to be ready by 2014. All the remaining shuttle missions will be to the International Space
Station, except for one repair mission to the Hubble Space Telescope.
Recent Space Missions
Since the 1986 Challenger disaster NASA has focused on missions without a crew, except for
the International Space Station missions. These recent missions are less expensive and less
dangerous than missions with a crew, yet still provide a great deal of valuable information.
Earth Science Satellites
In recent years, NASA and space agencies from other countries have launched dozens of
satellites that collect data on the current state of Earth’s systems. For example, NASA’s
Landsat satellites take detailed images of Earth’s continents and coastal areas, such as those
inFigure23.33. Other satellites study the oceans, the atmosphere, the polar ice sheets,
and other Earth systems. This data helps us to monitor climate change and understand how
Earth’s systems affect one another.
Figure 23.33: The two images above are from NASA’s Landsat 7 satellite. The left shows
New Orleans and Lake Pontchartrain on April 26, 2000. The right shows the same area on
August 30, 2005, shortly after Hurricane Katrina flooded the city. Dark blue areas in the
city are underwater. ( 6 )
Space Telescopes
Some of the greatest astronomical discoveries—and greatest pictures, like the one inFigure
23.34, have come from the Hubble Space Telescope. The Hubble was the first telescope in
space. It was put into orbit by the space shuttle Discovery in 1990. Since then, four shuttle
missions have gone to the Hubble to make repairs and upgrades. A final repair mission to
the Hubble is scheduled for 2008.