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This is a spectacular gamble, however Musk has a track record and I think Superheavy/Starship will pay off with unpredictable dividends. But the elephant in th

This is a spectacular gamble, however Musk has a track record and I think Superheavy/Starship will pay off with unpredictable dividends. But the elephant in the room that Musk appears to be ignoring is the life sciences side of things. Only 12 humans have sortied outside the Van Allen belts (which protect us from the deep space radiation environment). Nobody has spent more than 18 consecutive months in space or reduced gravity, and we know there are biological changes that affect astronauts. The same goes triple for the plants and bacteria and fungi (never mind animals) we depend on for agriculture, and a closed-loop agricultural system and air plant is implicit in Musk's goal of a self-sufficient colony on Mars. We haven't even repeated the (failed) Biosphere 2 experiment. We need the giant payload capacity before we can test the life sciences problems in a realistic manner (small and ferociously expensive lab experiments on the ISS are useful but fail Musk's iteration test because the lead time for running one is measured in years if not decades). So we won't know if a Mars colony is even possible until some time after Musk builds the ships to put one there.

zionic 7y ago
One interesting idea I heard: Send starships in pairs. When in interplanetary coast attach each at the nose with a long (300+m) tether. Use RCS to start a spin. You can then simulate 1G the entire way.
- viklove 7y ago
  What are you building the starships out of that they can withstand those forces continuously over multiple years?
  - nopzor 7y ago
    wouldn't 1g of force be the same as they'd be subject to sitting on earth?
    - cstross 7y ago
      Starships sitting on Earth are under compression. Starships hanging from one another's nose via a tether are presumably under tension, unless the tether is somehow anchored to the engine support structure at the base of each vehicle. So some non-trivial structural modifications would be required.
baking 7y ago
I'm not sure how big of a gamble that is. If he gets Starship into orbit he can start getting serious revenue from Starlink. Then he needs to transfer fuel in orbit to send cargo to the moon and mars. At that point he can send people and the return trip after two years will basically be free because some Starships will be returning to Earth anyway. I'm pretty sure he can get enough guinea pigs to commit to a 2-year trip. Then you iterate on the next batch of guinea pigs. Maybe he sends retirees who don't have that much life expectancy anyways.
gentleman11 7y ago
What about the sci-fi ships that rotate very quickly and use the momentum as a form of false gravity - iirc, the basic physics seems legit (I recall an Einstein thought experiment along those lines). Or: use the acceleration/deceleration to create gravity. Are they impractical to build or power?
- carapace 7y ago
  Are you thinking of an O'Neill colony? https://en.wikipedia.org/wiki/O%27Neill_cylinder https://en.wikipedia.org/wiki/O%27Neill_cylinder > The O'Neill cylinder (also called an O'Neill colony) is a space settlement concept proposed by American physicist Gerard K. O'Neill in his 1976 book "The High Frontier: Human Colonies in Space". O'Neill proposed the colonization of space for the 21st century, using materials extracted from the Moon and later from asteroids. > An O'Neill cylinder would consist of two counter-rotating cylinders. The cylinders would rotate in opposite directions in order to cancel out any gyroscopic effects that would otherwise make it difficult to keep them aimed toward the Sun. Each would be 5 miles (8.0 km) in diameter and 20 miles (32 km) long, connected at each end by a rod via a bearing system. They would rotate so as to provide artificial gravity via centrifugal force on their inner surfaces.
  - cstross 7y ago
    O'Neill's colony design is flawed (and needs updating): in particular they had huge glassed-in window areas to admit sunlight (focussed via reflectors) for agriculture: he didn't account for differential heating-induced expansion/shrinkage. On the other hand, he didn't have modern CAD back in the early 1970s. So in principle we can come up with something better. The biggest problem is exposure to cosmic radiation -- L5 is way outside the Van Allen belts and high energy cosmic rays take roughly a metre of water to attenuate, or magnetic fields of 10-20 Tesla strength around the spacecraft. Which is a lot of mass (or a ridiculously strong magnetic field). See also: https://en.wikipedia.org/wiki/Health_threat_from_cosmic_rays https://en.wikipedia.org/wiki/Health_threat_from_cosmic_rays
    - deleted 7y ago
      [deleted]
carapace 7y ago
Then we'll merely go to the Moon. :-) (And LEO and the Lagrange points.) You raise a good point IMO in re: viability of space. In the limit it may turn out that humans can't live anywhere but on or near the surface of Earth. What is certain is that living in space will suck for many years, or likely decades. It will be like living in a mine, but there are more things that can kill you and you're much much further from fresh air and safe ground. And I suspect living on Mars would suck anyway just due to the ~0.4G surface gravity. At least on the Moon you can go home (in a few days rather than lots of months) or fly like a bird under your own power if your cave is big enough. ("The Menace from Earth", Heinlein; "Welcome to Moonbase", Bova) But even if we can't live there it's still really useful and important to go: micro-gravity manufacturing; robotic asteroid mining; science... I hope we can live in space, I want to colonize the galaxy. (The green galaxy on the cover of "The Millennial Project" book is one of the more compelling images I've personally ever seen. A photosynthesizing galaxy... https://en.wikipedia.org/wiki/The_Millennial_Project:_Colonizing_the_Galaxy_in_Eight_Easy_Steps https://en.wikipedia.org/wiki/The_Millennial_Project:_Coloni... ) But even if we can't go at all these rockets are really important!
- cstross 7y ago
  This is why I like to draw a distinction between space exploration and space colonization. The former is definitely within the realm of possibility, using existing technology (never mind the Superheavy/Starship system). But Musk, with his talk of a self-sufficient city, is clearly targeting the latter, and there are a whole lot of details we haven't worked out.
  - carapace 7y ago
    It's one of those things, robots are much less romantic than astronauts, but they make so much more sense it's not even a contest. I wonder how starry-eyed Elon Musk really is in re: Mars colonization? I know for myself that it was hard to admit robots make more sense (at least at first).
hutzlibu 7y ago
Well, for context, it seems, that he know, that the whole thing is not so easy ... "“I’ll probably be long dead before Mars becomes self-sustaining, but I’d like to at least be around to see a bunch of ships land on Mars,” Musk said."
kamaal 7y ago
Like every other discovery on earth, the first set of explorers will have to risk life and limb, make sacrifices to get there. The one's that follow will build several stops along the way. You will be able to stop, stay for a while, and move forward towards your journey. Also Asteroid mining is going to be a thing. So economy, space labs and all.

