Space Station Science Picture of the Day: Speed Limit

Explanation: Somebody up there is a comedian. In
the Unity
node of the International Space Station (ISS), just above
the head of ISS Flight Engineer Nikolai Budarin, hangs a sign:
"Space Station Construction: Speed Limit 17,500 mph."
In metric units: 28,000 km/h.

Seriously, folks, the space station
is a construction
zone. Since the first module (Zarya) was launched in 1998,
spacewalking astronauts have added to the station a science laboratory,
living quarters, a robotic arm, an airlock, solar arrays spanning
125 feet from tip to tip … fifteen
major elements in all. The habitable volume has increased
to 15,000 cubic feet, and the outside surface area of the station
is now so
great that it catches enough sunlight to flare like
a supernova when it flies over backyards on Earth.

Somehow the busy crew also find
time to do scientific
research. They must be moving quickly!

And they are. The ISS circles
Earth once every 90 minutes; each hour the crew travels 17,500
miles or 28,000 km–hence the sign. It’s… well… you know…
astronaut humor.