Waldrop leads $75 Million NASA mission to investigate Earth's atmosphere

Lara Waldrop, Illinois ECE Assistant Professor and Y. T. Lo Fellow in Electrical and Computer Engineering, has been selected by NASA to develop a Solar Terrestrial Probes (STP) Science Mission of Opportunity, budgeted for $75 million.  Her mission, titled “Global Lyman-alpha Imager of the Dynamic Exosphere”, or “GLIDE” for short, was chosen for implementation after a competitive selection process and is expected to be launched in 2025. 

GLIDE will make unprecedented measurements of the far ultraviolet light emitted by hydrogen atoms in Earth’s outermost atmospheric layer, known as the exosphere, which extends more than 100,000 miles above Earth’s surface, about halfway to the moon.  This emission serves as a tracer of exospheric density, knowledge of which is needed to advance understanding of upper atmospheric physics, particularly regarding Earth’s recovery from solar-driven disturbances known as space weather. 

“The exosphere is a critical component of Earth’s protection against solar storms,” said Waldrop. “GLIDE is the first mission designed explicitly to investigate this key atmospheric region, and it will reveal the nature and origins of the exosphere’s global structure and temporal variability for the first time.”  Such data will provide researchers with better ways to forecast and, ultimately, mitigate the ways in which space weather can disrupt modern technology, such as satellite electronics, radio communication, electric power distribution, and even air travel.

GLIDE's data will also help explain how exospheric hydrogen atoms can overcome Earth’s gravity and escape into space.  “Since water is made mostly of hydrogen, its gravitational escape can lead to the permanent loss of a planet’s surface water reservoirs, as it did on ancient Mars,” explained Dolon Bhattacharyya, an ECE ILLINOIS Research Scientist who is serving as Project Scientist for the GLIDE mission.  “Although this process is very slow on Earth, GLIDE will advance understanding of the fundamental physics of hydrogen escape and its role in atmospheric evolution in our solar system and beyond,” she added.

Only a few observations of Earth’s exosphere have been made at large enough distances to capture its structure and behavior on global scales.  GLIDE would fill this long-standing measurement gap by acquiring wide-field images of Earth’s global exospheric emission from its vantage in orbit around the first Lagrangian equilibrium point (L1), which is located about 1 million miles toward the Sun.

GLIDE’s deployment to such a distant vantage is enabled by its launch as a secondary payload with NASA’s Interstellar Mapping and Acceleration Probe (IMAP) mission.  The IMAP mission is a pathfinder for NASA's new RideShare policy, whereby excess launch capacity of primary missions is used to increase access to space for smaller secondary missions and thus provide more avenues for learning about the solar system and developing innovative technical capabilities.

“RideShare with IMAP offers the rare opportunity for satellite deployment to the ideal vantage for exospheric remote sensing,” explained Waldrop. “From the L1 point, GLIDE will acquire nearly continuous, global-scale images of ultraviolet emission at unprecedented spatial and time resolution, exactly the data that’s needed to reveal exospheric variability in response to the sun above or the atmosphere below.”

All aspects of the mission will be handled by the GLIDE team, from design, to development, construction, and even the eventual post-launch operations.   Team members at the University of California at Berkeley’s Space Sciences Laboratory will develop GLIDE’s ultraviolet imagers, while Ball Aerospace will provide the spacecraft and subsystems that host the instrumentation.  Scientific analysis of the mission data will be conducted at the GLIDE Science Data Center, located in UIUC’s Laboratory for Advanced Space Systems at Illinois (LASSI), in collaboration with GLIDE team members at Boston University’s Center for Space Physics.  Graduate and undergraduate students will be involved at all stages of the project.

“This mission represents an end-to-end research endeavor, undertaken by a highly multidisciplinary team spanning expertise in space science, remote sensing and imaging technologies, optics, computational science, communications, signal processing, and aerospace engineering” said Waldrop.

In order to be chosen for the Mission of Opportunity, Waldrop and her team went through a rigorous and competitive selection process that began more than two years ago.  In 2019, the GLIDE mission was one of two finalists chosen to develop a detailed concept study report that described the proposed scientific investigation, mission concept, and plans for implementation.   GLIDE’s selection to proceed into the implementation phase of mission development is the outcome of NASA’s extensive, multi-phased evaluation of the concept study that the team developed.

The full press release by NASA.