C. Deagle, Jr.

ID:2666
First Name:C.
Last Name:Deagle, Jr.
Last Change:2023-05-29
Number of Files:58 (12th most prolific)
Number of Downloads:577 (2,372nd most downloaded)

Aero-assist Orbital Transfer   (details) Prime ENG   283KB/8KB
Program that can be used to estimate the propulsive delta-v required for aeroassisted coplanar orbital transfer from a high Earth orbit (HEO) to a lower Earth orbit (LEO).
By C. Deagle, Jr.. 2023/05/28

Altitude Above a Triaxial Ellipsoid   (details) Prime ENG   155KB/18KB
Calculates the altitude relative to a triaxial ellipsoidal planet or other celestial body.
By C. Deagle, Jr.. 2023/05/29

Angle between Two Coplanar Position Vectors   (details) Prime ENG   83KB/7KB
Calculates the transfer or “included” angle between two position vectors, assuming both position vectors are coplanar and relative to the same celestial body. Coplanar implies the two position vectors are locations on the same Keplerian orbit.
By C. Deagle, Jr.. 2023/05/29

Apparent Place of a Star   (details) Prime ENG   229KB/103KB
Calculates the geocentric and topocentric apparent place of a star. Most of the routines used in this program have been ported from the Naval Observatory Vector Astrometry Software (NOVAS). The coordinates and motion characteristics of the star of interest should be coded similar to the data for Altair.
By C. Deagle, Jr.. 2023/05/28

B Plane Coordinates   (details) Prime ENG   209KB/14KB
Performs the conversion of inertial coordinates of an arrival or departure hyperbola to fundamental B-plane coordinates and vectors.
By C. Deagle, Jr.. 2023/05/28

Calendar Dates and Julian Days Conversion   (details) Prime ENG   142KB/26KB
Converts between calendar dates and Julian days. A UTC calendar date and time can be converted to the corresponding Julian days on the UTC (universal coordinated time), TDB (barycentric dynamical time) and TDT (terrestrial dynamical time;) time systems. A TDB Julian day can be converted to a UTC calendar date and time
By C. Deagle, Jr.. 2023/05/28

Chebyshev Approximations of an Analytic Function   (details) Prime ENG   6KB/17KB
Demonstrates the procedures for calling several Chebyshev subroutines. These subroutines can be used to approximate the integral, derivative, and function value of a user-defined analytic function.
By C. Deagle, Jr.. 2023/05/28

Classical and Modified Rquinoctial Orbital Elements   (details) Prime ENG   187KB/29KB
Demonstrates how to interact with several subroutines which convert between classical orbital elements, modified equinoctial orbital elements and position and velocity vectors.
By C. Deagle, Jr.. 2023/05/28

Classical Orbital Elements of a Hyperbolic Flyby Orbit   (details) Prime ENG   156KB/15KB
Calculates the classical orbital elements of a hyperbolic flyby orbit. The user provides the x, y and z components of both the incoming and outgoing v-infinity velocity vectors along with the periapsis radius of the flyby orbit and gravitational constant of the flyby planet with statements.
By C. Deagle, Jr.. 2023/05/28

Creating a Chebyshev Ephemeris of an Inner Planet   (details) Prime ENG   25KB/78KB
Creates a Chebyshev representation of the geocentric and heliocentric position vectors of an inner planet of our solar system. The first part of the software demonstrates how to create the coefficients and the second part illustrates how to evaluate the coefficients and produce a planetary position vector.
By C. Deagle, Jr.. 2023/05/28

Creating a Chebyshev Ephemeris of the Moon   (details) Prime ENG   24KB/81KB
Creates a Chebyshev representation of the geocentric position vector of the moon. The first part of the software demonstrates how to create the coefficients and the second part illustrates how to evaluate the coefficients and produce a lunar position vector.
By C. Deagle, Jr.. 2023/05/28

Creating a Chebyshev Ephemeris of the Sun   (details) Prime ENG   19KB/51KB
Creates a Chebyshev representation of the geocentric position vector of the sun. The first part of the software demonstrates how to create the coefficients and the second part illustrates how to evaluate the coefficients and produce a solar position vector.
By C. Deagle, Jr.. 2023/05/28

