SpaceX is planning to launch at least three private missions in the coming years, culminating in the first crewed flight of the company's Starship next-generation rocket.
Why it matters: These privately-funded missions — collectively known as the Polaris program — are further evidence that private companies are now occupying a domain once reserved for the wealthiest nations.
Some people don't get COVID despite being exposed to the virus — a mystery researchers are trying to unravel.
Why it matters: Understanding the small cohort of "never COVID" people could lead to new vaccine targets or other protections as the world enters the third year of the pandemic.
