Buzz Aldrin's Apollo 11 Felt-Tip pen sells for $857,600 at auction

The felt-tip pen American astronaut Buzz Aldrin used to repair a faulty circuit breaker during the 1969 Apollo 11 mission has sold for $857,600 at a Sotheby's auction in New York after fierce bidding among five buyers.

The sale also included the broken circuit breaker, with both items coming from Aldrin's personal collection. Sotheby's had estimated the pen's value at between $800,000 and $1.2 million, according to The Guardian.

Aldrin said the incident dates back to July 1969, when he discovered a faulty circuit breaker in the lunar module's ascent engine. The breaker was responsible for supplying the power needed to launch the engine from the lunar surface and begin the journey back to Earth.

The astronauts reported the problem to mission control, but engineers were initially unable to find a solution.

"I wrote in my journal that my heart skipped a beat when I realised the seriousness of the situation before I figured out how to use a felt-tip pen I had with me to push the breaker into place," Aldrin said.

"The pen did the job... we could return to Earth after all," he added.

Aldrin, now 96, is one of only four living astronauts to have walked on the Moon.

NASA plans to return astronauts to the Moon by 2028, while China aims to carry out a crewed lunar landing by 2030.