About ASTRO

Background

Created in the Fall of 2000 as a research and design project for students interested in aerospace engineering, the original goal of the Aerospace Systems Technology and Rocket Operations (ASTRO) team was to design an autonomous landing vehicle similar in design to the Mars Rover lander - able to land safely using rocket engines to slow its descent. After development and initial testing, the autonomous landing vehicle (ALV) would be dropped from a height sufficient to allow the vehicle to achieve terminal velocity. This ALV would then land itself under its own power and without the aid of parachutes or stabilizing fins, making it operational in a generic environment – an important part of the project.

This year, ASTRO’s goal is to complete one of many steps which will take place before completion of our ultimate goal: developing a vertical-takeoff, vertical-landing (VTVL) vehicle which will initially rise a few feet of the ground under its own power, autonomously hover and demonstrate its stability over the course of a few seconds, and then land safely and without damage. After this goal is achieved, the current design will be improved to either be able to translate laterally while retaining stability, and ultimately to achieve the goals set out for the original ALV concept. A model of the original ALV design concept can be seen below:

Work in Previous Semesters

The project began with determining overall system performance requirements and the testing of a commercially available liquid-fueled rocket motor. The original rockets used ran on gasoline and hydrogen peroxide, two propellants readily available to us, but there were many problems with their design. Sealing poppets would never seat, presenting a safety hazard; the engines weren’t throttleable, and they weren’t designed to burn for more than ten seconds. By ASTRO’s second year, design had begun on our own rocket engines, which were meant to burn for a minute and operate on hydrogen peroxide and gasoline, producing a target thrust of 100 lbs. At the same time, our electrical group was trying to determine what type of control system we wanted to use for autonomous control of the ALV. Neural networks were initially considered, and a PID controller was developed for a 3 degree of freedom test-bed, which was created to obtain practice in developing a sample control system on a simpler, lower cost dynamical system.

During the 2001-2002 academic year, ASTRO’s test site was also developed, located on a plot of land owned by the University. This land was first cleared out, and a testing region built to establish a permanent testing site for the ALV rocket engines. In addition, test stands were designed and built to work with the commercially purchased gasoline-peroxide engines being tested at that time.

The team then spent a year developing and testing the next generation of engines, with limited successes. These engines had a stainless steel body with ceramic lining to prevent overheating, and a titanium throat plug. Due to new problems obtaining hydrogen peroxide caused by health and safety concerns as well as complications with its storage, the propellants were switched to propane and Nitrous Oxide. The problem with these engines turned out to be the injector-manifold system, an overly complex design which was unable to provide the required flow rate to achieve ignition with our new gaseous propellants. The test stand was also redesigned to work with the new engine design.

Last year, the electrical group did a lot of control system development with the previously mentioned test-bed, and also developed a 6-degree of freedom helicopter system which allowed us to test on a system similar to the ALV. By the end of the spring semester, the electrical group had the helicopter operational, and had developed a control system for the VTVL in VX Works, a small, quick operating system. Since then, work has begun on second- and third-generation control systems for the VTVL.

The VTVL structure was also built last year, designed to mount the three rocket engines, fuel tanks, the onboard electronics, and onboard computer and sensors rigidly and with low weight. A picture of the structure can be seen below (without mounted components):

2005-Progress and Goals

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