Building the Interplanetary Internet

sighted writes "Internet pioneer Vint Cerf, now a Google VP, is leading a NASA effort to create a permanent network link to Mars within the next two years. As Cerf outlined in a recent talk, the 'InterPlaNet' protocol is designed to handle the delay caused by interplanetary distances. A signal traveling between the Earth and Mars can take up to 20 minutes."

Comments

Re:Open protocol

[Leif_Bloomquist]

Actually, the majority (at least recently) use CCSDS

Current limits of technology

[Valdez]

Now, IANACG, so check my math. ;)

Mars is, roughly, between 50 and 250 million miles away from earth, depending where we are in our solar orbits. Recently, the closest it's been in a long while is nearly 35 million miles (back in 2003 according to the Intertron)... but the distance swings rapidly as we race around our orbits... it can go from 40 million to 200 million in the space of a few months. I'm using 50 million as a rough average for the sake of illustration.

Given the speed of light, as fast as we think we can go, is *only* 670 million mph... that means the fastest one way trip we think anything can do is still going to take 4.5 minutes... it'll be better when it's closer (just over 3 minutes) and worse when it's on the opposite side of the sun (22 minutes)... and remember thats just one way!

Even if we plant a colony on mars, you won't be seeing ms ping times between earth.sol and mars.sol until there a breakthrough in our understanding of physics and we figure out how to go faster than the speed of light.

For those who didn't want to bother to read this post, if you want to play Halo XXV on a Mars server, you'll need to figure out a way to communicate with that installation at superluminal speeds.

Re:talking without delays using quantum entangleme

[mhall119]

You can transmit information this way, but not faster than light.

The problem is that whenever you observe one atom, the super-position collapses instantaneously for both. That means the receiver needs to know that the sender has already measured the atom on the sending end before observing their atom on the receiving end, this would have to be done by a standard, non-FTL signal. You also have the problem of not being able to collapse the super-position into a specific value (say 0 or 1), so while the receiver would know what state the sender's atom is in, that state is a random value (0 or 1), so no data is actually conveyed.

The first problem may be overcome with some time-based scheme, where the sender and receiver have syncronized clocks, and have agreed at what time the sender will measure his atom. The problem with random waveform collapse, however, would be harder to overcome, though I think the quantum computers in recent articles have managed to make it slightly less-random.