Hello all, im a electrician student, and in school we got the task (not having anything to do with electricity) to explain about something in 5-10 min, it could be hobbies..well, also something about electricity, anything goes. But, actually the night before i saw this video by Scott Manley:
, and was instantly thinking about the video when we got the task telling about something, i just want to try it on the real moon (the one turning red in 1 hour time, im staying awake to see it atm, at about 04.30 am danish time ).Anyway, what does it take to stop the velocity of the REAL Moon??? My plan is, to leave out the factor of the forces of gravity in the calculations, by putting a gravitymanipulator on the surface of the moon (so it wont fall "down" when loosing speed). But, in the video, Scott Manley just show some number without explaining where he got em from and why. The calculation he show at 1:28, says (280x124 trillion) / (800x9.81) = ..... Well, i guess the (280x124 trillion) = (deltaV x mass of gilly), but then this / (800x9.81) I spoke to a friend who play this game alot more than i do, and he is talking about that the 800 might be isp of the engine used, but then we are in doubt of the 9.81? Also i wanna leave out the factor of the weight of all the fuel, as its stored in a big ballon in orbit, with a long hose connected to the engine(s) on the surface... I wanna use this rocket engine: https://en.wikipedia.org/wiki/RD-170 And i want to stop all velocity in one single orbit (27.3 days), not Scott Manley's 19 million years. So first im gonna figure out how much fuel is needed, then how many engines is needed to complete the stop in only 27.3 days. So far i have these notes: 1 orbit = 2,412,517.5 km / 27,3 / 24h / 60 min / 60 sec = 1022,8 m/s Moon mass = 7,349×10^22 kg > 7,349×10^19 t > 73.477.000.000.000.000.000 t Orbital period = 27.321582 d (27d 7h 43.1) delta v / masse = (1022 x 73.477.000.000.000.000.000) / (isp? x 9.81?) = Strongest rocket engine: Russian RD-170 (https://en.wikipedia.org/wiki/RD-170) Thrust (vac.) 7.887 MN (1,773,000 lbf) > ibf = pound force > 1 ibf = 4.448222 N (https://da.wikipedia.org/wiki/Newton_%28enhed%29) Thrust to weight ratio: 82 (TWR > wiki.kerbalspaceprogram.com/wiki/Thrust-to-weight_ratio) Any ideas/help would be very much appriciated, and thanks in advance