Keeping The ISS In Orbit

[L5 Vision]

Yes, ISS is in a vacuum, which is very good for preservation, however it is also subject to cosmic radiation that we don't have on Earth's surface due to our atmosphere overhead. The cosmic radiation degrades everything, metals, insulation, semiconductors, plastics. Failures will occur without warning and can have catastrophic results. There is no room for taking chances in outer space. No one wants to champion a dead horse that might go on to kill people. Let them decommission it according to the schedule of the people who pay for it. And they will not give or sell it to anyone. Too much liability.

Sounds like talking points for the contractors building the new parts at astronomical expenses

 

[billslugg]

Sounds like talking points for the contractors building the new parts at astronomical expenses

Yes, you are correct, it could be. It could also be the truth.

 

[L5 Vision]

Yes, you are correct, it could be. It could also be the truth.

Yup you got me there. Facts as facts, i just wonder now who benefits by getting the ISS de-orbited? With the Billions invested in building and maintaining the old rust bucket as the ISS is now billed, why can't the best and brightest among us spend a few Million US to really study if there is a useful afterlife for the ISS? Will we be kicking our selves for not at least thinking about recycling half a million kilos of somewhat useful human habitat at the dawn of human interplanetary history?

 

[billslugg]

They already studied it. The risk of killing someone is on everyone's mind, no one wants to sign up. Everyone is running away from the possibility as fast as they can. The current air leak fiasco is exhibit #1. There is not a single dollar available to revive an ailing horse. It's dead, Jim.

 

[L5 Vision]

They already studied it. The risk of killing someone is on everyone's mind, no one wants to sign up. Everyone is running away from the possibility as fast as they can. The current air leak fiasco is exhibit #1. There is not a single dollar available to revive an ailing horse. It's dead, Jim.

Thanks Jim. I wounder if it was in private control without the prestige of NASA at risk if the study would have yielded different options. Musk can blow up a dozen starships and nobody gets blamed for the process but SpaceX. Also thanks for your patience as I work out my cynicism about the right way, the wrong way and the NASA way

 

[billslugg]

What Musk does with his money is his own business. What NASA does with my tax dollars is my business and I don't like how they spend them. You are free to send all the money you want to them.

 

[Ken Fabian]

I am not keen on the continuing use of Earth's atmosphere as a way to dispose of space junk if it can be avoided, especially as the amount of it keep growing. I had also wondered if putting a shut down ISS into a higher, more stable orbit could leave useful materials for future space industries but wasn't putting all that material into the low orbit preferred because pushing it all to a higher orbit in the first place added too much cost? ie to get the most ISS for the cost.

I can't see any serious prospects emerging for in-space industries capable of recycling the materials - something space history buffs would very likely oppose anyway, preferring preservation.

 

[billslugg]

LEO was as high as they could toss it.
The delta V needed to deorbit from 250 km runs around 90 meters/second.
The delta V to get from 250 km orbit to geosynchronous is around 2440 m/s.
They are spending $840 million to deorbit.
By a simple ratio, getting to geosynchronous might cost $23 billion.

 

[Ken Fabian]

LEO was as high as they could toss it.
The delta V needed to deorbit from 250 km runs around 90 meters/second.
The delta V to get from 250 km orbit to geosynchronous is around 2440 m/s.
They are spending $840 million to deorbit.
By a simple ratio, getting to geosynchronous might cost $23 billion.

Yes, in space it is not so much about how high or how far but about how fast; differences in speed are very large and take a lot of rocket power and fuel to overcome.

 

[Pogo]

Not to mention the thermal stresses every 90 minutes from a couple hundred degrees to minus a couple hundred degrees. Although there is insulation, much of the pressure envelope has been heated and cooled millions of times. Aluminum doesn’t like that so much. I wonder if stainless steel or titanium would hold up better.

 

[billslugg]

Steel is too heavy for its strength to find much use in aerospace applications. Titanium is very difficult to work with but has good strength and corrosion resistance. For the best combination of cost, weight and strength, alloys of aluminum are preferred. The fatigue life expectancy was calculated very carefully when the ISS was built. It is a very complex calculation, dependent on many, many factors. Once the station has exceeded its lifetime, the engineers will not stand behind it. It cannot be recertified in place, must go back to Earth and be stripped down. This is cost prohibitive.

 

[Classical Motion]

We ought to make our space stations out of elastic fabric. To be inflated or even manufactured in space.

A self sealing fabric.

 

[billslugg]

Elastic fabric does not fatigue like metals do. It is easy to make in many layers which complement each other. Each layer sealing where another layer might have a hole. Inflatables can be made small for launch and then inflate to large sizes in space. Self sealing might be achieved with some sort of glue inside tiny micro capsules. Only when ruptured would the glue come out and fill the tiny hole.