# Tag Info

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Here is a theoretical physicist's answer to this problem (see below for what I mean by this). This should be adequate to get a handle on the relative positions of satellites when they are distant from each other, and when the time after some known position & velocity of the satellites is not too long. The theoretical physicist's approach First of all ...

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An early concept for the Apollo mission relied on launch from space. Several Nova rockets with 8 F-1 engines for the first stage would have been used to lift the parts into a low Earth orbit. After assembling all parts the whole stack would launch from orbit to the Moon. The return capsule to Earth would land on the Moon and return to Earth from the surface. ...

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We do 'launch from space'. Indeed that's exactly what Apollo did, for instance. They got themselves into low Earth orbit, and then from that orbit went to the Moon. And the numbers behind this tell you why this is not some magic bullet: The Saturn V stack had a wet (fueled) mass of about 3,000 tonnes. It could put about 140 tonnes into LEO. Getting to ...

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As you correctly noted, the S he's using is a combination of effective surface area and drag coefficient. All literature I've come across uses S for surface area and expresses drag as $D = C_D\frac{1}{2}\rho V^2S$ where $C_D$ is the drag coefficient and S is the effective surface area. Combining these two into one parameter makes sense to me however. $C_D$ ...

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Beyond the Roche limit orbiting material coalesces forming an object (a planet or moon, depending on whether said material is orbiting a star or a planet, respectively), within the Roche limit orbiting material disperses and forms rings. Much as objects have a Schwarzschild radius which traps light (the escape velocity is equal to the speed of light) they ...

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