[X] My Assistant

[lyford]

Most of the members probably have all of these programs installed already, but a few were new to me:
The Software of Space Exploration
Includes a whole bit about "Penguins in Space" - Linux

[Guest_JamesFox_*]

Speaking of space software, one personal thing I've been looking for is trajectory optimization software: something akin to NASA's STOUR, MIDAS, MOSES, PLATO, and the like. The closest I've come to is JASC's Swing-by Calculator, but they've unfortunatly changed the license, and the version 5 that can be used now is fairly crippled compared to the version 7 that I was able to play with for a few months.

[Guest_DonPMitchell_*]

Speaking of space software, one personal thing I've been looking for is trajectory optimization software: something akin to NASA's STOUR, MIDAS, MOSES, PLATO, and the like. The closest I've come to is JASC's Swing-by Calculator, but they've unfortunatly changed the license, and the version 5 that can be used now is fairly crippled compared to the version 7 that I was able to play with for a few months.

I used to use Swingby too. I've been slowly tinkering together a replacement. You can get a lot done with a few basic routines:

1. Look up planetary positions and velocities in DE405
2. Calculate an elliptical trajectory given two positions and a time-of-flight
3. Look up position and velocity from an elliptical tranjectory (from Keplerian elements)
4. Get rotation matrix of the Earth or planet at a given Julian date. (There are simple models for the planets, and a very complex but highly accurate model for Earth).

One big thing I have left to do is handle near-Earth trajectories, within the strong gravitational influence. Lambert's theorem is OK for doing interplanetary trajectories, but the departure and arrival regions need to be modifed to plot trajectories. I'm looking for a nice exposition on this, but I can probably get some sort of shooting-method approach to work otherwise.