The link between Earth and spacecrafts relies heavily on fixed or mobile ground
stations. Ground antennas are a key part of the complete microwave receiving system
that includes feeds, low-noise amplifiers, cryogenics, and other microwave components.
The telecommunications links consist of an uplink (command) and a downlink (telemetry).
This uplink/downlink capability enables the sending of commands to and the receiving
of telemetry from spacecraft, permitting the collection of valuable scientific data
generated by on-board science instruments and of data to monitor the performance
of the spacecraft. In addition, these links provide radiometric data to navigate
the spacecraft and to support various radio science experiments.
Using the Google Earth plugin, Space Alliance is able to provide you with several
locations of fixed ground stations. It's not an exhaustive list, but a selection
of what we thought to be the most important and well known ground stations used
for space telecommunications throughout the world.
This is a collection of locations of spaceports and space (operations) centers around
The Lunar near-side, the hemisphere visible from Earth, is occupied by
maria (large, dark, basaltic plains, formed by ancient volcanic eruptions)
on 30 percent of its surface, while the rest is made up of terrae (highlands,
or uplands). As a whole, maria occupy 16 percent of the lunar suface, while terrae
are present on 84 percent. Most of the maria are approximately circular and appear
dark to the naked eye, due to their iron-rich compositions.
The Moon page contains links to some of these locations on the Moon. So we invite
you to enjoy a few of the catanae, dorsa, rimae, terrae on Earth's fascinating natural
A warning, though, might be applicable: the page can load rather slowly. Please
be patient and ignore any alert the browser might produce with the following content:
"A script on this page may be busy, or it may have stopped responding. You can stop
the script now, open the script in the debugger, or let the script continue.".
Hit "Continue" and you'll have to wait no more than 20 seconds on a typical computer.
Display objects in the sky, such as stars, constellations, planets, and galaxies.
When the application switches to Sky mode, the viewport transitions to show the
sky at a point above the camera's current position, as measured from the center
of the Earth (the zenith). The celestial data is mapped onto the inside of a virtual
sphere that surrounds the Earth.
The collection of predefined locations is, of course, limited, but growing constantly.
This page enables you to view detailed imagery of Mars, including 3D terrain. The
plugin uses most of the images which were acquired by missions Mariner 9, Viking
1 and 2, Mars Global Surveyor, Mars Odyssey and Mars Express (a total of 329,240
images on December 15, 2005)
Space Alliance has compiled a list of most interesting locations. As with the lists
above for Earth, Moon and Sky, this list will be continuously widened to include