Cubic Spline "Fit" and Interpolation of Tabular Data   (details) Prime ENG   33KB/24KB
Demonstrates how to interact with cubic spline subroutines which "fit" and interpolate two-dimensional tabular data of the form y = f(x).
By C. Deagle, Jr.. 2023/05/14

Earth Orbit Lambert Problem   (details) Prime ENG   488KB/56KB
Solves the Earth orbit Lambert problem. The user provides classical orbital elements for an initial and final orbit, and the time required to transfer from the initial to final orbits.
By C. Deagle, Jr.. 2023/05/28

Earth to Mars Trajectory Design   (details) Prime ENG   811KB/77KB
Calculates ballistic interplanetary trajectories between the Earth and Mars. The orbit transfer is modeled as a two-body system with an impulsive delta-v at departure and arrival. The user can provide an Earth departure calendar date and a Mars arrival calendar date.
By C. Deagle, Jr.. 2023/05/28

EME2000 and True-of-Date Coordinate Conversion   (details) Prime ENG   68KB/69KB
Converts between true-of-date and eme2000 state vectors and classical orbital elements, requiring an initial UTC calendar date and time along with position and velocity vectors.
By C. Deagle, Jr.. 2023/05/28

Ephemeris for the Inner Planets   (details) Prime ENG   21KB/61KB
Calculates an ephemeris of the inner planets. The code is based on "Planetary Programs and Tables from -4000 to +2800" written by Pierre Bretagnon and Jean-Louis Simon.
By C. Deagle, Jr.. 2023/05/28

Frozen Orbit Design   (details) Prime ENG   302KB/15KB
Determines the mean orbital eccentricity required for a frozen orbit. The user provides the mean semimajor axis and inclination and the program calculates the eccentricity using Brent’s method to solve the single constraining nonlinear equation. A frozen orbit is characterized by the absence of long-term changes in orbital eccentricity and argument of perigee. This type of orbit maintains almost constant altitude over any particular point on a planet’s surface. The design of frozen orbits involves selecting the correct value of orbital eccentricity and argument of perigee, for a given semimajor axis and orbital inclination, which satisfies a system of nonlinear perturbation equations.
By C. Deagle, Jr.. 2023/05/29

Gauss-Kronrod Quadrature   (details) Prime ENG   5KB/10KB
Integrates a user-defined function of the form y = f(x) using a 15-point Gauss-Kronrod method.
By C. Deagle, Jr.. 2023/05/28

Geocentric-to-Geodetic Algorithm   (details) Prime ENG   220KB/20KB
Converts geocentric coordinates (declination and position magnitude) to geodetic coordinates (altitude and latitude). Two algorithms in text format for converting geodetic coordinates to geocentric coordinates are also included.
By C. Deagle, Jr.. 2023/05/28

Geosynchronous Orbit Design   (details) Prime ENG   77KB/20KB
Calculates the equilibrium longitudes and radii of geosynchronous satellites based on the EGM96 gravity model of degree (zonals) and order (tesserals) 3. These are the four Earth-relative locations where the proper combination of geocentric radius and east longitude will minimize the longitudinal drift of satellites located at these points.
By C. Deagle, Jr.. 2023/05/29

Hohmann Transfer   (details) Prime ENG   366KB/17KB
Solves the Hohmann two impulse orbital transfer between planar and non-coplanar circular Earth orbits.
By C. Deagle, Jr.. 2023/05/29

IAU 1980 Nutation Algorithm   (details) Prime ENG   122KB/44KB
Evaluates the nutation series and return values for nutation in longitude and nutation in obliquity. Wahr nutation series for axis b for Gilbert & Dziewonski Earth Model 1066a.
By C. Deagle, Jr.. 2023/05/28

IAU 2000b Nutation Algorithm   (details) Prime ENG   189KB/36KB
Implementation of a nutation algorithm based on the IAU 2000b theory, for celestial mechanics and dynamical astronomy.
By C. Deagle, Jr.. 2023/05/28

