Congressional critics and outside analysts are taking aim at the Department of Homeland Security's plan to defend passenger planes against shoulder-fired missiles.

On Monday, Dr. Charles McQueary, the department's undersecretary for science and technology, announced an "aggressive" two-year study to "determine if in fact there is a viable and effective technology we could deploy to protect commercial aircraft."

Under McQueary's plan, three defense contracting teams will have six months and $2 million each to put together road maps for adapting military antimissile systems to civilian jets. Then the department will decide whether to build and test a prototype. That process could take up to a year and a half.

But that's too few decisions in too much time, critics contend. In a little more than a year, so-called MANPADS (short for man-portable air defense systems) have been used to attack an Israeli jet over Kenya, a DHL cargo craft over Iraq, a U.S. Army Chinook helicopter, and an Air Force C-17 transport plane. More than half a million of the weapons have been made since the mid-'60s, and tens of thousands of them are unaccounted for. The military's planes already have MANPADS countermeasures on board, argues Sen. Charles Schumer (D-New York). Why wait to put them on passenger jets?

"Shoulder-fired missiles are probably the greatest danger commercial airliners face in today's world. While I'm glad DHS (Department of Homeland Security) is finally moving forward, it's at much too slow a pace. We can't afford to wait another two years to outfit planes -- it's already been 14 months since the Kenya attacks," Schumer said in a statement.

My Wired News article has details on the MANPADS debate.

THERE'S MORE: In September, the Bush Administration pledged $100 million towards jet defense -- and $60 million is budgeted this year towards these efforts. The month before, Northrop Grumman revealed a project to zap oncoming missiles with a chemical-powered laser.

AND MORE: In the Boston Globe, MIT's Theodore Postol and Geoffrey Forden argue that "foiling aircraft attacks isn't rocket science." They point to a number of relatively simple technologies which could help prevent jetliner hijackings.

"Multiple tiny video cameras could be placed throughout a plane's passenger compartment to record initial actions that might lead to a takeover," they suggest. "Wireless videocams could even be worn on the clothing of flight attendants."

AND MORE: On Thursday, an Air Mobility Command C-5 transport plane was hit by a missile, witnesses say. Luckily, the craft made it back safely to Baghdad airport. A Black Hawk helpicopter, struck near Fallujah, was not so lucky. Nine soldiers are dead.