Conceptual Design and Analysis of Rockets and Their Missions
Latest Available Version: 2102
Released in February, 2021
is a windows-compatible computer program that determines the
quasi-optimum trajectory and rocket configuration for a mission
objective and constraints defined by the user. The program is very
useful for conceptual design and analysis studies. ZOOM has been tested
with Windows XP, 7, 8.1, and 10 operating systems and works
with keyboard/mouse and touch-screen interfaces.
ZOOM incorporates many of the
algorithms and procedures
developed and refined over decades beginning in the 1970's. The
uses the Simplex algorithm of Linear Programming in an innovative way
that has proven robust and effective in solving a wide variety of
trajectory optimization problems. These include long-range,
low-altitude intercepts of re-entry vehicles, deliveries of large
payloads from the earth's surface into various earth orbits including
geostationary orbits, deliveries of payloads from an airborne platform
to low earth orbit, rendezvous with orbiting satellites in
sun-synchronous and other earth orbits, re-entry of the Space Shuttle,
descent from lunar orbit to the moon's surface, and a variety of other
Falcon F9R Mission
Two of the sample missions provided with the program simulate the
delivery of payload by Space-X's Falcon F9R rocket to low earth orbit
and the return of the rocket's first stage to the launch site. The
payload delivery mission is of mission type "Inject Into Conic", and
the first-stage return is of mission type "Achieve Specified State"
Falcon Heavy to Low Earth Orbit
sample mission provided with the program is an approximation of payload
delivery to low earth orbit by Space-X's Falcon Heavy rocket. Like the
other sample missions, this one can be modified to update the parameter
values used in the approximation.
ZOOM is probably unsurpassed in the wide variety of in-flight and
end-point constraints that can be imposed on the trajectory solution.
These include constraints on initial mass, aerodynamic normal
acceleration, axial acceleration, dynamic pressure, aerodynamic heating
rate, propellant loading, and rocket-motor thrust. The intercept of a
target spacecraft or re-entry vehicle can be an impact or rendezvous. A
wide selection of mission objectives is available. These include
minimizing the rocket's initial mass, maximizing payload, minimizing
flight time, minimizing aerodynamic heating, maximizing altitude,
maximizing ground range, and maximizing or minimizing final speed.
Scope of the Program Code
The ZOOM program is written
in the FORTRAN 95 language. The source code is contained in 66 text files (with .f95 file
consists of the main program, 195 subroutines, 346 function routines,
modules. These program units contain a total of 36112 FORTRAN code statements.
The FORTRAN compiler (FTN95) and the "Plato" integrated development environment (IDE) used
in the development of ZOOM were developed by Salford Software Limited,
a company owned by the University of Salford, near Manchester,
England. In August 2004 Salford Software relinquished control of
FTN95 to Silverfrost Limited. Silverfrost FTN95 is often referred to as
Salford FTN95 because of its University of Salford pedigree.
Silverfrost markets several versions of FTN95 and Plato from their website.
For ZOOM users with a previous ZOOM version, the upgrade package
can be downloaded from: ZOOM 2102 Upgrade Package
Comprehensive information about ZOOM can be obtained from the ZOOM
A free copy of the latest ZOOM version can
be downloaded from: ZOOM (Version 2102)
the download is complete, the ZIP file can be unzipped to reveal the
ZOOM Folder. The "Read Me" file in the folder explains how to execute the program.
Any user of ZOOM is entitled to a reasonable amount of free technical assistance by contacting the developer, David Williams, at email@example.com. Any comments that can improve ZOOM are welcomed.
ZOOM is being offered free of charge in order to
facilitate the conceptual design and analysis of rockets and their missions. Anyone who is
inclined to express their appreciation is encouraged to donate to a
worthy charity. Of special worthiness to the developer of ZOOM are children's hospitals. Four notable such
Children's of Alabama hospital in Birmingham, Alabama,
St. Jude Children's Hospital in Memphis, Tennessee,
Cincinnati Children's Hospital in Cincinnati, Ohio, and
Boston Children's Hospital in Boston, Massachusetts.