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[[{"type":"media","view_mode":"media_large","fid":"40327","attributes":{"class":"media-image","typeof":"foaf:Image","style":"","alt":"Why won"}}]]We all have questions about space—So why not ask an astronaut? This series of Never Stop Asking "WHY?" includes questions submitted by YOU and answered by the museum's Extraordinary-Scientist-in-Residence—astronaut Dr. David Wolf!
Why won't a regular watch work in space?
Most regular watches actually do work in Space but since the beginning of spaceflight astronauts have usually used the Speedmaster watch. These watches have a lot of functions that astronauts use to set up multiple alarms and different time zones. On the space station, we tend to use Houston, Texas or Moscow/Russian time. We have to pick a time zone to keep everybody working together and synchronized.
The day-night cycle is very different in space because we orbit the Earth every 90 minutes. This means we get 45 minutes of day and 45 minutes of night. Because it takes 90 minutes to go around the earth, there are 16 sunrises and 16 sunsets every 24 hours. These sunrises and sunsets happen very quickly because we are moving so fast and they’re extraordinarily beautiful. So even though we have sunrises and sunsets in space, you don’t want to set your watch or go to bed by them!
In addition to the Speedmaster watch, astronauts can also use a master clock in the spacecraft to set their working hours, meals, and sleep times. Since there are 16 “orbital” days and nights for every regular Day and night on Earth we need to use “Earth time” so our bodies will have a normal circadian rhythm. Our bodies are adapted to function and sleep correctly on a 24 hour Earth day. We are careful to cover the windows of the spaceship while we sleep so we will not be woken up by the sun rises occurring every 90 minutes. And we use bright lights during our work day so we can see during all the nights and our bodies will not feel like it is time to go to bed. We try to eat when people on Earth are eating including a main meal for dinner.
[[{"type":"media","view_mode":"media_large","fid":"40328","attributes":{"class":"media-image","typeof":"foaf:Image","style":"","alt":"NASA watch"}}]]During a spacewalk the rapid sunrises and sunsets are really dramatic and can be very distracting from our work. The temperature can drop by 400 degrees (Fahrenheit) every sunset so we have to adjust our spacesuits to be ready. We also must be very careful to lower our protective visors at every sunrise because the sun is so bright and powerful above the Earth’s atmosphere. Our spacesuit helmets have built in lights so we can see to keep working.
The watches that astronauts take into space are inscribed and are very rare artifacts. I often wear one of the watches that I had in space, and I’ve loaned another one to the museum.
Looking for more Never Stop Asking "Why?" questions? Catch up on all of the past "Why's" on the blog!
