Mitchell was diagnosed with ALS, a neurological disease that causes muscle weakness and paralysis, in 2018 and had used a wheelchair since 2019.

“For five and a half years, Ken faced a series of awful challenges from ALS,” his obituary stated. “And in truest Ken fashion, he managed to rise above each one with grace and commitment to living a full and joyous life in each moment. He lived by the principles that each day is a gift and that we never walk alone. His life is a shining example of how full one can be when you live with love, compassion, humor, inclusion and community. Ken was an inspirational work of art to all the hearts he touched.”

Among those were his friends and colleagues.

“Rest in peace, Ken. Was just thinking of you,” Ethan Peck, who plays Spock on Star Trek: Discovery, commented on the obituary, using an emoji of the Vulcans’ “Live Long and Prosper” hand gesture.

And Jonathan Frakes, who directed several episodes in the series and played William Riker on Star Trek: The Next Generation, wrote, “One of the best RIP.”