John ShirleyJul 28, 2023

from Wikipedia article about David "I saw the aliens" Grusch

Australian political commentator Caitlin Johnstone pointed out that this resurgence of UFO/UAP coverage is coincident with a renewed U.S. emphasis on weaponizing space: "Is it a coincidence that this new UFO narrative began its rollout in 2017, around the same time as the rollout of the Space Force? Are we being manipulated at mass scale about aliens and UFOs to help grease the wheels for the movement of war machinery into space?"

Show threadJohn ShirleyJul 28, 2023
Johnstone's speculation is not far fetched. There is a history of military intel using UFO claims and hysteria to smokescreen foreign intel regarding our stealth planes, and other experiments and efforts. That could apply to the weaponization of space. These theoretical weapons would be pointed downward, at human targets--not outwards, at approaching flying saucers.
Show threadJohn ShirleyJul 28, 2023

For my own speculation on the militarization of space, see my technothriller novel, which just came out:

https://bookshop.org/p/books/suborbital-7/18871631?ean=9781803363820

Show threadSeán FenianJul 28, 2023
@JohnShirley2023 👍👍 just bought a copy.
Show threadSeán FenianJul 31, 2023
@JohnShirley2023 It's very good as a Clancyesque technothriller ... but I find myself compelled to note that it contains some pretty significant orbital mechanics errors. S-7 can't be "geosync over Canada" at 2000km. Geosync doesn't work that way. They're 33,000km too low to be geosync over anywhere.
Show threadJohn ShirleyJul 31, 2023
@zakalwe you're right--although! Although geosync has become a bendier term than that, it has come to mean, geostationary relative to a place on the ground. Maybe I should have said geostationary.
Show threadSeán FenianJul 31, 2023
@JohnShirley2023 actually that's even harder, because you can only be geostationary over the equator (the Clarke orbit).
2000km is about a two-hour orbit.
Show threadJohn ShirleyJul 31, 2023
@zakalwe rats. Well then, what's the proper term for being stationary (relatively, though of course the object is moving in space) over a specific spot on the ground, at 2000 km? If there are further printings I may be able to make some corrections.
Show threadSeán FenianJul 31, 2023
@JohnShirley2023 The short answer to that is you can't do it without continuously burning fuel. But only the purists like me are going to worry about it, so .... 😉
Show threadSeán Fenian
@JohnShirley2023 I just did the math ... at ~2000km gravitational attraction is about 5.7 meters per second squared, so you need to be maintaining roughly 0.58G of thrust to hold station over a point on the earth. Neglecting the continuous orbital plane change because you're not over the equator.
Jul 31, 2023 at 6:00pmWeb
Show threadJohn ShirleyJul 31, 2023
@zakalwe would an ion thruster, as an adjunct, provide enough thrust?
Show threadSeán FenianJul 31, 2023
@JohnShirley2023 no, the strength of ion thrusters is being able to maintain low accelerations (like 0.01G) for months on end on almost no fuel, because they have insane specific impulse as high as 50,000 seconds. (The Space Shuttle main engines managed 450.) If we had an ion thruster that could produce enough thrust to maintain the 0.58G boost you'd need to hold station over ground at 2000km, it would open up the solar system at a stroke.

(We are working on them by the way. One example to look up is something called VASIMR.)