Republican U.S. Sen. Susan Collins has her first challenger for the 2026 election cycle: Phillip Rench, a former senior engineer for Elon Musk’s SpaceX, who lives in Waterboro.

Phillip Rench is an independent candidate for U.S. Senate. Photo courtesy of Phillip Rench

Rench is a 37-year-old board member of the Maine Space Corp., a quasi-governmental nonprofit created by the state Legislature to establish sites to launch small vehicles and satellites into low orbit. He is challenging Collins — who is seeking her sixth term — as an independent, according to paperwork filed with the Federal Election Commission.

Rench, who is originally from southern Maine and owns Ossipee Hill Farm and Observatory, said in an email Friday that he was not ready to discuss his candidacy.

Rench and his wife returned to Maine in November 2019, according to a biography on his farm website. Before that, Rench lived in South Texas, where he worked as a senior engineer at SpaceX’s Boca Chica launch site.

According to his LinkedIn page, Rench contributed to the success of the Falcon 9, Falcon Heavy and Commercial Crew programs during his five years at SpaceX, where he also managed command, control and instrumentation at Launch Pad 39A. He later became site director of the Starship Program in Boca Chica, Texas.

Once the pandemic hit and highlighted the fragility of the supply chains and food security, the couple began growing their own food. And then in spring 2022, the couple established an observatory.

Rench joined the 14-member Maine Space Corp. board in June 2023, after being nominated by Gov. Janet Mills.

Collins, 72, is expected to face a tough election cycle, especially with Donald Trump returning to the White House. She has had a tortured relationship with the man who has remade the Republican Party in his own image. She has not supported any of his three campaigns for president, most recently writing in former South Carolina Gov. Nikki Haley for president last fall.

But Collins has navigated this dynamic before, having warded off a challenge from former Maine Speaker of the House Sarah Gideon in 2020 — an expensive campaign in which Democrats were riding a wave of resistance to Trump and outrage over Collins’ pivotal vote to confirm Brett Kavanaugh to the U.S. Supreme Court, which helped remake the court majority and end federal abortion protections under Roe v. Wade.

Despite being down in polling before the 2020 election, Collins went on to win by 9 points, even as Trump lost the statewide tally by 9 points to Joe Biden.

And Collins, who has been delivering key votes in support of Trump’s controversial Cabinet nominees, such as Robert F. Kennedy Jr. and Tulsi Gabbard, is beginning the cycle with a big fundraising advantage. Through December, her campaign committee reported nearly $2.7 million in cash on hand.

Collins has criticized Musk’s effort to slash federal spending.

So far, no other candidates have yet emerged. Gov. Janet Mills would not rule out a run when asked by the Portland Press Herald/Maine Sunday Telegram in December; she is in her final two years as governor because of term limits.