• An engineer alleges he was sidelined at SpaceX over fears he might "retire or die."

• John Johnson, 62, made the allegations in an essay published on Wednesday on whistleblower site Lioness.

• He wrote that he had "consistently solid" performance reviews and a "quite hardcore" work ethic.

A 62-year-old engineer alleged he was sidelined at SpaceX over colleagues' fears that he might "retire or die."

John Johnson said he had been the victim of age discrimination at Elon Musk's rocket company in an essay published on Wednesday on the whistleblower website Lioness.

Johnson said he has filed a complaint with the Washington State Human Rights Commission. Insider has viewed a copy of the complaint that was provided by Johnson. The commission did not respond to a request for comment from Insider.

Johnson joined SpaceX in 2018 as a principal engineer in optics engineering when he was 58 and received "consistently solid" performance reviews for what he described as his "quite hardcore" work ethic.

He had back surgery in early 2020 and returned to work after just a few days. However, Johnson said in his complaint that he was then stripped of responsibilities that were given to far younger, less experienced engineers – some of whom he was asked to train without explanation.

In his essay, Johnson wrote that one engineer was asked to shadow him because there were fears he might "retire or die."

Despite reporting those comments to human resources and later contacting Gwynne Shotwell, SpaceX's chief operating officer, Johnson said "nothing was done to remedy my situation or restore my job duties."

Johnson said HR told him at a meeting earlier this year that he would be helped to find another role at SpaceX, but no assistance was forthcoming and he resigned in June.

SpaceX did not respond to requests for comment from Insider.

Johnson told Insider in a telephone interview: "SpaceX has this business model of promoting young people, so having someone who's decades older is countercultural. Sometimes I wondered whether they looked at me and thought: 'Wow, this guy is a loser because he hasn't obtained independence and wealth at this ripe old age'."