5 ms·

The author is a physicist, not an engineer and shows in all of his articles. Physicists are trained to check whether a concept passes the constraints of the cu

by qayxc 5y ago

The author is a physicist, not an engineer and shows in all of his articles. Physicists are trained to check whether a concept passes the constraints of the current theoretical models. If it does, the rest is just an engineering problem - i.e. take the theoretical upper limits of mechanics and material science and extrapolate from there. No concern for the pesky 10% that take up 90% of the development time and make or break a product. In this context: sure, there's equipment that can work in space. But all of this equipment needs to be operated and maintained by humans and there's where your problem starts. Remote operation is impractical beyond the Earth-Moon system.

TeMPOraL 5y ago
> No concern for the pesky 10% that take up 90% of the development time and make or break a product. You're missing the author's main point and the whole reason Starship is a big deal. With current launch costs, all that equipment has to be designed, reviewed and tested up front to guarantee, as much as humanly possible, that it'll work in space the first time, because there's no money to try again. With launch costs Starship offers even under pessimistic estimates, even non-space companies will be able to afford to just send stuff to space to see what breaks, and then iterate until it works. That "10% work" becomes orders of magnitude cheaper.
- giantrobot 5y ago
  > With launch costs Starship offers even under pessimistic estimates, even non-space companies will be able to afford to just send stuff to space to see what breaks, and then iterate until it works. That "10% work" becomes orders of magnitude cheaper. That is a ridiculous position to take. If you have a drill on Earth that burns out you might pop a circuit breaker and have to deal with some acrid smoke for a second or two. You wave it away and it will dissipate into the five and a half quadrillion metric tons of atmosphere. If some parts fly off they'll fall to the ground pretty quickly. If you drop the drill it will fall to the ground. If you've got a drill on a spacecraft that burns out popping a circuit breaker or some acrid smoke is a thousand times more dangerous. Just spalling of some parts can send debris flying around the craft to cause short circuits or damage life support equipment. If you let the drill go because it hurt you it doesn't fall to the ground but instead float there being dangerous or bouncing off equipment that won't like a drill bouncing off of it. Lot's of stuff works fine on Earth, even down in mines or other places, because we've got a relatively thick atmosphere with favorable temperature and gravity. Lubricants don't literally boil off equipment if they're left in the sun for a few minutes. We also don't have to deal with temperature variations of hundreds of degrees between shade and full sunlight. Sending random crap to space without understanding the environment or failure modes would be extremely foolish.
  - TeMPOraL 5y ago
    > Sending random crap to space without understanding the environment or failure modes would be extremely foolish. Well, of course I'm exaggerating, but the point is: with low enough costs, you can afford to iterate on designs you previously had to do perfectly up front. Learning from failures becomes cheaper than having to predict every possible failure mode up front.
    - giantrobot 5y ago
      > Learning from failures becomes cheaper than having to predict every possible failure mode up front. But this assertion is wrong. There's a minimum price of failure in space. To have just a bare minimum of safety you must understand at least some failure modes of things you're sending into space. That requires testing and qualification. It doesn't matter if our hypothetical drill costs $10 or $100, to even think of launching it in the first place requires thousands of dollars in qualification for the environment. At that point the difference in launch cost is negligible to the point of unimportant. Safety regulations are written in blood. The Apollo I disaster occurred in part because the behavior of nylon (Velcro and cargo netting)[0] in the crew cabin in a pure oxygen environment was not understood. A material that was perfectly safe in an Earth-like environment had a catastrophic failure mode in a pure oxygen at high pressure like during the "plugs out" test being conducted. You can't just throw random crap into enclosed environments to tear them out in situ. That's how to write uncomfortable letters to next of kin. Real life isn't Kerbal Space Program. You don't respawn or reload a save game if your ship explodes. [0] https://www.space.com/14379-apollo1-fire-space-capsule-safety-improvements.html https://www.space.com/14379-apollo1-fire-space-capsule-safet...

by qayxc 5y ago

TeMPOraL 5y ago

> No concern for the pesky 10% that take up 90% of the development time and make or break a product. You're missing the author's main point and the whole reason Starship is a big deal. With current launch costs, all that equipment has to be designed, reviewed and tested up front to guarantee, as much as humanly possible, that it'll work in space the first time, because there's no money to try again. With launch costs Starship offers even under pessimistic estimates, even non-space companies will be able to afford to just send stuff to space to see what breaks, and then iterate until it works. That "10% work" becomes orders of magnitude cheaper.

giantrobot 5y ago
> With launch costs Starship offers even under pessimistic estimates, even non-space companies will be able to afford to just send stuff to space to see what breaks, and then iterate until it works. That "10% work" becomes orders of magnitude cheaper. That is a ridiculous position to take. If you have a drill on Earth that burns out you might pop a circuit breaker and have to deal with some acrid smoke for a second or two. You wave it away and it will dissipate into the five and a half quadrillion metric tons of atmosphere. If some parts fly off they'll fall to the ground pretty quickly. If you drop the drill it will fall to the ground. If you've got a drill on a spacecraft that burns out popping a circuit breaker or some acrid smoke is a thousand times more dangerous. Just spalling of some parts can send debris flying around the craft to cause short circuits or damage life support equipment. If you let the drill go because it hurt you it doesn't fall to the ground but instead float there being dangerous or bouncing off equipment that won't like a drill bouncing off of it. Lot's of stuff works fine on Earth, even down in mines or other places, because we've got a relatively thick atmosphere with favorable temperature and gravity. Lubricants don't literally boil off equipment if they're left in the sun for a few minutes. We also don't have to deal with temperature variations of hundreds of degrees between shade and full sunlight. Sending random crap to space without understanding the environment or failure modes would be extremely foolish.
- TeMPOraL 5y ago
  > Sending random crap to space without understanding the environment or failure modes would be extremely foolish. Well, of course I'm exaggerating, but the point is: with low enough costs, you can afford to iterate on designs you previously had to do perfectly up front. Learning from failures becomes cheaper than having to predict every possible failure mode up front.
  - giantrobot 5y ago
    > Learning from failures becomes cheaper than having to predict every possible failure mode up front. But this assertion is wrong. There's a minimum price of failure in space. To have just a bare minimum of safety you must understand at least some failure modes of things you're sending into space. That requires testing and qualification. It doesn't matter if our hypothetical drill costs $10 or $100, to even think of launching it in the first place requires thousands of dollars in qualification for the environment. At that point the difference in launch cost is negligible to the point of unimportant. Safety regulations are written in blood. The Apollo I disaster occurred in part because the behavior of nylon (Velcro and cargo netting)[0] in the crew cabin in a pure oxygen environment was not understood. A material that was perfectly safe in an Earth-like environment had a catastrophic failure mode in a pure oxygen at high pressure like during the "plugs out" test being conducted. You can't just throw random crap into enclosed environments to tear them out in situ. That's how to write uncomfortable letters to next of kin. Real life isn't Kerbal Space Program. You don't respawn or reload a save game if your ship explodes. [0] https://www.space.com/14379-apollo1-fire-space-capsule-safety-improvements.html https://www.space.com/14379-apollo1-fire-space-capsule-safet...