Iss

[Chinahand]

most satellites are in the lower orbit.

Huh ... are you telling us you think most satellites are lower than the ISS?

 

That's not right - most earth observing satellites are over 700 miles up, GPS satellties are 20,000 km high, while geostationary ones are 35,000 km high.

 

The ISS is about the lowest satellite, Hubble is also low, but at 500km alot higher than the ISS - the reason why is so they can be serviced by shuttles/soyuz rockets.

 

If the ISS was higher it couldn't be serviced or used - the astronauts wouldn't have a rocket to reach it - and it would just take up orbit from other instruments.

 

Why spend billions to do something useless.

[pauld]

you contradict yourself, if the shuttle can repair and release satelites upto 700 miles out then how can they not reach a space station twice as far out as it is now, thats about 550.

 

and you think you are telling me something i dont know, i said before, for someone else to explain the difference in orbit types.

 

geostationary at around 22,000 miles out, and leos.

 

the shuttle has a maximum of 600miles altitude range.

and almost all satelites made in modern times were made to be upgradable/serviceable, and stay in orbit for many decades.

 

http://www.fas.org/spp/military/program/nssrm/initiatives/shuttle.htm

 

Interplanetary spacecraft can be placed into orbit by Space Shuttles with the use of a propulsion unit called the Inertial Upper Stage (IUS). After the satellite or spacecraft is deployed from the shuttle payload bay, the IUS is ignited to accelerate the spacecraft deep into space. The IUS is also used to boost satellites into an orbit higher than the Space Shuttle's maximum altitude of 600 miles.

[VinnieK]

feel; free to explain to him how satelites stay in orbit for decades.

 

Surely you're comparing apples and oranges here. Firstly, satellites are small, have less mass and require less fuel to maintain their orbit than the ISS (and much less fuel to propell into a graveyard orbit). Secondly, a lot of satellites tend to be in a higher orbit than the ISS (Vanguard, for instance, is about twice as far from Earth as the ISS even at its closest point). Thirdly, sticking a satellite in a graveyard orbit is safer than doing the same thing with the ISS, since due to size the chance of colliding with other debris is limited and it's not as big a deal should it fall back to Earth, since they're likely to burn up completely in the atmosphere.

 

To be honest, I don't really understand why this is such an emotive issue. The space station is a great accomplishment, and it has a certain romance about it, but the fact is that it was a huge expense to build, and is massively expensive to maintain.

[Mutley]

The space station is a great accomplishment, and it has a certain romance about it, but the fact is that it was a huge expense to build, and is massively expensive to maintain.

 

Agreed - just a pity they will have to dump it in the Ocean.

[pauld]

vinney thats the thing to me, all those billions for it to crash and burn, [and its not the money, it wasnt mine, the achievement however is for all] instead of money being spent on maintaining it for future use, even if its for scavenging off for future projects, its already had the expensive part done, and thats getting it into orbit in the first place, obviously the yanks and other investor countries think its purpose served.

And vinney do you really think theres more junk at a higher orbit, i dont believe their is, however i am open to being proven wrong as i am going on memory, but it seems logical to assume theres more debri at lower orbits as drag takes effect on it, and draws it back to earth.

[VinnieK]

vinney thats the thing to me, all those billions for it to crash and burn, instead of money being spent on maintaining it for future use, even if its for scavenging off for future projects, its already had the expensive part done, and thats getting it into orbit in the first place, obviously the yanks and other investor countries think its purpose served.

 

It just seems to me that it would be counter productive to spend yet more vast sums maintaining it in order to make the most of the initial expenditure. It would be a bit like spending your savings maintaining a clapped out motor on the basis that you resent throwing it away because it cost so much to purchase in the first place

 

Remember, the ISS requires an awful lot of money and effot to keep it running. It has to be manned, with about two or three people on board taking care of the housekeeping, and manned launches are very expensive (about $450 million per mission) and a lot of work. It also has a projected lifespan of about 15 years (that's a cautious estimate, to be sure, but it's worth keeping in mind that microfractures and other structural problems are going to manifest at some point or another).

