UA SEDS ROCKET PROJECT

UA SEDS ROCKET PROJECT

University of Arizona SEDS has been actively developing rocket related hardware as well as actual filght vehicles since August of 1993. The motivating force behind the rocket project is the hands on element that most space-related college majors lack. Seldom does one see an entire project through in engineering, even at universities where pactical experiance is stressed. The rocket project gives all participants the opportunity to get their hands into every element of the development phases, from initial design to final launch prep.

Why a practical project?

Simple frustration with 4.0 GPA aerospace engineers who can't mix two part epoxy. So often space related engineers and scientists get caught up in the "paper spaceships". In fact, every year millions of dollars go into such craft which are neither practical or flyable. Of those who aren't entirely impractical, few every have the opportunity to work on an entire project from drafting to analysis to fitting the final pyrotechnics at launch. This lack of holistic experience is the motivation for UASEDS rocket project. Just as there is no substitute for doing problem sets to learn class material, there is no better cure for impractical engineering than practical experience as close to the center of things as possible. Practical space related professionals are better equipped to deal with the current environment of smaller budgets and higher technology.

The goal of a supersonic first flight to a minimum altitude of 12,500 feet, as well as the ability to use staging later on was matched with a minimum deliverable payload mass of 1.25 kilograms to create the intial challenge. Launch costs for the first flight, apart from the rocket itself and launch towers, was to be less than $200, including an allowance for inevitable repair costs. All these goals were met in the design phase with a minimum of compromise.

The current design is a fibreglass airframe which accepts commercial rocket motors available from independent vendors. Vital statistics on the rocket follow:

The use of rocket design software was crucial to the development of
the best possible combination of speed, altitude, practicality, payload
mass, and cost. Rodgers Aeroscience package was selected for ease of
operation, compatibility with commercial motor data, and overall accuracy.
Employing this package, it was possible to estimate drag coefficients up
to 15.0 mach should the occasion arise, and simulate flight data for a
variety of airframe geometries and motor configurations with high
accuracy.
The motor selected for the first flight is a 250 Newton peak thrust
(total impulse of 2560Ns.) ammonium perchlorate solid fueled disposable,
manufactured by Industrial Solid Propellants of Las Vegas, Nevada. Flight
performance has been estimated using a Runge-Kutta integrator included in
the Rodger's Aeroscience package. At a peak velocity of Mach 1.10 and an
apogee of 17,420 feet (Approx. 3.30 miles), this configuration minimizes
extreme accelerations for payload considerations while still delivering
needed payload mass.
The ability to stage to well over 60,000 feet with a high thrust
first stage has been also considered during the design phase. The
two-stage configuration is the goal of this portion of the rocket project,
and will deliver over 2.0 kilograms to the upper stratosphere and possibly
the mesosphere.
Experiments to be included in the repetoire of UASEDS include
solid-state acceleration sensors for the first flight, and later
barometric, temperature and photometric sensors, the latter with various
filters for determining local atmospheric composition. Flying cosmic ray
collecting emulsions has also been suggested. The emphesis is on low
budget practical payloads.

Electronics for the control of the rocket include an on-board computer
for staging control, recovery system control, and failsafe modes. A data
logging board for interfacing with various instruments. A modular design
has been used to allow stand-alone capibility for all electronic elements.
No active guidance systems are included in the current electronics
package. The Data Acquisition package is being headed by
Ric Zaller

The overall dimensions of the completed package should be approximately
6 inches X 4 inches X 1/4 inches.
The heart of the system is an 8-bit, 8 channel Analog to Digital converter (ADC).
Our design goal is to achieve a four channel system operating at
150Hz-200Hz per channel, although this can be slowed in order to
achieve longer recording times.
The data collected will be immediately dumped into an 8k-byte EEPROM.
The use of an EEPROM will allow for total power failure possibly
due to high-G decelerational forces) without the loss of data.
The final board will has the 8k EEPROM expandable to 16k.
Initial design considerations include an interface to any IBM compatible
computer for data recovery.
Currently, the the board is using a simple program
to retrieve the test data.
Once the data is retrieved on to the computer it is stored asimple ASCII integer numbers.
It is up to the flight analysis team to coordinate the sorting
of this data
A standard 9 volt battery will suffice for a power supply, although for those seeking complete mass reduction, a 7 volt supply could conceivablye built from hearing-aid
batteries.

Recovery is a parachute system ejected by pyrotechnic charges, with
seperate systems for the main propulaion section and the
electronics/instrument bay section. An on-board radio beacon will be used
in conjunction with a directional reciever to locate the rocket segments
after landing.
UASEDS rocket project is organized by Chris Greene and maintained
and operated by the UASEDS rocket team, composed primarily of
undergraduate engineering and science students with a thing for space
exploration.

UASEDS Rocket Project may be reached at SEDS, University of
Arizona, Box 119, Building #92, Tucson, AZ 85721; email to:
greenec@seds.lpl.arizona.edu for question, comment or
gratiutous financial contribution.

UASEDS HPR Division