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NASA DTN Protocol: How Interplanetary Internet Works

samzenpus posted about 2 years ago | from the in-space-nobody-can-hear-you-click dept.

ISS 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.'"

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First post (5, Funny)

JonWan (456212) | about 2 years ago | (#41949877)

The main problem is the long delay at light speed.

Re:First post (5, Funny)

JonWan (456212) | about 2 years ago | (#41949901)

Holy shit! that just blows the crap out of that joke. All these years on Slashdot and the one time I try to do a first post joke I really get first post.

Re:First post (2, Funny)

SteveFoerster (136027) | about 2 years ago | (#41950001)

Were you measuring light speed in American units instead of metric ones?

Re:First post (2)

JonWan (456212) | about 2 years ago | (#41950421)

Nah, I'm in Texas we use furlongs per fortnight.

Re:First post (1)

stfvon007 (632997) | about 2 years ago | (#41951373)

According to google:
the speed of light = 1802617500000 furlongs per fortnight
Though it may be less for you, since everything is bigger in texas (bigger furlongs = lower speed of light in fpf). Ive been wondering though, since everything is bigger in texas, does that mean everything is redshifted due to the wavelengths being longer?

As an Alaskan... (1)

Anonymous Coward | about 2 years ago | (#41951717)

I fucking hate that saying.

Sarah Palin is our revenge for you assholes acting like we don't exist.

Re:As an Alaskan... (1)

Thuktun (221615) | about 2 years ago | (#41954245)

I've always thought things got smaller in the cold.

Re:As an Alaskan... (0)

Anonymous Coward | about 2 years ago | (#41954915)

I fucking hate that saying.

Which is why you should say "Well maybe we'll cut Alaska in half and make Texas the third largest state."

And as a Montana resident, I like to refer to a Steinbeck quote:
"Montana is the kind of place Texas would be, if Texas was actually the way Texans describe it."

Re:First post (1)

bkcallahan (2515468) | about 2 years ago | (#41958113)

Yes, just look at an election map.

Re:First post (2)

CanEHdian (1098955) | about 2 years ago | (#41950553)

There's no need to create confusion about that; how about being DTN compatible?

it’s a protocol called Delay-Tolerant Networking, better known as DTN.

NASA’s experimental Disruption Tolerant Networking (DTN) protocol

Re:First post (0)

Anonymous Coward | about 2 years ago | (#41950899)

It is more than that. I'd say they should go as far as caching most if not all of the internet as often as they can. When dial up was the most common method, ISPs would (could still be, but doubt it en mass) cache popular web pages to help speed up their service, and not have to deal so much with outside lines.

Simply create a local library of the internet. Information may change often, but it doesn't change that often. At least nothing that world shattering would happen off world that would require post-light speed information exchange. I'd go so far to say that even within a system, a hour latency wouldn't be a harsh matter.

Re:First post (0)

Anonymous Coward | about 2 years ago | (#41955385)

The joke would have been funnier if you actually hadn't gotten first post. Can somebody modify the reply to 4? Or move it down in the thread to keep the 5? I feel that would be more beneficial humor-wise for future generations who will marvel at this thread in the centuries to come.

I would also accept an edit of the first post content to "light speed's my bitch, yo"

AC.

Re:First post (0)

Anonymous Coward | about 2 years ago | (#41949951)

They'll need a "Do not invade" flag soon.

Re:First post (1)

canadiannomad (1745008) | about 2 years ago | (#41952125)

Having spent the last 3 weeks in the Galapagos, I can assure you there are long delays and dropouts even in tourist spots here at home(earth)... I do wish someone would implement some better protocol for those locations where speed and reliability aren't up to a reasonable standard. It would definitely help with satellite based ISPs in out of the way locations.. Having a system that would optimize the transaction(automatically send images, js, css despite not requesting it yet..) and automatically re-request lost packets would go a long way to making better connections even here at home when we can't have fiber.

Re:First post (1)

delt0r (999393) | about 2 years ago | (#41955135)

Its probably easier and cheaper to just get/pay/invest in a more reliable network. Don't forget all the software that would need to be DTN aware.

Re:First post (2)

Muad'Dave (255648) | about 2 years ago | (#41955859)

In the old days, we had exactly what you describe with regard to protocol optimization. A company I worked for used VSAT [wikipedia.org] comms to all their stores, and the VSAT hardware would spoof the IP and X-25 protocols on either earthbound end. What went over the sat link was a very optimized protocol tailored for the relatively long double hop delay.

