1. Justin Phillips
    Offline

    Justin Phillips Active Member

    Joined:
    Mar 31, 2016
    Messages:
    239
    Likes Received:
    144

    Space station behind the moon

    Discussion in 'General Writing' started by Justin Phillips, Apr 12, 2016.

    Ok, for all you sci fi or scientific folks out there, I want to put a space station behind the moon. That's not the problem, as it seems NASA is already planning something like this, sitting it inside the L2 pocket behind the moon, which is one of 5 pockets outside our atmosphere where the moon cancels out the Earth's gravity.

    However, I can't think of how to get there, and Google isn't helping. I'm not sure if you can fly a shuttle straight to the moon, and then just go around, or if we need to leave on the opposite side of earth and slingshot around... any ideas? and any ideas on how long it would take, given which route is best? Definitely want the shortest, not cheapest, route.
     
  2. Shadowfax
    Online

    Shadowfax Contributing Member Contributor

    Joined:
    Aug 27, 2014
    Messages:
    2,504
    Likes Received:
    1,338
    I Googled L2 pocket beyond the moon and got http://www.airspacemag.com/space/beyond-the-moon-3835846/?no-ist=&page=2, which tells me: The quickest way to get there—in only three to five days—is to use the Apollo approach: take aim and fire. This, however, requires extra fuel. So NASA would prefer to take a slower and more circuitous route, using a gravity assist from the moon to hurl Orion to its destination.
     
  3. Justin Phillips
    Offline

    Justin Phillips Active Member

    Joined:
    Mar 31, 2016
    Messages:
    239
    Likes Received:
    144
    oh thanks, well I guess I'm not that google efficient huh

    *just read the site, it's very helpful, but really all they say is point the rocket straight at the moon and fire.. wondering when you need to slow down and make your way around the moon, but maybe I can just make that up.
    This is near future, so in my world the tech is there to do it properly, safely, and will fly straight up to and dock at station, instead of staying in halo orbit like that article suggests.
     
    Last edited: Apr 12, 2016
  4. Shadowfax
    Online

    Shadowfax Contributing Member Contributor

    Joined:
    Aug 27, 2014
    Messages:
    2,504
    Likes Received:
    1,338
    http://scienceline.ucsb.edu/getkey.php?key=1702

    It took Apollo 11 4 days 6 hours and 45 minutes to get to the moon. They took off from the Kennedy Space Center in Florida at 1:32 pm on 7/16/1969, and the lunar module landed on the moon at 8:17 pm on 7/20/1969. The speed needed for Apollo 11 to break free of the Earth's gravitational field was about 7 miles per second.

    Apollo 10, a spaceship that only orbited the moon in 1969 holds the record for the highest speed attained by a manned vehicle with 11.08 km/s (24,791mph).


    The basic mission design was to blast out of Earth's gravity well, and then coast the rest of the way, gradually slowing down enough to enter lunar orbit. The final descent had to use quite a bit (relative term!) of fuel to slow the gravity-assisted descent speed. You'd have a similar plan when reaching L2 another 40k miles out, but as you've got further to go, you can get away from the Earth faster because you've got a greater distance to slow down; plus, you'll have the moon's gravity to slow you once you're past it, rather than it accelerating you in for the final few miles.

    And we've got technology currently that will do the job of reaching L2...just configure a Space Shuttle properly and you could do it...so you can hand-wave a little without creating a massive incredibility gap.
     
  5. Justin Phillips
    Offline

    Justin Phillips Active Member

    Joined:
    Mar 31, 2016
    Messages:
    239
    Likes Received:
    144
    awesome you are great. I'm better at the creative stuff, not the technical stuff. or googling, apparently.
     
  6. newjerseyrunner
    Offline

    newjerseyrunner Contributing Member

    Joined:
    Apr 20, 2016
    Messages:
    283
    Likes Received:
    209
    The Chinese recently moved one of their Lunar orbiters to the L2 location as a test of their navigational ability, you can see how they did it.

    Your shuttle will likely need fairly intense shielding, to get to the moon, you have to travel through the Van Allen belts, then once there, the solar winds will be lethal if you're there for too long. Apollo crew simply were not exposed long enough to make them sick, however, if they had been hit by a solar event, it could make them very sick in minutes.
     
  7. Rob40
    Offline

    Rob40 Active Member

    Joined:
    Jan 23, 2016
    Messages:
    101
    Likes Received:
    48
    Location:
    Colorado
    Hohmann transfer.

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

    It's changing orbit alttitudes around a planet but in this case its used to change orbit to a radius near the moon orbit path. time it and the moon is near, it's gravity grabs the carft, and the craft will have to retro-burn and slow to be captured by the moon energy and not be swung past via-slingshot into open space in it's own independant orbit around the sun.

    With that, comes the study of planet positions and convenient times to burn a hohmann transfer to catch another planet. So papers published in 1997:

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

    they show the right times to do this anda burn less fuel. timing it right.

    A game, fabulous for kids: Kerbal space project. it accurately simulates orbital dynamics and allows building of ships to accomplish things amazing. really inspiring for kids and a huge time suck at the same time.
     
    Last edited: Apr 20, 2016
  8. Justin Phillips
    Offline

    Justin Phillips Active Member

    Joined:
    Mar 31, 2016
    Messages:
    239
    Likes Received:
    144
    wow thanks guys those were both very helpful
     
  9. Cave Troll
    Offline

    Cave Troll Bite the bullet, do your own thing. Contributor

    Joined:
    Aug 8, 2015
    Messages:
    3,774
    Likes Received:
    2,399
    Location:
    Where cushions are comfy, and straps hold firm.
    Get KSP (Kerbal Space Program), you can do it with a degree of accuracy for yourself. Though the time differential between the game and real life is an issue, the physics is pretty darn accurate. :p
     

Share This Page