Washington (CNN) -- The National Oil Commission, just beginning its investigation into the Gulf of Mexico oil disaster, faces a daunting task: Collect information, process it and within six-months make recommendations to President Obama.

And unlike presidential commissions examining the September 11, 2001, attacks, the space shuttle Challenger explosion and the Three Mile Island nuclear plant accident, this one is unique: The disaster is still going on.

"In some ways, it really doesn't make much sense because the importance of commissions is that they have data that no one else has," said Stephen Hess, a presidential historian and scholar at the nonpartisan Brookings Institution.

Obama signed an executive order on May 22 creating the seven-member commission, tasked with investigating the April 20 Deepwater Horizon oil rig explosion in the Gulf and the subsequent oil spill that has become the worst environmental disaster in the country's history.

The commission is tasked with three things: determine why the oil rig exploded; make recommendations about preventing similar disasters; and determine whether offshore oil and gas drilling should continue.

"We will look at all aspects of the cause. ... We should go well beyond April 20 to see whether there were decisions made or even a culture that was established that may have contributed to the series of problems and the faulty decisions that were made," committee co-chairman William Reilly said.

Reilly, chief of the Environmental Protection Agency during President H.W. Bush's administration, is leading the committee with former U.S. Sen. Bob Graham of Florida.

Is the six-month time frame feasible?

"It's a much tighter time frame than that which characterized earlier commissions like the 9/11 commission," Reilly said.

The 9/11 Commission began its work in November of 2002. Its final report was released two years later in July 2004. The Challenger commission, though, had a relatively quick investigation. It first met in early February of 1986, just days after the explosion, and published its report in June that year.

Reilly is confident the commission will complete two of its three tasks: make recommendations about preventing similar disasters; and determine whether offshore oil and gas drilling should continue.

Read more about the oil commission

As for the third task, the precise determination of the causes, Reilly said the group will do its best. He acknowledged that the commission is also fighting for information as other commissions and the Department of Justice are running concurrent investigations.

While the road ahead is daunting for the commission, Hess said they have some advantages: the backing of the president, the immediate attention of the American public, and the anger and frustration of Gulf Coast residents.

Hess said the residents and environmentalists are using the open hearings held by the commission as a way to vent their frustration.

"That defines this sort of commission," he said. "A lot of commissions don't hold open hearings. ... When they hold open hearings they know exactly why they are doing it: to let people give their emotional pitches."

A woman shouting about dispersants in the water interrupted the first commission hearings on Monday. BP is blocking LSU scientists from doing tests, she said, adding, "Everybody's got to get upset about this."

Tight mandates make for successful commissions, said Reilly.

"If [commissions] can be very specific and they can be very focused -- and of course get a lot of attention -- they can be useful." He said the oil commission has some of those qualities.

Many recommendations from the Challenger and Three Mile Island commissions resulted in changes to operating procedures, stricter safety measures and stronger oversight.

But the oil commission also faces criticism, especially Republicans who charge that the makeup of the commission is unbalanced.

Several Republican senators, including John Barrasso of Wyoming and Robert Bennett of Utah, have criticized the lack of oil and gas experts on the commission and the use of what they call pro-environmental members.

And an editorial in New Orleans' largest newspaper on Sunday questioned the makeup of the commission.

"The president weighted the group with experts who appear more qualified to deal with the spill's effects than with its causes," according to the Times-Picayune editorial. "We're concerned commission members who have been environmental advocates may put their own agenda first, ignoring the nation's energy needs and the livelihood of Louisianans."

The editors went on to say that the president's commission needs to keep an open mind and "make a balanced assessment of our need for oil and of ways to mitigate the risks."

Advocates for the commission point out commission chief Reilly, a Republican, has ties to the energy industry, having served on the board at Conoco-Phillips. The Obama administration said the commission is full of well-qualified and unbiased scientists and experts.

"The 9/11 commission had certain advantages because you didn't have to put any terrorists on it," Hess said. "There was one American point of view. But with the oil commission, we see there [is] more than one point of view."

But even the 9/11 commission had trouble implementing some recommendations.

The 9/11 commission's heads discussed their frustration in May, saying several of their recommendations had not been properly implemented.

All of the problems are bureaucratic in nature, but threaten public security, said former commission Chairman Thomas Kean and Deputy Chairman Lee Hamilton.

CNN's Mike Ahlers and Shelby Lin Erdman contributed to this report.