orbiter (Viking)![click to hear](/images/speaker.jpg)
Part of the probe that flies over a celestial body before placing itself in orbit around the latter and studying it; the two Viking orbiters were launched in 1975.
thruster engine ![click to hear](/images/speaker.jpg)
Machine that burns a liquid fuel mixture, thereby providing thrust.
star tracker ![click to hear](/images/speaker.jpg)
Instrument that serves to direct the probe, in Viking’s case pointing it toward the star Canopus.
solar panel ![click to hear](/images/speaker.jpg)
Power supply device that converts solar energy into immediately usable electrical energy.
infrared thermal mapper ![click to hear](/images/speaker.jpg)
Instrument used to analyze the surface and atmosphere of a celestial body by measuring its temperature variations.
camera ![click to hear](/images/speaker.jpg)
Captures thousands of images, thereby providing an overall view of the celestial body.
attitude control thruster ![click to hear](/images/speaker.jpg)
Small rocket engine that directs the orbiter to the desired position.
low gain antenna ![click to hear](/images/speaker.jpg)
Secondary antenna used to communicate with Earth when the high gain antenna cannot be used.
high gain antenna ![click to hear](/images/speaker.jpg)
Principal antenna pointed toward Earth to transmit large quantities of scientific data as well as photographs.