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Charles Stross wrote a whole thing on why we point to point rockets weren't a thing that would work https://www.antipope.org/charlie/blog-static/2015/01/why-we

by cwmma 7y ago

Charles Stross wrote a whole thing on why we point to point rockets weren't a thing that would work https://www.antipope.org/charlie/blog-static/2015/01/why-were-not-going-to-see-sub-.html https://www.antipope.org/charlie/blog-static/2015/01/why-wer...

martythemaniak 7y ago
Let me try to break it down: 1. Expensive. For sure, it inherently uses a lot more energy. There's not going to be an economy class on these and they'll never replace jets en masse. 2. Security. Not really. He talks about hijacking/terrorism, but these things won't have pilots or free movement on board. Everybody's going to be strapped into their seat for 45 minutes to withstand the forces and the rocket's gonna do all the flying. 3. Spaceports. See my sibling comment, these will have to be build on water far away from cities. 4. Inconvenient. No, these will be massively convenient if you can afford them. It takes 90 minutes to complete an orbit around the earth, so any two points will be at most 45 minutes away. Spending a bit over an 1hr flying New York-Sydney downtown-to-downtown is incomparable to the slog that exists today.
- FlyMoreRockets 7y ago
  > 2. Security. Not really. He talks about hijacking/terrorism, but these things won't have pilots or free movement on board. Everybody's going to be strapped into their seat for 45 minutes to withstand the forces and the rocket's gonna do all the flying. It isn't just the cabin that is a potential terror threat, but a huge part of the supply chain and operations/management. If these are built on water, a distance from land, it should be possible to construct a nearby floating rectenna to crack and cryocool hydrogen and oxygen for propellant via beamed energy from a solar sat. Granted, there is a fair bit of infrastructure requirement, but with interest rates so low, compounding interest isn't a big deal, like it was in the original SPS calculations.
  - outworlder 7y ago
    > If these are built on water, a distance from land, it should be possible to construct a nearby floating rectenna to crack and cryocool hydrogen and oxygen for propellant via beamed energy from a solar sat. That's such an enormous undertaking that it dwarfs the rockets themselves. SpaceX, which is the only company that's even close to achieving this, prefers kerolox. So what threat are we trying to mitigate? Liquid oxygen is not very problematic. We transport large amounts of the stuff on roads with no issue. Kerosene is used everywhere.
    - njarboe 7y ago
      The Raptor engine for SpaceX's next rocket that would do these orbital/sub-orbital flights is fueled by liquid methane and LOX. A better fuel in many ways and much easier to make on Mars.
- outworlder 7y ago
  > Security. Not really. He talks about hijacking/terrorism, but these things won't have pilots or free movement on board. Everybody's going to be strapped into their seat for 45 minutes to withstand the forces and the rocket's gonna do all the flying. Superpowers already have the capability to intercept things that travel faster and are smaller than these. > It takes 90 minutes to complete an orbit around the earth Except these are suborbital. And 90 minutes is for a full orbit around ISS altitudes. For most routes, it would be around 30 minutes (https://www.youtube.com/watch?v=zqE-ultsWt0 https://www.youtube.com/watch?v=zqE-ultsWt0)
outworlder 7y ago
That piece is talking about suborbital Spaceplanes I agree with the article. But we may have suborbital rockets. Which are much more feasible.

by cwmma 7y ago

martythemaniak 7y ago

Let me try to break it down: 1. Expensive. For sure, it inherently uses a lot more energy. There's not going to be an economy class on these and they'll never replace jets en masse. 2. Security. Not really. He talks about hijacking/terrorism, but these things won't have pilots or free movement on board. Everybody's going to be strapped into their seat for 45 minutes to withstand the forces and the rocket's gonna do all the flying. 3. Spaceports. See my sibling comment, these will have to be build on water far away from cities. 4. Inconvenient. No, these will be massively convenient if you can afford them. It takes 90 minutes to complete an orbit around the earth, so any two points will be at most 45 minutes away. Spending a bit over an 1hr flying New York-Sydney downtown-to-downtown is incomparable to the slog that exists today.

FlyMoreRockets 7y ago
> 2. Security. Not really. He talks about hijacking/terrorism, but these things won't have pilots or free movement on board. Everybody's going to be strapped into their seat for 45 minutes to withstand the forces and the rocket's gonna do all the flying. It isn't just the cabin that is a potential terror threat, but a huge part of the supply chain and operations/management. If these are built on water, a distance from land, it should be possible to construct a nearby floating rectenna to crack and cryocool hydrogen and oxygen for propellant via beamed energy from a solar sat. Granted, there is a fair bit of infrastructure requirement, but with interest rates so low, compounding interest isn't a big deal, like it was in the original SPS calculations.
- outworlder 7y ago
  > If these are built on water, a distance from land, it should be possible to construct a nearby floating rectenna to crack and cryocool hydrogen and oxygen for propellant via beamed energy from a solar sat. That's such an enormous undertaking that it dwarfs the rockets themselves. SpaceX, which is the only company that's even close to achieving this, prefers kerolox. So what threat are we trying to mitigate? Liquid oxygen is not very problematic. We transport large amounts of the stuff on roads with no issue. Kerosene is used everywhere.
  - njarboe 7y ago
    The Raptor engine for SpaceX's next rocket that would do these orbital/sub-orbital flights is fueled by liquid methane and LOX. A better fuel in many ways and much easier to make on Mars.
outworlder 7y ago
> Security. Not really. He talks about hijacking/terrorism, but these things won't have pilots or free movement on board. Everybody's going to be strapped into their seat for 45 minutes to withstand the forces and the rocket's gonna do all the flying. Superpowers already have the capability to intercept things that travel faster and are smaller than these. > It takes 90 minutes to complete an orbit around the earth Except these are suborbital. And 90 minutes is for a full orbit around ISS altitudes. For most routes, it would be around 30 minutes (https://www.youtube.com/watch?v=zqE-ultsWt0 https://www.youtube.com/watch?v=zqE-ultsWt0)

outworlder 7y ago

That piece is talking about suborbital Spaceplanes I agree with the article. But we may have suborbital rockets. Which are much more feasible.