Recent content by Ken Fabian

  1. Ken Fabian

    Artemis 2 launch - humans return to the Moon after 54 years

    So... like a composite image but not?
  2. Ken Fabian

    Artemis 2 launch - humans return to the Moon after 54 years

    @PeterDonis - Colour me surprised; I was thinking it might be a composite image - the thin crescent and some glow further out indicating light from behind. I didn't realise night time pictures could be enhanced like that.
  3. Ken Fabian

    Artemis 2 launch - humans return to the Moon after 54 years

    You sure the sun is behind the Earth in this pic? Remarkable colour photography of night-side if that is the case. More usually we would be seeing city lights.
  4. Ken Fabian

    Undergrad What causes knots and stress when untwisting ropes?

    Not sure, but it does seem like Lang's lay is used primarily in wire ropes rather than fibre ropes. I think fibre ropes would be inclined to unravel that way, without the opposing winding to sustain it, whereas metal ropes will retain their winding.
  5. Ken Fabian

    High School Uracil found in carbonaceous asteroid

    The planet is VERY large and over very long periods of time - hundreds of millions of years - meteors will hit in all kinds of places with all kinds of uniquely local conditions. Yes, such materials would mostly land in oceans or on land but when a carbonaceous meteor hits a shallow sea the...
  6. Ken Fabian

    Trying to find a story (YASID)

    @DaveC426913 I thought SFFWorld did - a few years since I visited - but when I looked to check I didn't find it. I did visit a couple of others here and there. Now I don't know which forum I saw that. (I didn't make that up, I swear!.)
  7. Ken Fabian

    Trying to find a story (YASID)

    YASID - Yet Another Story ID - is common usage on forums dedicated to fiction, sometimes having its own dedicated thread.
  8. Ken Fabian

    Undergrad What causes knots and stress when untwisting ropes?

    Twisted fibre type ropes usually have three smaller twines (fibres twisted together) combined by twisting in the opposite direction - the smaller twines are initially overtwisted whilst under tension so that they provide a counter force that will wind the three together. The finished rope has a...
  9. Ken Fabian

    Method of storing energy on the Moon

    @AI_ It is possible that flywheel storage will emerge as the superior option; predicting the future is hard. Nuclear is high on the list of options, but may need improved versions that can be ramped up and down according to varying demand or else need storage to go with it, but less storage...
  10. Ken Fabian

    High School Is it safe to fly in a spinning hollow asteroid?

    Wouldn't the Coriolis Effect for a person walking on the inside of a centrifuge be between head and feet? Or flying, between their axis side and perimeter side? (And dependent on circling the axis?) One of the Rama stories (1st?) had someone flying the axis in a person powered craft... and...
  11. Ken Fabian

    How effective is nuclear propulsion?

    Which is not as much as I would have expected. Also I would expect higher 'dry' mass for a nuclear rocket, so less than twice for similar payloads, so not nearly as much gained by using them as comparing exhaust velocities suggest. Dry mass (is that the correct term?) is an issue for ion rockets...
  12. Ken Fabian

    Can Electric Car Charging from Highway Lights Prevent Cold Weather Stranding?

    I expect we will see mobile emergency power systems (big batteries) adopted by emergency services - oversized onboard batteries, 'slide on' or trailer mounted with the fast charging outlets and cables to deal with stuck EV's. Five minutes of fast charging per car might be enough. They could...
  13. Ken Fabian

    Method of storing energy on the Moon

    Good point about radiation shielding. Except I think that, along with the dire absence of commercially exploitable opportunities, it builds the case for NOT attempting any long term habitation on the moon and for making our future 'explorations' crewless. What are they going to be doing above...
  14. Ken Fabian

    Method of storing energy on the Moon

    I am doubtful anyone will build underground on the moon in the foreseeable future. I expect it to be an extraordinarily difficult challenge to attempt that kind of construction. Modular buildings on the surface with high grade insulation and active heating/cooling systems will be good enough...
  15. Ken Fabian

    Method of storing energy on the Moon

    Making anything complex and technically demanding out of moon resources is going to require large pre-investments in infrastructure and equipment. A whole lot of pre-planning and testing too; few factories doing novel things in difficult conditions work perfectly first go. Seems like in-situ...