- published: 17 Feb 2016
- views: 2030
The Deep Space Network, or DSN, is a world-wide network of large antennas and communication facilities that supports interplanetary spacecraft missions. It also performs radio and radar astronomy observations for the exploration of the solar system and the universe, and supports selected Earth-orbiting missions. DSN is part of the NASA Jet Propulsion Laboratory (JPL). Other similar networks include ESTRACK of the European Space Agency, the Soviet Deep Space Network, the Indian Deep Space Network, and the Chinese Deep Space Network.
Tracking vehicles in deep space is quite different from tracking missions in low Earth orbit (LEO). Deep space missions are visible for long periods of time from a large portion of the Earth's surface, and so require few stations (the DSN has only three main sites). These few stations, however, require huge antennas, ultra-sensitive receivers, and powerful transmitters in order to transmit and receive over the vast distances involved.
Deep space is defined in two different ways. The first is when a mission gets sufficiently far from Earth that it is always in view of one of the tracking stations. This distance, about 20-30,000 km or 10-16,000 miles, was the definition used during Apollo and early days of the DSN. The more modern definition is from the International Telecommunications Union, which sets aside various frequency bands for deep space and near Earth use. According to this definition, deep space starts at a distance of 2,000,000 km from the Earth's surface.
Deep Space may refer to:
These stars
No one else can see
Trapeze the height of thee
Vanish as they call
These blues
No one else can hear
No one else can sing
This one for you
Can they, dear?
Things that you do are always with me
When you're laughing
You're always here
What's the use in crying?
It won't matter when we're old
This tear will
Finally fall
Keep your eyes here
When there's no net at all
Where the Lord's face
Is an all-night cafe
There's a woman who will wait on
What you have to say
And your dreams are like marbles
In the pocket of a little boy
And they whisper when you hold them
Like a beautiful girl