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25

No, unless your structure is located directly on the equator and your satellite follows a perfectly circular orbit, atmospheric "orbits" aren't possible, even in a vacuum tunnel. Because the Earth is on an axis of ~23 degrees and rotates every day, it is not possible to create an orbit which has no ground track precession except for equatorial ...


23

The thing your're missing is that the Hohmann Transfer orbit takes time, and both Mars and Earth are moving around the sun. For the Hohmann Transfer orbit to work, the position of Mars at arrival has to be opposite the point of of Earth at Departure. The following image depicts Earth's and Mars' orbit as circular, rather than elliptical to simplify ...


15

Such a tunnel is not plausible for a number of reasons. 1. Problems with orbits First of all, as other people have said it would only work for equatorial orbits which were either circular (very long tunnel) or had a period which is some rational multiple of the Earth's rotational period. And, again as other people have said, the real Earth is nothing like ...


8

This would be a tunnel a couple thousand kilometers long, that extends from the surface of the Earth to approximately low earth orbit altitude at both ends, strong enough to keep vacuum inside and the atmosphere out at sea level, such that its openings are in place for a space station in a highly-elliptical geosynchronous orbit comes flying through at about ...


4

The Eq. 4.43 is in Battin's An Introduction to the Mathematics and Methods of Astrodynamics where he does not derive it. The derivation is outlined in his earlier book Astronautical Guidance (1964) on page 46. Starting from Kepler's equation for the two positions $E$ and $E_0$: $$M-M_0=E-E_0 -e(\sin E -\sin E_0) $$ make the substitution $\sin E = \sin[E_0 + (...


3

Much of engineering is about compromises. One can find an ideal solution, like a Hohmann transfer orbit. Yes, that is the most fuel efficient way to get from earth orbit to Mars orbit. It is like the top of a rounded mountain. That is the peak, but there is a lot of ground near the peak that is almost as high. Maybe you are willing to give up a bit of ...


3

There is no stable orbit around the Earth. Earth is not homogenous, there are tides from the Moon, the Sun, etc, ... well, sun-synchronous orbits sound promising, but one can never create an orbit that is both sun-synchronous and moon-synchronous. Even the geostationary orbits require station-keeping or the satellite starts swinging north/south. In space, a ...


2

You actually can do this as long as you properly set the Earth-centered angle to prevent satellites from 'seeing' the point through the Earth. My errors in accuracy came from not setting the orbit exactly as STK set it. This is a valid method to use that also has fast run time.


2

Maybe I'm not understanding the question correctly, but it sounds like to me that you are describing "Orbital Ring". You can find more about them at Orbital Rings on Wikipedia. There is a great video about it on Orbital Rings by Isaac Arthur on YouTube. He does a good job of describing physical limitations vs engineering limitations. Sorry for the ...


2

Yes, if you could build the vacuum tunnel. For example, the Sentinel 1A satellite (which currently orbits the earth every hour or so) is designed to maintain its orbit within a 100m diameter virtual tube, fixed with respect to the surface of the earth, for a decade. (Like many other remote sensing DInSAR satellites, the quality and usefulness of the data it ...


1

This is intended as an addition to other answers. It's more than a comment as it is (hopefully) worth maintaining: You could 'steer' the vehicle electromagnetically while within the 'tunnel' and by whatsoever means are appropriate when out of the tunnel. If the structure broadened at entry and exit you could apply precession correction on exit and approach. ...


1

Yes, loads! You can see the StarLink trains at Heavens Abve:


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