The new Air Force One arrives in 2024. Here's what we know so far.

Sometime in 2024, if all goes according to plan, whoever the president of the United States is at the time will receive two new airplanes: the future version of Air Force One. The current planes are Boeing 747s, and the next ones will be too, although they will be a new model that is longer, wider, and capable of going further and cruising faster than its predecessor.

Like the White House, Air Force One is a symbol that is supposed to transcend any presidential administration. “It doesn’t represent an individual president,” says Todd Harrison, the director of the Aerospace Security Project at the Center for Strategic and International Studies. “It represents the presidency and the U.S. government.”

Here’s what we know about the next version of Air Force One, which the Air Force calls the VC-25B.

Presidents haven't always flown in a Boeing 747. Kenneth Walsh, author of Air Force One: A History of Presidents and Their Planes, points out that President Truman wanted a distinctive design for his two-prop aircraft, the Independence. "It was painted to look like an eagle," Walsh says. He notes that it even had "tail feathers."

Later, President Eisenhower had a four-engine jet, a Boeing 707, which had, Walsh says, a "military style."

It wasn’t until the Kennedy administration that the plane, the same 707 from Eisenhower, received a blue and white paint job similar to what the current craft has. That’s also when the term “Air Force One” was born.

“They wanted a code name for air traffic control that would never be confused with another plane, and Air Force One seemed to have a certain majesty to it,” Walsh says. That code name, of course, also became the public term.

Kennedy made it into “a presidential plane,” Walsh says. Four-engine 707 jets served as Air Force Ones from 1959 to 1990.

The Air Force One of today dates back to the George H.W. Bush administration. He was the first president to fly in the same Boeing 747-200s that are still cruising today, known as VC-25A.

“The basic reason for updating them is that the existing fleet of planes are just getting old,” Harrison, of CSIS, says. Switching to newer planes provides the obvious benefits that come with a modern aircraft—more efficient engines and better reliability—and is also a chance to install new defence and communications equipment.

For example, during September 11, 2001, President George W. Bush had trouble with the on-board communications system, according to Walsh, who is a White House and political analyst for U.S. News and World Report, and has traveled on Air Force One some 300 times. "President Bush was upset a few times because his phone calls were getting cut off and dropped," Walsh says. "Now they've apparently fixed that."

Walsh also says that since 9/11 they made it easier for the president to address the country from the airplane.

The current plane also has understandably secretive defence capabilities. “What we do know is that Air Force One has a skin on it designed to ward off electromagnetic pulses if there was a nuclear war,” says Walsh. He presumes that the next version would have a similar system.

Walsh also says the current plane has the capability to deal with a weapon like a shoulder-mounted heat-seeking missile, which would be a risk during takeoff or landing. “We know there are countermeasures,” Walsh says, which could “ward off” an attack like that.

“Beyond that, the military doesn’t like to talk about it,” Walsh says. “We all suspect, in the press corps, that there’s a lot more protective systems there, but they’re kept very, very secret.”

For its part, the Air Force described the new planes, which are 747-800s, in a statement:

“Though modification specifics are not fully discussed due to operational security, expected updates include electrical power upgrades, a mission communication system, a medical facility, executive interior, a self-defense system and self-sufficient ground operations. The VC-25B, which will function as an airborne White House to allow the Commander in Chief to execute constitutional responsibilities while in transit, will also use the highest level of command and control military capabilities to maintain national security for all possible national contingencies or emergencies.”

And while the next-gen Air Force One reportedly won't be able to refuel in mid-air, Walsh says he's skeptical that that will ultimately be the case. "The whole point is that Air Force One can keep the president flying and safe during a calamity."

Oh, and they will cost $3.9 billion.