A new book has claimed that Buzz Aldrin was not happy when he learned that Neil Armstrong was selected to be the first astronaut to step foot on the Moon for the Apollo 11 mission. Aldrin even reportedly tried to persuade other astronauts to go against NASA’s mission plans.

Claims regarding Aldrin’s actions prior to the launch of the Apollo 11 mission in 1969 were made by James Donovan, author of the book “Shoot for the Moon: The Space Race and Voyage of Apollo 11.” The book focuses on the details that surrounded the historical mission.

According to Donovan, Aldrin heard about a rumor that Deke Slayton, NASA’s Director of Flight Crew Operations at that time, selected Armstrong to be the first astronaut to exit the lunar module and plant the American flag on the Moon.

Donovan noted that the rumors indicated that NASA decided to go with Armstrong due to his civilian status instead of Aldrin, who previously served as a jet fighter pilot for the U.S. Air Force before becoming an astronaut.

“When Aldrin heard a rumor that Slayton had decided that Armstrong would be the first to walk on the Moon, he was not happy,” Donovan stated, according to Express.

“He also heard that Neil’s civilian status was a reason for the choice – NASA wanted to make a clear statement about the non-military nature of the landing and of the American space program as a whole,” he added.

According to Donovan, NASA’s decision affected Aldrin so much that he even tried to convince the agency’s other lunar module pilots that he should be the first astronaut on the Moon. Apollo 11’s command module pilot Michael Collins, on the other hand, refused to listen to Aldrin.

“Aldrin approached a few other lunar module pilots and used charts and graphs and statistics to show why he, and they, should step out on the Moon before other crewmen,” Donovan stated. “When he tried to discuss it with Mike Collins, Mike cut him off.”

Word about Aldrin’s behavior eventually reached Slayton. The former NASA official immediately explained to Aldrin that the reason why the agency selected Armstrong was simply because of his status as a senior astronaut.

Slayton’s explanation, fortunately, calmed Aldrin. The former astronaut later admitted that the reason why he was affected by the rumors was due to the initial vagueness of NASA’s decision.

“Slayton heard about Aldrin’s evangelizing and decided a talk with him was necessary,” Donovan said. “He explained that since Neil had seniority, it was only right that he be the first.”

apollo 11 landing
Aldrin, Armstrong and Collins on the deck of the NASA Motor Vessel Retriever preparing for water egress training in the Gulf of Mexico. NASA