NASA Spacecraft Set for Uncontrolled Reentry, Small Risk of Debris Reaching Earth

A retired NASA spacecraft is expected to make an uncontrolled plunge back into Earth’s atmosphere as early as Tuesday evening, potentially years earlier than originally predicted.

Scientists say most of the spacecraft — known as Van Allen Probe A — will burn up during reentry. However, NASA says a small number of components could survive the intense heat and reach the ground.

The 1,323-pound spacecraft is projected to enter the atmosphere around 7:45 p.m. Eastern time, though experts note there is about a 24-hour window of uncertainty around that estimate.

NASA says the odds of a piece of debris harming a person are extremely small — about 1 in 4,200.

Van Allen Probe A was launched in 2012 alongside a twin spacecraft to study the powerful radiation belts that surround Earth. These belts contain high-energy particles trapped by Earth’s magnetic field and play an important role in shielding the planet from harmful cosmic radiation and solar storms.

The mission lasted far longer than originally planned, with both spacecraft continuing to collect valuable data about space weather until 2019 when they ran out of fuel.

Mission planners originally expected the probe to fall back to Earth around 2034. However, increased solar activity during the current solar cycle caused the upper atmosphere to expand slightly, creating more drag on the spacecraft and pulling it out of orbit sooner than expected.

NASA engineers had planned for the spacecraft’s eventual return to Earth from the beginning, positioning it so atmospheric drag would eventually bring it down instead of leaving it drifting in orbit where it could collide with other satellites.

Experts say debris reentries like this are relatively common. On average, pieces of space hardware return to Earth about once a week, though most burn up before reaching the surface.

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