• Content Count

  • Joined

  • Last visited

Community Reputation

1,670 Excellent


About mikegarrison

  • Rank
    Junior Rocket Scientist

Recent Profile Visitors

The recent visitors block is disabled and is not being shown to other users.

  1. mikegarrison

    Running out of air in spacesuit vs removing helmet

    A buildup of CO2 is not as benign (symptom-wise) as just a lack of oxygen. So the exact failure mode matters.
  2. mikegarrison

    Running out of air in spacesuit vs removing helmet

    I believe that was the point of the discussion.
  3. mikegarrison

    SpaceX Discussion Thread

    I wonder if steam locomotives were intentionally designed so that the front plate was the weakest point in the pressure vessel? I mean, you don't want them to explode, but if they do explode, then that's probably the safest way for them to explode.
  4. That's what I referred to. The IDS docks will actually be IDS plugged into PMA plugged into CBM. It would make more sense to have IDS plug directly into CBM and get rid of the possible point of failure of the PMA, except that as far as I know there is no way to remove a docking port without depressurizing the entire ISS.
  5. You can go here to see real Apollo 11 videos. Now that I look at them, I realize that of course the video clip in the OP is fake. Remember the bandwidth for video from Apollo was so limited that it only got 10 frames per second. Anything that moved quickly turned into a smeared ghost image. No way it could capture an image like what is shown in the OP video.
  6. I'm sure that footage is fake.
  7. Reading past the woo-woo hype, it seems like they have found a novel way to get thermal energy to act like other potential energy. Normally it would violate the laws of thermodynamics for a weight to move up against a gravitational field without an external force, but when we use a pendulum it happens. The key is that you start the weight from an even higher position. As it swings down the energy transforms into another type (mgh -> mv^2) and back again (mv^2 -> mgh). With this device, it appears that the heat energy between a hot object and room temperature transforms into another type of energy (probably electrical potential?) and then that energy transforms back again -- except that instead of using it to reheat the initial input like a pendulum swings back up, they use it to further cool the initial input. It doesn't violate physics or thermodynamics any more than a pendulum does.
  8. Some these make me think of attending business meetings, where I have seen UK computers plug into an adapter to use a US powerstrip, which in turn is using an adapter to plug into a European socket. The IDAs, for instance, only exist to permanently plug into the PMAs, effectively converting the PMA interface into the IDA interface.
  9. Four months late is really good compared to the KC-46A.
  10. mikegarrison

    Help name a dwarf planet

    I assume Tyrion Lannister is off the table?
  11. mikegarrison

    SpaceX Discussion Thread

    Well, I did point out that the inclination thing doesn't really apply to equatorial orbits.
  12. mikegarrison

    SpaceX Discussion Thread

    I was using a globe on a desk today to explain to people at work why launch windows. "If you want the rocket to end up *here*, you need to wait for the Earth to rotate around so Florida is *here*."
  13. mikegarrison

    Is it feasible to synthesize RP-1?

    Jet A has 25% aromatics (maximum allowed), while RP-1 allows a maximum of of only 5% aromatics. Synthetic jet fuel has almost no aromatics, so it's probably closer to being "ready to go" RP-1 than it is jet fuel. (Typically synthetic jet fuel is used in a blend with refined jet fuel because if the aromatic content gets too low, then the seals in the fuel system can start to leak.) I'm not a chemistry guy, so I don't know all the details. I do know that the main concern with using synthetic fuels is that the specs were originally written assuming natural petroleum. So some aspects of "fit for purpose" (like keeping the seals functional) were not originally part of the spec simply because nobody really imagined that they needed to be specified.
  14. mikegarrison

    Is it feasible to synthesize RP-1?

    A quick read-though seems to indicate that nothing in that spec would prevent a synthetic hydrocarbon from meeting it.