Parts of NASA’s Van Allen Probe Expected to Reenter Earth’s Atmosphere
Scientists are keeping a close eye on the re-entry into Earth’s atmosphere of debris from one of NASA’s pioneering space exploration projects. Pieces from NASA’s Van Allen Probes, a pair of spacecraft launched to explore Earth’s radiation belts, are forecasted to re-enter Earth’s atmosphere after years in orbit. While most of the pieces are expected to burn up in Earth’s atmosphere, it is a growing problem of space debris and what happens after a mission is over.
A Historic Mission
The probes were launched in August 2012 with the main goal of exploring the Van Allen radiation belts, which are two significant regions filled with high-energy charged particles and are contained by the Earth’s magnetic force. These regions are significant threats to both satellites and astronauts passing through these regions.
The twin probes were launched with the main goal of helping scientists understand more about the dynamic nature of these radiation belts during solar storms and other space weather occurrences. The mission was later renamed the Van Allen Probes in honor of Dr. James Van Allen, who discovered these radiation belts in 1958.
During their mission, the probes managed to achieve significant milestones. Scientists were able to understand that these radiation belts are more dynamic than they had earlier thought. In fact, there were instances when scientists were able to detect the presence of a third radiation belt, which had never been seen before.
Mission End and Orbital Decay
Finally, after almost seven years of gathering critical scientific data, they officially ended the mission of the Van Allen Probes in 2019. Once the mission was over, engineers shut down the spacecraft and left them to orbit in space.
Unlike other satellites that orbit in higher orbits and stay in space for decades and even centuries, the Van Allen Probes orbit in an elliptical orbit that decays over time due to atmospheric drag. Even at an altitude of several hundred miles above Earth’s surface, the thin outer atmosphere of Earth slowly draws satellites closer to Earth.
As the spacecraft get closer to Earth, friction increases. This eventually leads to reentry, where the spacecraft falls back to Earth.
According to NASA and other space organizations, a part of one of the probes is expected to re-enter Earth’s atmosphere in the near future due to further decay of its orbit.
Courtesy of SDASM Archives (Flickr CC0)What Happens During Reentry
When a satellite re-enters Earth’s atmosphere, it is exposed to extreme heat generated due to friction with atmospheric gases. During this process, the satellite’s components are exposed to thousands of degrees Fahrenheit, resulting in most of them melting or vaporizing before even reaching the ground.
According to experts, in most satellite re-entry cases, 80 to 90 percent of a satellite’s structure is burned up. Lighter satellite components such as aluminum, wiring, and solar panels are completely vaporized during this process.
However, in a few satellite re-entry cases, satellite components such as metal and fuel tanks may survive this extreme heat and reach the ground. Nevertheless, even in this case, there is a negligible possibility of damage being done to human property since 70 percent of Earth’s surface is covered with water, and a large percentage of that is not inhabited.
For the Van Allen Probe satellite, NASA engineers have specifically designed it in a way that most of its components would burn up harmlessly in Earth’s atmosphere.
Monitoring by Space Agencies
For example, the National Aeronautics and Space Administration (NASA) and the U.S. Space Force often monitor objects orbiting the earth, such as satellites, rockets, and space debris. By using radar, scientists can calculate the exact time of re-entry into the atmosphere.
Nevertheless, it is not always easy to accurately determine the exact time and place of re-entry. This is because small changes in atmospheric density, solar activity, and speed can affect the exact time of re-entry, which may be delayed by several hours or even days.
Therefore, authorities can only give an estimated time for the debris to fall, but not the exact location.
Growing Concerns About Space Debris
The Van Allen Probe’s reentry coincides with the rising concern of experts about the increasing amount of debris in Earth’s orbit. Thousands of satellites, rocket stages, and debris from past collisions are orbiting Earth.
According to the European Space Agency, there are tens of thousands of traceable pieces of space debris, along with millions of other smaller debris that cannot be monitored. Even small debris can cause damage to satellites or other spacecraft if they are traveling at orbital velocities.
While some satellites are intentionally brought back to Earth to safely dispose of them, some old satellites are naturally brought back to Earth once their orbits decay.
Scientific Legacy of the Van Allen Probes
Even though they would eventually return to Earth, the Van Allen Probes left a lasting legacy in the field of space science. The mission offered some of the most detailed data ever collected about Earth’s radiation environment.
The data collected by the probes is still used to further understand space weather, which can affect communications, satellites, GPS, and even power grids here on Earth.
The mission also helps engineers create a safer spacecraft for astronauts by further understanding the effects of radiation in near-Earth space.
Looking Ahead
The reentry of parts of the Van Allen Probe is a reminder that even pioneering scientific missions come to the end of their life expectancy at some point. Although it is likely that the spacecraft itself will burn up in the Earth’s atmosphere, it is clear that the knowledge it helped us gain is at the heart of modern space science.
For scientists and engineers, it is an example of how well-designed spacecraft not only help us gain new knowledge but can also come back to Earth at the end of their life expectancy.
As space activity continues to rise with new satellites and missions launching every year, it is likely that satellite design and end-of-life planning will be crucial in keeping Earth’s orbital space safe for future exploration.
By Luis Garcia Jr
A Successful Journalist, Editor, and Media professional for over 8 years, where my focus is to inform the community and the world on current events.
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Featured Image Courtesy NOAA Satelites Flickr Page – Creative Commons License
Inset Image Courtesy of SDASM Archives Flickr Page – Creative Commons License
