NASA on April 24 launched a football-stadium-sized, super-pressure balloon on a mission that aims to set a record for flight duration while carrying a telescope that scientists at the University of Chicago and around the world will use to study cosmic rays.
Researchers from 16 nations hope the balloon, which lifted off from an airfield in Wanaka, New Zealand, will stay afloat for up to 100 days as it travels at 110,000 feet around the Southern Hemisphere. From its vantage point in near-space, the telescope is designed to detect ultra-high energy cosmic rays as they penetrate the Earth’s atmosphere. An ultraviolet camera on the telescope will take 400,000 images a second as it looks back toward Earth to try and capture some of the particles.
“The mission is searching for the most energetic cosmic particles ever observed,” said Angela V. Olinto, the Homer J. Livingston Distinguished Service Professor at the University of Chicago and principal investigator of the project, known as the Extreme Universe Space Observatory on a Super Pressure Balloon (EUSO-SPB). “The origin of these particles is a great mystery that we’d like to solve. Do they come from massive black holes at the center of galaxies? Tiny, fast-spinning stars? Or somewhere else?”
The next step for Olinto and her fellow scientists is a space mission, now being designed by NASA centers under her leadership, to observe a greater atmospheric area for detecting high-energy cosmic rays and neutrinos. These extremely rare particles hit the atmosphere at a rate of only one per square kilometer per century.
As the NASA balloon travels around the Earth in the coming months, it may be visible from the ground, particularly at sunrise and sunset, to those who live in the mid-latitudes of the Southern Hemisphere such as Australia, Argentina and South Africa. (The flight can be tracked on a map in real-time here.)
The complex balloon launch depended on the right weather conditions on the surface of the Earth all the way up to 110,000 feet, where the balloon travels. The launch window for lift-off opened March 25, and it a full month until the 18.8-million-cubic-foot balloon could take flight. Scientists now hope the balloon, made of a polyethylene film stronger and more durable than the type used in sandwich bags, can break the previous flight record of 46 days, set in 2016.
At a relatively low cost, NASA’s heavy-lift balloons have become critical launch vehicles for testing new technologies and science instruments to assure success for costlier, higher-risk spaceflight missions, said Debbie Fairbrother, chief of NASA’s Balloon Program Office.
“For decades, balloons have provided access to the near-space environment to support scientific investigations, technology testing, education and workforce development,” Fairbrother said. “We’re thrilled to provide this high-altitude flight opportunity for EUSO-SPB as they work to validate their technologies while conducting some really mind-blowing science.”
Balloons also are part of UChicago’s storied history of cosmic ray research, which dates to 1928 when Nobel laureate Robert Millikan first coined the term in a research paper. Pierre Auger, the namesake of the cosmic ray observatory in Argentina, launched hot air balloon experiments in the 1940s from the former site of Stagg Field. UChicago scientists used balloons in the Arctic Circle to discover positrons (the anti-particles of electrons) in the 1960s.
The EUSO-SPB project includes two UChicago undergraduates, Leo Allen and Mikhail Rezazadeh, who built an infrared camera under the supervision of Olinto and Stephan Meyer, professor of astronomy and astrophysics, to observe the cloud coverage at night.
Sixteen countries were involved with the design of the telescope and construction involved the U.S., France, Italy, Germany, Poland, Mexico and Japan. The U.S. team, funded by NASA, is led by UChicago, with co-investigators at Colorado School of Mines, Marshall Space Flight Center, University of Alabama at Huntsville and Lehman College at the City University of New York.
Read more about the scientific mission of the project here.
—Prof. Jacqueline Stewart
