Astronauts have conducted all sorts of experiments in the International Space Station—from observations of microgravity on the human to body to growing space lettuce. But recently, cosmonauts bioengineered human cartilage cells into 3D structures aboard the station, using a device that utilizes magnetic levitation.  The results were recently published in the journal Science Advances. Electrical engineer Utkan Demirci and stem cell biologist Alysson Muotri what removing gravity can reveal about basic biological questions, and how you design experiments to run in space.  Major League Baseball’s season opened to great fanfare last week, amid the pandemic. But 18 players and staff of the Miami Marlins have already tested positive for COVID-19—forcing the team to pause their season until at least next week. Meanwhile, the NBA has quarantined their entire roster in a bubble in the Magic Kingdom in Florida.  Sports reporter Ben Cohen and epidemiologist Zachary Binney talk about the strategies and effectiveness of different leagues as competitive sports attempt to make a COVID-19 comeback.  Ketchup has long been central to American culture. We use it in hot dogs, burgers, fries—and the list goes on. But have you ever wondered why we even call it ‘ketchup,’ or where the condiment came from?   It turns out there are many words related to food—like restaurant, umami, and “rocky road”—that have an interesting science backstory. To trace the origins of these words, Science Friday’s word nerd Johanna Mayer joins John Dankosky to talk about the origins of the word ketchup, and the new season of her podcast ‘Science Diction.’ As American pharmaceutical company Moderna’s COVID-19 vaccine candidate entered Phase 3 of human clinical trials this week—an important step in what is still an early phase of its development—Russia claims a vaccine of its own will be approved for use as soon as mid-August, prompting safety concerns. But questions about vaccines extend far beyond who is first. What happens next for the people around the world waiting for protection from the pandemic? As Science Magazine reports, rich nations have placed hundreds of millions of advance orders for successful vaccines, while poorer countries worry that there will be little left for everyone else. Maggie Koerth, senior science reporter for FiveThirtyEight, discusses this story and more news from the week, including the discovery of 100-million-year-old microbes living beneath the ocean floor.