X.25 with big buffers (1)

vlm (69642) | about 2 years ago | (#41949885)

TLDR X.25 with big buffers

Delays, delays (4, Informative)

Immerman (2627577) | about 2 years ago | (#41950411)

The problem is most any terrestrial network protocol expects a minimal signal-response delay between nodes, whereas even a perfectly functioning terabit/s Earth-Mars link would still have between a 6 and 40 minute delay due to the speed of light.

Re:Delays, delays (2)

RDW (41497) | about 2 years ago | (#41950745)

The problem is most any terrestrial network protocol expects a minimal signal-response delay between nodes

RFC 1149 does not assume this, though the current implementation would have to be modified to avoid complete packet loss in a non-terrestrial environment - BF Skinner's work suggests one obvious adaptation:

http://tools.ietf.org/html/rfc1149 [ietf.org]
http://historywired.si.edu/object.cfm?ID=353 [si.edu]

Why are we wasting money on this? (-1)

Anonymous Coward | about 2 years ago | (#41949889)

This is something for private industry to figure out. Why are our tax dollars being wasted on stuff like this when in reality, we have no mechanism to get men past the Moon for the next 20-30 years? Shouldn't we spend tax dollars on stuff that is useful, such as not being beholden to our #1 creditor, China?

We don't need Internet connectivity near Saturn, we need to fix a deficit problem right here on Earth.

Re:Why are we wasting money on this? (5, Insightful)

TheDarAve (513675) | about 2 years ago | (#41950031)

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:Why are we wasting money on this? (1)

kipsate (314423) | about 2 years ago | (#41951019)

Sending a 3D printer to Mars? Are you out of your mind?

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?"

Re:Why are we wasting money on this? (0)

Anonymous Coward | about 2 years ago | (#41951599)

It makes sense if the raw material used for printing can be obtained easily on mars. For a rover, that basically means martian dust. Melting it might yield some form of glass once it cools.

Re:Why are we wasting money on this? (3, Insightful)

Jeremi (14640) | about 2 years ago | (#41951885)

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 ;^))

Re:Why are we wasting money on this? (1)

Archimonde (668883) | about 2 years ago | (#41955983)

You are not thinking creative enough. You can have a 3D printer which of course can print spare parts for itself and have say a robot who can gather materials etc. Of course, the printer can print another 3D printer and another robots so we can infest the Mars in no time.

The only problem is that the printer which can print its own parts must be complicated and of course converting raw materials to printable ink is nigh impossible.

But in any case, imagine the possibilites! It isn't logically impossible, there are technical difficulties but not impossible barriers.

Re:Why are we wasting money on this? (0)

Anonymous Coward | about 2 years ago | (#41954975)

Sending a 3D printer to Mars? Are you out of your mind?
Better anticipate on the things you want to do on Mars

What we want to do on Mars, is have the ability to remotely manufacture shit so we don't have to fly it all the way the fuck out there from the Earth.

than to send over raw materials and a 3D printer

Send the raw materials? Are you out of your mind?

Re:Why are we wasting money on this? (0)

Anonymous Coward | about 2 years ago | (#41951907)

That in itself is probably one of the smartest things we can do, assuming we can overcome tech hurdles like an energy source, mining and processing local resources into something usable.

I wouldn't mind seeing more work in 3D printing. One can picture some interesting composites if a 3D printer could insert metal bits and plastic ones at the right places. Then there are substances such as nanotubes or carbon fiber which would need a form of lattice. Perhaps the 3D printer would make the the actual factory is needed to make the intricate parts to make a usable encampment.

As for the OP, every time I see someone whine about space being "private only", I die a little bit.

Governments brought us the Hoover Dam, the Autobahn, the Interstate highway system. Private industry brings us McDonald's, Love Canal, and Justin Bieber.

Re:Why are we wasting money on this? (0)

Anonymous Coward | about 2 years ago | (#41950129)

Yawn... 2/5.

Troll harder next time.

Re:Why are we wasting money on this? (1)

aaaaaaargh! (1150173) | about 2 years ago | (#41950275)

Well, the protocol could also be useful on earth, for example when there is a huge catastrophe. Besides, basically the whole Internet has been developed by government agencies at the expense of tax payer money. If the Internet had been developed by private industry, we'd all have $49.95/month AOL network access over modem that would provide about 8 network-capable applications with pay-per- use extra services.

