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US Air Force Building Space Router
Saint Aardvark writes "From the ISTS daily news comes a story on the US Air Force seeking to build a space router. From TFA: "Northrop Grumman and Caspian Networks are collaborating to develop an Internet Protocol router that can withstand the constant barrage of solar radiation in orbit. The space-hardened IP router will be part of the Air Force's Transformational Satellite Communications System, which will provide IP-based communications to warfighters." I wonder what the ping times would be like..."
I wonder what the ping times would be like...
(nb: I worked on some satellite internet stuff a few years ago.) If this unit is in geosynchronous orbit (so a fixed dish can always hit it), it's sitting almost 36,000 Km over the equator. Assuming your dish is at the equator a round trip is ~72,000 Km / 300,000 Km/sec (the speed of light) means the signal travels about a quarter second earth->earth not including any processing time at the satellite midway point or either end.
Trolling is a art,
We already have TDRS (tracking data relay system). It is a system that can acquire data from satellites in low-Earth orbit with near-global coverage. A set of specialized satellites in geosynchronous orbit are used to track, command, and acquire data.
Mea navis aericumbens anguillis abundat
You didn't catch that current technology doesn't do the routing IN space, it does it at a single point on the ground. This allows several uplinks to be used more effectively. As an example, if you make use of these vsat IP providers to connect between two remote sites, the communications would be ground->sat->ground (hub)->sat->ground, meaning the packets have to traverse twice as far as they otherwise would if routed in space.
You're pings are not being routed through a satellite.
The Router
Here's an ISS status report that mentions it.
/sig
Almost totally wrong, the chances of your data going though a satelite on a normal day are pretty low, unless you have satelite internet access.
There are two options to the location of a space-router, one is a geo-stationary orbit, this would take it to 36,000 km, so a round-trip for the signal of 72 milion meters and a 'lag' of 240ms just in getting there and back (slightly longer since you don't want to send/recieve from the same palce).
The other choice is that if the system works they opt for a selection of fast-orbiting satelites which won't stay over the same spot and instead work 'shifts' over the diferent parts of the globe, these satelites could orbit at significantly lower orbits, the lowest being 320km, which would only incur a latency of just over 1ms (to a station directly below).
Most commercial satelites tend to opt for the geostationary, Iridium is the only one I can think of which has enough satelites to cover the world at a relatively low orbit around 750km I believe, 66 satelites that takes, lower would need more due to the curvature of the earth.
Uh, many many military folks use the word warfighter. It describes the jobs of the front-line combat service personnel from all branches of the military (not cooks or other non-combat personnel).
"We provide the best XYZ possible to our nation's warfighters".
I've seen it for a number of years in (a) magazines devoted to military equipment (Journal of Electronic Defense (JED)) (b) heard it from the various military customer-type people I come into contact with as a defense contractor (they may have been infected with 'bizspeak', though, for all I know).
JED in particular has a column called "I: First Person Singular" that is usually accounts of retired service personnel describing their experience with various electronics defense systems (radar, ECM, ECCM, other EW gear) in combat situations (World War II, Korea, and Vietnam). The people writing these columns often use warfighter without any indication of discomfort or irony.
It's a real word that is just now percolating into common usage via the enlightened interest in things military spurred on by the conflict in Iraq.
I work for a corporation that uses a satellite for data communications.
As of five minutes ago, I did a ping test from my computer on our WAN, through the AMERICOM-4 satellite, to a location connected to a VSAT dish.
PING RESULTS:
Approximate round trip times in milli-seconds:
Minimum = 1412ms
Maximum = 2013ms
Average = 1682ms
Looking further into it using a tracert, I have the following results (IPs/Hosts removed):
(less than signs should be infront of each 10 ms entry)
1 10 ms 10 ms 10 ms LAN/WAN
2 10 ms 10 ms 10 ms LAN/WAN
3 10 ms 10 ms 10 ms LAN/WAN
4 10 ms 10 ms 10 ms LAN/WAN
5 10 ms 10 ms 10 ms LAN/WAN
6 10 ms 10 ms 10 ms LAN/WAN
7 10 ms 10 ms 10 ms Sat Hub
8 1482 ms 1392 ms 1442 ms VSAT Host
As you can see from the numbers above the ping times would be like 1.5 seconds!!