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Interplanetary Network (IPN) Tested
CETS writes "Slim on detail but...USA Today reports of the first test of an Interplanetary Network. 'In a sign of cosmic communications to come, last week mission controllers sent signals to a Mars-orbiting European spacecraft, which relayed the instructions to NASA's Spirit rover on the surface, and a signal was returned to Earth back along the same path.'" NASA also has a press release.
get people excited about space exploration. I for one am overwellmed by the string of success. Heck .. I even have NASA TV constantly running on my computer just so I don't miss a press release and to lean more about the rovers. Previously we were limited to bot's being in a "Direct line of sight" with Earth to transmit data. Now with the IPN we can get data faster and more often. KUDO's to NASA and the ESA for great job !
The bulk of data coming back from the Mars Exploration Rovers comes back through relay sessions through the Mars Odyssey and the Mars Global Surveyor satellites. The orbiters are simply much closer to the rovers than Earth is, the path loss is less, and so the data rates are much higher... and the satellites have direct visibility of earth for much longer and much higher EIRPs to talk to earth with.
A couple of weeks ago they tried the first "interplanetary network" where the sessions were up "live", rather than store and forward.
The really big advantage of this is they'll be able to command the rovers in near-realtime and get answers back right away for much more of the day than direct to earth communications is possible. And with 3 communications satellites above Mars, they are likely to have quite a few communications windows. Expect them to be fairly risk adverse, though, and for it to be several weeks before this is included in their operations.
>> Radio signals take several minutes, travelling at the speed of light, to traverse the void between the two planets
> Hmmm. Funny, NASA does not say anything about that.
That's because it's obvious to anyone with a 3rd grade education. NASA has a lot of interesting stuff to report and thankfully they're not dumbing down their releases even further.
> Too bad Gene Roddenberry is not alive to see the begenning...
Actually, Pioneer and Voyager were the beginning, even if they didn't use relay satellites.
NASA spent billions of dollars on the development and deployment of the Tracking Data Relay System (TDRS), which can track spacecraft in low-Earth orbit. Even there they had to cheat a bit, by doing the beam-forming for the phased array multiple access antenna on the ground instead of on the TDRS spacecraft.
Mea navis aericumbens anguillis abundat
That ISP will probably bring one website online first, so if you slashdot it before it can bring any more online, you will have slashdotted the whole planet.
Orbiting networks via NASA Rover -> NASA Sat -> NASA ground have been done repeatedly since the rovers landed well over a month ago.
This InterPlanetNet is a giant leap for mankind, compared to the small step for a man on the first "spacewalk". Yet it receives less press coverage than the first American spacewalk (Russian Alexi Leonov was the first "man in space", spacewalking 3 months earlier). This demonstrates the point driven home so well in _The Right Stuff_: the space program is primarily a human adventure, and secondarily a science/engineering program. Our species will be living on the IPN grid for millennia, but it's not photogenic. When we get a "JenniCam in Orbit" reality show, about 5 unlikely ISS roommates, we'll see space colonization become a priority.
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make install -not war
Mars isn't any fixed number of light-minutes from Earth, since their orbits aren't in lockstep. When they're farthest apart, they're, what, about five times as far apart as when they're closest?
You must be thinking of Earth's distance from the Sun...