The orbiter's radio operates in the X-band of the radio spectrum, at a frequency of around 8 gigahertz. That means that the electromagnetic carrier wave -- onto which the data is modulated -- oscillates at 8 thousand million cycles per second. For comparison, your radio at home is designed to receive signals from AM stations in the range of 535 - 1,700 kilohertz, and from FM stations in the range of 88 - 108 megahertz.
Now, here's a question: If you could make an electromagnetic wave that oscillates at 500 Terahertz -- that's 500 million million cycles per second -- what would you have? Answer: Visible light! And you produce these amazing waves every time you flip on a light switch!
|Antennas||for transmitting and receiving commands|
|Amplifiers||for boosting the power of radio signals so that they are strong enough to be received at the Deep Space Network antennas|
|Transponders||for translating navigation and other signals from the orbiter|
Also on board is Electra, a UHF telecommunications package that is one of the engineering instruments providing navigation and communications support to landers and rovers on the surface of Mars. Electra allows the spacecraft to act as a relay between the Earth and landed crafts on Mars, which may not have sufficient radio power to communicate directly with Earth.