Ultraviolet Spectrometer Successfully Integrated into the Spacecraft

The ultraviolet (UV) spectrometer was successfully integrated into the satellite bus of the Carruthers Geocorona Observatory.

A large, square instrument sits in the middle of the image in a lab with a dark blue and teal background.
BAE Systems successfully completes the integration of the Carruthers Geocorona Observatory’s ultraviolet (UV) spectrometer onto the satellite bus, the next major step in completing the NASA Earth-monitoring satellite. NASA/BAE Systems

Carruthers is a small satellite (SmallSat) and once in orbit at Lagrange Point 1 (L1), the observatory will use an advanced UV imager to observe the exosphere — the outermost part of the atmosphere — to determine how it changes in response to space weather caused by the Sun. Carruthers is expected to be the first SmallSat to operate at L1, a gravitationally stable orbit point between the Earth and Sun about one million miles away, and it will be the first satellite to provide continuous observations of the Earth’s exosphere.

A person in a white suit stands on the right side of the image, looking and touching a large instrument on the left side of the image.
BAE Systems technician inspects the Carruthers Geocorona Observatory satellite after integration of the ultraviolet (UV) spectrometer onto the satellite bus.

The mission was previously called the Global Lyman-alpha Imager of the Dynamic Exosphere (GLIDE), but it was renamed in 2020 in honor of Dr. George R. Carruthers, the renowned scientist responsible for designing and building the moon-based telescope that took the first images of the Earth’s geocorona from space as part of the Apollo 16 mission.

Carruthers is currently scheduled to launch in 2025 as a rideshare component of NASA’s Interstellar Mapping and Acceleration Probe (IMAP) mission.

NASA Mission Announces Space Weather Explorers Week

In the midst of the Heliophysics Big Year, one NASA mission, the Carruthers Geocorona Observatory, is launching a new outreach campaign. This campaign aims to inspire teens to learn more about STEM (science, technology, engineering, and math) careers, Earth and space science, and about the Sun-Earth connection in particular. Get ready for Space Weather Explorers Week!

Space Weather Explorers Week offers a collection of lessons and activities about the Sun-Earth connection. The campaign’s website features information and educational activities laid out in week-long courses that can be accessed any time of the year. However, “live” weeks occur several times a year where scientists will interact with participants through a social platform. The next live week is April 1-5, 2024, to coincide with the Heliophysics Big Year monthly theme for April, the April 8 total solar eclipse. The lesson plans for this live week are geared towards learning more about the Sun, Earth, space weather, eclipses, and careers in space science.

Two children demonstrating an eclipse with an Earth-printed beach ball and a Moon-shaped ball.
Photo of children simulating a solar eclipse on a representation of Earth. Credit: NASA

The website and programs also emphasize the importance of role models and feature volunteers from underrepresented groups in science. This is inspired by the mission’s namesake, George R. Carruthers, an African American physicist who designed and built the Moon-based telescope that first observed the geocorona.

The Carruthers Geocorona Observatory mission will study Earth’s exosphere, the outermost layer of Earth’s atmosphere. This mission will be the first dedicated to charting changes in this expansive region we know little about. It seeks to answer basic questions about the nature of Earth’s exosphere, such as its shape, size, and density, and what causes these aspects to change over time.

The exosphere is a transitional region from Earth’s environment to the space environment and is difficult to observe in any global sense from the surface of our planet. The exosphere plays an important role in Earth’s response to space weather, the changing conditions in space driven by the Sun. That space weather can impact our technology, from satellites in orbit to communications signals in the upper atmosphere to power grids on the ground. Carruthers Geocorona Observatory will help us better understand the fundamental physics of our atmosphere and improve our ability to predict the impacts of the Sun’s activity.

To date, only four images exist of the exosphere. The first image was from Carruthers’ telescope when it was placed on the Moon during the Apollo 16 mission in 1972. The telescope was sensitive to ultraviolet light that was absorbed and re-emitted by neutral particles of hydrogen in the exosphere. Scientists call this ultraviolet emission the geocorona, which is Latin for “Earth’s Crown.”

An image depicting what the exosphere looks like in ultraviolet light. The background is in shades of blues, with a yellow half-moon shape in the center, surrounded by reds and greens.
This photo of Earth’s exosphere was taken by a telescope on the Moon during the Apollo 16 mission in 1972. Credit: NASA

The mission is led by Lara Waldrop from the University of Illinois Urbana-Champaign, which was where Carruthers earned his bachelors, masters, and doctorate degrees in the 1960s. “Women and men of color have long been underrepresented in space physics, and we plan to buck that trend,” said Waldrop. “One of our core principles on the Carruthers team is building a diverse team across the mission’s science, engineering, and administrative leadership teams.

Check out the Space Weather Explorers Week website at https://spaceweather.ssl.berkeley.edu/, spread the word, and prepare to ask scientists a lot of questions!