Re:Why are we wasting money on this? (5, Informative)

Immerman (2627577) | about 2 years ago | (#41950341)

You mean the same way private industry invented the current internet protocols? Hint - they didn't. I think the point is while we don't have people out beyond the moon we do have an ever-increasing number of *machines* out there, every one of them equipped with a custom communication mechanism rendering them incapable of communicating with each other. If we work out a nice robust, standardized protocol now then not only do future probe developers (also mostly government funded) not need to spend time and money developing a new communication protocol, but future probes have the potential to intercommunicate with each other as well. One obvious application would be using "healthy" probes to act as relay stations for probes whose antennas or power supplies have degraded to the point that they no longer have the necessary gain to reliably communicate with Earth, but are otherwise operational. Or to route signals along clean signal paths where much lower transmission power is necessary - for example if a probe is in conjunction with Jupiter, the sun, or some other powerful radio source it is presumably much more difficult for Earth to receive a clean signal directly from it (or contrariwise if it was Earth in conjunction from the probe's perspective) Beyond that, who knows? Certainly few people envisioned most of the current uses of the internet when the protocols were being developed.

Oh, and we have plenty of mechanisms to get people past the moon, just getting into high orbit puts us half way to anywhere in the solar system, and it's actually easier to reach Earth's L3- and L4-point asteroid fields than it is to reach the Moon, we just haven't really had the motivation to do so yet. We could even get to Mars pretty easily with current technology if we wanted to, though arranging a return trip complicates things a little since we'd be down at the bottom of a gravity well again - i.e we'd need to either carry a staggering amount of extra fuel along, or establish a refueling base there. There'd be no shortage of volunteers for a one-way trip though, *especially* if the plan was to set up a sustainable base which would eventually (after years/decades) enable round trips to begin.

Re:Why are we wasting money on this? (0)

Anonymous Coward | about 2 years ago | (#41954179)

"You mean the same way private industry invented the current internet protocols? Hint - they didn't."

Yawn. That is such a tedious bromide. I wonder if it will ever fall out of favor.

Were it not for the monopoly on labor, were it not for the monopoly on production, and were it not all done with money siphoned from the private sector, inventing network protocols is not even remotely(heh) the exclusive realm of governments. A man is not going to reinvent the wheel when a gang of thugs steal his money and pay people to do it. A man is not going to be able to compete with the free evil of stolen money used to fund such projects. So what? It does not follow that because something was achieved under an economic condition of violence that it could not be done(and be done better) in conditions of peace. It does not follow that the way it was done through theft is the standard by which to judge how well society could do it voluntarily. It would be like pointing to some monument created by slavery and smugly proclaiming that private industry couldn't do that; it ignores the fact that peaceful cooperation certainly can achieve better than coercion but it also begs the question if such an endeavor is what society really wants at that given time.

Re:Why are we wasting money on this? (0)

Anonymous Coward | about 2 years ago | (#41954603)

Hey psst... Ayn Rand called, she wants her delusions back!

Re:Why are we wasting money on this? (1)

Mabhatter (126906) | about 2 years ago | (#41954689)

What I've seen the Ayn Rand types want everything to be a meritocracy. The average engineer really only invents things on the scale of "years". The number of "landed & monied" inventors like Thomas Jefferson is considerably less than 1%. The average engineer has to have a "day job"... That means you invent what the boss is paying you for. For every engineer threatening to "go Galt" there ten more hungry, eager kids out of school that will do what the boss ASKS. It's is also the reason we don't have tech unions... We know we're glorified "boys with toys" and far more replaceable than we like to admit.

Back on topic, in the 1960's AT&T had the best engineers in the world... Working to make your phone bill "do more things". UNIX was entirely built to make sure AT&T could recoup charges from businesses that wanted to use its new computers. This is the same AT&T that demo'd video phones and watch phones In the 1960s... Still banning those features from phones right now. BECAUSE THEY CAN'T FIGURE OUT HOW TO PROFIT.

Fortunately there was still enough "blue sky" research going on at the tech titans that when baby-ARPA came looking for sci-fi projects the suits were happy to collect the Federal money but not quite clever enough to understand just what the research going on was about to pull off. In fact, it still took 20 more years for the full effect to be realized...

Re:Why are we wasting money on this? (0)

Anonymous Coward | about 2 years ago | (#41955003)

Yet despite your claims, there are plenty of people in the private sector who are doing exactly what you claim they are not. Go jerk off on your Ayn Rand novels somewhere else.

Re:Why are we wasting money on this? (1)

DNS-and-BIND (461968) | about 2 years ago | (#41955179)

Hmm, you must have been on a different Internet than I was. Do we remember when .com sites were considered poison and site admins refused to route traffic for them? Because they were profit-driven and diametrically opposed to the government-run version of the Internet? I do.

