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View Full Version : Pulse & Glide on the International Space Station


Chuck
03-20-2007, 11:21 AM
Did you know the International Space Station sinks about 90 yards (or meters) closer to the Earth daily? The periodic boosts required to maintain orbit is more challenging, since the use of the Shuttle is more limited - only Russian spacecraft can do it. The orbit has varied from 246 to 207 miles today.

While a lower earth orbit means more cargo can be sent per launch, it also increases the drag on the ISS. The Shuttle is about to do some of it's heaviest lifting, so the orbit will be lower until work is finished.

MSNBC Story (http://www.msnbc.msn.com/id/17630218/)

raguru
03-20-2007, 04:31 PM
Chuck,

Thanks for the link. I had not seen that story. I knew that it sinks due to the drag and that it required periodic re-boosting. But it was interesting that they like the current level of sink since that helps the heavy-lifting shuttle. I guess Atlantis will re-boost it after its next mission.

BailOut
03-20-2007, 04:41 PM
Has anyone yet figured out what the ISS is for?

Tochatihu
03-21-2007, 09:37 AM
At high times of the sunspot cycle, the thermosphere (the v. thin layer of the atmosphere where ISS and many other satellites are) becomes denser, and the satellites sink faster. Those sink rates are actually how the density of that layer is measured.

A thick thermosphere is handy because it hastens the reentry of lots of orbital debris. Avoiding running into that stuff is a significant part of the current space effort.

What' it for? No doubt most know the standard answers to this question. Here is a different, long term view:

"MOSCOW, January 30 (RIA Novosti) - The International Space Station will likely remain operational until 2025, the head of the Russian spacecraft manufacturer Energia said Tuesday, adding that by 2009-2015, Russia will be the only country able to deliver crews to the station.

"No one is going to sink or drop the ISS, as all countries realize that the station is becoming a full-scale industrial facility in space. Although it is scheduled for decommissioning in 2015, its operational life could be prolonged until 2025," Nikolai Sevastyanov said.

He said Energia has proposed making the station permanent.

"If we terminate its existence, it would be hard for mankind to implement such a project anew," he said.

Sevastyanov said spaceships destined for the Moon and Mars could be built near the ISS from prefabricated modules sent into orbit by Russian Soyuz, Progress and other booster rockets. He said that Energia is designing a shuttle to link the Earth, the ISS and the Moon, and that by 2009-2015 Russia would be the only country able to send crews to the station..."

http://en.rian.ru/world/20070130/59917397.html

It's likely to be a bit pock-marked by then, what with all that orbital debris. Kinda stanky on the inside too, given the frequent effect of microgravity on human digestion.

Or you might like this blog, called "Sink the Space Station?"

http://cosmiclog.msnbc.msn.com/archive/2006/06/09/290.aspx

Or, it's for looking at. Check out your next view at:

http://www.heavens-above.com/

DAS

Chuck
03-21-2007, 12:34 PM
My unscientific reply to suppporting the ISS is if we can't learn and gain from a low-orbit outpost - what point is a moon base? It seems much of the problem with the ISS and the space program in general is developing a better way of getting from ground to orbit. It's too expensive, too dangerous, too unreliable. We need to improve getting there and everything else will fall into place.

Pravus Prime
04-02-2007, 06:15 PM
My unscientific reply to suppporting the ISS is if we can't learn and gain from a low-orbit outpost - what point is a moon base? It seems much of the problem with the ISS and the space program in general is developing a better way of getting from ground to orbit. It's too expensive, too dangerous, too unreliable. We need to improve getting there and everything else will fall into place.


And I wonder how much of that is due to the nations joint effort rather than a single force leading the way.



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