WASHINGTON, Jan 15 (Reuters) - Last year when NASA researchers in Baltimore discovered the fleeting glimmer of an exploding star, they named it "Supernova Mikulski," after one of their chief patrons in the U.S. Congress.
Known for years as a champion of so-called pork-barrel politics, Maryland Senator Barbara Mikulski has steered government money to many pet projects, from astronomy research to new buildings on military bases, protecting federal agency operations in her home state.
Her long record of securing "earmarks" - the practice of budgeting money for specific projects that has fallen into disfavor in Washington - also reveals a set of priorities that has made her one of America's most liberal lawmakers.
She has, for example, marshaled funds to clean up polluted waterways and improve schools in poor neighborhoods nationwide.
Now, as the new head of the Senate committee that helps make government spending decisions, Mikulski will be one of the most powerful players in Congress at time when an axe hangs over the national budget.
This may help her continue to shield her constituents and causes from the cold, hard politics of austerity gripping Washington.
"We can be frugal without being heartless," Mikulski said in a speech on the Senate floor last month when she became chairwoman of the chamber's Appropriations Committee.
Mikulski, who entered the Senate in 1987 and is the longest serving woman in Congress, got involved in politics in the late 1960s organizing opposition to a highway slotted to cut through a Baltimore neighborhood where she worked as a social worker.
She had also considered becoming a Catholic nun, but was uneasy vowing obedience to church superiors, a sign of the headstrong nature that has given her a reputation for toughness.
Known for her temper, Mikulski is frequently seen complaining about the throngs of people blocking the Senate chamber entrance. She has consistently endured the barbs of anonymous critics who participate in Washingtonian Magazine's Capitol Hill survey and rank her among the Senate's most irritable members.
Mikulski's spokeswoman said the senator can get impatient when Washington grinds to a halt, but this is a sign of her commitment to her constituents.
"She's tough when she needs to be," said spokeswoman Rachel MacKnight.
Friends noted her intensity. "She has a fiery personality," said Norm Dicks, a former Representative from Washington state, who was the ranking Democrat on the House Appropriations Committee until he retired this month.
The 4-foot-11-inch East Baltimore native now faces the unsavory task of helping decide on government program cuts.
A consensus has formed in Washington that government spending must fall because of the soaring national debt, a view Mikulski embraces.
"I agree we need cuts," Mikulski told Reuters. But she advocates "thoughtful cuts instead of cuts that hit middle-class families or the most vulnerable among us."
Mikulski was coy, however, on specific areas in need of trimming, although she said she advocates "responsible discretionary and military cuts."
Records of her efforts to fund pet projects for Maryland show millions of dollars steered toward her state and to progressive causes.
In 2010, the last year before a congressional earmark ban, her state ranked 11th in the amount of earmarks tacked on to the budget by Maryland lawmakers, according to an analysis by Taxpayers for Commonsense, a watchdog group.
She sponsored or co-sponsored earmarks totaling $127 million that year, the watchdog group's analysis shows. These outlays included $1.35 million to help Girl Scouts visit their incarcerated mothers, and $292,000 to install plumbing in low-income housing in Charles County, Maryland.
From 2008-10, a period when lawmakers were pressed to disclose earmark requests, she helped secure at least $13 million for NASA, including funds to develop space-exploring robots and to recruit science teachers.
The space agency has a significant presence in Maryland, including the Goddard Space Flight Center which employs more scientists than any other NASA center. In Baltimore, the Space Telescope Science Institute named its astronomical archive after Mikulski, and records of the supernova bearing her name are housed there.
"Chairwoman Mikulski has consistently ensured that NASA has the resources needed to carry out its mission," said Seth Statler, NASA's Associate Administrator for Legislative and Intergovernmental Affairs.
Mikulski makes no excuses for her record on earmarking, defending it as part of Congress's responsibility to determine federal spending.
As appropriations chair, Mikulski will face tough choices pitting her liberal priorities - she opposed the invasion of Iraq, for example - against her inclinations to boost defense spending in her state, which is home to major military bases like Fort Meade.
"She is really cross-pressured on defense," said William Galston, a fellow at the Brookings Institution who was previously a policy advisor to former President Bill Clinton.
President Barack Obama last year proposed cutting the size of so-called discretionary spending over the next decade when measured as a share of national economic output.
This spending includes categories like education and defense which get their funding renewed every year by congressional appropriators. A bill supported by Republicans in the House of Representatives last year would cut discretionary spending.
That suggests Mikulski's committee, along with appropriators in the House, will be divvying up an ever-shrinking pie.
"There is nothing about this process that is going to be pleasant," said David Rohde, a political scientist at Duke University.
Discretionary spending's budget share is expected to decline largely because of social welfare program costs, such as Medicare health spending, which avoids the appropriations process. Pulling troops out of Afghanistan will also shrink discretionary spending.
Many observers were surprised Mikulski - the third in line for the chairmanship - stepped into the role following the death last month of committee chairman Daniel Inouye of Hawaii. The senators in front of her declined to take the helm.
The shrinking appropriations purse - and the informal earmark ban imposed in 2011 - have diminished the power of Mikulski's new position. Earmarks were a time-honored part of legislative dealmaking and allowed lawmakers to deliver bacon to their constituents.
"Obviously, without earmarks, you can't do as much as you used to do in one of these powerful positions," said Dicks.