Raising ISS altitude?

[Artlav]

Now that the shuttle is gone, why keep the ISS in such a low and constantly decaying orbit?

Even at 500 km it would stay up much longer, and at about a 1000 the problem would be minimal.

Objections i recognize is the radiation and debris, are there any others?

The radiation belts extend down to about 100 km, and ISS is often in it.
How much worse would it be, if at all, at 1000km?

How much is the debris situation different higher up?
There should be a cloud of debris from old mistakes at about 2000km, and generally less of the same drag that clears the lower orbits, which implies variety of other potential debris.
On the other hand, these are less travelled orbits, so the initial amount of debris should be less.

Is there any science that can be better done higher than lower?

 

[Grover]

well, further from earth, the perbutations from the sun and moon are also stronger, probably only a little, but you'd notice it over a week or so.

 

[agentgonzo]

Soyuz, progress, atv, htv still need to get there. The lower it is, the cheaper it is to get there

 

[Capt_hensley]

It's in a nominal LEO, for all factors. Debris avoidance, Speed, Decay rate, cost of intersection, efficiency of power generation, ground communications, space communications, science(exposed facility) radiation mitigation, optical range, both space ward, and earth ward, temperature regulation, and a host of other factors not always in the light.

While the altitude, and attitude are not perfect, they are optimized for the best result post factor calculations.

No one has put out a good paper on the merits of a Med or High altitude station operation. But because different factors are involved, you would get benefits and dis-advantages from those profiles.

ISS is what it is, and we armchair engineers can't improve it. Unless it's in Orbiter. If you think it's worth it, build a scenario file for it, and post it.

 

[Wishbone]

While the choice has many facets, debris, power, radhaz are constraints, the objective function is still getting more payload delivered within the known resupply vehicle schedule limitations (at least that's what I remember from the familiarization handbook).

 

[kwan3217]

Radiation gets a LOT worse as you ascend. The survival time for a person in a spacecraft drops from basically indefinite at ISS altitude to hours up a couple thousand km in the core of the inner belt.

 

[Capt_hensley]

Radiation gets a LOT worse as you ascend. The survival time for a person in a spacecraft drops from basically indefinite at ISS altitude to hours up a couple thousand km in the core of the inner belt.

As I said, no one has written a good paper on the subject, there is little to no data to support any conclusion. No "one" has loitered in any part of the belts to prove or disprove exposure limits.

What we do have is only speculation based in math and measurements made by unmanned experiments. To a certain extent this is good but far from perfect. Sure we think it gets bad, but does it really? Apollo was never in any real danger, it passed through the belts without incident every time. Its visit to the belts was very brief. And it was not equipped with long term measurement devices. Low tech dosimeters and strips were used and yielded sketchy at best results.

I really wish we had hard evidence from human physiology, although I don't wish any astronaut or test subject to die trying to get it.

Gateway Station in GEO would gather the data we need but at what cost? So far shielding = increased cost, but what about dosages at current shielding techniques, we seem to forget as stated above, no one has tried a human test out of fear from what may result, not out of proof of what will result.

The Russian radiation experiments, and American radiation experiments were a horrible guessing game, dosages were massively gross through pitifully minor, but not much in between. The scale was skewed to one side or the other. We just need more real time evidence, we have guessed long enough. Simulation only tells us what we program it to. We have the technology to move into real time gathering, so lets just get it over with so we can move on.