from Hacker News

We need a better way to get to space

by vishaldpatel on 11/9/15, 4:58 AM with 69 comments

  • by lmm on 11/9/15, 2:36 PM

    Much as I love to cheer for British engineering, I don't understand the logic here. A rocket would require an expensive inspection before reuse but a spaceplane wouldn't? Why?

    Also not one SABRE engine has even been built yet, whereas SpaceX has got very close to landing their rockets.

  • by rm_-rf_slash on 11/9/15, 4:55 PM

    I'm no rocket scientist but I could imagine rockets having a place in regular space travel. Lets assume that we can harness solar power efficiently and safely store the extra energy in hydrogen and oxygen gas. Then let's say that we could construct sturdy and modular components that can be disassembled and re-assembled at some kind of orbital station, so that the boosters that take people into orbit for whatever reason could be rebuilt in orbit to carry a load of asteroid-mined metals back to the surface.

    Again, I don't know any of the mechanics or physics, but if energy was abundant and parts could be reused, would rockets really be all that bad?

  • by drewg123 on 11/9/15, 4:51 PM

    I was hoping the article would talk about space elevators, and not space planes. I'm eagerly awaiting materials science and geo-politics to mature enough to allow the construction of space elevators.

    https://en.wikipedia.org/wiki/Space_elevator

  • by 7952 on 11/9/15, 5:44 PM

    This thread [1] gives a good explanation of why Skylon should be treated with scepticism.

    [1] https://m.reddit.com/r/engineering/comments/2wstn6/i_am_very...

  • by blisterpeanuts on 11/9/15, 5:37 PM

    It's a slick looking video, but what about reentry? It's not that hard to get a ship up there (the X-15 was flying to the edge of space 50 years ago), and launching like a jet plane obviously has many advantages over rockets, but when it comes back down it's going to hit the atmosphere at a pretty high velocity, unless it's carrying enough fuel to gradually lower itself back into airspace where the jets can kick in. The craft in the video does not appear to have VTOL capability.

    But, if they can solve such problems, great. I'm thinking that eventually we'll have some kind of electrical or hybrid mass driver (catapult) system for getting non-human cargo into low orbit[1], much cheaper (and quieter) and obviously could accomplish many launches a day for one-way missions.

    You could get a large space station or interplanetary craft up there rather affordably using this approach. Specialized reentry vehicles as well. Launch the parts cheaply, robots assemble the parts in orbit, then launch the humans expensively.

    1. https://en.wikipedia.org/wiki/Mass_driver

  • by Amorymeltzer on 11/9/15, 2:29 PM

    Space planes should absolutely be part of our strategy, but their effectiveness diminishes once you get past LEO. An effective program would have different vehicles for different purposes, using the right tool for each job.

  • by rikkus on 11/9/15, 3:17 PM

    20 years ago, I remember dreaming up a train pulling a cable with a glider at the far end. I'm sure there are many technical issues with this approach, possibly including the cable needing to be incredibly strong, light and flexible. Please tell me it would work, though, as I still enjoy the mental image.

  • by skizm on 11/9/15, 4:26 PM

    So is infertility in astronauts still a problem? I could be totally wrong, but I was under the impression we haven't solved the problem of increased radiation negatively affecting fertility in both male and female astronauts.

  • by Mvandenbergh on 11/9/15, 6:41 PM

    For all that effort to reduce oxidiser mass by using atmospheric oxygen, it's still 80% propellant by mass. Saturn V was 85%.

    Still impressive if they can make it work, since of course Saturn V wasn't reusable.

  • by anon8764 on 11/9/15, 3:37 PM

    www.et3.com gradually leading up to the top of everest, jettisoning the capsule (6,500 km/h (4,000 mph)) to break out of the atmosphere.

    I have not done the math, physics, etc on this, but it's an interesting idea worth exploring.

    But that said, do we really belong in space when we cannot care for our own? Wouldn't that be akin to giving sugar to ants? only multiplying suffering and cruelty exponentially in space? Perhaps a refactoring of our culture and our methods of using/allocating/expending resources should be our first priority.

  • by aggieben on 11/9/15, 3:06 PM

    Giant railguns. That is all.