lander (Viking)
Spacecraft designed to touch down on the surface of the celestial body so as to study it.
radioisotope thermoelectric generator 
Device that supplies electrical power; converts the heat released by the radioactive decay of a substance it contains into electricity.
collector head 
Shovel used to collect soil samples, which are analyzed on-site.
UHF antenna 
Antenna used to establish radio contact with the orbiter.
shock absorber 
Piece of equipment deployed to cushion the impact when the lander touches down.
propellant tank 
Place where fuel for the descent engines is stored.
high gain antenna 
Principal antenna pointed toward Earth to transmit large quantities of scientific data as well as photographs.
camera 
Two cameras make it possible to obtain three-dimensional color images of the celestial body’s surface.
terminal descent engine 
Rocket engine that allows the lander to slow down before it touches the ground.
temperature sensor 
Instrument that measures the surface temperature of the celestial body.
furlable boom 
Mobile extension arm serving to dig into the soil and collect samples.