How Long Can the ISS Last?

R3d M3rcury writes with the story that "NASA and Boeing, along with other nations, are studying the feasibility of keeping the International Space Station in orbit until 2020 and possibly until 2028 — the 30 year anniversary of the launch of the first module." From the article: "To assess the long-term structural health of the station, Boeing engineers developed detailed computer models based on NASA's projected use -- the expected stresses caused by future dockings, reboosts, crew activity and thermal cycles -- and combined that with actual data from on-board accelerometers and strain gauges. ... "What we're looking at is theoretical crack growth," Pamela McVeigh, the engineer in charge of the Boeing structural analysis in Houston, told CBS News. "So the failure mode would be you'd have a crack beginning, probably (at) a bolt hole, and the crack would grow to another edge. So you'd lose like a flange on a C-beam, or an I-beam. The stiffness of your structure would then change, the bolt hole you that you were growing the crack out of, now that bolt wouldn't be effective."

Comments

I seriously doubt we'd build the ISS now

[Anonymous Coward]

The US have given up on space. The NASA budget is treated as pork, with no thought of genuine long-term progress.

Re:I seriously doubt we'd build the ISS now

[ShanghaiBill]

Why did it have to be assembled in tiny pieces instead of using big components with heavy rockets like Skylab was? If the ISS was made of big components with a heavy lift rocket, it could have been assembled in only 5 Saturn V launches (at about $1 billion a launch) or 1 Sea Dragon launch. Reviving a heavy lift rocket program would have paid for itself.

The whole point of the ISS was to give the space shuttle something to do. Using heavy lift rockets would have defeated its purpose.

Re:I seriously doubt we'd build the ISS now

[Teancum]

I seriously doubt that a Sea Dragon launch could have sent up the ISS, but I would agree that sending up 5-10 Saturn V launches would have most certainly done the trick. If anything, shutting down the Saturn V program was a huge mistake... when viewed in hindsight.

Every single mission that was accomplished with the Shuttle program (including sending up 7-man crews) could have been done with a Saturn V and done by far and away cheaper as well. Improvements in materials, guidance computers, and an evolutionary design change over time as has happened with the Soyuz rocket and spacecraft would have made the Saturn V and Apollo spacecraft a very modern and versatile platform to continue a real space exploration program and maintained at least the capability of going to the Moon as an option instead of having to re-invent the wheel again now that that capability has long since been lost.

What would have been lost, perhaps, is the need for international cooperation that went into building the ISS, but even that is not certain. Much of the basis for building the ISS came from the Apollo-Soyuz mission, where exchanges of technical information already were happening between the Soviet space program and NASA.

Even funnier is how the test stand originally built to handle a production run of over 100 Saturn V vehicles is now being used by SpaceX in Texas for testing the Merlin engines. That was the projection done by Werner Von Braun, and contracts were signed to have a contingency of building that many vehicles.

I do think the ISS would look quite a bit different than the current structure had it been built using Saturn V/I/Apollo hardware, although the modular approach would likely have been done still. It would likely have been an upgraded version of the Skylab modules, and I would even dare say that the Skylab backup that is currently in the Smithsonian very likely would have been a part of or even would have become the core American module for the ISS. It definitely would have been much roomier for the astronauts in the ISS with Saturn V launched modules.

Unfortunately, that is not the path that history took.

Why not use it as a site to build the next one?

[GrpA]

It would be nice if they could use the existing one as a site-office to begin building an even bigger one with a longer life expectancy. Use better materials, a piece at a time, and start building a replacement.

14 years isn't far from now. So what then? Start from scratch again? Seems a shame when they could begin stockpiling for the next generation and have it well underway by the time it comes to decommission the existing ISS.

GrpA

Re:Why not use it as a site to build the next one?

[dbIII]

Since it's modular it should be a matter of replacing a bit at a time, barring the sort of politics that stopped such a thing being done with Mir, which also had some relatively new modules.

Regardless of longevity.

[wjcofkc]

Regardless of when the ISS is retired, I can only hope that the powers that be have the good sense to push it into a higher orbit. Someday space travel will be accessible and we will have orbital museums and when that time comes we will regret a good number of historical items the were de-orbited. Honestly we should have kept and boosted into higher orbit one of the last space shuttle launches along with an external tank, since the external tanks are perfectly capable of making it to orbit. Basically wrap them in shielding and stow them away in high orbit until their time as accessible historical artifacts comes. There is a lot that will simply have to be re-created as mock ups, considering the sheer importance of this early age in space travel, it won't be the same but will be better than nothing. In the fifth grade I had the surreal honor of holding a piece of the Berlin wall as it was passed around class. I will never forget the sense of historical understanding that washed over me. If it had been a replica, I would have still found sentiment, but it would not have been the same.

Where on earth? I'll tell you where

[dbIII]

Where on Earth did you get the idea that NASA wasn't interested in a space station?

Western Australia July 11 1979
Or if you prefer, the 8th of February 1974 off the coast of San Diego when the last mission finished.
They showed so much of a lack of interest that they threw a working space station away despite having enough Saturn V stages to move it into a higher orbit and five years to do it in.

Re:Where on earth? I'll tell you where

[Anonymous Coward]

Actually there was excessive atmospheric heating that brought it down early. But even still, in the post Vietnam era every NASA program was being massively cut and NASA didn't know how to react to that.

keep it going as long as possible

[usuallylost]

Hopefully they continue to work on it and refurbish it. If we are ever going to have a robust long term presence in space we are going to have to learn how to build reliable structures that can be repaired and maintained over the long term. The IIS seems like a perfect test bed for that sort of development and we already have a huge sunk cost so why not use it?

Another viewpoint

[PNutts]

The stiffness of your structure would then change, the bolt hole you that you were growing the crack out of, now that bolt wouldn't be effective.

That's what she said.

Re:Do we seem a little too risk averse these days?

[CrimsonAvenger]

Bah!

DeltaV to deorbit ISS - ~180 m/s

DeltaV to move ISS to L4/L5 - ~3160 m/s.

Preview, you fool, always preview!