30 orbital birds? By 2017?
Aren't they (ESA that is) 14 years behind schedule anyway?
Two Galileo satellites have been blasted into the wrong orbit, red-faced officials at the European Space Agency said today. Errant sats Doresa and Milena were launched on a Russian-built Soyuz rocket on Friday. But launch service outfit Arianespace admitted that the satellites failed to go into the correct orbit. " …
If they don't get the constellation working, the chinese Beidou-2 system (formerly known as COMPASS) will take the frequencies, which would cause more delays as systems would then need rejigging.
There are 2 fully working GPS systems up there (navstar, glonass) 2 being built (galilleo, beidou-2) , at least 2 more planned (France, Japan) and 2 regional ones already in place (inrss, beidou-1)
The Indians may yet expand INRSS to a full GPS setup, but they're concentrating on their own backyard in the first instance.
What's surprising is despite the "competition" between the various systems (there's a hell of a lot of "flag waving" going on), there's also a good degree of cooperation in terms of both standardisation of data streams and transmission frequencies and collaboration between design teams - what that means is that an appropriately setup GPS receiver will be able to listen to all systems without having to run over-complex multiple-RF setups and that problems encountered by one consortium will be solved amongst all of them.
Also, what about music (the metronome which clicks off the metre of the music)?
Also, is it meter or metre for Shakespeare's sonnets (iambic pentameter)?
Who is Zed, and why is he in your alphabet?
Stupid English speakers who argue the order of letters, but the pronunciation not so much. Prove, Proof, Provide (prostitute and process). Hove, hoof, hover. Wind and wind. Read and read.
(a Yank with Canadian spell check... Colour is ok, color is not. Ok is not ok. Admit it, the ou and -re is a desire to be french...)
Please ignore the 'Little Englanders' on spellings (and on most other things).
While it pains me to say it, the US spellings without the Frenchification are correct - Noah Webster (your original dictionary guy) stuck firmly to the basics.
Meanwhile, Dr Samuel Johnson (our original dictionary guy), great brainbox though he was, was a glutton for Frenchification and stuck in many of the surplus letters that we now see (e.g. 'color' was quite acceptable in British English until Johnson messed it up, 'ax' without the silent 'e' was also fine, etc., etc., etc.).
Also, while I think of it, the US has 'pants' correct - as an abbreviation of 'pantaloons', the reference is properly to outer leggings. The current British usage of 'pants' for undergarments (derived wholly improperly in this context from 'underpants') is a vile neologism to be roundly and robustly deprecated at all times.
This post has been deleted by its author
Positioning satellites like Galileo can't be geostationary--too far away. Instead, these constellations go into Medium Earth Orbit (MEO, about halfway between LEO and GEO) and account for their movement by numbers.
Based on what I understand about Galileo, with the satellites in the wrong orbits, they won't synchronize with the rest of the satellites. I suspect they'll need to be reprogrammed for their new locations, with new formulas, coordinates, etc. calculated for them.
That'll likely be two replacements needed, either straight away or at least before planned end of life.
But it'll likely not impact on the initial usability of the system. They've almost certainly planned the coverage so that there'll be more satellites in view than are required for a position fix.
It's going to cost a lot of station-keeping propellant to boost the orbit and shift the inclination. Presumably, they are now doing the calculations to see if it's worth it. The trick is to give a ittle push (delta V) - in the right direction - each time the satellites reach just the right point in their orbit. Eventually, they will get up to the right altitude, then the orbits will be circularized with a similar technique. If this process takes too much manuevering fuel, they will probably be de-orbited to avoid creating space junk. Their current orbits are low enough that atmospheric drag will get them eventually, but it would take a long time from 20,000-odd km up.
"As The Register reported on Friday, ESA boffins are increasing the frequency of launches to get the entire network of 30 orbital birds ready by 2017 – an ambitious three years ahead of schedule."
Not a problem because, as we all know, there's never time to do it right, but there's always time to do it over.
Well I believe that the normal approach will be to launch the sats in groups of 4 on Ariane 5 (which has an excellent record for very precise orbits). However, they wanted to launch fewer for the first launch to test out the design of the satellite to allow the following satellites to be modified if required. Hopefully, the booked Ariane launches will go without a hitch. Note that SpaceX has also failed to deliver 2 payloads to their correct orbits.
Also the European union /ESA probably would prefer to use Ariane because it helps to assure European access to space (Ariane was originally developed because the US said that Europeans could launch sats on their rockets, but would not be allowed to keep any money made by the satellites - imagine how the telecoms market would look in that case). This may be seen as similar to SpaceX receiving a large amount of cash so that the US can launch cargo/people to the ISS without using Russian launchers, or satellite manufacturers in the US being banned from using launches provided by the Chinese.
This post has been deleted by its author
Perhaps these are actually GCHQ electronic intelligence gathering satellites, busy doing what GCHQ does?
Do they have permission to occupy these slots in the firmament? Wonder what the ITU is going to have them do?
Or was it yet another case of mixing Metric up with Imperial measurements?
Biting the hand that feeds IT © 1998–2020