You could fill a book with communications protocols which never took off due to not being widely adopted. Indeed, many books of this type exist. You could even fill a book with communications protocols whose creators were vehemently opposed to their being used by profit-making entities - which probably explains why they never went anywhere.

Re:Why are we wasting money on this? (0)

Anonymous Coward | about 2 years ago | (#41950807)

Shouldn't we spend tax dollars on stuff that is useful,

Ahem, that is the role of private industry. Tax dollars/euros should be spent on basic research which has 1/100 or less change of producing anything useful, or a whole new area of industry. Nobody expects the industrial revolution.
  BP sounds like a solution for sensor or data network where the nodes spool up very slowly because of the limited energy available. Lets put this thing on the networks where the only way of powering up a node is via crank-shaft or a solar panel.

Re:Why are we wasting money on this? (1)

Sulphur (1548251) | about 2 years ago | (#41952237)

This is something for private industry to figure out. Why are our tax dollars being wasted on stuff like this when in reality, we have no mechanism to get men past the Moon for the next 20-30 years? Shouldn't we spend tax dollars on stuff that is useful, such as not being beholden to our #1 creditor, China?

We don't need Internet connectivity near Saturn, we need to fix a deficit problem right here on Earth.

Its saturnine enough here?

Re:Why are we wasting money on this? (1)

firewrought (36952) | about 2 years ago | (#41952367)

This is something for private industry to figure out.

Private industry R&D looks 5-10 years down the road. A great nation will look 20, 50, and even 100 years down the road.

Why are our tax dollars being wasted on stuff like this

Wasting? This stuff is peanuts for the federal budget, and it probably even saves money (e.g, allowing different missions to use a common communication infrastructure).

we have no mechanism to get men past the Moon for the next 20-30 years

We put man on the moon with less than a decade's worth of work using 60's technology. If we were motivated, we could put men on mars within a decade too.

All of which is beside the point... we're sticking unmanned infrastructure out there (in various orbits, at Lagrange points, on the Martian surface, etc.) and the amount of data we want to ship around is getting progressively larger and larger.

such as not being beholden to our #1 creditor, China

We can always print more dollars. The real worry with China, it seems to me, is that we gave them our manufacturing capacity and business know-how. Now their economic ascendency is putting a strain on world resources (e.g., see gas prices) and we have to fret over whether or not their hardware is spying on us. Credit isn't a big worry since we control our own currency (unlike Greece, for instance).

We don't need Internet connectivity near Saturn, we need to fix a deficit problem right here on Earth.

To fix it, you're going to have to find the political will to cut defense, cut entitlements, and raise taxes. Good luck.

Re:Why are we wasting money on this? (1)

Thuktun (221615) | about 2 years ago | (#41954259)

Shouldn't we spend tax dollars on stuff that is useful, such as not being beholden to our #1 creditor, China?

My, don't we sound talking-pointy.

http://finance.yahoo.com/news/biggest-holders-of-us-gov-t-debt.html [yahoo.com]

That’s right, the biggest single holder of U.S. government debt is inside the United States and includes the Federal Reserve system and other intragovernmental holdings.

Re:Why are we wasting money on this? (0)

Anonymous Coward | about 2 years ago | (#41954933)

such as not being beholden to our #1 creditor, China?
We don't need Internet connectivity near Saturn, we need to fix a deficit problem right here on Earth.

China has announced plans for space. We can sit around in our horse-drawn carriages with you, or kill two birds with one stone and charge China to use our communications network.

Shouldn't we spend tax dollars on stuff that is useful

Yes. This is useful.

TFA does not describe how DTN/BP works. (2)

yincrash (854885) | about 2 years ago | (#41949891)

:( :( :(

Re:TFA does not describe how DTN/BP works. (1, Informative)

cultiv8 (1660093) | about 2 years ago | (#41949939)

sorry to hear you don't know how to use Google: http://en.wikipedia.org/wiki/Delay-tolerant_networking [wikipedia.org]

Re:TFA does not describe how DTN/BP works. (1)

Thuktun (221615) | about 2 years ago | (#41954261)

I generally prefer lmgtfy [lmgtfy.com] indirection, myself.

Re:TFA does not describe how DTN/BP works. (1)

TrueKonrads (580974) | about 2 years ago | (#41949971)

I agree,

it is a horrible article - regurgitates a press release without providing any details. Even the sole picture is not described.

Re:TFA does not describe how DTN/BP works. (2)

1u3hr (530656) | about 2 years ago | (#41950229)

regurgitates a press release without providing any details

It even slavishly copies the typos "BP network â" the one that will the Interplanetary Internet possible".

