The Pentagon has awarded a contract to begin development of the most expensive helicopters ever made.

Each helicopter will probably cost at least $400 million. The entire project, to build at least 23 helicopters, has been estimated to eventually cost between $10 billion to $17 billion. By comparison, the project could pay the combined defense budgets of Finland, Norway, and Sweden for one year ($16.9 billion).

The passengers for this enormously expensive helicopter fleet? The President of the United States and his entourage.

The first president to fly regularly in helicopters was Dwight Eisenhower. Eisenhower faced a two-hour commute to and from his summer home in Rhode Island, a commute that could be shaved down considerably if taken by helicopter. In these early days of the Cold War the president needed to be moved around quickly—the president could not be stuck on a ferry for an hour in case the Soviet Union launched a nuclear attack.

The South Lawn of the White House was designated as the official presidential helicopter landing pad, and official flights to Andrews Air Force Base began.

A Marine Corps helicopter squadron, HMX-1 (“The Knighthawks”) is responsible for flying and maintaining the fleet of presidential helicopters. The current Marine One helicopters are derivatives of the Sikorsky Sea King helicopter, which was phased out of the U.S. military during the 1990s. Those currently flying were built somewhere around 1975, making them only 14 years younger than President Obama himself.

In 2002, the U.S. government solicited proposals for replacing the Sea Kings with a new, modern helicopter. In the wake of 9/11, with concerns about terrorist attacks against the president, the call went out for a helicopter that could fend off a terrorist shoulder-fired surface to air missile and keep functioning in the wake of a nuclear attack on Washington, D.C.

In 2005, the Department of Defense announced that the team of Lockheed Martin and the Anglo-Italian helicopter giant AgustaWestland had won the contract to build 28 presidential helicopters. The helicopters would be known as the VH-71 Kestrel. (The “V” stands for “VIP Transport”)

At the time the contract was signed, the estimated cost of the program was $6.5 billion, or $232 million per helicopter, including development costs. Unfortunately, the Kestrel program spun rapidly out of control, dragged down by the weight of program requirements and other “good ideas.”

Marine One helicopters must satisfy a number of requirements. The president’s helos must be small enough to land on the South Lawn, but large enough to lift 14 people and several thousand pounds of equipment a distance of 300 miles. The helicopters must be armored, with a bullet-resistant fuselage and glass.

The president’s helicopters must have a full suite of defensive countermeasures to throw off the targeting and guidance systems of missiles. They must be “hardened” against the electromagnetic pulse of a nuclear blast that could fry electronics and knock out everything from smartphones to helicopters.

Secure communications are must-haves. Marine One must be able to send and receive encrypted communications and hold secure videoconferences with U.S. military and government leaders worldwide, including those in charge of U.S. nuclear forces.

Finally, the president’s helicopter must include a toilet.

So many requirements were piled on the Kestrel program that it was decided the helicopters would need new engines, gear boxes, and drive trains just to lift everything, not to mention a 180-pound President of the United States. The program quickly became so expensive each helicopter—then estimated to cost about $400 million in 2009 dollars—rivaled the cost of Air Force One, the president’s Boeing 747 jumbo jet.

Even President Obama seemed bewildered by the runaway program. “The helicopter I have seems perfectly adequate to me," Obama said. "Of course, I've never had a helicopter before. Maybe I've been deprived and I didn't know it.”

The program was cancelled in 2009, with $3 billion already spent.

The new, initial contract awarded to the American defense contractor Sikorsky, is valued at $1.24 billion. Under the terms of the new contract, the U.S. military will take delivery of two prototype helicopters—based on the Sikorsky S-92 medium helicopter--in 2016. Another 21 fully capable helicopters will follow.

Why so many helicopters, essentially for one person? Marine One always flies with decoys—as many as five—when transporting the president. Multiple helicopters are also needed when the president travels outside Washington D.C., as fresh helicopters are cached along the route ahead of time.

Time will tell if Sikorsky can hold down costs and deliver the helicopter on time. One thing’s for sure, though: President Obama himself will never ride on one, except as a guest. The fleet of new presidential helicopters should be fully operational by 2022, long after Obama has left office.