[Retric]

Having people in space is kind of pointless right now. Yes, it's a low G environment, but ISS is in such a low orbit that people in my state can be further from me than an overhead ISS 'Astronauts'. It's even protected by earths magnetic field making it a poor test of long term space flight.

[rtkwe]

Absolutely wrong. Having a manned station is a boon for the research taking place. Without a station anyone wanting to do research like the packed bed or the docking and refueling experiments would require the investigating institution to design and launch a vastly more complicated automated satellite or to rely on short manned missions that would have more competition for space and time. Instead it's much easier to package an experiment and send it to the station which has a lot of equipment to support experiments and humans that can troubleshoot and modify experiments.

As for studying long term space flight the only thing it really doesn't provide a model for is radiation which we can model on the ground pretty well. You still get the other health impacts from microgravity that we're still trying to figure out how to effectively combat.

[Retric]

ISS cost ~200 billion, saying we can't do the same research for less is kind of a high hurdle when it's close enough for minimal lag, nobody tried, and people need a lot of ridiculously expensive consumables.

[rtkwe]

The lag isn't the hurdle it's making the robotics on the satellite to run the experiment. The closest analog is probably the robot that's used to service the JET reactor at Culham Centre for Fusion Energy [0]. With a station for some types of failures with experiments an astronaut can work around or heavily reconfigure the equipment to still get good data. Without a person up there every experiment launch would have to either just accept failures and write off the whole thing or include whatever system we're talking about that would replace the repair and reconfigure ability of people. Instead the various governments front the cost of having a person in space and it's way easier and cheaper for companies to package and run their experiments. It's a subsidy that opens up the ability to do microG science more easily.

Also there's no good alternative way to study the long term microG effects on humans other than a station since you need both space for people to live for up to a year and space for the various experiments on how to combat the deterioration that happens. Having a station up there also teaches us how to work and repair things in space and how things break when they've been running for 15+ years.

[0] https://www.youtube.com/watch?v=IrtGp8hv-0Y

[Retric]

No, the ITER robot needs to deal with heavy loads, micro G means even small forces add up. https://en.wikipedia.org/wiki/Mobile_Servicing_System did not need to be that strong. http://iss.jaxa.jp/en/kibo/about/kibo/rms/ was also relatively weak. Also, don't forget without people they could send 3x the science payloads. So, scrapping things and trying again really is viable.

Consider, fixing Hubble was a big thing, but we could have sent 3 of them up for less money.

As to micro G, we could send a mars mission with simulated gravity. Which is something we really should be testing instead of simply yet another long stay in micro G.

PS: Some of the most interesting recent experiments have been flame studies in micro gravity. But many of these can be done with 20 seconds of vomit comet zero g time or just a simple drop test like: https://www.youtube.com/watch?v=SZTl7oi05dQ

[rtkwe]

> Consider, fixing Hubble was a big thing, but we could have sent 3 of them up for less money.

Not even close. It cost ~900M for the repair mission and the cost to build Hubble was ~2.5B.

>No, the ITER robot needs to deal with heavy loads, micro G means even small forces add up. Don't forget without people they could send 3x the science payloads. So, scrapping things and trying again really is viable.

Less forces only means that the motors can be weaker but it doesn't lower the overall complexity required, you still have to have X degrees of freedom to get an arm that can barely replace a human in limited circumstances. Telerobotics just isn't there or cheap enough to make it make sense.

> As to micro G, we could send a mars mission with simulated gravity. Which is something we really should be testing instead of simply yet another long stay in micro G.

We /could/ do simulated gravity but there's a lot of engineering issues with that that make it a Gen 2+ solution for a Mars trip or for a more long term solution like a Mars cycler. Just the size required for a spinning torus to be comfortable and provide enough gravity to be worth it would make it much larger than the ISS [0] [1]. There are other problems like dealing with communication equipment and docking which would want a stationary center which brings in more complexity with the seals between the stationary section and the ring. There's other options like a bolas but they're also pretty complex. Until then we'll need to deal with space travel as it comes to us which is without gravity. In short to test and build them we'll need either a large decrease in launch costs or a truly massive pile of money.

[0] http://www.spacefuture.com/archive/artificial_gravity_and_th...

[1] http://space.stackexchange.com/questions/1308/why-are-there-...

[Retric]

> Not even close. It cost ~900M for the repair mission and the cost to build Hubble was ~2.5B.

There where 6 Hubble servicing missions. "this last Hubble servicing mission is expected to cost about $1.1 billion" http://www.space.com/6648-hubble-faq-space-telescope-repair-...

Further, 15 years is considered a relatively short lifetime for a satellite, so Hubble 2 and 3 could have easily had a longer total lifespan if they had kept them in a higher orbit because there was no need for servicing. Instead "the space telescope was designed to typically go only three years between overhauls."

AKA, they designed it to need 'fixing'.

[dTal]

I won't take a strong position on the larger point of whether humans in space are worth it, but there are other uses for a space station than "being far away", "being low g", and "seeing how many astronauts get cancer".