Allan McDonald, a NASA contractor, refused to approve the Challenger launch in 1986 due to safety concerns, and later exposed a cover-up by NASA officials. His actions were seen as heroic, and he continued to advocate for ethical decision-making throughout his career. McDonald's story serves as a reminder of the importance of prioritizing safety and ethics in high-stakes decision-making. He passed away at the age of 83, leaving behind a legacy of integrity and courage.