Space Stations

Kitmacher Miller Pearlman 629.442 KIT Bvtn 2018

Mostly pictures.

Orbit

Altitude

Perigee

Apogee

Vperigee

Vapogee

Vinsertion

Mars Launch

Period

Low

750 km

7128 km

7128 km

7478 m/s

7478 m/s

~8300 m/s

3488 m/s

5989 s

Elliptical

7128 km

11378 km

8292 m/s

5192 m/s

814 m/s

2674 m/s

8858 s

High

5000 km

11378 km

11378 km

5919 m/s

5919 m/s

724 m/s

2940 m/s

12078 s

The escape velocity from the Earth's surface is 11.18 km/s. Vector summed with Mars Hohmann transfer orbit "V excess" of 2900 m/s, that is 11550 m/s. Minus Earth's rotational velocity of 465 m/s, that is a direct launch velocity of 11085 m/s.

Via low orbit, the direct delta V from Earth is 8300 + 3488 m/s = 11788 m/s, 703 m/s worse than direct delta V. Via high orbit, the delta V from Earth is 8300 + 814 + 724 + 2940 m/s = 12778 m/s, 1693 m/s worse than direct delta V. The high orbit launch is far worse. A launch to lunar orbit, and launch from there, is vastly worse; much more energy lost moving propellant to the Moon, putting it in orbit, taking it back out again. Kepler's laws can be counterintuitive unless you think about gravity and velocity, not altitude.

SpaceStations (last edited 2019-01-24 08:39:17 by KeithLofstrom)