NASA Flight Week: When engineers become heroes
The 2013 Nebraska team readies their freeflyer equipment for a super experience: testing their experiment on reduced gravity flights at NASA's Johnson Space Center.
JULY-AUGUST 2013: The UNL Microgravity Team’s Flight Week in Houston began in Nebraska, with a final session in the UNL lab during the regular Wednesday check-in with NASA. You can catch some of the last minute action in this story by the Lincoln Journal Star (there was also some local tv news coverage).
On Thursday, August 1 at about 11:30 p.m., the team arrived in Houston to get settled. Unfortunately they did not get much sleep that night because the next morning the team had to be up bright and early for briefings on safety requirements at the Johnson Space Center and to start setting up the experiment.
After their morning meetings the team went to the Active Gravity Response Offload System, to start the initial testing of the Octocopter in ARGOS. They ran into a little excitement on the way because a propeller loosened and came off the flyer during on-site testing. This led to lots of new information and plans for how to fix some problems that were discovered, which gave the team lots to do on Saturday.
On Sunday the team returned to the ARGOS system and was able to test for the entire day, as well as prepare everything for their first flight day on Tuesday.
First thing Monday morning, the team attended the Test Readiness Review, which is where 30 or so engineers inspect the experiment and determine whether or not it is flight ready. The electrical review team was quite impressed with how the Nebraska team had managed to deal with the lithium polymer batteries and said that the Nebraska team had gone above and beyond the requirements necessary.
The excitement of Tuesday--first flight day—built with a slight delay at the start, but the team reported that everything went extremely well. It took a little getting used to certain activities--especially releasing the flyer--in zero gravity, but once they adjusted for that condition, it all went great. Another day, a second group of UNL flyers enjoyed their experience.
The UNL team gained worthwhile data and must now prepare reports for NASA. They anticipate good results and look forward to further opportunities to develop projects with NASA.
Here's a photo from 2012 UNL Microgravity during flight week at NASA JSC, just a reminder of what the team is working toward.
JUNE 2013: Work by the UNL MG team advances into the hot days of summer. School is out and the team has spread across the countryside, but they still find time to work on their task at hand.
With little more than a month until flight week, the team is beginning to finalize the project. Many hours of substantial paper work have been submitted to NASA as well as team correspondent, Larry Dungan. These documents outline the purpose and plan for every phase of the experiment, from how the aspects work to why the team chose the methods and ideas that they did.
Software and coding work continue, as always. The team is constantly tinkering with code, trying to develop and optimize the controls of the free flyer. Another tedious task for the team is balancing each individual propeller, ensuring stable flight on board the “vomit comet” (Microgravity aircraft) during flight. The Nebraska team also has finished assembling all the motors and continued testing them with the batteries at varying speeds, so they can know the flight time they will have for a given battery. The nial designs for the ducting are also underway.
The electrical system of the flyer is assembled and working properly; modifications to optimize the circuit are underway, though. The team hit a few hiccups along the way with some capacitors, but it’s nothing the team can’t overcome in the time they have before flight week.
Work also continues on the ground station and the stereo-vision cameras that will collect flight data for post processing for the experiment. The team’s plan to use Bluetooth to communicate from the onboard ground station to the flyer is coming along nicely, with more testing and software work ongoing—all showing good signs and progress.
As flight week approaches the team is rushing to finish their project and is excitedly awaiting their chance to prove themselves in Houston.
APRIL 2013 - UNL Microgravity team members Tricia Foley and Eli Van Boening get young minds excited about engineering for NASA during UNL Astronomy Day at Morrill Hall.
As the end of the academic year arrives, UNL students are busy studying and the microgravity team’s project is increasingly active.
The past month included many developments for the team. In addition to much outreach in the community, the team fabricated and assembled the finalized frame for the free flyer. The batteries arrived and are undergoing testing, along with mountains of work on programming and coding.