 

Also, it could be argued that the most valuable and useful knowledge we got from the ISS was in its very development and construction. By the time it actually got up there the project had already delivered most of what it was going to do, and then became an incredibly expensive and risky to maintain platform for a handful of experiments which couldn't be done better and cheaper using unmanned satellites and probes.

 

To put this into some perspective, if what I've read is correct the yearly operational costs of the ISS are three billion dollars. That is roughly half of what the UK's entire science research budget was in 2008. That buys a hell of a lot of science, and could be spent on an array of much more worthy projects than what goes on on board the ISS

[pauld]

aye it will be all eyes on the chinese for the next 20 years atleast, the yanks are too busy maxing out their credit card on bombs and bullets, chinese seem to be the only ones with the resources to do it, whether they have the will, is another thing, they are sure showing an interest.

[GD4ELI]

aye it will be all eyes on the chinese for the next 20 years atleast, the yanks are too busy maxing out their credit card on bombs and bullets, chinese seem to be the only ones with the resources to do it, whether they have the will, is another thing, they are sure showing an interest.

 

I'm sure the Chinese will take over where the Americans have left off.

[Tempus Fugit]

dont ya, 17.5 [k]thousand mph was my estimate as of my memory for the shuttles, it may be 17.5 kilometres per hour, but i think its miles per hour.

 

i will check and edit in the exact speeds.

 

edit

aye nowt wrong with my memory.

The shuttle orbiter and external tank continued to ascend on an increasingly horizontal flight path under power from its main engines. Upon reaching 17,500 mph (7.8 km/s), necessary for low Earth orbit, the main engines are shut down.

just the convention of kmph being kilometres/hour not kilomiles/hour

 

but who cares

[pongo]

aye it will be all eyes on the chinese for the next 20 years atleast

 

China is a bubble economy.

[Alias]

you contradict yourself, if the shuttle can repair and release satelites upto 700 miles out then how can they not reach a space station twice as far out as it is now, thats about 550.

 

and you think you are telling me something i dont know, i said before, for someone else to explain the difference in orbit types.

 

geostationary at around 22,000 miles out, and leos.

 

the shuttle has a maximum of 600miles altitude range.

and almost all satelites made in modern times were made to be upgradable/serviceable, and stay in orbit for many decades.

 

http://www.fas.org/spp/military/program/nssrm/initiatives/shuttle.htm

 

Interplanetary spacecraft can be placed into orbit by Space Shuttles with the use of a propulsion unit called the Inertial Upper Stage (IUS). After the satellite or spacecraft is deployed from the shuttle payload bay, the IUS is ignited to accelerate the spacecraft deep into space. The IUS is also used to boost satellites into an orbit higher than the Space Shuttle's maximum altitude of 600 miles.

The shuttle has a maximum range of 600 miles altitude. The higher the shuttle goes, the less payload it has as it needs a lot more fuel to burn to reach this point (see Chinahand's xkcd gravity well picture). The fuel the shuttle expends getting to the ISS is a hell of a lot more than the ISS needs to compensate for the drag of the Earth, hence the low orbit.

[Bobbie Bobster]

Also, it could be argued that the most valuable and useful knowledge we got from the ISS was in its very development and construction. By the time it actually got up there the project had already delivered most of what it was going to do, and then became an incredibly expensive and risky to maintain platform for a handful of experiments which couldn't be done better and cheaper using unmanned satellites and probes.

It's a common view amongst policymakers that the great benefit of the ISS was in terms of developing a successful approach for international co-operation in HSF activities, significantly outweighing the potential scientific benefits. That doesn't sound like a lot, until you consider that it is unlikely that future major manned space exploration activities are feasible for any nation on its own. It may be, therefore that the experience of internation co-operation gained through the ISS may provide a platform for far future exploration and colonisation

 

Oh, and please don't feed the troll.(ETA addressed generally, not just VK)

[Stavros]

Why spend billions to do something useless.

It's worked quite well for the Manx Government so far.