 By Dr. Bryan Mendez

Planetarium Director, University of California, Berkeley

NASA’s GLIDE Mission Renamed in Honor of Dr. George R. Carruthers

NASA has renamed its Global Lyman-alpha Imager of the Dynamic Exosphere, or GLIDE, mission in honor of Dr. George R. Carruthers.

On Dec. 2, 2022, Carruthers’ family and friends gathered with leaders from the mission’s participating institutions to officially name the mission the Carruthers Geocorona Observatory. The renaming event took place at Carruthers’ alma mater, the University of Illinois Urbana-Champaign, where he earned his bachelor’s, master’s, and doctorate degrees in the 1960s.

Learn more about Dr. Carruthers, the renaming, and the mission here.

Updates on the mission will now be available on blogs.nasa.gov/carruthersgeocoronaobservatory.

A photo montage. On the foreground, Dr. Carruthers looks into the camera holding an award. On his left, another image of Dr. Carruthers in a white lab coat and the golden telescope on the moon. To his right, another image of Dr. Carruthers in a suit and tie.
Dr. George R. Carruthers (1939-2020) was a visionary scientist, inventor, engineer, and educator. Now, he is the namesake of a new NASA mission formerly known as GLIDE.

GLIDE Mission: One Step Closer to Exploring the Exosphere

NASA’s Global Lyman-alpha Imager of the Dynamic Exosphere, or GLIDE mission, passed a mission review on January 13, 2021, moving the mission into its next phase with a target launch readiness date of 2025.

The layers of Earth's atmosphere: Earth, 6,400 km radius. Troposphere, 1 to 10 km. Stratosphere, 10 to 50 km. Mesosphere, 50 to 85 km. Thermosphere, 85 to 500 km. Exosphere, 500 to 10,000 km. Interplanetary Space, Beyond 10,000 km
GLIDE will survey the exosphere, the outermost layer of Earth’s atmosphere. The exosphere is seen here in this illustration that shows the layers and their distance from Earth. Credits: NASA’s Goddard Space Flight Center/Mary Pat Hrybyk-Keith

The review, Key Decision Point C, evaluated the mission’s preliminary design and project plan to achieve launch by its target launch readiness date. With the successful review, GLIDE now moves into phase C, which includes the final design of the mission and building of the instruments.

GLIDE will survey the exosphere, the outermost layer of Earth’s atmosphere. GLIDE is the first mission dedicated to charting changes there. It seeks to answer basic questions about the nature of Earth’s exosphere, like its shape, size, and density, and what causes them change over time.

The little-understood exosphere constantly changes in response to space above and Earth below. This region is made almost entirely of hydrogen that mainly comes from methane or water in Earth’s oceans, which is broken down by sunlight and slowly rises to this hinterland between Earth’s atmosphere and space. Hydrogen then leaks from the exosphere, joining the sea of space. The exosphere stretches from about 310 miles above the surface to at least halfway to the Moon.

The exosphere plays an important role in Earth’s response to space weather, the changing conditions in space driven by the Sun. That weather can impact our technology, from satellites in orbit to communications signals in the upper atmosphere or power lines on the ground. During space weather storms, the exosphere experiences huge spikes of energy and mediates Earth’s recovery from these disturbances. GLIDE will help us better understand the fundamental physics of our atmosphere and improve our ability to predict the impacts of the Sun’s activity.

Studying Earth’s atmosphere, which makes life possible on our home planet, builds our understanding of atmospheres throughout the universe. GLIDE will observe the natural process of atmospheric escape, which occurs slowly at Earth. Atmospheric escape played an important role in the story of Mars’s atmosphere, where it siphoned water from the planet’s surface. This process also happens outside the solar system and impacts the habitability of exoplanets, shaping NASA’s search for life.

The solar wind soaring toward Earth
The GLIDE mission will provide insights into how Earth’s exosphere is influenced by changes in space, including the solar wind, shown here flowing from the Sun in this illustration. Credits: NASA

Orbiting the Sun at Lagrange point 1 (a gravitational balance point between Earth and the Sun), GLIDE will have the perfect vantage point to image the entire exosphere. At this distance, 1 million miles from Earth, GLIDE’s field of view around Earth will reach more than halfway to the moon – crucial for documenting the full extent of the exosphere and its changes.

GLIDE will ride to space along with IMAP, the Interstellar Mapping and Acceleration Probe, which will explore the boundaries of the heliosphere, the bubble that is inflated by the solar wind and surrounds the Sun and planets. GLIDE is a vital addition to NASA’s fleet of heliophysics satellites. NASA Heliophysics Division missions study a vast, interconnected system from the Sun to the space surrounding Earth and other planets to the farthest limits of the Sun’s constantly flowing streams of solar wind.

Led by University of Illinois Urbana-Champaign, GLIDE will provide key information about the dynamics of Earth’s outermost atmosphere and how, in turn, this region interacts with this complex space system at large.