After completing the frame, the mechanical team moved on to work on the ducting that will surround each propeller of the free flyer. This ducting will be 3D printed so it is both strong and light weight. The mechanical team is also working on stress analysis for use when the team proves to NASA’s top brass that free flyer is safe and functional for the flight. Finally the mechanical team plans to alter the position and angle of each motor’s mounting. The reason for this adjustment is that right now the copter has no yaw control. Adjusting the angle of the motors so they can translate motion in one more direction, ever so slightly, provides yaw control and allows for a more accurate and manageable flight, which is ideal because one never knows just what will happen in microgravity.
Another aspect receiving attention is the ground station: where the team will mount all their hardware that is not the free flyer, on board the plane. This will include both cameras for data acquisition; a laptop to compute, receive and send information to the free flyer; and the LED to emit the IR flash used to synchronize the two cameras. The original plan was to mount this LED on the free flyer itself but with further research, the team now thinks that it would be simpler to mount on the ground station--easier for the electrical team because the batteries on board the free flyer will not be able to supply the desired charge to the LED to make it work. All of these components will be mounted on the frame of the ground station, which will be mounted to the floor of the plane.
As we approach flight week it is important that the team keeps in mind the paper work regarding the function and safety of the experiment, due at the end of May. The team looks to accomplish this by mid-May and send it to NASA contact Larry Dungan for review before it’s due.
The electrical and coding teams are moving faster to keep on pace with the project. A great deal of work has been done regarding the programming and coding for not only the flight path, but also the data acquisition. The team meets diligently with faculty mentors to make the most effective and efficient code that is both simple to use, and to trouble shoot so adjustments can be made quickly inflight if needed. The biggest development in this area is a new idea to preprocess all of the commands before sending them to the free flyer. The team would determine the desired flight path and input that information to the program, as code that the free flyer understands for flying the desired flight path. This would all be done at the onboard computer mounted to the ground station.
Just like the weather outside, the UNL microgravity team is heating up and reaching new heights. Stay tuned here for more updates as the project finishes up and the team heads to Houston for flight week.
As the weather begins to warm, we reach the exciting time of the year when the world comes back to life. The UNL Microgravity team had a booth at the Big Red Road Show on March 3 in Omaha's CenturyLink Center, and now the team begins the more exciting parts of their project.
The team has worked for many months on perfecting the design of the frame for the free flyer. Trying to overcome challenges such as motor mounting, modeled stress testing to increase the safety, eliminating potentially dangerous aspects of the frame, and much more all have finally come together on the final design. The team’s persistence paid off--in their search for someone to manufacture the laser cut frame they were lucky enough to find TMCO who agreed to build the frame for free. TMCO will also be powder coating the flyer a beautiful and appropriate scarlet.
With the money the team is saving thanks to the free cutting, they are exploring the options of upgrading their battery packs to lighter and longer lasting ones. This will help performance of the free flyer when it is put through its paces in the microgravity environment of the reduced gravity aircraft at the Johnson Space Center this summer.
With the new batteries, new ideas also arise for the rest of the electrical hardware as the team begins to look more extensively at the wiring and electrical hardware that will be onboard the free flyer. Many ideas still circulate concerning everything from gyroscopes that will monitor acceleration to fuses that save the craft from potentially harmful battery spikes.
Another interesting development is that the team has been writing code for control of the motors that will propel the free flyer during testing. Much to everyone’s delight, the code they have written thus far has shown to give them active and accurate control over the motors.
As the semester boils down and the weather heats up, you can be sure that the UNL MG team will have their noses to the grindstone ensuring this project is an overwhelming success.
Another month of work has come and gone for the UNL Microgravity team. Many hours of labor have gone into research, design, and testing for the team’s free flyer, and with the decision on the traveling team that will make the trek down to NASA’s Johnson Space Center in Houston this July. Our travel team includes the flight team--Caleb Berggren, Tricia Foley, Eric Fritz, and Jake Reher—along with alternate flyer Joan Yule, and the ground team of Nick Goeser and Effie Greene. They are committed to be ready to test our final product in ARGOS (the Active Response Gravity Offload System) and on NASA’s reduced gravity aircraft.