An awesome Awesome Star Topology. (0)

Anonymous Coward | about 2 years ago | (#41949937)

: ) I've often fantasized about the internet in space and what could make it work. It's very cool to hear that it's already thought of and implemented!? Amazing! I think the next step is to dispatch satellites one per planet so a full network can be fleshed out. Can you imagine how crazy a full traceroute would look like? I'd love to see it! I really would. I feel like a kid again. My packets can finally go into space.

Re:An awesome Awesome Star Topology. (0)

Anonymous Coward | about 2 years ago | (#41950219)

Well one per planet wouldn't work very well. You know how long it takes a satellite to orbit? Actually you don't, or you wouldn't have suggested one per planet. Never mind.

Re:An awesome Awesome Star Topology. (0)

Anonymous Coward | about 2 years ago | (#41951047)

You know how long it takes a satellite to orbit?

Do you?

Re:An awesome Awesome Star Topology. (0)

Anonymous Coward | about 2 years ago | (#41951299)

I think the next step is to dispatch satellites one per planet so a full network can be fleshed out.

Why not put them in solar orbits? That way a planet wouldn't be blocking them half the time.

Re:An awesome Awesome Star Topology. (0)

Anonymous Coward | about 2 years ago | (#41952375)

Why not just put them in higher orbits so that the planet is blocking it only a small fraction of the time?

UUCP (2)

DamageLabs (980310) | about 2 years ago | (#41949941)

I thought something like this already existed. And it worked pretty well at the time.

http://en.wikipedia.org/wiki/UUCP [wikipedia.org]

Re:UUCP (0)

Anonymous Coward | about 2 years ago | (#41950177)

I would think Token Ring [wikipedia.org] would sound more appropriate.

More like fidonet (4, Informative)

Narrowband (2602733) | about 2 years ago | (#41950301)

Actually it sounds more like fidonet. Store and forward networking just like early infrastructure that let email from dial up bbs nodes eventually reach a destination.

Re:More like fidonet (0)

Anonymous Coward | about 2 years ago | (#41950897)

Except UUCP is about 7 years older than Fidonet and UUCP was exactly store and forward protocol which enabled copying files, running commands remotely over multiple computer path and also was first used to carry email and usenet-news. With UUCP it was common to use modems and X.25 before ethernet and other networking gear was available. Later UUCP was adapted to run top of TCP/IP and use DNS names etc.

I quess not that many slashot readers were hacking UUCP back then -70'ties in academia before most BBS:ses even existed and thus many associate store and forward to Fidonet which only came 1984.

Re:More like fidonet (1)

collinc (899981) | about 2 years ago | (#41951625)

So Fidonet is the old, but not ancient, mans UUCP?

Re:UUCP (0)

Anonymous Coward | about 2 years ago | (#41950541)

Yes, except first versions implemented were not exactly end to end protocol. Later once it was ported on tcp and was also able to use dns it achieved end to end goal although it could have it's own routing and hop by hop directives combined, which is/was very flexible solution to reach only occationally connected nodes.

Sounds great that someone is finally tacking the issue and that if BP on its way to be implemented adjacent to IP. That could clearly be beneficial implementing connectivity with now practically disconnected networks and avoiding dirty hacks that were needed in projects like Stuxnet had to take.

Re:UUCP (1)

Minwee (522556) | about 2 years ago | (#41953247)

Well, sure, but how do I route to Mars through kremvax?

Re:UUCP (1)

DamageLabs (980310) | about 2 years ago | (#41954903)

mcvax!moskvax!kremvax!soyuz!ISS

after that I'm lost..

DTN: 1 (0, Redundant)

VortexCortex (1117377) | about 2 years ago | (#41949955)

Awe hell, at first I thought this was NASA's implementation of the DNT (Do Not Track) header -- It almost made sense: Some objects in space might not want to be tracked; Spy satellites for instance.

Damn Lexdysia...

BP protocol? (5, Funny)

TheDarAve (513675) | about 2 years ago | (#41949965)

The only problem with the BP protocol is the data mining rigs that burst and spread raw SQL queries all over the coast of Amazon.com and then wonder why people are pissed that they can't buy or sell from that site until its cleaned up!

"weâ(TM)ll get down and dirty... (1)

John Hasler (414242) | about 2 years ago | (#41949975)

...with the tech lower in the piece"

Except, they never do.

