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Ephemeris: 11/12/2024 – SpaceX uses Cargo Dragon to change orbit of the ISS

November 12, 2024 Comments off

This is Bob Moler with Ephemeris for Tuesday, November 12th. Today the Sun will be up for 9 hours and 40 minutes, setting at 5:17, and it will rise tomorrow at 7:37. The Moon, halfway from first quarter to full, will set at 4:39 tomorrow morning.

After the last SpaceX cargo mission arrived at the International Space Station, they used the thrusters on the SpaceX capsule to raise the orbital space station a little bit as a test. SpaceX capsules dock at the forward end of the space station according to direction of travel so in order to boost the station’s orbit they had to flip the station around so that the docking port was at the rear before they could apply the needed thrust. When thrust is applied to an object in orbit the effect of the change occurs mostly at the opposite side of the orbit. In order to permanently raise or lower an object’s circular orbit one must make 2 adjustments 180° away from each other. This is the essence of the Hohmann Transfer Orbit, proposed by German scientist Walter Hohmann in 1925.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT – 5 hours). Times will be different for other locations

Addendum

Hohmann Transfer Orbit
Hohmann Transfer Orbit (2) moving, in this case. from one circular orbit (1) to a higher one (3). Moving from point a to point b. The triangle symbol is the Greek capital letter delta, which means change. It reads as delta V, or change in velocity. Image credit: Leafnode based on image by Hubert Bartkowiak in Wikimedia Commons with a and b points added by this author.

Categories: Concepts, Ephemeris Program Tags: , , ,