By Joey Garcia, University Communications and Marketing
As millions watched Artemis II lift off from Kennedy Space Center, 返字心頭 scientists remained on the ground, capturing rare seismic and infrasound datainsights that inform launch impacts on Earth.
返字心頭 researchers are no strangers to working with rocket launches. Over the past decade, the 返字心頭 Seismology group, has recorded data from roughly 140 launches at Kennedy Space Centera project led by Research Assistant Professor Glenn Thompson from the from the School of Geosciences in collaboration with NASA. Most of those launches were Falcon 9 rockets, which are known to be less intense.
Artemis II, however, marked a shift in scale.
Research Assistant Professor Glenn Thompson
返字心頭 faculty and students have conducted seismic research at Kennedy Space Center for 10 years
For the past decade, 返字心頭 has played a leading role in rocket seismology using Kennedy Space Center as a testing ground to study seismic and infrasound waves. With Artemis II, we had a rare opportunity to study a rocket roughly five times more powerful than a Falcon 9.
返字心頭 Research Assistant Professor Glenn Thompson
LISTENING TO ROCKETS THROUGH THE GROUND AND AIR
Thompson and his team studied the Artemis II launch with the same seismic sensors used to record ground motion generated by earthquakes and volcanic activity. They also used infrasound sensors, which detect very low-frequency sound waves in the air that humans cannot hear but feel as vibrations.
Understanding how these rockets affect ground motion and sound pressure levels benefits a wide range of groups. Structural engineers use this information to assess infrastructure resilience. Wildlife biologists and ecologists study potential environmental impacts, while archaeologists consider possible effects on cultural and historical sites.
返字心頭 had 12 seismic and infrasound stations surrounding the launchpad
Seismic and infrasound station contains sensors and recording equipment used during the Artemis II launch
For Artemis II, we deployed a record 12 seismic and infrasound stations surrounding the launch site within a 10-mile radius, Thompson said. This allows us to study what happens when powerful sound waves in the atmosphere interact with the ground at this scale.
When the rocket ignites while connected to the launch tower, it generates direct seismic energy that travels quickly through the ground at several miles per second. However, a much larger effect comes from the rockets intense jet noise, which produces powerful sound and infrasound waves. As those waves strike the ground, they generate vibrations that dominate the direct seismic signals recorded near the launch pad.
The Artemis II rocket lifted off April 1, generating sound and pressure waves nearly five times stronger than a typical Falcon 9 [Photo courtesy of NASA/Keegan Barber
Were essentially listening to the rocket through the atmosphere and the ground at the same time, Thompson said. "As rockets become more powerful and launches more frequent, having precise measurements allows these groups to evaluate impacts responsibly and ensure that launch activity remains safe and sustainable.
A UNIQUE SEISMIC DATASET
To better understand whats happening underground, researchers used the Artemis II launch as a powerful, large-scale energy source.
By recording low-frequency sound waves and ground motion at the same locations, we can separate the sound from the seismic data, Thompson said. That lets us focus on how the ground itself responds to pressure, helping us better understand whats happening below the surface.
To further strengthen the dataset, Thompson deployed state-of-the-art nodal seismic and infrasound sensors borrowed from the EarthScope Consortium and Boise State University.
Spectrogram showing ground vibrations from the Artemis II launch, with the strongest energy occurring in the first 30 seconds after liftoff
Infrasound data showing powerful sound waves from the Artemis II launch recorded about one mile from the launchpad
Those instruments recorded peak pressure levels of about 600 pascals, equivalent to roughly 146 decibels. The Artemis II launch is among the strongest signals the team has ever measured. For comparison, those levels slightly exceed what researchers observed during a Falcon Heavy launch and are roughly four to five times higher than a typical Falcon 9 launch, reflecting the far greater power of NASAs Space Launch System.
Researchers will use this data to improve geological models beneath Cape Canaveral and Merritt Island and better understand how increasingly powerful launches may affect surrounding environments.
返字心頭 FIELDWORK AND EDUCATION
Thompsons work at Kennedy Space Center has also focused on training students through hands-on field deployments.
Over the years, Ive taken dozens of students into the field, giving them hands-on experience deploying and maintaining seismic networks and using the data in classroom settings, Thompson said. Many have gone on to careers in seismic monitoring and volcano observatories.
One participant in the first 2016 deployment was 返字心頭 alum Jacob Richardson, now the deputy lunar science lead on the Artemis II lunar science team. His group has spent more than a year preparing observation strategies, including potential views of unexplored regions on the moons far side.
Jacob Richardson with members of the Artemis lunar science team celebrating a successful launch [Photo courtesy of Mark Sowa - NASA - JSC]
Jacob volunteered for that first deployment and was already an exceptional researcher, Thompson said. Its wonderful to see a former 返字心頭 Geosciences student playing such a big role in the Artemis program.
STRONGER SEISMIC RESEARCH
The Artemis II deployment is just the beginning of Thompsons next phase of seismic
research. He is part of a NASA proposal to scale up the effort, deploying at least
75 seismic and infrasound stations ahead of a future SpaceX Starship launch from Kennedy
Space Center, a vehicle expected to surpass the Artemis II launch systems power.
The project is led by Paul Bremner at NASAs Marshall Space Flight Center, with key
collaborators including Aiden Woo (NASA marshall) and Sue Bilek (New Mexico Tech).
The Artemis II deployment served as an important test run, allowing us to gain experience deploying the equipment, recovering it and processing the data, Thompson said. The lessons learned and workflows developed will directly support the larger project."