Didn't we have this figured out with FidoNet? (5, Informative)

AllanNienhuis (2772209) | about 2 years ago | (#41950115)

Reminds me of the problems the old FidoNet had to deal with - nodes not being available, or only available for short times, poor quality connections, low speed, etc. It worked remarkably well for all of those conditions I thought :)

Re:Didn't we have this figured out with FidoNet? (0)

Anonymous Coward | about 2 years ago | (#41950367)

I didn't believe a word you said because of your high slashdot user id.

gtfo.

Re:Didn't we have this figured out with FidoNet? (1)

msk (6205) | about 2 years ago | (#41950701)

AC is a C.

It worked with Fidonet. Store-and-forward is the viable way until we figure out FTL communication.

Re:Didn't we have this figured out with FidoNet? (0)

Anonymous Coward | about 2 years ago | (#41953791)

I remember reading an old science fiction story from the 50s or the 60s. It was about some teenage space cadets (co-ed). I think it was that they were launched in a new rocket ship that was to go to Jupiter or somewhere far enough that there would be delays of a few hours for radio delay back to Earth. At one point in the story, the communication system had a malfunction where they were unable to describe what it is they needed quickly enough. Their solution was to have the girl cadet do the talking to their girlfriend back on Earth since they knew how much girls talked over the phone about everything and nothing. TLDR: saved the day; happy ending.

Rather than store and forward, just store, repeat, repeat, repeat.

Re:Didn't we have this figured out with FidoNet? (0)

Anonymous Coward | about 2 years ago | (#41950837)

Mod parent up.
Fidonet did this in the 80s.
Store and forward.

Repeater/router stations (2)

a_hanso (1891616) | about 2 years ago | (#41950149)

While on the subject, when are we going to establish repeater stations around the solar system so that space probes don't need massive transceivers and line-of-sight to communicate with the Earth?

Re:Repeater/router stations (1)

Zocalo (252965) | about 2 years ago | (#41950403)

Sounds like a good idea, but I suspect there would be a problem with signal power and/or fuel. A deep space relay would need to be able to either receive signals from any direction, at any time, or to point a directional antennae towards a given point in the sky whenever a signal is due. The former approach means that it becomes a lot more difficult to pickup a faint signal and the latter is almost certainly going to require fuel in order to either keep the satellite stable as antennae move around or to reorientate the entire satellite to point an antennae in the right direction.

What might motivate this kind of plan would be when we finally get serious about sending actual people to Mars or some other distant object for an extended duration where the communications issues can't simply be worked around by timing the mission to ensure that the DSN can always provide coverage. You can afford to "hibernate" a robotic probe if it goes behind the sun for a couple months, and if you do lose communication you can ultimately just shrug your shoulders and give up on it. That's simply not going to be an option for humans for whom an extended break in comms could well mean the difference between life and death - if someone were taken ill and medical advice were needed, for instance - as well as the more mundane but still more or less essential need to be in some kind of contact with family back on Earth.

Re:Repeater/router stations (3, Insightful)

Nyeerrmm (940927) | about 2 years ago | (#41950681)

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:Repeater/router stations (1)

Zoxed (676559) | about 2 years ago | (#41950467)

Would this count as a start ? Artemis [wikipedia.org] (SKDR S/Ka band Data Relay).

Re:Repeater/router stations (1)

Thuktun (221615) | about 2 years ago | (#41954267)

While on the subject, when are we going to establish repeater stations around the solar system so that space probes don't need massive transceivers and line-of-sight to communicate with the Earth?

IIRC, isn't that what the Mars orbiters are effectively doing for all the rover missions?

IP already delay tolerant? (1)

danhuby (759002) | about 2 years ago | (#41950267)

Isn't IP already delay tolerant? I remember in the IPoAC trial for obvious reasons there were huge delays, but it still worked.

Re:IP already delay tolerant? (0)

Anonymous Coward | about 2 years ago | (#41950345)

IP doesn't care about delay

but TCP doesn't really work very well with very long highly variable delays. its a poor choice here and
its worth thinking about forgoing the stream model

Re:IP already delay tolerant? (1)

isorox (205688) | about 2 years ago | (#41950437)

Isn't IP already delay tolerant? I remember in the IPoAC trial for obvious reasons there were huge delays, but it still worked.

Ip over air canada? Yes certainly delays and rerouting.

Ip over avian carrier can cope with high delays and dramatic jitter, re-ordering and packet loss. I'm not sure udp/tcp can cope though, and Ip itself can't cope very well with a situation where the route only partially exists (say your orbiter acts as a router but is on the other side of the planet to your target lander, and needs to store the packets for a few hours)

Re:IP already delay tolerant? (1)

Crypto Gnome (651401) | about 2 years ago | (#41951985)

Isn't IP already delay tolerant? I remember in the IPoAC trial for obvious reasons there were huge delays, but it still worked.