zionic 7y ago

One interesting idea I heard: Send starships in pairs. When in interplanetary coast attach each at the nose with a long (300+m) tether. Use RCS to start a spin. You can then simulate 1G the entire way.

viklove 7y ago
What are you building the starships out of that they can withstand those forces continuously over multiple years?
- nopzor 7y ago
  wouldn't 1g of force be the same as they'd be subject to sitting on earth?
  - cstross 7y ago
    Starships sitting on Earth are under compression. Starships hanging from one another's nose via a tether are presumably under tension, unless the tether is somehow anchored to the engine support structure at the base of each vehicle. So some non-trivial structural modifications would be required.

baking 7y ago

I'm not sure how big of a gamble that is. If he gets Starship into orbit he can start getting serious revenue from Starlink. Then he needs to transfer fuel in orbit to send cargo to the moon and mars. At that point he can send people and the return trip after two years will basically be free because some Starships will be returning to Earth anyway. I'm pretty sure he can get enough guinea pigs to commit to a 2-year trip. Then you iterate on the next batch of guinea pigs. Maybe he sends retirees who don't have that much life expectancy anyways.

gentleman11 7y ago

What about the sci-fi ships that rotate very quickly and use the momentum as a form of false gravity - iirc, the basic physics seems legit (I recall an Einstein thought experiment along those lines). Or: use the acceleration/deceleration to create gravity. Are they impractical to build or power?

