Researchers launch rocket to study the upper atmosphere during polar night
When the Polar Night Nitric Oxide (PolarNOx) experiment sounding rocket blasted off from Poker Flat Research Range in Alaska earlier this year, traveling at more than 2,400 mph into the upper atmosphere, it carried equipment designed at Virginia Tech to measure nitric oxide high above the Arctic.
Led by Scott Bailey, professor in the Bradley Department of Electrical and Computer Engineering, and supported by a grant from NASA, the PolarNOx experiment seeks to understand how nitric oxide generated by the Northern Lights accumulates in the upper atmosphere during the the months of continuous winter darkness.
The lack of sunlight prevents the normal destruction of the gas, which can contribute to ozone depletion and influence wind patterns, atmospheric temperatures, and global climate.
Bailey said that after months of feverishly working on the data analysis, "we see nitric oxide to a lower altitude than expected, and we see multiple peaks in density. This is important as it tells us how the nitric oxide is getting to lower altitude. We're very excited about the observations." His team plans to present its findings at the December meeting of the American Geophysical Union.
After years of preparation, discussions, and development, launching PolarNOx came down to four weeks in Fairbanks and dozens of researchers and engineers collaborating in negative 40 degree weather.
Unpacking at Poker Flat
The detailed process of launching of a rocket began in January with the mundane task of opening boxes and setting up equipment. The research and NASA Wallops teams unpacked massive crates, moved computers and miles of wires to temporary homes, and settled into the payload assembly building at the research range.
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(From left) Scott Bailey and NASA Wallops team members chat about the PolarNOx experiment at the payload assembly building. Photo by Niki Hazuda for Virginia Tech.
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This side of the PolarNOx payload highlights the hatch that will open in-flight, revealing the star tracker inside. Photo by Niki Hazuda for Virginia Tech.
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Undergraduate physics student Savannah Church stands between the experiment boxes. Photo by Niki Hazuda for Virginia Tech.
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(From left) Sowmya Muthurangan and Aklima Khatun unpacking at Poker Flat. Photo by Niki Hazuda for Virginia Tech.
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(From left) Sowmya Muthurangan, Justin Carstens, Savannah Church, and Aklima Khatun discuss unpacking plans at Poker Flat Research Range. Photo by Niki Hazuda for Virginia Tech.
Time for testing
Even rockets have to pass their tests before they can graduate to the launchpad. To ensure the accuracy of the experiment equipment and to perfect the connections with NASA technology, PolarNOx went through four rounds of testing: ultraviolet (UV), alignment, cradle, and sequencing.
UV tests
The research team tested the experiment's spectrograph and telescope using a duo of UV lamps: deuterium and tellurium. The lamps verified the sensitivity of PolarNOx's tools, which are used to lock onto the star Algenib — the point of reference that ensures the experiment can gather nitric oxide data.
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(From left) Justin Carstens and Savannah Church reflected in a mirror in the clean room. They discuss the tellurium lamp aimed at the closed experiment hatch. Photo by Niki Hazuda for Virginia Tech.
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Sowmya Muthurangan adjusts the tellurium lamp. Photo by Niki Hazuda for Virginia Tech.
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Close-up of the deuterium lamp used in one of the UV lamp tests. Photo by Niki Hazuda for Virginia Tech.
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A camera built inside the PolarNOx experiment will be used for guiding the rocket's trajectory to lock onto Algenib, a star in the Pegasus constellation. Photo by Niki Hazuda for Virginia Tech.
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Justin Carstens holds up a deuterium lamp in the dark clean room for one of the UV light tests. Photo by Niki Hazuda for Virginia Tech.
Alignment tests
The alignment test was critical to ensure the altitude control system pointed PolarNOX in the correct direction when launched.
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Justin Carstens plugging in a device for testing.
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The experiment team and NASA team collaborate on the video feed for the PolarNOx experiment.
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A NASA Wallops team member installs the star tracker into the experiment.
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Close-up of the star tracker installed in the experiment.
Cradle and sequencing tests
After the experiment was married to the NASA Sounding Rocket Operations Contract (NSROC) instruments portion, creating the "experiment payload," it was lifted onto the NASA cradle: a large-scale mechanical device that simulates rocket flight.
Similar to the alignment tests, the cradle test confirmed that the NSROC instrumentation was working properly and ready for flight. This double- and triple-checking assured the experiment and engineering teams that launch day would be smooth.
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NASA Wallops technicians work together on the payload. Photo by Niki Hazuda for Virginia Tech.
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The NASA Wallops team works together outside and inside the clean room in the Payload Assembly Building at the Poker Flat Research Range during the sequencing test. Photo by Niki Hazuda for Virginia Tech.
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Sowmya Muthurangan observes the experiment side of the payload during the sequencing test. Photo by Niki Hazuda for Virginia Tech.
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The experiment side of the payload will open during sequencing in the clean room. Photo by Niki Hazuda for Virginia Tech.
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(From left) Chris Hoxworth, a NASA Wallops contractor, and Justin Carstens discuss the sequencing tests. Photo by Niki Hazuda for Virginia Tech.
Getting clean
The experiment faced one last research need before leaving the payload assembly building and connecting with the launch motors: vacuuming. The research team vacuumed the experiment with nitrogen, ensuring a clean and sterile environment for the delicate equipment inside.
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(From left) Sowmya Muthurangan and a NASA Wallops technician talk through how to attach the hose to the nitrogen tank and turn the tank on. Photo by Niki Hazuda for Virginia Tech.
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The experiment team and NASA Wallops team members in the payload assembly building stand around the assembled PolarNOx payload while the team vacuums the experiment. Photo by Niki Hazuda for Virginia Tech.
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Justin Carstens holds the vacuum hose up to the experiment payload. Photo by Niki Hazuda for Virginia Tech.
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The team vacuums the experiment with nitrogen to ensure a fully clean and sterile environment for the telescope and spectrograph inside the sealed payload. Photo by Niki Hazuda for Virginia Tech.
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(From left) Justin Carstens, Aklima Khatun, and Sowmya Muthurangan monitor the vacuum pump attached to the experiment. Photo by Niki Hazuda for Virginia Tech.
Rehearsal and launch day
After weeks in Fairbanks and years of work in Blacksburg, all that remained between the rocket and the upper atmosphere was time. The research and NASA Wallops team practiced the launch steps during the rehearsal, carefully logging and correcting any last-minute errors. And in the early morning hours of January 30, PolarNOx successfully launched into the upper atmosphere, landing a few minutes later in the Alaskan wilderness surrounding Poker Flat.
