NASA DTN Protocol: How Interplanetary Internet Works 109
First time accepted submitter GinaSmith888 writes "This is a deep dive in the BP protocol Vint Cerf developed that is the heart of NASA's Delay-Tolerant Networking, better known as DTN. From the article: 'The big difference between BP and IP is that, while IP assumes a more or less smooth pathway for packets going from start to end point, BP allows for disconnections, glitches and other problems you see commonly in deep space, Younes said. Basically, a BP network — the one that will the Interplanetary Internet possible — moves data packets in bursts from node to node, so that it can check when the next node is available or up.'"
Re:Why are we wasting money on this? (Score:5, Insightful)
This is where you're completely wrong. Having a network infrastructure that extends outside of our planet (an extranet if I ever heard one!) is a requirement for being able to do things like set up bases and control robotic devices remotely. What we're doing is setting the groundwork for more than one user or group to both control and receive the telemetry from whatever mechanized device we send outside of our own atmosphere! This is huge!
Consider this: We send a basic construction rover and a 3D printer to Mars. Both are controlled by DTN/BP. We can send the 3D printer blueprints for parts and assembly instructions to the construction rover. That would allow us to build up an infrastructure before we even get there and monitor it by adding parts on an as-needed basis. It would allow us to do so cheaper as well, as things can be sent in smaller chunks, and some of it could be manufactured on the fly on site. Doing this using any of the older protocols or even proprietary mechanisms could make things much more complicated, especially if you decide to handover control or add members to a project you've already started.
Re:Repeater/router stations (Score:4, Insightful)
Actually, the DSN model would work fine for a manned mission to Mars. You're never actually behind the Sun (well it might be possible, but it would be for less than a day). There is an issue where the Sun-Earth-Probe angle drops down to around 3-degrees (so, close to behind the sun), because of radio interference from the sun, but thats about a week long period that you could probably get away with. The biggest cause of comm issues at Mars is Mars itself. Fortunately, all orbiters have an Electra package that allows them to act as relays for each other and for surface assets.
Relay systems are actually more useful in the Earth-moon system at this point. A Lagrange point relay would be important for a far-side base on the moon, or a lander on that side. Earth orbit is where the biggest need for relays is, because the Earth is always in the way for LEO assets. Thats why we have TDRSS.
The biggest issue right now is simply the load on the DSN. Its underfunded and its hard to get enough time on it.
Re:Why are we wasting money on this? (Score:4, Insightful)
Better anticipate on the things you want to do on Mars, than to send over raw materials and a 3D printer, and think... "gosh, what shall we put together today?"
It's more like "gosh, what broke today?"
Assuming a 3D printer could work on Mars (no idea if that's possible), you could use it to greatly increase efficiency. Instead of sending over 2 or 3 of every possible item that might break or wear out, you could just send over 2 or 3 3D printers, and use them to replace broken tools as necessary. (Including, of course, worn-out 3D printers ;^))