• The sun emits high quantities of radiation
• Earth's atmosphere protects everything on Earth from most of the sun's harmful radiation
• In space, where there is no atmosphere, satellites are not protected
• Satellites must use materials resistant to radiation to cover instruments sensitive to radiation
• Engineers use materials that absorb highly charged, radioactive particles to cover the instruments
• Many heavy metals, such as lead, absorb radiation
• Lead is very heavy, very durable, and very inexpensive
• Lead is used when x-ray photographs are taken, to protect patients and x-ray technicians from radiation