Testing
- Environmental Testing
- Propulsion Testing
- Relative Navigation Testing
- Satelllite Structure Testing
- Communications System Testing
- KC-135 Test
Environmental Testing
Read full details... (PDF) --[Get Adobe Reader]- Thermal Vacuum Test: Thermal Balance
This test shows the capability of the satellite to operate at the balanced temperature of the orbit cycle. The operation of the passive thermal control will be checked. The test also assures that the radio equipment will function correctly in LEO. - Thermal Vacuum Test: Thermal Cycle
This test ensures that the satellite meets the design qualification requirements. - Complete 72 Hour Test: Integrated Flight Stack Diagnostic
This test focuses on the general functioning of the satellite. All modes of operation will be simulated. The power consumption of the integrated spacecraft and the ability of the power system to satisfy the system power requirements will be monitored.
Propulsion Testing
Read full details... (PDF) --[Get Adobe Reader]- Microdischarge Characterization Test
The purpose of the Microdischarge Characterization Test was to determine the Current-Voltage characterization of a micro-plasma (Microdischarge) with an electrode separation of 250 microns and a diameter of 350 micron using Helium (He) and Argon (Ar) gas. Data from this experiment would be used to determine the power requirement to sustain the Microdischarge. - Microdischarge Plasma Thruster Demonstration
The purpose of this test was to demonstrate the application of Microdischarge Plasmas for propulsion. - Thruster Microdischarge Characterization Test
The purpose of the Thruster Microdischarge Characterization Test was to determine the current-voltage characteristics of the thruster Microdischarge during operation. - EMCO Voltage Converter Demonstration Test
The purpose of this test was to demonstrate the use of EMCO voltage converters for portable power supply of the Microdischarge Plasma Thruster. - Independent Microdischarge Plasma Thruster Test
The purpose of the Independent Microdischarge Plasma Thruster Test was to demonstrate that the thruster could operate independently of laboratory equipment.
Relative Navigation Testing
Read full details... (PDF) --[Get Adobe Reader]- GPS Subsystem Test
Energy storage devices such as Lithium batteries and supercapacitors pose an explosion and/or leak risk in the near-vacuum space environment anticipated during the FASTRAC mission. A benchmark test was performed on the FASTRAC Orion GPS Engineering Model to determine its performance with all energy storage devices removed and isolated from the main board. This configuration more accurately models the environment which will be present aboard the FASTRAC spacecraft.
Satellite Structure Testing
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- Vibration Test
A prototype of the satellite (consisting of two structures connected by a separation system called the LightBand) was tested on a shaker table to determine its natural frequency. The satellite is constructed from 6061-T6 and 5052 H32 Aluminums. The satellite held dummy weights made from aluminum boxes filled with lead pellets and epoxy. The structure weighs approximately 30 kg.
Communications System Testing
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- High Altitude Balloon Launch
A 1.7 kg payload containing a Hamtronics TA451 transmitter, Orion GPS receiver, Kantronics terminal node controller, HOBO temperature sensor, and HOBO pressure sensor was flown via a balloon/parachute setup to 80,000 ft to gather GPS, temperature, and pressure data into order to test part of the FASTRAC communications system.
KC-135 Test
Nasa selected four teams of undergraduate students from The University of Texas to participate in NASA's KC-135 Reduced Gravity Student Flight Opportunites Program. The program offers undergraduat students a unique experience--to design and perform an experiment aboard the KC-135, the aircraft that engineers use to simulate zero gravity.
The FASTRAC team designed a project to complement their nanosatellite research already underway. Many formation-flying space mission concepts begin with two or more satellites attached (or "stacked") to one another during launch. Once in orbit, these "stacked" satellites must separate from each other in a way that is both reliable and predictable. The zero-gravity environmnet on the KC-135, lasting about 30 seconds, is ideal to study this very important event. The analysis was done by designing two small 30-pound satellites and integrating the necessary sensors and electronics to wirelessly command them to separate several times in conditions very similar to what would occur in space. The data collected by the team in Houston is currently being used to design an actual space mission that is currently under development in the UT Austin ASE/EM Department.
The "Particle Damping" team designed an experiment to quantify the effective-ness of particle damping in microgravity. Particle damping involves filling structures with particles to allow the frictional and viscoelastic effects from particle interactions to damp out unwanted vibrations. The equipment for the experiment consisted of 10 different copper pipe samples fi lled with different amounts and types of BBs and sand that were mounted on a shaker. The shaker shook each sample, and an accelerometer mounted on the tip of the sample recorded the system output. This data allowed team members to estimate a transfer function and calculate the damping in each sample. Although software error prevented the team from gathering data from the first flight, modifications were made and the second flight went without a hitch. Team member Tim Allison says, "Designing and performing a KC-135 experiment was a great learning experience for everyone on the team. We learned a lot about structural dynamics and team-work and were able to gather and interpret good data from our flight."
The "FLOAT" team explored the capability of a Fluidic Momentum Controller (FMC) in microgravity. An FMC is an alternative device for spacecraft attitude control that uses the angular acceleration of fluid within loops to transfer angular momentum, offering potential benefi ts over conventional spacecraft attitude controllers. The FLOAT team designed an FMC control system, using National Instruments Compact FieldPoint hardware, to accept inputs from 6 PCB accelerometers and to provide outputs to 6 Jabsco pumps. The team programmed 26 LabVIEW subroutines to examine various rotation combinations of yaw, pitch, and roll. A stationary video camera recorded the duration of the flight for qualitative analysis, and a CompactFlash memory card recorded the control variables for quantitative analysis. The FLOAT team achieved 6 successful runs of the FMC during microgravity testing on the KC-135. While laying the groundwork for future FMC research, the team was also able to enjoy the rare and exhilarating sensation of being weightless.
The "Combustion" team examined how buoyancy affects a pulsed laminar jet flame in microgravity. To observe the flame, a Schlieren imaging system was used to get a glimpse of what was occurring inside the flame, rather that trying to discern the effect by observing the luminosity alone. Visualizing the flame in microgravity proved to be easier said than done, as the flame expanded greatly and faded to a transparent blue color. This phenomenon, coupled with the disorienting sensation of weightlessness, made performing the experiment somewhat difficult, but the team eventually got the routine down. Team lead Eric Rogstad says, "The actual flight aboard 'The Weightless Wonder' was like nothing else! And yes, we did the same hop that Apollo astronauts did on the Moon landings back in the 60's and 70's--we successfully studied flames in microgravity and had a lot of fun doing it."