Why NASA spacesuits are white
What do Neil Armstrong, Ed White, and today's ISS (International Space Station) astronauts have in common? They all wore a white spacesuit. And they're not alone. Beyond NASA, space programs in countries like Russia and China also use white suits. Not the colors of the Russian flag or China's iconic yellow and red, just white. That basic color has saved countless astronaut lives. NASA didn't always have white spacesuits. Their very first manned spaceflight featured silver suits, but none of those astronauts actually explored the vacuum of space. And that's the key because out there, spacesuits have to be highly reflective. And the best color for that isn't silver, it's white. Here on Earth, our atmosphere shields us from 77% of the sun's radiation. But astronauts in space don't have that natural shield, which makes them vulnerable to blistering temperatures, severe sunburn, and even cancer-causing cell damage. So to combat that, they wear white suits that reflect the sun's harmful radiation. But those white EVA (extra-vehicular activity) suits aren't the only garment in an astronaut's closet. When heading into space or coming home, NASA astronauts wear a bright orange suit because that loud orange stands out against the blue ocean and sky and is perfect for attracting attention, so if there's a malfunction during landing and astronauts have to abandon ship, so to speak, they need to be easy to spot for rescue crews. That being said, times are changing. Nowadays we have more sophisticated ways of locating astronauts in need of rescue, like GPS trackers and transponders, so space agencies are now free to get creative with their color choices. NASA and other programs are already starting to use other colors like deep blue and mustard yellow. And in the future, they could look a lot different because NASA is heading to Mars. It will be the longest crewed space mission to date, taking as long as three years from start to finish, and during that time, astronauts could suffer from boredom or depression. That's where colorful spacesuits could be useful.
Adapted from https://www.businessinsider.com/why-are-nasa-spacesuits-white-2019-4
Choose the alternative that correctly substitutes countless in the sentence “That basic color has saved countless astronaut lives.” (paragraph 1)
a few
few
too many
some
no