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1

Reference 1, citing Reference 2, reports that hypothetical trojan-type asteroids are invariably unstable at the proposed Mercury L4 and L5 points, whereas stable Lagrange-point vibrations at least over millions of years are available at the L4/L5 points of both Venus and Earth(+Moon). The predictions were made in the 1990s. The discovery of Earth and Venus ...


1

A "classical" fairing is a ballistic object, meaning it has no active controls. You'll find that trying to model its tumbling path through a highly variable atmosphere exceeds our current computational capacity. If you're thinking about the SpaceX fairing recovery techniques, be aware that there are some active controls, as explained in this space.SE ...


2

You have to calculate the deltaV that these thrusters can provide you. You can do this by using the Rocket Equation. You need the ISP value of those thrusters and the starting and final mass of your cubesat (i.e. mass when you are deployed in LEO and mass after you have expended all your Xenon). That will give you the maximum available deltaV. This needs to ...


3

The length of the tunnel is going to be, IMO, the biggest factor. Acceleration According to Wikipedia, the escape velocity of Earth is 25,020 mph (40,270 km/h), or 6.951 mi/s (11.186 km/s). Even if we reduce that to, say, 16,000 mph (25,750 km/h) (as suggested by Alexander Vandenberghe in comments) to compensate for the height of the mountain, it's still ...


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What you're describing is (more or less) the StarTram "gen 1" design. The reference design has: 40 tonne unmanned cargo projectile, 25 tonnes of payload, ~2 m wide, ~13 m long. A 130 km maglev acceleration tunnel, evacuated. An exit point 6000 m up, on a mountain. A plasma window to allow projectile egress into atmosphere without repressurising the entire ...


18

Many novel launch schemes need some amount of help from rockets. What kills a lot of them is doing a tradeoff study of just enlarging the rocket part and getting rid of the non-rocket part. Surprisingly often, that works out to be better and cheaper. --Heny Spencer This is a system that needs a rocket part, as one of these two cases would necessary ...


0

Here's a simulation to answer your question: Would we not expect to have a seen a greater decay than what has occurred so far? Answer: no. The simulation includes the Newtonian and the relativistic accelerations of all the planets, Sun and Moon. The Earth's gravity field is modeled with the SGG-UGM-1 gravity model (computed using EGM2008 derived gravity ...


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This additional answer is just to show the effect of the solar activity on the decay rate. The graphs were obtained from 15279 TLEs downloaded from https://celestrak.com/NORAD/archives/request.php processed with the CSpOC's SGP4 library freely downloadable from www.space-track.org. The following graph shows the mean radius vector and the mean air density (...


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