• The satellite's payload must be protected from things travelling through space - small meteorites (micrometeorites), space junk, charged particles
• The material used to cover the outside of the satellite must be lightweight but strong and resistant to puncture by particles travelling very fast
• Many satellites protect their payloads in small containers that encase just the instruments.
• These containers are always very sturdy
• They can be made out of lightweight steel, mined in Canada, which is also often used as a bicycle frame, or in cars
• Steel refers to many alloys of iron and 0.1-1.5% carbon (often with other metals like chromium (for stainless steel), manganese, nickel, etc.)
• Steel is very heavy
• Another possible material is high core matrix aluminum which must be imported
• Aluminum is very durable and often used in aircraft bodies, trains, window frames, housing siding, and pots and pans