An out-of-control NASA satellite has plunged back to Earth after more than 14 years in orbit.
The 590-kilogram (1,300 lbs) Van Allen Probe A crashed down in the East Pacific Ocean near the Galapagos Islands at 10:37 GMT (06:37 EDT) yesterday morning.
NASA says it expected most of the spacecraft to burn up in the atmosphere, but some parts may have survived re-entry and reached the surface.
Due to the remote location, around 680 miles (1,100 km) due south of Puerto Vallarta, Mexico, it is extremely unlikely that the satellite would have harmed anyone.
The space agency had previously estimated that the chances of Van Allen Probe A harming anyone at all were around one in 4,200.
Dr Marco Langbroek, an expert satellite tracker, says the re-entry fireball was detected by the US Space Force, likely with a military infrared early warning system.
Dr Langbroek adds that the re-entry side had been particularly difficult for space agencies to predict due to the satellite’s highly elliptical orbit.
This means that the probe only slowed down as it briefly dipped into the atmosphere at the closest point of its oval-shaped orbit.
The 590-kilogram (1,300 lbs) Van Allen Probe A (artist’s impression) crashed down in the East Pacific Ocean near the Galapagos Islands at 10:37 GMT (06:37 EDT) yesterday morning
Originally launched for a two-year mission, the Van Allen Probe A and its twin Van Allen Probe B were launched into orbit in August 2012.
For over six years, the twin spacecraft travelled through the Van Allen Belts, the invisible, doughnut-shaped rings of highly charged radioactive particles that surround Earth.
The Van Allen Probes were designed to orbit within this dangerous region, gathering data on how the rings gain and lose particles.
No one had expected that the probes would be able to survive and keep gathering data for more than two years, but both were still delivering scientific insights until 2019.
NASA requires that its spacecraft be safely ‘de-orbited’ at the end of their lifespans so that they don’t orbit Earth as space junk for thousands of years.
That meant the space agency had to use the last of the remaining fuel to push them out of orbit.
Over two weeks, scientists fired the probes’ engines five times, with each two-hour burst burning more than two kilograms (4.5 lbs) of propellant.
This brought the closest point of the orbit from 370 miles (595 km) above Earth down to just 190 miles (305 km), where the friction from Earth’s atmosphere would slowly drag them down.
NASA had originally expected that Van Allen Probe A would re-enter the atmosphere in 2034.
However, these predictions were made before scientists learned how active the current solar cycle would be.
In 2024, studies confirmed that the sun had reached its ‘solar maximum’, a period of unusually intense space weather events such as solar flares and coronal mass ejections.
These events caused Earth’s atmosphere to swell slightly, increasing the atmospheric drag on the craft and pulling it out of orbit much faster than expected.
The probe’s twin, Van Allen Probe B, is not expected to re-enter until after 2030.
The Van Allen Belts help to shield Earth from powerful solar winds and dangerous cosmic rays that could have prevented life from ever forming on the planet’s surface.
However, they also pose a problem for satellites in high orbits and for astronauts, who must pass through these dangerous regions to reach the moon.
While travelling through the Van Allen Belts, astronauts are exposed to high doses of ‘high-energy radiation’, which is far more damaging than the radiation from X-rays.
The probes spent seven years gathering data on the Van Allen Belts (pictured), doughnut-shaped rings of charged particles that surround the planet, before running out of fuel
With the Artemis program now targeting its first crewed lunar mission for April this year, it is critical for NASA to understand the exact shape and structure of these regions.
NASA says: ‘Data from NASA’s Van Allen Probes mission still plays an important role in understanding space weather and its effects.’
‘By reviewing archived data from the mission, scientists study the radiation belts surrounding Earth, which are key to predicting how solar activity impacts satellites, astronauts, and even systems on Earth, such as communications, navigation, and power grids.
‘By observing these dynamic regions, the Van Allen Probes contributed to improving forecasts of space weather events and their potential consequences.’
WHAT ARE THE VAN ALLEN PROBES?
NASA launched the twin Van Allen Probes in 2012 to understand the fundamental physical processes that create this harsh environment so that scientists can develop better models of the radiation belts.
These spacecraft were specifically designed to withstand the constant bombardment of radiation in this area and to continue to collect data even under the most intense conditions.
A set of observations on how the radiation belts respond to a significant space weather storm, from this harsh space environment, is a goldmine.
