Internet

The first permanent settlement on Mars will be of a size that does not necessarily require a distributed computer network. Nevertheless, there is the need for a mutual communication between people on Mars and people on Earth. The Martian settlement can, therefore, be connected to the terrestrial Internet, which in fact makes it an Interplanetary Internet.

The speed of any communication between Mars and Earth is limited to the speed of light, which results in a delay of 8..20 minutes for one way. Without special buffering the result of a mouse click appears 16..40 minutes later on the screen. The pictures on HTML pages take the same time on top. So, the complete page is displayed after 32..80 minutes.

Concept

The first step can be a single computer and a radio transmitter that is brought from Earth to Mars. On Earth there is a corresponding radio transmitter and a buffered interface to Earth's Internet. Internet access is then possible only during some time windows.

An extension is possible to widen the time windows with additional transmitters on other continents and relay stations orbiting Earth and Mars.

The buffer on Earth side should have some additional functionality:

• Collect all files (e.g. pictures) that are related to a requested HTML page and send them together with the HTML page. This reduces the time from mouse click to complete screen display to 16..40 minutes.
• Reduce solution of pictures if appropriate.
• Compress data stream.
• Add redundancy to the signal to allow data reconstruction for lost bits. The retransmission of TCP data packets is awfully time consuming in this case and should be avoided.

First use cases

• Technology information from Earth to Mars
• Scientific results from Mars to Earth.
• Personal E-Mails in both directions

Open Issues

• What minimal transmitter is required for a radio link from Earth to Mars (surface to surface) ?
• What data rate can be achived by simple technology?
• What time windows exist with a single transmitter on both sides?