Impulsive Deorbit from a Circular Earth Orbit   (details) Prime ENG   341KB/40KB
Calculates the single impulsive deorbit maneuver required to establish a reentry altitude and flight path angle relative to a non-rotating, spherical Earth. The algorithm uses a tangential delta-v applied opposite to the velocity vector of an initial circular orbit to establish the de-orbit trajectory.
By C. Deagle, Jr.. 2023/05/29

Impulsive Hyperbolic Injection from a Circular Earth Orbit   (details) Prime ENG   330KB/30KB
Determines the characteristics of the single impulsive maneuver required to transfer a spacecraft from an initial circular Earth park orbit to a departure hyperbola.
By C. Deagle, Jr.. 2023/05/28

Inertial to Flight Path Coordinate Conversion   (details) Prime ENG   187KB/40KB
Converts an inertial state vector (position and velocity vectors) to flight path coordinates (east longitude, geocentric declination, flight path angle, azimuth, position magnitude and velocity magnitude).
By C. Deagle, Jr.. 2023/05/28

Kepler's Equation for Parabolic and Near-Parabolic Orbits   (details) Prime ENG   290KB/9KB
Solves Kepler’s equation for heliocentric parabolic and near-parabolic orbits. It is based on the numerical method described in Chapter 4 of "Astronomy on the Personal Computer" by Oliver Montenbruck and Thomas Pfleger. This algorithm uses a modified form of Barker’s equation and Stumpff functions to solve this problem.
By C. Deagle, Jr.. 2023/05/28

Low-Precision Ephemeris for the Sun, Moon and Planets   (details) Prime ENG   250KB/69KB
Computes low-precision ephemerides of the sun, moon, and planets, based on the algorithms described in Low-Precision Formulae for Planetary Positions, T. C. Van Flandern and K. F. Pulkkinen, The Astrophysical Journal Supplement Series, 41:391-411, November 1979. To the precision of implemented algorithm (one arc minute), these coordinates can be considered to be true-of-date.
By C. Deagle, Jr.. 2023/05/28

Machine Epsilon   (details) Prime ENG   2KB/2KB
Calculates the machine epsilon, an upper bound on the relative approximation error due to rounding in floating point arithmetic.
By C. Deagle, Jr.. 2023/05/14

Mean and Osculating Classical Orbital Elements   (details) Prime ENG   331KB/26KB
Converts between osculating and mean classical orbital elements using an algorithm due to C. Uphoff.
By C. Deagle, Jr.. 2023/05/29

Mean or Apparent Greenwich Sidereal Time   (details) Prime ENG   17KB/47KB
Computes mean or apparent Greenwich sidereal time.
By C. Deagle, Jr.. 2023/05/29

Nodal Period of an Earth Satellite   (details) Prime ENG   238KB/43KB
Calculates the nodal period of a satellite using a numerical integration technique. The algorithm first uses the RKF78 method to propagate the first-order perturbed equations of satellite motion forward in time to bracket a "nodal objective function". Once a bracket is found, the algorithm then uses Brent's root-finding method to find the time at which the objective function is zero to within a user-defined tolerance. While looking for the root the software also uses the RKF78 method to propagate the satellite's orbit subject to the main oblateness gravity perturbation of the Earth.
By C. Deagle, Jr.. 2023/05/29

Optimum Launch Mass of a Single Stage Model Rocket   (details) Prime ENG   19KB/15KB
For a given model rocket engine and aerodynamic characteristics, this program determines the optimal launch mass of a single-stage model rocket which maximizes total altitude (Bengen's maxima).
By C. Deagle, Jr.. 2023/05/29

Orbital Periods of an Earth Satellite   (details) Prime ENG   228KB/8KB
Calculates the orbital periods of an Earth satellite. The user can define the classical orbital elements of the satellite.
By C. Deagle, Jr.. 2023/05/29

