To expand a little more on my post....This is an excellent idea. In fact, it could probably be done for not a whole lot. The entry-level SpaceX rocket costs $6million per launch, and NASA could probably get a (very) bulk discount, so lets say $5m. If they launch 50 times a year (take a couple weeks off for christmas or something), that's only $250million...just chump change in NASA's budget.

Then it would be an issue of finding payloads for these 50 launches each year. Ideally NASA could have a competitive process that would let individuals or organizations compete for the free launches. Then if the org isn't able to get their payload ready in time, you could have a pool of ready-to-launch payloads that didn't win the competition, but are willing to launch if there is a chance. If all that fails, the rocket should launch anyway, and just do a sub-orbital flight, so that the system stays sharp.

There's a couple issues with this...one if the biggest is range tracking and availability. Having to be available to launch every week would be very tough for the range, because it usually takes them 24hrs+ to get set for a launch, then there are several days booked where the launch can happen any time in that window. To solve this problem, something that launches with this regularity would need to be independent of the current assets, which with cheap GPS and sat data links shouldn't be too big of a deal.

Another thing to think about would be orbital debris. Launch every week, with the competitively determined payloads, which probably won't be as long lived as traditional payloads, could contribute negatively to the amount of debris in orbit. To mitigate this, a big part of the competitive selection process should be how the payload will de-orbit itself, even in the event of a failure.

A 2048 bit key usually denotes an Asymetric encryption (like RSA or DSA). AFAIK, there are no 2048 symetric encryptions in use today (the largest I know is 256 bits like AES-256).

So, you *REALLY* aren't using a 2048 bit password. Your password is most likely a hash to a key used to perform a symetric encryption of the private part of a RSA or DSA key.

What happens when you use asymetric encryptions, is that your system generates a random key. That key is then used to encrypt your data. That key is then encrypted with the public key of your RSA/DSA key. The encrypted key is then included to the encrypted contents. The private key is protected by another symetric encryption (may be different from the one used to encrypt that data itself) - and THAT is your password since it allows you to recover the encryption key used to encode your data. You need both the Public/Private key pair and the password used to encrypt the private key part in order to recover the original data.

--Ivan

..and the point of open source is a number of people offering their source code to everyone. These people are the source of "open source", and the names on that list don't resonate with that crowd, hence they are not influential. The list should include notable (and leading) contributors to such project as Firefox, Linux, Net/Open/FreeBSD, OpenOffice, SAMBA, Wine, OpenSolaris, etc. (I am sure I missed a lot of important OS projects, please do forgive me in advance).

It's just another case of epitomizing the managers over the engineers - yes, it's a cliche, but it fits. Managers just can't seem to be satisfied with raking in the most dough - they need the kick of fame, too, even though in the OS world they are the least relevant - remember, cathedral vs. bazaar.

Get your tin foil hats out.

If you look at the boards of the top 25 open source boards you'll find many of these people on the list present. I'd say this is likely a significant factor in establishing these folks as the 2009 Most Influential Open Source Executives? Wouldn't you?

Yeah and in 1985 a brand new Mustang GT cost what, $9k? How much would your $1300 Amiga cost in today's dollars, and how does it compare in capability to a $300 bottom of the barrel Microsoft-powered netbook?

But TNG rather often managed to deliver both! (Well, not literaly literary works, of course...) Just remember episodes like "The inner light" (you may want to remove the Star-Trek-Bookends from that one) or "Chain of Command". Pure work of art every now and then.

As usual, Zen is ignored. They don't take into account that when nothing happens that can also be your computation (accuracy -> oo).

Stephan

Its also against the license agreement which requires Leopard.

Win7 upgrades will upgrade just fine if you supply them a disk that makes them think you own a previous version, then you give the disk back to whoever you borrowed it from and save yourself the cost of the full version.

Both are illegal, but thanks for trying.

Why call it the "Oort Cloud" if there's nothing in it? My view is that such solar sails would be first used for Kuiper Belt targets and the heliopause (the latter not needing trajectory accuracy aside from making sure the probe heads away from the Sun). Later as we discover targets in the Oort cloud to investigate, probes could be sent out in this way. It's also good for interstellar missions. These velocities provide a good first stage boost. Accurate trajectories might greatly reduce the propellant consumed to correct the trajectory to another star.

Nobody ever said there was nothing in the Oort Cloud. But we're not going to be sending a lightsail out to the Oort Cloud to do more than fly past an Oort Cloud object really fast. Like 500+ km/sec fast.

And no, it's not particularly useful for interstellar missions. We're still talking about 2000+ years to make an interstellar jump. Note that the deltaV we're talking about for this lightsail is higher (but not much higher) than a similar amount of reaction mass being pushed out of a VASIMR or ion drive that we can build right now. In other words, by the time we get ready for interstellar trips at any reasonable speed (~10% c), this particular technology will be essentially useless.

Also, let us consider that hypothetical interstellar trip, and the inaccuracy of this proposed system. We have an expected error of 1 Gm in 2500 AU. Alphacent is about 270000 AU away. So this vehicle would be about 110 Gm off course by the time it reached Alphacent, absent relativistic corrections to its course. 110 Gm is rather less than one AU (150 Gm), so I doubt seriously we'll be really hard put to call that a trajectory requiring massive course corrections.

Again, remember that the relativistic effects only apply during the first very small part of the acceleration of the lightsail. By the time the lightsail reaches one AU from Sol, we'll be back to flat enough space that Newtonian approximations will suffice. And that leaves us (hypothetically) 2499 AU to make a 1 m/s course correction to get back in the groove.

Note that if we had a conventional rocket onboard to make such corrections, it would require about 100 grams of reaction mass to make the required correction. And that's the worst possible case - letting the lightsail do the work is a trivial two-week correction done anywhere out to 100 AU....

I not only don't see the full word, in a well written tome I don't see any words at all. My brain somehow translates the words into actions, figures, etc. without ever noticing that I'm reading. I don't see the words "he fell screaming to his death", I actually see the man falling and screaming and splattering on the ground with a sickening thud.

Because of that I simply can't read Stephen King; he's too good a writer and his stuff just freaks me out too much.