Mission GLIDE: a step closer to exploring the exosphere – WeForNews
NASA’s Lyman-alpha Global 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 review, Key Decision Point C, assessed the mission’s preliminary design and project plan to achieve launch by its launch readiness target date. With the review passed, GLIDE is now moving into Phase C, which includes final mission design and instrument construction.
GLIDE will study the exosphere, the outermost layer of the Earth’s atmosphere. GLIDE is the first mission dedicated to mapping changes there. It seeks to answer fundamental questions about the nature of the Earth’s exosphere, such as its shape, size and density, and how they change over time.
The little-understood exosphere is constantly changing in response to the space above and the Earth below. This region is composed almost entirely of hydrogen, mostly 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. The hydrogen then leaks out of the exosphere, joining the sea of space. The exosphere extends 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. This 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 energy spikes 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 solar activity.
Studying the Earth’s atmosphere, which makes life possible on our planet, enhances our understanding of atmospheres throughout the universe. GLIDE will observe the natural process of atmospheric escape, which occurs slowly on Earth. Atmospheric escape played an important role in the history of Mars’ atmosphere, where it siphoned water from the planet’s surface. This process also occurs outside the solar system and impacts the habitability of exoplanets, shaping NASA’s search for life.
Orbiting the Sun at Lagrange Point 1 (a point of gravitational equilibrium between the Earth and the Sun), GLIDE will have the perfect vantage point to image the entire exosphere. At this distance, 1 million kilometers from Earth, GLIDE’s field of view around the Earth will reach more than half the Moon, which is crucial for documenting the full extent of the exosphere and its changes.
GLIDE will soar into space with IMAP, the Interstellar Mapping and Acceleration Probe, which will explore the limits of the heliosphere, the bubble which is inflated by the solar wind and which surrounds the Sun and the planets. GLIDE is a vital addition to NASA’s fleet of heliophysical satellites. NASA’s Heliophysics Division missions study a vast, interconnected system extending from the Sun through space surrounding Earth and other planets to the farthest limits of the solar wind currents that constantly flow from the Sun.
Led by the University of Illinois at Urbana-Champaign, GLIDE will provide key insights into the dynamics of Earth’s outermost atmosphere and how, in turn, this region interacts with this complex space system as a whole. .