Paul F. Eastman and Dr. Thomas J. Utley, Jr., Mechanical Engineering
The GoldHelox X-Ray Telescope is an undergraduate project of the Brigham Young University Physics Department in conjunction with the National Aeronautics and Space Administration. It is a fully autonomous robotic telescope and camera system capable of converting x-rays in the range of 171 angstroms into visible light and capturing the source images on 35mm film. This particular wavelength corresponds to the frequency of x-rays emitted by solar flares erupting from the surface of the sun, and by imaging only the x-rays emitted by the flares themselves, the effect will be to strip away much of the rest of the solar radiation, both visible and invisible. This will provide a window into the origins of the eruptions which interfere with much of the world’s communications networks. At the same time it will give researchers vital information about the sun’s activity below the visible surface.
Due to the complex nature of the telescope, the various subsystems have been divided according to expertise. Basically, physics students designed the x-ray optics and specified the requirements for the support systems. Electrical engineering students designed the electrical subsystems, including the computer which controls the telescope’s movements as it tracks the sun during exposure and the circuitry which acts as the x-ray equivalent of a shutter to expose the film. Finally, mechanical engineering students have designed the mechanical structure which integrates the optics and electronics into a functional telescope which NASA deems safe to fly aboard a manned Space Shuttle mission.
My Involvement with GoldHelox
I originally joined the project as a CAD specialist, with the assignment to produce working drawings of several parts to be machined. Within a short while it became apparent that the project needed a complete virtual assembly of the entire payload. Due to a lack of funding which had previously plagued the project for several years, a complete set of working assembly drawings had never been prepared in any one CAD system. The various teams had been left to their own devices to produce drawings from which parts could be manufactured, and designing across team boundaries was nearly impossible. After several months of work, I produced a complete assembly model in Pro/Engineer mechanical design software, thus providing all teams with accurate scaled drawings from which to work.
The many hours that I spent measuring and modeling more than 200 individual components left me as the person most knowledgeable about the interactions between the different subsystems. I was eventually asked to accept the position of Systems Integrator, responsible for resolving design conflicts between teams while constantly verifying compliance with NASA manned space flight regulations for every component and assembly. In addition, I also took upon myself the task of learning to machine many of the telescope’s mechanical components in order to lessen the strain on our meager budget.
Since accepting that position some sixteen months ago, I have learned several invaluable skills. First, I have learned that engineering is a group effort, no matter how small the project. Working with physicists, electrical engineers, technical writers, and NASA personnel has made me keenly aware of the damaging effects of “over-the-wall” engineering, whereby one team throws its designs over to another without first evaluating the ramifications of its decisions on the project. Successful, profitable engineering is a result of excellent communication between all the disciplines that are involved. This is especially true of the designers, but it also includes administration, public relations, finance, and technical documentation. No one group can succeed alone.
Next, I have become proficient at designing parts for manufacture. Too many mechanical engineers leave the university setting knowing how to design aesthetically interesting parts, but not appreciating the complexities of manufacturing the parts that they have designed. Many engineers aren’t trained in what has become known as “design for manufacture,” wherein a part is optimized for production while maintaining its function. Many times, design for manufacture requires foregoing some of the aesthetics which would make it “cool,” but which would also make it cost-prohibitive or even impossible to machine. Working on the limited budget of GoldHelox, I very rapidly came to appreciate the value of design for manufacture. It is a skill which I am sure will do much to further my career as a mechanical engineer.
Another benefit of this past year’s work on GoldHelox is that I have gained a solid understanding of generating CNC (computer numeric control) machine code from CAD models. This code allows computer-controlled milling machines to fabricate parts directly from the geometric information stored within the CAD model itself. No paper drawings are required, and incredibly complex parts can be manufactured in a very short time using equipment found within BYU’s own machine shops. Based upon normal machine shop rates, to date I have been able to save the project over $10,000 in design and fabrication charges it otherwise would have incurred, thus allowing both prototypes and flight parts to be produced in a limited time frame and on our very limited budget. While this was monetarily valuable to the project, this is yet another skill that I can now carry with me to future employers.
Current Project Status and Future Prospects
Over the course of the past year we have been able to complete the full-scale integration of the mechanical structure with the electronics and optics, and we have also successfully completed the preliminary stress, fracture, and vibration testing required by NASA. Additionally, this past summer we completed the initial optical calibration at NASA’s X-Ray Calibration Facility adjacent to Marshall Space Flight Center in Huntsville, Alabama. We verified that the original optical design is fully functional; the camera took its first pictures of an x-ray source emitting radiation within in the design spectrum, with only minor adjustments necessary to capture images. Instead of the initial specification of 300 images, we now have the capacity for over three times that amount, many of which will be sequenced to provide time-lapse photos, hopefully catching entire flare eruptions frame by frame.
There remains several hundred man-hours of computer programming, mostly to control the camera’s tracking and sequencing of images, then a final optical verification. A final vibration test must be performed to verify the integrity of the entire payload, and we are in the process of locating a facility with a shake table powerful enough to generate the 10 g’s required by NASA. An environmental chamber is being prepared to subject the telescope to extremes of pressure and temperature, and a team of technical writers from the English department is finalizing several hundred pages of required safety documentation prior to flight.
Our largest obstacle between now and launch is money–we are still looking for some $35,000 that will be required in order to complete the above tests, buy final flight-grade components for the optical system, and provide transportation for two required trips to Goddard Space Flight Center and Kennedy Space Flight Center for launch preparations. Representatives of NASA have informed us that launch could be as early as December of this year, pending completion of our work and NASA’s final scheduling around other, larger payloads.
Although the project nearly died in its infancy, it is now moving steadily forward, with every indication that it will be a success, not only for BYU but also for the several dozen undergraduates who have made it happen. I would like to extend my sincere appreciation to the BYU Office of Research and Creative Activities for helping me, and others, contribute to undergraduate research at our University. True learning does not take place in books, and projects like GoldHelox are an excellent medium by which we can fill the void between the classroom and the real world.