 17, and will make things much clearer.

The launch will be webcast here

http://www.videocorner.tv/index.php?langue=en

and launch is due off 2330 Thursday night UK time. IF theres a sat transmission I'll list the details later in the week when they are made public.