A lawsuit was filed in Sacramento County Superior Court last week challenging the validity of a Democratic Congressional candidate’s stated occupation on the ballot.

José Hernandez, who worked at NASA for 10 years and is challenging Rep. Jeff Denham (R) in the redrawn 10th district, will have “Astronaut/Scientist/Engineer” listed next to his name on ballots this year unless the challenge is successful. The Sacramento Bee reported that the lawsuit argues Hernandez must list his current occupation, which no longer includes astronaut.

The newspaper further reported that the law firm that filed the suit, Bell, McAndrews & Hiltachk, has done work in the past for Denham’s campaign and has other GOP ties, including to the state party.

To combat the challenge, the Hernandez campaign Monday released the candidate’s résumé, and Hernandez described in a statement how in 2009, he “went into space onboard Space Shuttle Discovery to the International Space Station.”

“I have directed my campaign to vigorously defend against these charges and look forward to getting more opportunities to talk about my life story with Californians,” Hernandez said.