To the MONEY RING: Musk's SpaceX to attempt boldest mission yet

I'd imagine it's geostationary transfer orbit. Then the satellite will have a booster to get it the rest of the way to where it's going.

GTO is highly ellptical with the apogee up close to the GEO altitude and the perigee only around the altitude of Low Earth Orbit. An extra motor on the satellite fires around apogee to bring the perigee up and circularise the orbit. It also often changes the inclination by a few degrees to bring it right over the equator.

GTO is Geosynchronos transfer orbit. The booster puts the satellite payload into GTO which loops between low earth orbit and GEO. At the high point an "Apogee kick motor" which is part of the payload makes the orbit into a circular GEO.

Re: Err.

That is simply not true. Delta IV and Atlas rockets typically deliver payloads to GEO without the payload having to provide the final burn.

Re: 80,000km > 35,786km

It actually takes less fuel that way, although it needs two engine burns to get to the final orbit rather than one. A burn at apogee (the 80,000km point) raises the perigee to GEO altitude, then half an orbit later a second burn drops the apogee and circularises the orbit.

There have been trajectories involving a trip round the moon calculated, although so far the only taker was a Russian launch that had a stage restart failure and used some of its manouvering fuel to do the loop and circularisation. It wasn't carrying enough fuel for a direct insertion. Satellite operators are very conservative and no-one wants to be the first to use a lunar fly-by for real, they all want someone else to demonstrate it works.

Re: Launch Window?

Could the relative positions of the sun and moon be significant to the placement of the satellite in orbit?

Re: Launch Window?

Partly sun angle in the transfer bit of the orbit, and partly how long the launch team have been working. You do not want a tired ground control team, or have to try and manage a shift change part way through.

Re: Launch Window?

Because there is an exact spot in that orbit that you want to be so that the satellite can service that part of the earth below it. To reach that exact spot in the orbit, there is an optimum launch time that will use the least fuel (propellant). There is some wiggle room in that optimum time where the coast times and the burn times can be adjusted to reach the target spot, but the further that you get from the optimum time, the more propellant that it takes to get there. Of course every rocket has a limit on the amount of propellant that it can carry. That determines the size of the launch window.