TMC is an independent, primarily volunteer organization that relies on ad revenue to cover its operating costs. Please consider whitelisting TMC on your ad blocker and becoming a Supporting Member. For more info: Support TMC

BFS Centrifuge running track

Discussion in 'SpaceX' started by malcolm, Jun 8, 2018.

  1. malcolm

    malcolm Active Member

    Joined:
    Nov 12, 2006
    Messages:
    2,803
    • Like x 1
  2. mongo

    mongo Well-Known Member

    Joined:
    May 3, 2017
    Messages:
    5,331
    Location:
    Michigan
    bungees attached to rollers on rails/ tracks? Step up from treadmill... Velcro/ magnetic shoes ala Lego Movie?
     
  3. ccutrer

    ccutrer Active Member

    Joined:
    Sep 3, 2015
    Messages:
    1,345
    Location:
    Saratoga Springs, UT
    It’s a scene from 2001: A Space Oddysey. I’m almost certain it’s a rotating wheel on its side, with the camera mounted to the wheel so that it “feels” stationary.
     
  4. Nikxice

    Nikxice Member

    Joined:
    Oct 31, 2014
    Messages:
    520
    Location:
    Hudson, NH
    For trips between Earth and Mars a slow thermal barbecue roll makes sense and could provide some artificial gravity. Don't know if SpaceX has finalized their plans for BFR/BFS solar panels, but maintaining proper orientation and support would be a major factors. Would like to hear more details from Elon.
     
  5. ecarfan

    ecarfan Well-Known Member

    Joined:
    Sep 21, 2013
    Messages:
    15,139
    Location:
    San Mateo, CA
    That 2001 film set was built like a Ferris wheel: the axis of rotation was at right angles to the ground so the actors could easily and realistically remain upright while moving. To film that scene the camera was bolted the floor, the camera operator and the director were strapped to their chairs, and they moved around the set while the actor remained at the bottom of the set while moving.

    What Elon’s tweet appears to be saying is that the BFS will have a section with an internally rotating wheel that passengers can run or walk on in a similar manner. Which would be pretty cool but I think will take some practice to learn how to do.
     
    • Like x 1
  6. ecarfan

    ecarfan Well-Known Member

    Joined:
    Sep 21, 2013
    Messages:
    15,139
    Location:
    San Mateo, CA
    And I love Elon’s followup tweet: the man definitely knows his classic sci-fi. :cool:

    AE23F58B-A1E3-45F5-B937-4E0FE1DAB3F9.jpeg
     
    • Like x 1
  7. ccutrer

    ccutrer Active Member

    Joined:
    Sep 3, 2015
    Messages:
    1,345
    Location:
    Saratoga Springs, UT
    So exactly as I had presumed. Except the director and cameraman. Poor guys! I’m sure they had a headache!
     
  8. Cosmacelf

    Cosmacelf Well-Known Member

    Joined:
    Mar 6, 2013
    Messages:
    5,119
    Location:
    San Diego
    Uh, shouldn’t take any practice at all. When not under acceleration (which is most of the time), you are in free fall. If they set the ship to spin radially, there will be apparent gravity towards the outer skin of the ship. It will appear that the outer skin is “down” as you walk around the outer skin from the inside.

    I am assuming they will rotate the entire ship, although, I guess, they could just rotate a wheel, but that strikes me as more complicated. But maybe it isn’t.
     
  9. mongo

    mongo Well-Known Member

    Joined:
    May 3, 2017
    Messages:
    5,331
    Location:
    Michigan
    If BFS is 9 meters in diameter, it requires a 14 RPM spin rate to generate 1g at the skin.
    F=v^2/r, 9.8=v^2/4.5
    44.1=v^2
    v=6.64 m/s
    v=pi×9×spinRate
    SpinRate=.235 rotations per second
    14 RPM

    Given that 6.64 m/s is about 15 MPH, if you sprint, you generate your own gravity equivalent force. Mobile exercise bike might be the way to go.
    Of course, the track radius would be less than the outside diameter.

    It seems like it would be really weird to have one's head moving at roughly half the speed of their feet (2 meter tall person typing). (One quarter the force at one's head also)
     
    • Informative x 2
    • Helpful x 1
    • Like x 1
  10. Cosmacelf

    Cosmacelf Well-Known Member

    Joined:
    Mar 6, 2013
    Messages:
    5,119
    Location:
    San Diego
    Ah, you might be right.
     
  11. mongo

    mongo Well-Known Member

    Joined:
    May 3, 2017
    Messages:
    5,331
    Location:
    Michigan
    Recumbent bicycle might work well. Keeps most of the body near the outer diameter, easy to get velocity, low impact on people/ spacecraft. Computer tells you which way to pedal (CW vs CCW)
     
    • Helpful x 1
  12. Doug_G

    Doug_G Lead Moderator

    Joined:
    Apr 2, 2010
    Messages:
    17,660
    Location:
    Ottawa, Canada
    I would assume 1/4 g or something, not a full g.
     
  13. mongo

    mongo Well-Known Member

    Joined:
    May 3, 2017
    Messages:
    5,331
    Location:
    Michigan
    Sure, I just used that for reference. 1/4 the force is 1/2 the velocity or 7 RPM.
     
  14. Cosmacelf

    Cosmacelf Well-Known Member

    Joined:
    Mar 6, 2013
    Messages:
    5,119
    Location:
    San Diego
    Actually, if you’re heading for Mars, set it to Martian gravity, about 1/3 g, IIRC.
     
    • Love x 1
  15. Doug_G

    Doug_G Lead Moderator

    Joined:
    Apr 2, 2010
    Messages:
    17,660
    Location:
    Ottawa, Canada
    Perhaps, but structural or control issues (with weight moving around all the time) might limit the max G.
     
  16. bxr140

    bxr140 Active Member

    Joined:
    Nov 18, 2014
    Messages:
    1,255
    Location:
    Bay Area
    It will be interesting to see how much solar coverage a Mars transport vehicle needs. Body mount of course is an ideal solution for a thermal+gravity roll if there’s ebough surface area.

    Slip rings on a solar drive mechanism are old hat though, so there could pretty easily be a sun-facing array bolted on the back/front of a spinning body.
     
    • Like x 1

Share This Page

  • About Us

    Formed in 2006, Tesla Motors Club (TMC) was the first independent online Tesla community. Today it remains the largest and most dynamic community of Tesla enthusiasts. Learn more.
  • Do you value your experience at TMC? Consider becoming a Supporting Member of Tesla Motors Club. As a thank you for your contribution, you'll get nearly no ads in the Community and Groups sections. Additional perks are available depending on the level of contribution. Please visit the Account Upgrades page for more details.


    SUPPORT TMC