It was meant to land on Venus in 1972 at the height of the first space race. But "Cosmos 482" failed to leave Earth's orbit and has been "parked" up there ever since. 

Now, 53 years later, this Soviet-era Venera mission lander is expected to re-enter Earth's atmosphere and come down in the Atlantic Ocean.

Space debris from rockets and satellites reenters Earth every day. Most of it burns up in the atmosphere and pose little threat to life on the ground. 

But Cosmos 482 is no ordinary space junk.

It was one of two Venera 8 mission spacecraft — the first successfully landed on Venus and sent back data for 63 minutes before dying due to the harsh surface conditions. 

But the other probe — that became known as Cosmos 482 — failed to leave orbit and has spent the rest of its life spinning around Earth.

What's special about Cosmos 482?

Venera spacecraft were built to be extremely resilient to Venus's harsh atmosphere and boiling 737 Kelvin (464 degrees Celsius, 867 degrees Fahrenheit) temperature.

For that very reason, Cosmos 482 may survive its Earth reentry.

Venus's atmosphere consists almost entirely of carbon dioxide (~96%), a little nitrogen (~3.5%), and clouds of sulfuric acid. That makes it extremely heavy. 

The lander was designed to withstand 100 units of atmospheric pressure because Venus' atmosphere is 90 times denser than Earth at sea-level at its surface. Earth's atmosphere is mostly nitrogen (~78%) and oxygen (~21%). That makes it cooler, lighter, and easier for objects to pass through.

What are the chances of Cosmos 482 hitting someone on Earth?

Most space debris is tiny:

• >100 million objects are known to be larger than 1 milimeter (.04 inches) in diameter
• 500,000 objects are between 1 and 10 centimeter (between .4 and 3.9 inches)
• 25,000 objects known to be larger than 10 centimeter

But weighing in at 495 kilograms (about 1,091 pounds) and measuring 1.17 meters in diameter, Cosmos 482 is far larger than the average piece of space debris. 

If it landed on the ground, rather than in the ocean, it could threaten life. 

In addition, its reentry is "uncontrolled", meaning it cannot be steered from the ground. 

Calculations and observations about its descent can only be made in real-time, but the European Space Agency notes that Cosmos 482's "smooth aerodynamical shape" may allow engineers to make reasonably accurate calculations as it falls to Earth. 

In any case, the annual risk of a person being injured by space debris is thought to be less than 1 in 100 billion — getting struck by lightning is more likely.

Groups such as The Aerospace Corporation and EU Space Surveillance and Tracking regularly track objects reentering Earth's orbit. They predict Cosmos 482 will reenter in the early hours of May 10 (UTC).

 

Return of a Venera Era?

Russia plans to launch a new, long-term mission to Venus, known as Venera-D or Venera 17.

As the name suggests, it would be a return to those earlier missions. There were 16 Venera missions between 1961 and 1983 and not all failed — the first to successfully land on Venus was Venera 3 in 1966.

Indeed, it was the first spacecraft to ever reach another planet. 

As of November 2024, Russia is targeting the early 2030s to launch Venera 17. 

Other missions to Venus — the United States' "Veritas," India's "Venus Orbiter Mission" and Europe's "Envision" — also hope to launch.

Edited by: Matthew Ward Agius