csbingel t1_j1w5w53 wrote on December 27, 2022 at 9:15 PM

Reply to comment by gbbloom in Why don't we plan for more "staging" at orbital platforms? by gbbloom

Again, not an expert, but volume isn’t the issue, mass is. Every gram costs fuel and infrastructure to launch. That was the benefit of SpaceX’s Falcon platform, and it’s reusable launch stages. But even with that, still beyond most non-government scale budgets to consider.

mortuus_est_iterum t1_j1w6xzk wrote on December 27, 2022 at 9:22 PM

This is the answer.

But tbh I would also like to see a much larger ISS in a higher orbit.

Morty

gbbloom OP t1_j1wc8f0 wrote on December 27, 2022 at 9:58 PM

Morty can we dig into why the higher orbit? That one intrigues me... is it to make it even easier to escape Earth's pull if you push off from there? Is there any reasonable way to a) expand the ISS and b) move it further out than it's current orbit?

ADSWNJ t1_j1won62 wrote on December 27, 2022 at 11:24 PM

There's a couple of different issues with the ISS. one - it's at an altitude that needs regular boosting or else it would reenter. Not a big deal, but annoying that you need to add thrust to keep it at a low orbit, versus putting it out to say 1500km or 2000km alt and it could stay for centuries with no boosting. Second... the inclination of the ISS is not ideal to launch to the moon or the planets due to the plane change needed. It would be much better if the orbital apogee (highest point) were on a nodal point with the planets, and as high as possible, to minimize the Delta-V to exit the base on the right plane and trajectory.

Ruadhan2300 t1_j1wok7a wrote on December 27, 2022 at 11:24 PM

The ISS is absolutely intended to be expandable, and moving it to a higher orbit is done routinely.

Basically the reason to put a bigger station in a higher orbit is to reduce the effects of atmospheric drag.

The ISS loses kilometers of altitude over a matter of months and has to be boosted regularly to compensate. A bigger station would have an even worse time of that. So putting it in a higher orbit would be worthwhile for that reason.

The ease of escaping earth's hill-sphere is a perk, but the reality is that half the work is achieving orbit. Once you're in LEO, you're halfway to anywhere. Higher or low orbit isn't a big difference compared to getting up there.

mortuus_est_iterum t1_j1ziuel wrote on December 28, 2022 at 3:52 PM

The ISS orbit is low enough to be affected by atmospheric drag (which slows it down so the orbit gets lower still, increasing the drag, etc.) and it needs fairly regular boosts to keep it orbiting. There is also a truly amazing amount of junk in LEO which poses a constant threat of collision damage to the ISS. If they detect a possible collision, the ISS can be maneuvered a bit to avoid it. And yet after all the effort to keep everything safe, the current Soyuz escape capsule was damaged by a meteor collision to the cooling system.

My desire for a much higher orbit is an attempt to minimize all of those factors because I still hope the ISS can become the research center it was touted to be.

Morty