Nibb31

The issues with radio waves doesn't have anything to do with ionizing radiation. It's the thermal effect that hurts. I would strongly encourage you not to sit in front a microwave transmission antenna or to use a leaky microwave oven. Folks that work on large antennas can get serious burns. https://en.wikipedia.org/wiki/Microwave_burn Where there is disagreement is in the level of exposure and what levels constitute a health risk, but it is a fact that the thermal effects of radio waves can be dangerous.

Not Zvezda, that's the oldest part of the station. The Russians had plans to reuse the Nauka, which is scheduled to launch to the ISS in 2017, but who knows if they'll have enough cash to start a new station.

I thought you said that you had read the thread? You need a lot more than that. There isn't one single rich guy who is rich enough for make a space colony, not even Musk. What you need is a business model that makes it worthwhile and sustainable, and nobody has invented that yet.

Please read the thread before proposing stuff that has already been proposed and dismissed. And the point of that would be ?

Boosting it over a long period means that you are keeping mission control and all the control systems running. In that case, you are still going to be spending a lot of money on it for no reason. Once you shut down the systems, then it's dead and it becomes useless. It can't be rebooted or restarted or reused or revisited, and it will break up eventually. Keeping it around for sentimental reasons just makes it a source of debris and a hazard. But the purpose of the ISS was not to work as an exploration gateway. It has always been a designed as a research facility. The ideas of using a space station for exploration go back to the early days of Space Station Freedom, when we were supposed to be flying the space shuttle every week and returning to the Moon with it.

That word probe. It doesn't mean what you think it means. What you are thinking of is an unmanned recovery spacecraft. A probe is an unmanned exploration spacecraft. Of course, the whole idea is stupid too. The cost of developing such a vehicle would be colossal and totally pointless. Of we had trillions to spend on space, we would be better of spending it on building a lunar outpost of going to Europa.

WAG. The EUS is supposed to be able to send a 50 MT payload into lunar orbit. The ISS is 400 MT (8x50), and reaching escape velocity requires more dV, and we're not even counting the mass of whatever structure you need to hold this massive contraption together. I'd say 8 upper stages is a low estimate.

How exactly do you think you can translate delta-V into dollars ? You need to figure out an engineering solution first. Let's say you need something like 6 to 8 EUS upper stages (magically modified to loiter several years in orbit instead of 5 days) to impart the dV needed. That means just as many SLS launches. You also need to build a massive frame to attach those boosters and to hold the station together. You would probably need several years of manned missions to build that framework and to remove or fold the solar arrays so that they don't get torn off. With one launch per year, it would take the best part of a decade and most of NASA's manned spaceflight budget. I'd say $10 to $20 billion just for the SLS hardware. Several billion more for designing the mission, the specific hardware, the manned launches, and extending mission control during that time. Oh, and you'd need to get the international partners to agree with your stupid idea. Because yeah, it is a stupid idea.

Dragon V2 won't be doing powered landings until the end of the Commercial Crew program at best. The five SpaceX pads at KSC are more than enough. What has Commercial Crew got to do with in-house astronauts? Commercial Crew will only be flying NASA astronauts to the ISS. SpaceX is a launch provider, not a space agency. NASA pays them to fly NASA astronauts.

There are regulations in place to limit the amount of debris. Most of the debris from launches decay naturally, including upper stages. Anything that has a perigee below a few hundred kilometers is going to come down after a few weeks or months. GEO sats go to graveyard orbits. It's not as much of a problem as some people think.

You wouldn't need to put it into solar orbit for that, and there isn't much to learn by watching it fall apart that we don't know already. Solar orbits close to Earth are unstable. Stuff that ends up there tends to come and go into Earth orbit in hard to predict orbits.

Translate into engineering terms first. What purpose would it serve to do that ?

I understood that and my comments still stand. It would take more dV to boost it up than to deorbit, and the laws of physics aren't going to change any time soon, so a Shuttle-type vehicle will still be impractical. There were vague plans to reboost Skylab on an early Shuttle mission, but those were scrapped early. It would have been an engineering nightmare, requiring them to develop a special docking module using the obsolete drogue/cone system and containing an airlock (Apollo/Skylab used a different pressure and atmosphere from the Shuttle). There were also concerns that the atmosphere inside Skylab would have become unhealthy, with the development of fungus and bacteria. That was all abandoned when it became clear that Skylab was decaying faster than expected and the Shuttle program was being delayed.

Pushing it up to a higher orbit requires more dV than deorbiting it. Are the laws of physics expected to change in 50 years?

