Yay! MESSENGER successfully went into orbit around Mercury tonight. An awful lot of us breathed a sigh of relief. There are three options when approaching a planet like they did – (a) You match velocity and make a successful orbit, (b) You shoot on past, or (c) You make a magnificent crater on another planetary body.
The rockit scientists did just fine. With an 8-9 minute lag in communications (one way), real-time control is impossible, so on autopilot the spacecraft executed a successful burn and decelerated pretty fast (without ABS, I might add) and went into it’s eccentric orbit. They’re waiting for more telemetry but all signs look good.
From the APL site:
MESSENGER Begins Historic Orbit around Mercury At 9:10 p.m. EDT, engineers in the MESSENGER Mission Operations Center at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Md., received the anticipated radiometric signals confirming nominal burn shutdown and successful insertion of the MESSENGER probe into orbit around the planet Mercury.
The spacecraft rotated back to the Earth by 9:45 p.m. EDT, and started transmitting data. Upon review of these data, the engineering and operations teams confirmed that the burn executed nominally with all subsystems reporting a clean burn and no logged errors.
MESSENGER’s main thruster fired for approximately 15 minutes at 8:45 p.m., slowing the spacecraft by 1,929 miles per hour (862 meters per second) and easing it into the planned eccentric orbit about Mercury. The rendezvous took place about 96 million miles (155 million kilometers) from Earth.
I’ll post a pic in a while of me sitting next to an engineering model of the FIPS instrument (it is attached to the EPPS instrument on MESSENGER). We were all damn near crazy once we finished the fabrication of parts and built the thing up, but we did it in just under a year.
Here is a picture of a handsome little fella who I happen to know very well standing next to an engineering model of FIPS. It’s packed with all the gooey sciencey goodness that only Sparks can dream up, folks, and looks just like the thing on MESSENGER, too. Well, except that the whole thing is alodined and the real thing is covered all over with MLI/ceramic-blanket stuff. The blanket is like asbestos underwear – keeps the precious stuff from getting too toasty (and can keep your drinks from getting too cold, too). It also keeps seagull droppings off the instrument. Now, you may be tempted to say “Oh, that isn’t a seagull-protective cover!” To which I respond: “How come? Do you see ANY seagull droppings on the instrument?”
Franken-Boy standing next to honest-to-goodness hardware.
For a size reference, the cylindrical thing pointed up and to the left is the size of a coke can and the whole thing is lighter than a popcorn fart. There’s so much crammed into that front section alone that it would make your head swim. As one of the project heads (a Spark) was introducing me to another attendee he said “Well, if you’d known what you were in for you might not have come on board.” And he was right, I might have run away like a scared little girl. What a great group of folks though. I think we all hated each other a bit towards the end but we got over it.
Lemur King's Folly 