In an instant, four tons of steel and explosives slammed into the 522-foot-long warship Schenectady, blowing it apart in a cataclysm of smoke, dust and sound. Overhead, a pair of U.S. Air Force Boeing B-52 bombers orbited, one of them having just released four laser-guided bombs. The huge, eight-engine warplanes had flown directly from Louisiana to attack the decommissioned Navy landing ship as part of** an exercise near Hawaii on Nov. 23, 2004.

*Schenectady'*s dramatic destruction marked a turning point in the Pentagon's approach to aerial warfare, and led directly to one of the flying branch's riskiest-ever investments. The sinking of the Schenectady by the Air Force was meant to prove to the flying branch's reluctant Pentagon masters that bombers could play an important role in a major ocean battle against China and its gigantic navy. In underscoring bombers' usefulness, the Hawaii demonstration was also part of the Air Force's efforts to get the Defense Department to sign off on a new bomber program. Two years later, the Air Force got its wish when the Pentagon finally gave the go-ahead for the so-called "Next-Generation Bomber."

But that program foundered and was cancelled three years later. After a change in leadership in the Defense Department, the Air Force once more pushed for a new bomber initiative – and, again, got it. This year the Pentagon launched a potentially $55-billion effort to build a better bomber, one capable of replacing the venerable B-52 and preserving the long-range, heavy strike prowess the Air Force demonstrated that day off Hawaii eight years ago.

The "Long-Range Strike Bomber" program is a subject of great concern inside the Pentagon, and the topic of my latest investigative feature for the Center for Public Integrity. (The Atlantic also has a version of my story.) Even more than the Air Force's notoriously expensive stealth fighters, bombers are susceptible to program delays, budget overruns, cutbacks and skyrocketing costs. For half a century, bombers have been a symbol of the Air Force's overwhelming firepower ... and a poster child for Pentagon waste.

If history is any judge, the development and production of up to 100 new Long-Range Strike Bombers has a high probability of ending disastrously. Every time the Air Force has tried to buy a new heavy warplane to replace the 1960s-vintage B-52, it has ended up spending tens of billions of dollars for a dwindling number of aircraft.

In the '50s and '60s the Air Force built nearly 800 B-52s for just $70 million apiece in today's dollars. The first bomber meant to replace the B-52, the '80s-vintage swing-wing B-1, ended up costing more than $200 million per plane. The third effort, the stealthy B-2 (pictured), shattered cost records with its eye-watering $3-billion-a-pop unit price. Today the Air Force possesses just 60 B-1s and 20 B-2s. The 70 surviving B-52s still form the backbone of the bomber fleet, more than 50 years after they entered service. All three bomber types have been heavily involved in aerial campaigns over Serbia, Afghanistan, Iraq and Libya in the past 15 years.

Even so, the Air Force's inability to replace the B-52 at reasonable cost led the Pentagon at one time to essentially abandon bomber development. As recently as 1999, the Defense Department had no plans to buy a new bomber before 2037. But the Air Force, nervously observing the rapid growth of the Chinese military, believed it needed a new bomber to stay ahead in the Pacific. The orchestrated destruction of the Schenectady was part of the Air Force-led campaign that helped convince the Pentagon that bombers were critical to winning any future air war against China. Sinking the old Navy ship was meant to prove that the Air Force could defeat a Chinese invasion fleet steaming towards Taiwan, according to retired Lt. Gen. Dave Deptula, who helped organize the 2004 demonstration.

Today Deptula is part of a group of current and retired senior officers who have spoken out on behalf of Air Force bombers. "They allow you to project power globally without projecting vulnerability," Deptula says of the heavy warplanes. In other words, bombers can deliver massive firepower without the need to deploy a big, vulnerable ground force.

Donald Rumsfeld, the secretary of defense from 2001 to 2006, was convinced by the bomber advocates' arguments and gave the flying branch permission to develop the so-called "Next-Generation Bomber." But that new plane design quickly grew to be as complex – and potentially as expensive – as the $3-billion-a-copy B-2. Robert Gates, who took over from the disgraced Rumsfeld, was aghast. "It makes little sense to pursue a future bomber – a prospective B-3, if you will – in a way that repeats [the B-2's] history," Gates said. In 2009 he cancelled the Next-Generation Bomber. Gates advised the Air Force to try again with a more affordable design.

The air service followed Gates' advice, but waited until the recalcitrant Pentagon chief and his closest advisers, including Marine general and noted bomber skeptic James Cartwright, retired in mid-2011. The Air Force found Gates' successor Leon Panetta more amenable to a potentially pricey new bomber program. With the Pentagon on board, the Air Force also lobbied Congress for support, and in the 2012 defense budget legislators ponied up $297 million to start work on the Long Range Strike Bomber's blueprints. That sum was $100 million more than the Air Force originally requested in its 2012 budget proposal. In essence, Congress is doubling down on the Air Force's risky bomber bet.

Mindful of its poor track record in developing bombers and still stinging from Gates' public rebuke, the Air Force has vowed the Long-Range Strike Bomber will be different than previous models. "We are ... cautious," Air Force Secretary Michael Donley said. "Cautious not to repeat the painful experience of previous Air Force bomber programs." The Pentagon has promised to cancel the new bomber again if projected development and purchase costs exceed $55 billion. To keep costs down, the Air Force says it's using only existing hardware in the new warplane. Nothing will be invented from scratch, like it was for the cutting-edge B-1 and B-2.

But there are good reasons to be very, very skeptical of the Air Force's assurances. For in addition to possessing traditional attributes such as long range and heavy payload, the flying branch wants the Long-Range Strike Bomber to include an optional robotic mode. With the flip of a switch, the new plane should be able to transform from a normal manned aircraft to one that can be flown remotely by crews on the ground.

That's meant to give the bomber the best attributes of a killer drone (long endurance, no risk to aircrews) and a manned warplane (greater flexibility and the ability to respond to a fast-acting enemy). But "optional manning," as it's known, has never been attempted on such a large scale before. It represents a big unknown in a program the Air Force insists will rely only on well-understood technologies.

"The new bomber will be both less expensive and more capable than its predecessor," Deptula says. If he's right, the Air Force could begin re-equipping with Long-Range Strike Bombers in around 10 years, sustaining for decades the promise of massive, long-range firepower that those ancient B-52s demonstrated near Hawaii that day eight years ago. If he's wrong, then the historical trend will continue. The Air Force will spend more and more on new bombers, with less and less to show for it.

Read the full story here.