Astro Apps

Welcome

This web site is a collection of Windows compatible Apps that can be used to solve a variety of practical problems in astrodynamics and aerospace mission design.  These apps were created using Intel Visual Fortran, version 11.1.  Astro Apps are offered as freeware and can be re-distributed for non-commercial purposes.

 

Last updated   September 16, 2011

Thanks for visiting.

 

Running the software

 

These programs should be run from a DOS command line.  For users unfamiliar with DOS, a DOS window can be created within Windows by selecting Start, then Programs, then Accessories, and finally Command Prompt.  Type cd \ to move to the root directory on your C drive.  Then type cd subdirectory where subdirectory is the name of the subdirectory that contains these programs.  Finally, type the name of the program you want to run and press the Enter key.  You may also want to create a Command Prompt shortcut on your desktop.

 

PDF documentation about many of these applications can be found in the Orbital Mechanics with Matlab website located at www.cdeagle.com/html/ommatlab.html.

 

Utility

 

A computer program for plotting tabular data – xyplot.zip

A computer program for coordinate calculations – csystems.zip

Geodetic and geocentric coordinate conversions – demo_geodetic.zip

A computer program that evaluates the U.S. 1976 standard atmosphere model – demo_atmos76.zip

A computer program for the numerical solution of Kepler’s equation – demo_kepler.zip

A computer program for orbit propagation using Kozai’s method – demo_kozai1.zip – demo_kozai2.zip

A computer program for two-body orbit propagation – demo_twobody.zip

A computer program for time-of-flight calculations – demo_tof.zip

A computer program that computes orbital periods – demo_period.zip

A routine that computes topocentric coordinates and rates – demo_topo.zip

A computer program that computes lunar libration angles and rates – lunar_lib.zip (requires JPL DE421 binary ephemeris)

 

Mission Analysis

 

Rise and Set of Earth Satellites

Rise and set of Earth satellites – Kozai J2 orbit propagation – riseset1.zip

Graphics display of rise-set conditions – griseset.zip

 

Predicting Orbital Events

Closest approach between two Earth satellites – ca2sats.zip

Closest approach between a ground site and an Earth satellite – rts2sat.zip

Mutual visibility between two Earth satellites – sat2sat.zip

Coverage characteristics of Earth satellites – coverage1.zip

Graphics display of relative motion between two Earth satellites – grmotion.zip

 

Orbit Design

 

Repeating Ground Track Orbits

Estimate time to repeat a ground track – repeat1.zip

Predict the osculating semimajor axis for a repeating ground track orbit – repeat2.zip

Predict the mean semimajor axis for a repeating ground track orbit – repeat3.zip

Predict the osculating semimajor axis for a repeating ground track orbit – repeat4.zip

 

Sun-synchronous Orbits

Predict the mean orbital inclination for sun-synchronous orbits – j2 solution – sunsync1.zip

Predict the mean orbital inclination for sun-synchronous orbits – j2 + j4 solution – sunsync2.zip

Predict the osculating orbital inclination for sun-synchronous orbits – sunsync3.zip

Sun-synchronous, repeating ground track orbit design – ssrepeat.zip

A computer program for composite orbit design – composite.zip

 

Frozen Orbits

Predict the mean orbital eccentricity for frozen orbits – frozen1.zip

Long-term evolution of frozen orbits – frozen2.zip

 

Geosynchronous Orbits

Equilibrium longitudes and radii of geosynchronous satellites – geosync1.zip

Osculating semimajor axis for geosynchronous satellites – geosync2.zip

Repositioning maneuvers for geosynchronous satellites – geosync3.zip

East-west stationkeeping of geosynchronous satellites – geosync4.zip

North-south stationkeeping of geosynchronous satellites – geosync5.zip

 

Orbital Maneuvers

 

One impulse transfer between intersecting circular orbits – maneuver1.zip

One impulse transfer between intersecting orbits – maneuver2.zip

Finite-burn transfer between coplanar orbits – maneuver3.zip

Impulsive de-orbit from circular Earth orbits – cdeorbit.zip

Impulsive de-orbit from elliptical Earth orbits – edeorbit.zip

Aero-assisted orbital transfer between coplanar, circular Earth orbits – assist.zip

Low-thrust orbit transfer – ltot.zip

Low-thrust orbit transfer using solar-electric propulsion – sep_ltot.zip

Primer Vector Analysis of the Coplanar Hohmann Transfer – primer.zip

Phasing Analysis of the Coplanar Hohmann Transfer – phasing.zip

 

Circular-Restricted Three-Body Problem

 

Coordinates and energy of the CRTBP libration points – crtbp1.zip

Graphics display of circular-restricted three-body problem (CRTBP) trajectories – g3body.zip

 

Ephemerides

 

A program that computes lunar coordinates using the JPL DE405 ephemeris – demo_de405.zip – (requires de405.bin)

A binary ephemeris file based on DE405 (valid from 1/2/1980 to 1/7/2040; ~ 10 MB) – de405.bin

Link to JPL ephemeris web site – ftp://ssd.jpl.nasa.gov/pub/eph

 

 

Web site contents copyright © 2006-2011 by C. David Eagle.  All rights reserved.

cdeaglejr@yahoo.com          www.cdeagle.com