(Image source from: Nbcnews.com)

An old satellite that NASA launched around 14 years ago to explore Earth's radiation belts is set to come back to Earth on Tuesday. This spacecraft, weighing around 1,323 pounds and called Van Allen Probe A, is predicted to re-enter the atmosphere at around 7:45 p.m. EDT, according to the United States Space Force's estimates. Its return will be uncontrolled, meaning NASA cannot steer or guide its landing. Most of the satellite is likely to disintegrate as it travels through the atmosphere on its way down. However, the agency mentioned in a statement that "some parts are likely to survive the re-entry. " "The chance of anyone on Earth being harmed is low, about 1 in 4,200," stated NASA. "NASA and the Space Force will keep tracking the re-entry and provide updates on predictions. "

There are currently thousands of satellites circling the Earth, providing services like television, internet, communication, and navigation. More than 5,000 satellites are already in space, and this number is expected to grow quickly in the next few years, with many more planned under SpaceX's Starlink project. Objects falling from space is not something new. Each year, more than 100 tonnes of space debris re-enters Earth's atmosphere. Most of it burns up before it hits the ground, which is why these incidents often go unnoticed. If a large number of satellites were to stop working and start falling back to Earth, the first major effect would be the sudden loss of satellite services. Communication systems, internet access, and GPS would be disrupted, impacting navigation, air travel, and global trade. The fall of satellites would not happen all at once. Depending on how high they are and how fast they are moving, some satellites may take years or even decades to return to the atmosphere. When they eventually fall, many parts would still incinerate during re-entry, but some pieces may endure and land on the surface.

Normally, scientists attempt to manage how a satellite falls and aim to steer it toward isolated ocean areas or places without people. If many satellites were to fall uncontrollably, debris could land anywhere on the planet. While oceans occupy most of Earth, some pieces might still hit land and cause harm because of their very high speeds. Nevertheless, the likelihood of this happening is very low. Most of the time, the atmosphere of Earth protects us by burning up many objects before they hit the ground. It's hard to predict exactly when and where a spacecraft that is out of control will fall back to Earth. Things like weather, space conditions, and the changing path of the satellite affect this. For the return of Van Allen Probe A, the United States Space Force has given a possible time frame with a 24-hour uncertainty. This probe was sent into space on August 30, 2012, together with its twin, Van Allen Probe B, by NASA. The purpose of the mission was to explore the Van Allen radiation belts, which are rings of high-energy particles held by Earth’s magnetic field. These belts provide protection for the planet against solar storms, cosmic radiation, and streams of charged particles called solar wind, even though astronauts must go through them when they travel into outer space.

Throughout the mission, the two probes offered valuable information about the radiation belts and even found a temporary third belt that can form during strong solar events. The spacecraft kept functioning until 2019, when they ran out of fuel, resulting in the end of the mission. Scientists originally thought that both probes would fall back into Earth’s atmosphere around 2034. However, increasing solar activity in recent years has led to more atmospheric drag, causing their orbits to lower gradually. While Van Allen Probe A is now expected to return sooner, Van Allen Probe B is probably not going to enter the atmosphere until after 2030.