Ip over air canada? Yes certainly delays and rerouting.

Ip over avian carrier can cope with high delays and dramatic jitter, re-ordering and packet loss. I'm not sure udp/tcp can cope though, and Ip itself can't cope very well with a situation where the route only partially exists (say your orbiter acts as a router but is on the other side of the planet to your target lander, and needs to store the packets for a few hours)

Actually he was talking about IPoverAnonymousCoward.

Or did you forget where you were?

Re:IP already delay tolerant? (2)

Zoxed (676559) | about 2 years ago | (#41950517)

I am running a test: still waiting on a result:

ping -W 118000 voyager1.nasa.gov

Re:IP already delay tolerant? (1)

Crypto Gnome (651401) | about 2 years ago | (#41951975)

Isn't IP already delay tolerant? I remember in the IPoAC trial for obvious reasons there were huge delays, but it still worked.

Huge, yes - but not astronomically huge. The main failing of TCP/IP in extra-planetary usage is that RTT/delay measured in minutes smacks up against many-and-various timeouts in TCP. Effectively TCP thinks RTT of 16 minutes (eg to the sun and back) is actually 100% packet loss, because TCP gave up waiting (timeout) ages ago.

Re:IP already delay tolerant? (1)

danhuby (759002) | about 2 years ago | (#41955065)

Huge, yes - but not astronomically huge.

The delays were longer than 16 minutes... over an hour in most cases. There's the printing of the data, strapping it to the pigeon, scanning it back in, it all adds time.

I'm not sure if they increased timeouts to cope with the problem.

Linux (1)

HyperQuantum (1032422) | about 2 years ago | (#41950363)

And now the question is: when will Linux support it?

Linux already supports it (1)

Anonymous Coward | about 2 years ago | (#41950515)

ION is probably the most popular open source implementation of DTN, and was developed on Linux machines..

Re:Linux (3, Informative)

John Hasler (414242) | about 2 years ago | (#41951577)

> when will Linux support it?

Package: ion
Version: 3.0.1~dfsg1-1
Installed-Size: 2618
Maintainer: Leo Iannacone
Architecture: amd64
Depends: libion0 (= 3.0.1~dfsg1-1), libc6 (>= 2.7), libexpat1 (>= 2.0.1)
Suggests: ion-doc
Description-en: NASA implementation of Delay-Tolerant Networking (DTN)
  Interplanetary Overlay Network (ION) software distribution
  is an implementation of Delay-Tolerant Networking (DTN)
  architecture as described in Internet RFC 4838.
  .
  This is a suite of communication protocol implementations designed
  to support mission operation communications across an end-to-end
  interplanetary network, which might include on-board (flight) subnets,
  in-situ planetary or lunar networks, proximity links,
  deep space links, and terrestrial internets.
  .
  Included in the ION software distribution are the following packages:
    * ici (interplanetary communication infrastructure) a set of libraries
        that provide flight-software-compatible support for functions on
        which the other packages rely
    * bp (bundle protocol), an implementation of the Delay-Tolerant
        Networking (DTN) architecture's Bundle Protocol.
    * dgr (datagram retransmission), a UDP reliability system that implements
        congestion control and is designed for relatively high performance.
    * ltp (licklider transmission protocol), a DTN convergence layer for reliable
        transmission over links characterized by long or highly variable delay.
    * ams - an implementation of the CCSDS Asynchronous Message Service.
    * cfdp - a class-1 (Unacknowledged) implementation of the CCSDS File
        Delivery Protocol.
    .
    This package contains the binary files.
Homepage: https://ion.ocp.ohiou.edu/ [ohiou.edu]

Subspace... (1)

Brad1138 (590148) | about 2 years ago | (#41950481)

Better figure out how to access "subspace" if you want to play Halo 27 with your friends on Titan. Or maybe quantum entanglement could accomplish the same thing?

This is going ... (1)

PPH (736903) | about 2 years ago | (#41950523)

... to turn "First Post" into a whole new game.

Moves the goal posts (1)

folderol (1965326) | about 2 years ago | (#41951015)

I've no doubt they'll succeed with this, but if they are going to do remote robot control they are going to have to develop a very 'interesting' command structure. I can see it now... Go Forward... Stop... Oops!

Re:Moves the goal posts (1)

John Hasler (414242) | about 2 years ago | (#41952767)

> if they are going to do remote robot control they are going
> to have to develop a very 'interesting' command structure. I
> can see it now... Go Forward... Stop... Oops!