carapace 7y ago
Are you thinking of an O'Neill colony? https://en.wikipedia.org/wiki/O%27Neill_cylinder https://en.wikipedia.org/wiki/O%27Neill_cylinder > The O'Neill cylinder (also called an O'Neill colony) is a space settlement concept proposed by American physicist Gerard K. O'Neill in his 1976 book "The High Frontier: Human Colonies in Space". O'Neill proposed the colonization of space for the 21st century, using materials extracted from the Moon and later from asteroids. > An O'Neill cylinder would consist of two counter-rotating cylinders. The cylinders would rotate in opposite directions in order to cancel out any gyroscopic effects that would otherwise make it difficult to keep them aimed toward the Sun. Each would be 5 miles (8.0 km) in diameter and 20 miles (32 km) long, connected at each end by a rod via a bearing system. They would rotate so as to provide artificial gravity via centrifugal force on their inner surfaces.
- cstross 7y ago
  O'Neill's colony design is flawed (and needs updating): in particular they had huge glassed-in window areas to admit sunlight (focussed via reflectors) for agriculture: he didn't account for differential heating-induced expansion/shrinkage. On the other hand, he didn't have modern CAD back in the early 1970s. So in principle we can come up with something better. The biggest problem is exposure to cosmic radiation -- L5 is way outside the Van Allen belts and high energy cosmic rays take roughly a metre of water to attenuate, or magnetic fields of 10-20 Tesla strength around the spacecraft. Which is a lot of mass (or a ridiculously strong magnetic field). See also: https://en.wikipedia.org/wiki/Health_threat_from_cosmic_rays https://en.wikipedia.org/wiki/Health_threat_from_cosmic_rays
  - deleted 7y ago
    [deleted]

carapace 7y ago

Then we'll merely go to the Moon. :-) (And LEO and the Lagrange points.) You raise a good point IMO in re: viability of space. In the limit it may turn out that humans can't live anywhere but on or near the surface of Earth. What is certain is that living in space will suck for many years, or likely decades. It will be like living in a mine, but there are more things that can kill you and you're much much further from fresh air and safe ground. And I suspect living on Mars would suck anyway just due to the ~0.4G surface gravity. At least on the Moon you can go home (in a few days rather than lots of months) or fly like a bird under your own power if your cave is big enough. ("The Menace from Earth", Heinlein; "Welcome to Moonbase", Bova) But even if we can't live there it's still really useful and important to go: micro-gravity manufacturing; robotic asteroid mining; science... I hope we can live in space, I want to colonize the galaxy. (The green galaxy on the cover of "The Millennial Project" book is one of the more compelling images I've personally ever seen. A photosynthesizing galaxy... https://en.wikipedia.org/wiki/The_Millennial_Project:_Colonizing_the_Galaxy_in_Eight_Easy_Steps https://en.wikipedia.org/wiki/The_Millennial_Project:_Coloni... ) But even if we can't go at all these rockets are really important!

cstross 7y ago
This is why I like to draw a distinction between space exploration and space colonization. The former is definitely within the realm of possibility, using existing technology (never mind the Superheavy/Starship system). But Musk, with his talk of a self-sufficient city, is clearly targeting the latter, and there are a whole lot of details we haven't worked out.
- carapace 7y ago
  It's one of those things, robots are much less romantic than astronauts, but they make so much more sense it's not even a contest. I wonder how starry-eyed Elon Musk really is in re: Mars colonization? I know for myself that it was hard to admit robots make more sense (at least at first).

hutzlibu 7y ago

Well, for context, it seems, that he know, that the whole thing is not so easy ... "“I’ll probably be long dead before Mars becomes self-sustaining, but I’d like to at least be around to see a bunch of ships land on Mars,” Musk said."

kamaal 7y ago

Like every other discovery on earth, the first set of explorers will have to risk life and limb, make sacrifices to get there. The one's that follow will build several stops along the way. You will be able to stop, stay for a while, and move forward towards your journey. Also Asteroid mining is going to be a thing. So economy, space labs and all.