The UNL Microgravity team made further accomplishments in the past month: finalizing the frame design and selecting the proper battery packs, wiring, and motherboard to use with the motors that will run the entire free flyer. The mechanical team has modeled the frame in Solidworks software, and laser cut an acrylic prototype.
These advances led to a design review conference including the team we will be working with in Houston on ARGOS. The conference covered all the major aspects of the progress the microgravity team has made thus far. During the review, UNL team leader Jake Reher explained to the ARGOS team, in Houston, the systems side of the free flyer. He discussed the acrylic prototype frame and that the frame for the final project would be made of laser-cut aluminum to reduce weight and retain strength. The NASA ARGOS team’s main critique and suggestion for us was to lower the U-joint that will connect the free flyer to the ARGOS system, aiding the stability of the free flyer.
Following the systems report, Caleb Berggren, UNL’s mechanical team leader, focused on physical stats of the free flyer. The octo-copter will be 18.7 x 18.7 x 11.9 in and weigh approximately 10.62 lbs. The ARGOS team made suggestions about the free flyer’s make up and design that will help with performance. When Nick Goeser, the UNL team’s safety officer, gave his report the ARGOS team offered many tips about safety factors for the frame, wiring, and battery packs onboard the free flyer. Goeser also explained the modeled stress testing done in Solidworks. The final report in this review was from Tricia Foley, UNL’s electrical team lead. Foley explained the current choices of batteries the team is considering, the expected max battery life, and how battery life would affect performance of the data collection from the free flyer. The ARGOS team suggested that during the flight, batteries could be swapped if a quick change battery apparatus is included in the design of the project.
Overall the ARGOS team was impressed with the progress that our UNL Microgravity team has made, and provided many useful tips to help the project succeed. Our team will use the tips and make alterations to the flyer in the coming weeks, as we begin to construct the flyer and prepare it for the trip to Houston for testing.
Since early December the UNL Microgravity Team has been designing an experiment, for NASA, to test at the Johnson Space Center in Houston. It will go on board NASA’s reduced gravity aircraft, more commonly referred to as the “vomit comet.”
The project is for NASA’s microgravity seed program in which schools around the nation create one of the projects suggested by NASA for testing in microgravity. The project chosen by the UNL team this year is a free-flyer. The free flyer is planned to be an octa-rotor (similar to a small helicopter with eight rotors) that will be tested in NASA’s ARGOS system of artificial microgravity, and in the known microgravity conditions on the reduced gravity aircraft during its flight.
ARGOS stands for Active Response Gravity Offload System, designed to simulate reduced gravity environments--such as Lunar, Martian, or microgravity--using a system similar to an overhead bridge crane. ARGOS uses an inline load cell to continuously offload of a portion of a human or robotic payload’s weight during all dynamic motions, according to NASA. Here is a link to see what ARGOS looks like in action: http://www.youtube.com/watch?v=m2DNbC_ljHs.
The UNL team holds weekly phone conferences with their NASA contact, ARGOS aficionado Larry Dungan, to discuss both plans for the experiment and advice on how the free-flyer will operate in the ARGOS system.
UNL’s Microgravity Team is currently in the design phase of their endeavor. They are working on finalizing a frame design, and running tests on the motors that will control the flight of the free-flyer. Another aspect of the project currently underway is the data collection. The data collection includes taking information gathered from accelerometers placed on the free-flyer, and also using visual data collected from two cameras. The data collected will show how the free-flyer behaves in the microgravity environments of the reduced gravity plane flight and the ARGOS system.
The UNL Microgravity Team will continue their efforts into flight week this July when they travel to Houston and put their work on display for NASA’s top brass, using their skills and research capabilities to help better understand the effects of reduced gravity on a free-flyer.