The Planetary Society Blog
By Emily Lakdawalla
Final preparations for Dawn's mission to Ceres and Vesta are under way
Apr. 12, 2007 | 12:34 EDT | 16:34 UTC
The Dawn spacecraft arrived in Florida on Monday morning, ahead of a planned June 30 launch. (There was recently a slight delay from a planned June 19 launch due to the availability of the launch vehicle.) To me, a spacecraft's arrival in Florida (or Kourou, or Baikonur, or wherever it's going to be launching from) really signifies the beginning of its countdown to launch and the start of the mission. The science part of the mission may not start for quite some time, but with its arrival at the spaceport, the impending voyage becomes real.
If I were an engineer or a scientist on a space mission, I think that I'd find this part -- the shipment from wherever it was being built to Florida -- to be almost as nerve-wracking as the launch. There are just so many stupid things that can happen to a spacecraft when you load it on a truck and drive it on real roads, with real bumps, and real idiot drivers whizzing by. Spacecraft are robust things; they are designed to handle the huge G-forces and bone-crumbling vibrations of being launched on the tip of a giant rocket. But that doesn't mean that one could survive an impact with the road if the truck it was riding on overturned in a traffic accident. So I'm very, very relieved that Dawn arrived safely.
I waited to post about this until I could get some pictures. Here's a few from the media gallery at Kennedy Space Center. Here's the spacecraft being unloaded from the truck: Dawn arrives in FloridaThe Dawn spacecraft and associated ground support equipment arrived at Astrotech Space Operations in Titusville, Florida, at 9:00 a.m. Eastern time on April 10, 2007. Credit: NASA / Jim Grossmann |
And here it is being unwrapped, like a birthday present:Dawn arrives in FloridaDawn arrives at Astrotech Space Operations in Titusville, Florida on April 10, 2007. Left: the shipping container is lifted from the spacecraft. Center left: an overhead crane lifts the spacecraft from its transporter. Center right: technicians roll the spacecraft into a clean room. Right: a worker wearing a "bunny suit" (a clean-room coverall) begins removing the protective bag surrounding the Dawn spacecraft. Credit: NASA / Jim Grossmann |
And finally, here's the spacecraft, ready for its final assembly and testing.DawnDawn sits in a cleanroom at Astrotech Space Operations in Titusville, Florida on April 10, 2007, awaiting final assembly and testing. Its solar panels have not yet been attached. Credit: NASA / Jim Grossman |
I'll just note here what a teeny spacecraft this thing is. The center set of images has some people that show the scale. It's hardly taller than they are. It'd fit in my office with room to spare. Miniaturization of components like science instruments, power and communications systems, and other electronics have really enabled low-cost missions like Dawn.
The press release that announced Dawn's arrival in Florida included quite a lot of detail about the timeline that leads up to its launch. There's a lot to be done in under three months:
April:- Install the batteries
- Check out the thrusters
- Test the science instruments
- Attach the solar arrays
- Deploy and test the solar arrays
May:- Test compatibility with the Deep Space Network
- Load hydrazine fuel
- Perform spin-balance testing
- Erect first stage of Delta II 7925-Heavy launch vehicle on Pad 17-B
- Attach nine strap-on boosters to first stage
June:- Mate spacecraft to upper stage booster
- Install spacecraft and booster in transportation canister
- Hoist second stage of launch vehicle atop first stage
- Hoist spacecraft fairing into clean room of launch pad mobile service tower
- Perform leak test on first stage (load first stage with liquid oxygen during a simulated countdown)
- Perform a simulated flight test (simulating post-liftoff flight events)
- Enclose spacecraft and upper stage booster inside fairing
- Hoist payload (fairing, spacecraft, upper stage booster) atop launch vehicle
- Perform integrated test of launch vehicle and payload
- Launch!
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