Welcome to the Orbital and Celestial Mechanics blog

Hello, I’ve decided to create a blogging capability in order to inform people about the computer programs I’m currently working on.  This is also a place where I can read and respond to current and prospective users of the software I’ve developed. I’ve been asked many times about why I offer so-called “freeware” computer programs.  Actually, it’s a way that I can give back to an aerospace community which has been very good to me over a career spanning more than 30 years.

The computer programming I do is not all about making money. It’s a way to keep my mind sharp (and to prevent it from totally turning to mush!) and it’s fun, too. I’m currently semi-retired, working part-time at Kennedy Space Center.  After 30+ years in the business, it can be hard to just walk away. I love to solve problems, especially those that involve optimization of space flight mechanics problems. The software that is offered for sale helps support my computer “habit”.  The income helps pay for the Fortran compiler, graphics package and other software products that allow me to create computer programs (and the companion documentation) for solving practical problems.  It also helps purchase hardware like a fast computer and a good printer.  I’m currently using a “homemade” core I7 computer running Windows 7.

Documentation is created with Word, MathType and Grapher. I’m currently working on a Fortran program that will solve the integrated, n-body gravity-assist problem.  The initial guess for this program is based on the patched-conic solution.  The program then attempts to solve the problem by numerically integrating the full n-body equations of motion while constraining the B-plane coordinates at the flyby or gravity-assist planet and flying on to the destination or arrival body. I will try to blog as often as possible. Your comments and questions are welcome. However, I will not do your homework nor will I provide software that you should create as part of your homework assignment.

David Eagle

cdeaglejr@yahoo.com