Wow... I'm here...in the MESSENGER situation room looking into the MOC (mission operations room)! It is 4am and about 5 minutes from MESSENGERs closest approach to Mercury.
There are about 40 folks sitting around watching the animations being produced from http://messenger.jhuapl.edu/encountersm2/index.php. While I'm typing, I'm listening to Jim the mission design lead engineer explain this animation to another gentleman in the room. Jim developed this animation program which uses images from the Mariner 10 expedition from 30 years ago and the fly by in January to show what the MESSENGER spacecraft is seeing and its location in relation to the planet. These images are now being updated by the MESSENGER spacecraft during the flyby with a resolution of 500m/pixel using the narrow angle camera and 4km/pixel with the wide angle camera. The approach for the spacecraft is, "4 degrees to the north of the equator,"," due to gravity it will be going.. " It is now 51 sec from closest approach. They both get up and go into the MOC.
There are a lot of side conversations in the room. I'm listening to Louise, the instrument scientist explain her role in the mission. She makes sure the Mercury Dual Imaging System is doing what is supposed to do. She is telling us about the images, how they are downloaded, compressed, and overlaid. In some of the images prior to the flyby, Saturn could be seen in the distance. Saturn is so small and so far away that they couldn't get any good images from the MESSENGER cameras on the spacecraft.
The conversation in the SRoom has quieted. Everyone is moving to the MOC. Well, everyone but us. We can't enter the MOC. We can only watch through a window and listen through a one way intercom system. The quiet in the room is interrupted, "for those observing the animation, the end for this animation is 08:50 spacecraft time." They are now starting the daytime surface scan. They are passing over to the light side of the planet using the wide angle camera. On the tv screen on the wall.
Eric Finnegan is the mission systems engineer. Solar sailing is being used to navigate the spacecraft. This source of energy to maneuver the spacecraft wasn't the planned propulsion but a new addition to the mission. "The solar panels are being used as a sail....this wasn't planned at take off. We always planned to use gas but have been able to use solar pressure to maneuver the spacecraft. It has taken two years to learn how the spacecraft will respond to the solar pressure. Each part of the spacecraft will reflect light differently so the the spacecraft will respond differently. We have to keep flipping the spacecraft to keep the sunshade facing the sun. Solar pressure is .... Learning about using solar sailing. Solar Pressure is a function of r squared.. 11 times greater on MESSENGER than on the Earth."
Over the intercom, "The next activity is the high resolution mosaic strip."
Sean is the geologist... So Mercury has a core... but it is very small relative to the Earth's core. Sean said that volcanism is a result of the planet releasing heat not because of tectonic plates. Earth is the only planet that has tectonic plates.....
The velocity of the spacecraft will be 148,000miles/hour on October 15th. This is the second fastest ever a space craft has ever gone. This speed is relative to the sun. We are now about 65 % closer to the sun than the earth.
Ok that is about it for now. It is now 6:36 am. We are powering down and packing up to go back to the hotel for a nap. We meet back for another meeting after lunch