Osculating Orbital Elements of the Moon   (details) Prime ENG   250KB/68KB
Calculates the osculating classical orbital elements of the Moon in the mean ecliptic and mean equinox of date coordinate system. This algorithm is based on the book Lunar Tables and Programs From 4000 B.C. TO A.D. 8000 by Michelle Chapront-Touze and Jean Chapront.
By C. Deagle, Jr.. 2023/05/28

Performance of a Single Stage Model Rocket   (details) Prime ENG   517KB/9KB
For a user-defined rocket engine, aerodynamic characteristics and launch site conditions, this program determines the flight performance of a single stage model rocket.
By C. Deagle, Jr.. 2023/05/28

Performance of a Single Stage Model Rocket   (details) Prime ENG   23KB/9KB
Program that can be used to predict closest approach between the Earth and Mars. The software will interactively request user inputs for an initial calendar year and a search duration in days.
By C. Deagle, Jr.. 2023/05/28

Precession Calculations   (details) Prime ENG   159KB/14KB
Calculates precession, which is the slow drift of the Earth’s rotational axis due mainly to the gravitational attraction of the Sun and Moon. The precession matrix transforms coordinates referred to the mean Earth equator and equinox of J2000 to coordinates measured with respect to the mean Earth equator and equinox of date.
By C. Deagle, Jr.. 2023/05/28

Predicting Lunar Eclipses   (details) Prime ENG   205KB/134KB
Predicts the local circumstances of lunar eclipses. Provides the eclipse type, the universal times and topocentric coordinates of the Moon at the beginning and end of the penumbra contacts, and the time and coordinates at maximum eclipse. It will also report the total eclipse duration.
By C. Deagle, Jr.. 2023/05/29

Predicting Perigee and Apogee of the Moon   (details) Prime ENG   248KB/31KB
Demonstrates how to calculate the perigee and apogee of the Moon. The software will ask the user to input the calendar month and year of interest. It will compute and display the calendar date and UTC time of each lunar event along with the geocentric distance of the Moon in kilometers.
By C. Deagle, Jr.. 2023/05/28

Predicting Phases of the Moon   (details) Prime ENG   14KB/42KB
Predicts the phases of the Moon. The user provides a calendar month and year and the software predicts the calendar date and UTC time of each lunar phase for that month.
By C. Deagle, Jr.. 2022/08/31

Predicting Rise and Set of the Moon   (details) Prime ENG   201KB/125KB
Predicts the rise and set times of the moon for a user-defined initial calendar date and geographic location. The user can also specify the search duration in days.
By C. Deagle, Jr.. 2023/05/29

Predicting Solar Eclipses   (details) Prime ENG   168KB/134KB
Predicts the local circumstances of solar eclipses, providing the universal times and topocentric coordinates of the Sun and Moon at the beginning and end of the penumbra phases, and the time and coordinates at maximum eclipse. It will also report the total eclipse duration.
By C. Deagle, Jr.. 2023/05/29

Predicting Sun Rise and Set   (details) Prime ENG   192KB/89KB
Predicts the rise and set times of the sun for a user-defined initial calendar date and geographic location. The user can also specify the search duration in days. It also calculates and displays the azimuth and elevation of the sun at rise, maximum elevation and set.
By C. Deagle, Jr.. 2023/05/29

Programs for Astronomy and Orbital Mechanics   (details) Prime ENG   185KB/1-720KB
A variety of astronomy and orbital mechanics programs. Also includes the support subroutines in case you want to write your own programs, as well as source code for some of the programs.
By C. Deagle, Jr.. 2022/08/28

Repeating Groundtrack Orbit Design   (details) Prime ENG   363KB/16KB
Estimates the time required for an Earth satellite to repeat its ground track. The mean orbital elements are propagated using Kozai’s algorithm and the user can select a closure tolerance for the ground track.
By C. Deagle, Jr.. 2023/05/29

