Conceptual Design and Analysis of Rockets and Their Missions
Latest Available Version: 1708
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 9R Mission
Two of the sample missions provided with the program simulate the
delivery of payload by Space-X's Falcon 9R 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"
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 67 text files (with .f95 file extension) and
consists of the main program, 155 subroutines, 286 function routines, and 7
modules. These program units contain 28,709 FORTRAN statements, 7209 blank
lines, and 6393 comments (most of which are on the same line with a FORTRAN
statement). Counting blank lines and statement continuation lines there are a
total of 38,541 lines (records) in the source code.
With Windows 8.1 and 10 operating systems, an apparently random and
"Stopped Working" error has been seen to occur, at least in the early
versions of these two operating systems. This error does not occur with
Windows XP or 7
operating systems. The cause of the error has
not been determined. In virtually all problem cases the error has
occurred while ZOOM solutions are being examined and has not
interrupted the solution process.
Comprehensive information about ZOOM can be obtained from the ZOOM
A free copy of the latest ZOOM version can
be downloaded from: ZOOM (Version 1708)
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. Three notable such
Children's of Alabama hospital in Birmingham, Alabama,
St. Jude Children's Hospital in Memphis, Tennessee, and
Cincinnati Children's Hospital in Cincinnati, Ohio.