NASA's robots are a bit more sophisiticated that that. It's closer to "Go over by the green rock" (not quite there yet, but close).

Layer3 UUCP (1)

Gothmolly (148874) | about 2 years ago | (#41951623)

It sounds like a UUCP implemented at layer3.

The Ping! (1)

Zyst (2772249) | about 2 years ago | (#41951675)

Gaming must really suck, how are astronauts going to play online!? Well at least they can Download their Steam library..

this was invented 40 years ago!!! (0)

Anonymous Coward | about 2 years ago | (#41951801)

it was called BITNET
http://en.m.wikipedia.org/wiki/BITNET

Lego Mindstorms Robot (1)

mathew42 (2475458) | about 2 years ago | (#41951867)

Does anyone have more information about the Lego Mindstorms robot that was used in this experiment? I'd like to use it as an inspiration with the kids.

The Curiosity Rover Made With Lego Mindstorms [wired.com] is pretty cool, but the fact that it uses "7 NXT Bricks, 13 NXT Motors, 2 Power Function Motors" makes it out of reach of the average home.

How Does DTN/BP Work? (1)

Crypto Gnome (651401) | about 2 years ago | (#41952055)

DTN is a store-n-forward protocol.

Conceptually kinda sorta like email in that regard.

The BP side of the equation brings the concept of bundling more information together in one unit (unlike IP, which tends to break info into smaller units , eg fragmentation).

The plan being to bundle together all the information required for The Application to do the next thing.

Imagine sending all the html-and-javascripts-and-css for a webpage in one (huge) packet. Your browser would have enough to render the page and start requesting the images (etc). If you were using a text-only browser, you'd have everything you needed - just waiting for the next user-input.

FIDO net reincarnate (1)

tokencode (1952944) | about 2 years ago | (#41953665)

This sounds just like FIDO used for inter-BBS and early internet email. Nodes would queue messages until the next hop was available. Why isn't the plan to use pairs on intangled particles to instantly pass information without regard for the speed of light or distance between end-points?

Re:FIDO net reincarnate (1)

burning-toast (925667) | about 2 years ago | (#41955387)

My layman's understanding is this:

Because entanglement does not transmit state between the entangled pairs. It only allows you to, after separation, determine the state of the remote node by reading the local one.

If you change the first node nothing is projected or expected to happen to the other in the pair.

Believe me, if they find a way to transmit information FTL in any method it would be plastered all over the papers, the internet, and Slashdot, and would call into question many parts of science as it is understood at the moment.

- Toast

Sounds like Packet Radio... (2)

alleycat0 (232486) | about 2 years ago | (#41953733)

...something amateur ("ham") radio operators have been using since the 1980's...

-allen
KC2KLC

Usenet to the planets. (1)

rdebath (884132) | about 2 years ago | (#41954909)

Forget all this talk of UUCP, Fido and normal packet protocols, the closest current similarity is sending binaries over usenet.

The most important part is the delay time, when you 'launch' a usenet message you won't receive anything at all from the remote end for a very long time. It will probably be long enough for you to transmit the entire message and then some.

The medium also has some limitations ...

  • you can't send a 'message' over a few (hundred?) kilobytes, still small, but a lot larger than a single packet.
  • The medium is unreliable, message will get corrupted or lost.

For usenet the binary files are packaged up into one archive them split into messages. Usually something isn't considered to be received until the entire archive has been received intact. It used to be that the receiving end would request repeats of messages that didn't get through. This takes a long time and wasn't simple to automate because of the multiple receiver nature of usenet. Nowadays more messages are added using the 'parchive' protocol the idea being that the extra messages are 'universal substitutes'. Say the transmitter needs to send out an archive of 1000 messages, furthermore it's likely that 4%-9% of messages will be lost, then adding 100 extra PAR messages will (normally) mean that the archive will get there intact first try. No retransmission request needed.

I expect 'bp' is very similar.

Propagation delays on layer 2 (1)

cpghost (719344) | about 2 years ago | (#41955187)

The UUCP analogy is wrong anyway. The point is that even in UUCP days, we connected two modems, which transmitted data with X, Y or Z protocol. And that protocol was even more sensitive to propagation delays, because acks had to be sent much more frequently. Try set up UUCP to a mars probe, and you'll see that the layer 2 protocols will probably break down pretty badly. That's why DTN is really important and an entirely different kind of beast.

How long before... (0)

Anonymous Coward | about 2 years ago | (#41955505)

Some idiot slows it all down again with SpaceBook....

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