Slashdot Mirror
First modernized GPS satellite Launched
A reader writes "The first GPS 2R-M satellite has launched from Cape Canaveral, Florida on top of a Boeing Delta 2 rocket. The government is now competing with Europe's Galileo system, and has added two additional military channels and one civilian channel, which will increase the accuracy and performance of GPS - as well as increase its resistance to jamming."
The sattelites up there are fairly old. Some of the newer ones were launched only a couple years ago, but some have been up there since the early 90's or before. We've had the math equations and the computing technology to be able to put up satelites with around 1m accuracy and better signal strength for a couple years now. Forget about the better jamproofing; with the newer eqipment you can sum the error of your integrals with newer algorithms and faster and determine position that much better less error-prone initial conditions.
Even those who arrange and design shrubberies are under considerable economic stress at this period in history.
" The government is now competing with Europe's Galileo system "
Lets see :
Galileo has not launched yet.
Galileo will not be free.
The 2R-M was planning before Galileo was anounced.
Galileo operational capibility is not planned until 2008.
I'm failing to see the link to the vaporware...
Is there a way to know which # (1..24) this one is replacing?
Just curious...it would be fun to know when i turn on my GPS receiver.
You have to remember that they're overengineering these things by terrestrial standards, because the satellites have to withstand some fairly harsh conditions while in orbit (such as radiation, EM storms from solar flares, etc). I imagine they're also hardened to some degree against human-generated interference, given all the worrying the Air Force has been doing lately about space warfare. Given all that, I'm not surprised that they seem excessivly bulky by the standards of present technology.
Problem with active GPS jamming is that it's a "damned if you do, damned if you don't" situation. Any sort of active jamming on the battle field is a huge beacon on the battlefield screaming BLOW ME UP! It then becomes a question of whether or not to turn on the jammer at all, as at most it'll be good for slightly de-accurizing (if that's not a word, it ought to be) one bombing run before being obliterated. If they were cheap enough, maybe, but even still...
If a job's not worth doing, it's not worth doing right.
The other thing to keep in mind is that there are many things that contribute to the total spacecraft mass in addition to the electronics. Not all of them have undergone the same kind of Moore's law reductions in mass (or improvements in capability) that electronics have.
Given the military nature of the project, perhaps it is just a "PR model" for secrecy.
These reasons apply to US government space programs. For an alternative approach, you might look at Surrey Satellite Technologies Ltd in the UK. They build and launch things quickly, have a well-defined strategy for integrating new technologies into spacecraft in a low-risk fashion and getting rapid flight-test information on them, make good use of the technologies appropriate to a mission instead of getting wedded to any one tech, and are extremely good at nailing down their requirements and building only what is needed. IMHO they are the best, and most innovative satellite manufacturer in the world today (and no, I don't work for them - although I'd do so in a heartbeat if I ever moved to the UK).
To being things slighly back on-topic, it's probably worth noting that SSTL has the contract to develop a testbed satellite for the Galileo system (the European competitor to GPS).