[X] My Assistant

[djellison]

I thought it was time, with the Atlas V about to roll out - for a new thread for NH for the launch etc.

Someone asked over at the HZ just how NH can go so fast, this was my reply....

How do you get a spacecraft to Jupiter in under a year? Easy. Make it very very light, and put it on a very very big rocket. The config of Atlas V rocket being used to launch NH (551 - 5m fairing, 5 solids, and one engine on the Centaur stage ) would typically put 8,670kg into GTO or 20,520 into LEO.
New Horizons is 478kg, and it's Star 48B 3rd stage is 2,137kg - so instead of hauling 20 tons, this vehicle is hauling about 2.5 tons thus you get a HUGE velocity out of it. AND, once it's done that, you have the final kick of the 48B, 591 thousand kgs-s (thus accelerating is all a further 3.5 - 4km/s ball park speed, if my maths is right)
At launch - the vehicle is 573,160kg. NH is 0.083% of it.
Imagine the Apollo entry capsule on top of a Saturn V...tiny tiny tiny... that was 5,800 kg on a 3,038,500kg rocket - 0.191% - more than double that percentage of NH. The cutaway's are almost comical, with this tiny gold-clad box on an enormous vehicle.
Basically - it's a LOT of rocket, and not a lot of payload.
For comparison, look how much fuss was made of Stardust that entered so quickly. It took >16 hrs to get from the distance of the moon to Utah. NH makes that journey in 9 hours
One thing the NH mission is not short of, is superlatives.

I'm not one for good luck charms (although I'll eat peanuts during a Martian EDL with the best of them), but this mission has been so long in coming, that it deserves every ounce of luck it can have - the best, most accurate launch possible, the cleanest checkout, and incident free cruise to Jupiter.

Goodluck and Godspeed little one, we're with you every step of the way.

Doug
PS - Alan, you're a credit to your field, spending so much time answering questions and writing the PI Perspectives, it's been a hell of a journey!