Featured Classroom: Mrs. Reams's 4th grade class at Rolling Acres Elementary School in Littlestown, PA

Featured Classroom

Sarah Reams wrote to say: "I am a fourth grade teacher in Pennsylvania. My class is currently studying the solar system. Today we had a wonderful conversation in which they brought up very interesting questions. I was hoping you could help us out with some answers."

"How far have humans travelled in space?"

Curious team's answer: Not very far in the grand scheme of things. The farthest a manned spacecraft has ever gone is to the Moon, 238,700 miles. The last moon mission was in 1972, thirty years ago! Since then, no human has been farther than 330 miles from the surface of the Earth.

There are unmanned spacecraft that have gone much farther, such as Pioneer 10 and 11 and Voyager 1 and 2, which are all headed out of the Solar System, billions of miles away.

"How fast do space shuttles and satellites travel?"

Curious team's answer: The Space Shuttle and many satellites travel in "Low Earth Orbit", around 100-200 miles above the Earth's surface. They must go pretty fast, around 17,000 miles per hour. It takes much less fuel to reach Low Earth Orbit than higher orbits, but some higher orbits are very useful. For example, if a spacecraft is 22,223 miles above the Earth's surface, it can orbit the Earth exactly once every 24 hours, so that it stays above exactly the same point on Earth, and is called a geostationary orbit. This is great for communications satellites. The velocity of a geostationary satellite is around 6000 miles per hour.

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