NASA was left “stunned” as a Russian spacecraft came within 10 metres of striking a satellite.
The United States space agency says a collision between the two would have essentially created “bullets” orbiting around the Earth.
Nasa’s deputy administrator Pam Melroy said experts had been “really scared” by the incident on February 28. She said it was not possible to manoeuvre either satellite.
The narrow escape happened when a defunct Russian Cosmos 2221 satellite drifted close to Nasa’s Timed (Thermosphere Ionosphere Mesosphere Energetics and Dynamics) satellite that monitor’s the atmosphere on Earth.
Colonel Melroy, a former astronaut herself, said the two satellites colliding would have been a “monumental issue”.
Speaking at the Space Foundation’s Space Symposium in Colorado, she said: “It was very shocking personally and for all of us at Nasa.
“Had the two satellites collided we would have seen debris generation, tiny shards travelling at 10,000 miles per hour, waiting to puncture a hole in another spacecraft and potentially putting human lives at risk.
“It’s kind of sobering to think that something that’s the size of the eraser on the end of your pencil could wreak such havoc – but it can. We’re all worried about this. Timed really scared us.”
NASA has this weeked launched its Space Sustainability Strategy that aims to better map and monitor satellites and debris. It wants to keep orbits as clear as possible.
Currently more than 10,000 satellites are orbiting the Earth and numbers are set to grow exponentially in future generations.
Some 400,000 satellites have already been approved for low Earth orbit. And Elon Musk’s SpaceX alone is set to launch another 44,000 for Starlink.
Is it believed that, one all of the planned internet constellations are fully operational, there will be 16,000 decaying satellites that will need to come out of orbit, reports The Telegraph.
Nasa scientists Donald Kessler predicted that when enough objects are in low orbit, any collision would set off a chain of reaction that would send the wreckage hurtling at other satellites, breaking them into pieces and releasing more debris. It has become known as Kessler syndrome.
While Nasa said it plans to invest more in detection, tracking and collision avoidance, private companies such as Airbus, Astroscale and ClearSpace are working on spacecraft which can catch dead satellites.
The first tests of the technology to clear space are thought to be on track for within the next two years.