A big day for a little spacecraft: MESSENGER

It was St. Patrick’s Day, and the crowd of nearly 400 waited expectantly in the Kossiakoff auditorium at APL. Irish dancing music was piped into the auditorium as recorded interviews of Daniel O’Shaughnessy, Eric Finnegan, and Eric Calloway played on the giant screen, reviewing the six planetary gravity assists, the five deep space maneuvers, and the big idea to add solar sailing that arose as the spacecraft approached the first Mercury flyby. “It really is akin to a ship on the ocean,” said Calloway, “sails tacking back and forth.”

Onstage, Ralph McNutt reviewed the mission design, interspersing one-liners with technical details to keep the crowd relaxed. “MESSENGER is a flying gas can. Over half the mass is propellant,” he explained, and as quickly as the audience laughed, his words were instantly tweeted by several eager space enthusiasts watching there and over ustream online. Social media was a presence at MOI, with @MESSENGER2011 tweeting her progress throughout the night in words that her followers could understand, with her impact multiplied with each tweet and retweet from space fans throughout the world.

The mood was quiet, expectant, jubilant, and a little tense at Kossiakoff, as the team waited with their families and invited guests to see confirmation that MESSENGER had indeed gone into orbit. Tom Krimigis was there in the second row, a few seats down from Bob Farquhar and others who had worked so hard from proposal to mission operations to make this dream come true. Co-Investigators and engineers were scattered through the audience, their inevitable worry tempered with the confidence that comes from years of solid design and development, followed nearly endless drills for the mission operations team, now prepared to handle any anomaly. The screen showed live shots of the engineers at their workstations, waiting the long eight minutes for confirmation of each maneuver from their faraway spacecraft, the one that they had only a few years ago built in the lab out of parts. Associate Administrator Ed Weiler had spoken to the team earlier, reminding them that this was a major accomplishment: “You only go into orbit around Mercury first once in human history, and that’s what is accomplished tonight.”

As speakers and videos entertained the audience, informing them about new technologies, materials, and designs used on MESSENGER, those in the know waited anxiously to hear the announcement from the Mission Operations Control Center (MOCC) that the burn had been completed successfully and the spacecraft nudged into its oval orbit around Mercury, 155 million kilometers (over 96 million miles) from Earth. Then, through the onstage talk, his words could be heard loud and clear, and the crowd burst into spontaneous applause.

The burn “was right on the money,” confirmed Finnegan, Messenger’s chief engineer, later in the evening. “This is as close you can possibly get to being perfect.” Principal Investigator Sean Solomon reminded the gathering that the science team was thrilled at a successful MOI because it would enable the science that was to come, saying, “This is when the real mission begins.”

In that moment, humankind completed its goal of orbiting Mercury, the sixth planet in the solar system to be orbited by a spacecraft built by humans out of parts.  There was relief and smiles on every face, and we began to relax at a reception in the next room, mingling with scientists, engineers, and managers who had made the mission possible, as @MESSENGER2011 tweeted: “We’ve done it! I’m in orbit around Mercury—the first spaceship to ever do (or tweet) that! #MOI2011.

This is just the beginning of the MESSENGER mission to Mercury.  Find out more about MESSENGER Deputy Project Scientist Louise Prockter and Participating Scientist Catherine Johnson on the Women in Planetary Science website — and find great resources for kids at the MESSENGER Education Site .  Let’s celebrate!