Shadow Conditions of Earth Satellites - Kozai Orbit   (details) Prime ENG   369KB/85KB
Accurate predictions of shadow conditions for any type of satellite orbit can be determined by using a combination of one-dimensional minimization and root finding. The algorithm used here searches for minimum values of the angle between the shadow axis and the satellite’s position vector as a function of time. If this angle lies within the penumbra angle, the algorithm uses Brent's root-finding method to look backward and forward relative to this minimum time to find entrance and exit conditions. This method can also be used to determine entrance and exit relative to the umbra, penumbra and cylindrical shadows.
By C. Deagle, Jr.. 2023/05/29

Shadow Conditions of Earth Satellites in Circular Orbits   (details) Prime ENG   350KB/19KB
Determines beta angle and eclipse characteristics for Earth satellites in circular orbits. Also prints shadow statistics consisting of the minimum and maximum values of shadow duration and beta angle, and the average shadow duration.
By C. Deagle, Jr.. 2023/05/29

Single Impulse Deorbit from an Elliptical Orbit   (details) Prime ENG   338KB/25KB
Calculates the single impulsive deorbit maneuver required to establish a reentry altitude and flight path angle relative to a non-rotating, spherical Earth. The algorithm uses a tangential delta-v applied opposite to the velocity vector of an initial elliptical orbit to establish the de-orbit trajectory.
By C. Deagle, Jr.. 2023/05/29

Solving Kepler's Equation using Gooding's Method   (details) Prime ENG   2349KB/12KB
Solves the elliptic form of Kepler’s equation using Gooding’s two iteration method. This algorithm performs two, and only two iterations when solving Kepler’s equation.
By C. Deagle, Jr.. 2023/05/28

Solving Systems of First-Order Differential Equations   (details) Prime ENG   11KB/32KB
Demonstrates how to interact with an rkf78 subroutine which solves first-order systems of ordinary differential equations. This is an HPPL implementation of the Runge-Kutta-Fehlberg method of order 7 with an 8th order error estimate. This estimate is used to determine the variable step size required to satisfy a user-defined "convergence" criterion.
By C. Deagle, Jr.. 2023/05/14

State Vector to C3, RLA and DLA   (details) Prime ENG   205KB/19KB
Calculates C3 (twice the specific (per unit mass) orbital energy), RLA (the right ascension) and DLA (declination) of the asymptote of a hyperbolic trajectory. This computer program assumes that the hyperbolic targets, state vector and classical orbital elements are all in the same Earth-centered-inertial (ECI) coordinate system.
By C. Deagle, Jr.. 2023/05/28

Sun-Synchronous Orbit Design   (details) Prime ENG   336KB/8KB
Computes the mean orbital inclination for a sun-synchronous satellite in Earth orbit, given either the mean semimajor axis and eccentricity, or the mean perigee and apogee altitudes.
By C. Deagle, Jr.. 2023/05/29

Time of the Seasons   (details) Prime ENG   177KB/50KB
Determines the UTC calendar date and time of the equinoxes and solstices of the Earth. These events are the times when the apparent geocentric longitude of the Sun is an exact multiple of 90 degrees. This script uses Brent’s root-finder and a precision solar ephemeris to calculate these events.
By C. Deagle, Jr.. 2023/05/29

Trajectory Modeling in the Flight Path Coordinate System   (details) Prime ENG   447KB/117KB
Models the trajectory of an aerospace vehicle in the flight path coordinate system. A provided example flies an STS maximum cross range re-entry trajectory using angle-of-attack and bank angle information extracted from a trajectory optimization program.
By C. Deagle, Jr.. 2023/05/28

Translunar Injection from a Circular Earth Park Orbit   (details) Prime ENG   829KB/114KB
Estimates the delta-v required to reach the moon. The algorithm assumes the translunar injection occurs impulsively from a circular Earth orbit.
By C. Deagle, Jr.. 2023/05/29

U.S. 1976 Standard Atmosphere   (details) Prime ENG   8KB/18KB
Demonstrates how to interact with the us76_atmos subroutine which computes the properties of the U.S. 1976 standard atmosphere between 0 and 950 kilometers altitude.
By C. Deagle, Jr.. 2023/05/28

Part of the HP Calculator Archive,
Copyright 1997-2023 Eric Rechlin.