Easier way to get to Mars and back to moon...

Discussion in 'General Science & Technology' started by cosmictotem, Feb 3, 2016.

  1. danshawen Valued Senior Member

    Messages:
    3,942
    Why not also take a page or two out of Arthur C Clarke's Fountains of Paradise and equip those intermediate habitat / space stations with solar powered spacecraft slingshots to save fuel for those longer journeys? This idea was proposed last decade as an upgrade to Clarke's space elevator idea. Tethers can be inexpensively deployed once a spacecraft is spun up, to pump its inertia even higher.

    It doubles as a gravity enabled part of the habitat when not in use launching spacecraft, as demonstrated in another of Clarke's fiction works, 2001.
     
    cosmictotem likes this.
  2. Google AdSense Guest Advertisement



    to hide all adverts.
  3. cosmictotem Registered Senior Member

    Messages:
    748
    Of course. And the biospheres would all be equipped with short range transport ferries to shuttle people from biosphere to biosphere.
     
    danshawen likes this.
  4. Google AdSense Guest Advertisement



    to hide all adverts.
  5. billvon Valued Senior Member

    Messages:
    12,795
    Why wouldn't it?
    Could be attached or could be freeflying. For example, they could be connected by a long (1000 meters) tether and spun to create artificial gravity.
     
  6. Google AdSense Guest Advertisement



    to hide all adverts.
  7. billvon Valued Senior Member

    Messages:
    12,795
    How would they have used the waypoint?
     
  8. cosmictotem Registered Senior Member

    Messages:
    748
    Assuming there was waypoints, the rocket could have be fitted with short range dockable vessels that could be jettisoned from it with their own onboard thrusters to slow down.
     
  9. brucep Valued Senior Member

    Messages:
    4,098
    The attitude is wanting to do it. IE A manned mission to Mars. My comment, about attitude, had nothing to do with a specific plan for getting there and surviving in the Mars environment. bilvon's proposal is very interesting. Fun to think about.
     
  10. billvon Valued Senior Member

    Messages:
    12,795
    I think you may have a misunderstanding of how things work in orbit. You might be 100 meters from another vessel and be completely unable to dock with it due to a difference in speed. You might be 1000 kilometers from another vessel and have no problem docking with it because you have a similar velocity vector.

    If the vehicle can have "short range dockable vessels with their own thrusters" then that's a lifeboat - and Earth will almost always be the easiest place to reach with that lifeboat. Indeed, it will be far easier to reach than that space station 100 meters away moving past at several km/sec.
     
  11. DaveC426913 Valued Senior Member

    Messages:
    7,223
    This - in a thread that posits a giant line of hundreds or thousands of space colonies, distributed all around the system, each containing 100,000 people - a feat orders of magnitude larger than the world has attempted to date?

    And you are skeptical about advancements in propulsion technology?

    You jest.
     
  12. cosmictotem Registered Senior Member

    Messages:
    748
    How many cities of 100,000 and above are there on the Earth?
     
  13. DaveC426913 Valued Senior Member

    Messages:
    7,223
    How many cities on Earth of 100,000 are domed air-tight against vacuum, and are thousands of miles from any resources and moving at several kilometres per second relative to Earth?

    You're talking about building, in a few decades, what took centuries to build on Earth, and doing it at a cost of transporting every single atom of it up out of a gravity well, and hundreds or thousands of times farther from its resources, at a cost of tens of thousand of dollars per kilogram. And making it radiation-proof, and airtight.
     
  14. cosmictotem Registered Senior Member

    Messages:
    748
    Well, it seems high speed spacecraft have issues stopping in space. Not really my problem as I am only proposing travel via supply line biospheres.

    Since there would be supply line points in my space scenario, your rocket might try using less thrust so it slows somewhere along the receding edge of the supply line. Then it could take a slower more maneuverable vessel for the final length of the journey.
     
  15. cosmictotem Registered Senior Member

    Messages:
    748
    No, I'm not in any hurry. I'm sure it will take a few centuries.

    And the cosmic ray issue I'm hoping advances in cellular maintenance will be able to address by periodically rejuvenating our cells after cosmic ray damage.
     
  16. billvon Valued Senior Member

    Messages:
    12,795
    ALL spacecraft are high speed. If they stop with respect to the solar system they fall into the Sun. Just to keep pace with the Earth spacecraft have to move at 30km/sec.
    Again, you are using your terrestrial experience and trying to apply it to space travel. That doesn't work. If your supply lines are stationary they fall into the Sun unless they have engines that allows them to "hover" in the Sun's gravity field. We have no technology that will allow that. If they are moving at 30km/s to remain in orbit, then you have the speed-matching problem.
     
  17. DaveC426913 Valued Senior Member

    Messages:
    7,223
    By which time, we'll certainly have faster travel, rendering the waypoint thing moot.

    Rather than making oases every 50 miles across the desert for world travellers to travel, we've found the commercial jets to be far more efficient.

    Wouldn't it make a lot more sense to instigate an ounce of prevention, rather than a pound of cure? Why not just make your habitat radiation-safe?

    If you're traveling underwater, which would you rather raise your children in? A water-proof submarine, or an open submarine with a lot of very high-powered bilge pumps and resuscitation rooms?
     
  18. cosmictotem Registered Senior Member

    Messages:
    748
    The biospheres would not be stationary. They would be orbiting about the sun.

    Could you elaborate on the speed matching problem? What would have a speed matching problem with them?
     
  19. cosmictotem Registered Senior Member

    Messages:
    748
    I imagine the solution would be a combination of both.
     
  20. cosmictotem Registered Senior Member

    Messages:
    748
    And how fast are you suggesting it would take to get to Mars with this new technology?
     
  21. DaveC426913 Valued Senior Member

    Messages:
    7,223
    When the first dockings were conducted in orbit, back in the 60's and 70's, the astronauts were flummoxed to find that two craft merely 100 metres apart in the same orbit were virtually unable to dock with each other. Each time they tried to move closer, they found they actually drifted apart.

    Moving closer meant one craft had to accelerate.
    Accelerating means you move into a higher orbit and eventually drift apart.
    Decelerating means you move into a lower orbit, and eventually drift apart.
    Moving outward means you move into a higher orbit, and eventually fall behind
    Moving outward means you move into a lower orbit, and eventually pull ahead.
     
  22. cosmictotem Registered Senior Member

    Messages:
    748
    But we can dock spacecraft. So what am I missing?
     
  23. DaveC426913 Valued Senior Member

    Messages:
    7,223
    I still don't understand this penchant for thinking penny-wise but pound-foolish. We know a simple path of increasing efficiency in propulsion over decades with improvements in design and technology.
    You suggest that this inner-solar-system-spanning giga-project of unproven, unrealized techniques and technologies to house millions of people is somehow more doable?
     

Share This Page