President Obama's executive order to close the Guantanamo Bay detention center by January and halt military trials of terrorism suspects there has revived painful memories of the Sept. 11 terrorist attacks for some relatives of the victims.

Obama has promised relatives of the victims that they would be part of the process of closing the prison. In February, he met with roughly 40 family members of the victims and said he wanted what they do: justice for their loved ones.

But some relatives have been frustrated by the administration's effort.

"I didn't go in there prepared for how frustrated I'd be afterward," said Melissa Long, referring to a meeting last month with Obama officials. "They listened, only one of them took notes and the rest of them took flak. They took a lot of heat. There was a lot of questions unanswered."

Melissa Long, who lost her boyfriend, a New York City firefighter, in the terror attack, is going to Guantanamo Bay to come face to face for the first time with the alleged Sept. 11 conspirators, whose case is before the military commission. Long secured a seat through a Defense Department lottery.

The Defense and Justice Departments are reviewing each of the 229 cases of terror suspects and foreign fighters currently at the U.S. Navy prison in Cuba.

Obama has ordered the prison closed by Jan. 22, 2010, but it's still unclear how many of the detainees will face trial, or where, and how many will be held indefinitely.

Long acknowledged the military commission are not perfect but still supports them.

"They based it on a court martial system, and if it's fair enough for our own military, why is it not fair enough for these enemy combatants," she said.

And Long fears evidence that could convict the Sept. 11 conspirators including Khalid Shiek Mohammed, the self-confessed architect, may not make it into federal court.

"What if the cases get thrown out?" Long asked. "Are we going to let them go?"

FOX News' Catherine Herridge and The Associated Press contributed to this report.