Paper blueprints are useless nowadays. Manufacturing techniques and materials have evolved. If you went to a modern machine shop with blueprints they'd send you home and ask you to come back with proper CAD files. The infrastructure and supply chain for Buran and Energia is long gone. Bringing them back would be a stupid as trying to rebuild a Ford Model T in a modern car factory. You would spend so much time redesigning parts and processes that it's cheaper to simply design a new Ford Focus from scratch.

I didn't say they would get stuck in the middle of the module and die there. I said it was an annoyance to drift away from a wall and have to wait until you drift to the other side or the air recirculation pushes you around. The issue was annoying enough for Skylab astronauts to raise it and for NASA to want to avoid large empty spaces in subsequent space station designs. In that picture, most of that inflated space is actually wasted. There is nothing in it and there is simply no need for it. If you want to fill that space, you are going to have to launch multiple cargo missions to fill it up. Remember BA330 is 20t empty. Destiny was 15MT equipped. BA330 is still heavier and carries less equipment. Oh yeah, tourists. *yawn* The only application that empty space might have is recreation for tourists. Wake me up when you have a decent business model for that. For the moment, neither private customers nor NASA are interested, and there are good reasons for that.

It can't folks. Did you even read the thread ?

Submarine crews manage pretty well in smaller spaces for long duration missions. So do ISS crews. The comfort of a larger habitat to float around in is not necessary and not worth the extra complexity and effort.

You need a cargo flight (probably several ones even) to bring up the equipment that didn't fit inside the deflated module. The inflatable module is heavier than an empty ISS module. Whereas the ISS module is pre-equipped on the ground, the BA330 goes up with only some of its equipment. It also needs to carry a whole stack of internal walls, floors, wiring, railing, plumbing, etc... that need to be installed after the inflation. That's a lot of assembly work for the crew before it can be operational, which probably requires at least one separate dedicated manned mission, so you need at least 3 launches before the hab is operational. Also, an ISS-type module with equipment racks on the outer walls is more efficient than large volume area with equipment around the central axis. A circular corridor is just wasted space and requires a lot of movement to go from one work area to another and you can't see what's going on on the other side of the central column. A central corridor allows you to access the 4 work areas around you just by turning around and you have a clear line of sight over the entire module. A large empty volume carries no major benefit (other than maybe some extra comfort). In fact, it's harder to move around in microgravity in a large volume area than in a series of corridors. Skylab crews complained that they could sometimes get stuck out of reach of a handrail or a wall, and had to wait until they drifted within reach.

Why would it be ? It's multiple layers of various materials, bladders, insulation, just like a conventional pressure hull. The walls are somewhat flexible, but they are much thicker. The material is less dense, but if it offers the same protection against MMODs and radiation, then the actual mass/area is likely similar. But then because the inflated volume is much larger, so is the surface area, and consequently the mass. Wikipedia says this Compared to their own weight, expandable modules offer more living space than traditional rigid modules. For example, the pressurised volume of a 20-ton BA 330 module is 330 m3, compared to 106 m3 of the 15 ton ISS Destiny module. Thus BA 330 offers 210% more habitable space, with an increase of only 33% in mass. That means that basically, you get more empty space with 33% less actual equipment, which is rather pointless. The problem is that Destiny's 15 tons included several tons of experiment equipment already, so the difference is actually more than 33%. Basically, you're going to need at least 2 more supply and outfitting flights to actually fill up the space inside a BA330, whereas launching 3 Destiny modules gets you the same volume and much more equipment.

Since it's pretty much the same material, but for a larger volume, there is no reason for a Bigelow module to be lighter. It also has to include the inflation equipment. Launchers are mostly defined by payload mass, not volume, so you don't save any money. You don't need (or even want) wide open areas on a spacecraft. They just make it harder to move around in (see Skylab). Volume is only useful if you have equipment to put in it and you still have to send up all the equipment to fill that space. Having an inflatable volume simply isn't that valuable. As I said, it might be a nice to have feature, but it's not a game changer.

Would they be cheaper ? GPS sats are pretty expensive birds, with an atomic clock and some unique hardware. It might not be possible to actually make them much smaller, and it might not be economical to make more of them.

I don't see why they would be cheaper. If anything, they are more complex and require quite a lot of orbital work. Their advantage is that they offer more habitable volume, which is a "nice to have" feature, but not a key enabler for anything. In other words, it's probably not worth the extra cost or work.

The SMs look the same to me. The Lunar mission is carrying an extra Block-D upper stage, probably for LOI.

I agree that the next administration will have to redirect its manned effort towards the Moon, or else they'll be going nowhere for another 30 years. They need to kill the "Journey to Mars" PR rubbish, whose sole purpose is to hide the fact that Orion/SLS is a lunar vehicle and can't do much else. It's time to give themselves goals that are actually achievable rather than pipedreams that are never going to get funded.