"The U.S. is going to be the first country in the world to reach every planet with a space probe — isn't that fantastic?" Mikulski said at a news conference "We're on the brink of some very, very new science."
Leaders of the mission said that Mikulski, a ranking member of the Senate Appropriations Committee, had been an essential advocate for getting the $720 million that has been needed so far for the New Horizons mission, which is expected to reach within a few thousand miles of Pluto Tuesday morning.
"We're all holding our breath, we're all having our fingers crossed," Mikulski said. "I feel so much a part of this endeavor. It's going to help us understand a world at the edge of the solar system."
Back in fiscal year 2000, NASA didn't have enough funding to keep Pluto on the budget for future exploration, Mikulski said. But with pressure from the National Academy of Sciences to continue exploration of the Kuiper Belt, the region of space that's home to Pluto and a bunch of smaller bodies, she led the effort in Congress to keep the project going each year until New Horizons was slotted by NASA in 2004.
"Policy should not be guided by politicians, but by scientists," Mikulski said. "I was willing to gamble and knew that I was standing on very solid ground."
The mission was contracted out to Johns Hopkins University, where scientists advocated that the flight could be done through the APL on a lighter spacecraft and for cheaper than anywhere else. The spacecraft launched in 2006 and has since traveled close to 4 billion miles to reach the dwarf planet on the edge of our system.
"The mission to Pluto may not have happened without her vision and voice," said Ralph Semmel, director of APL, at the event.
Mikulski, who said she was inspired to advocate for science funding by Marie Curie, the first woman to win the Nobel Prize for her research on radioactivity, is set to retire from her Senate seat in 2016. That means NASA will lose a major ally in the Senate as as it enters a period in which it will try to resume a more robust human spaceflight program while maintaining a science budget that hovers just above $5 billion a year.
The New Horizon spacecraft also has enough fuel to collect data beyond Pluto, with power enough to last until around 2030, but that would require further funding. Mikulski said a successful flyby on Tuesday would be a good boost for support from Congress, but she will be pushing to get a budget agreement that would end NASA's sequester and get new money to the space program.
"I'm counting on the flyby more than Congress at this point," Mikulski said. "If we don't innovate, we're going to stagnate. We need to make significant investments in space program."
"I hope that when the pope comes, that miracles will flow," she added.