The wild blue yonder -- it's been the domain of the US Air Force for seven decades. That's when the USAF became an independent military branch, breaking away from the US Army at the dawn of jet planes and the atomic age.
In this slideshow, we'll take an anniversary tour of the aircraft that Air Force pilots have flown, from 70 years ago to the present day. Pictured here are F-16 Fighting Falcons flying in tight formation for the Thunderbirds, the Air Force's demonstration squadron.
Captions by Jon Skillings. Originally published July 26, 2017. Updated Sept. 16 with additional slides.
The Air Force arose out of the National Security Act of 1947, which -- quite appropriately -- President Harry Truman signed aboard this aircraft, the one-of-a-kind Douglas VC-54C known as the "Sacred Cow." In the early 1950s, the propeller-driven plane would become the first to take on the designation Air Force One.
Truman signed the bill on July 26, 1947, and the Air Force became an independent branch two months later, on Sept. 18, making this year the 70th anniversary.
In its first decade, the US Air Force was still flying a good number of vintage propeller-driven planes even as jet aircraft were taking over. Pictured here, at top right, is the North American F-82 Twin Mustang, which entered service shortly after World War II ended and which saw action in the early months of the Korean War. Bottom right is the jet-powered Lockheed F-94 Starfire that replaced the F-82 in 1951. Top left is the Lockheed F-80 Shooting Star and bottom left, the North American F-86 Sabre.
The F-86 was born at almost the very same moment as the US Air Force. Its first test flight was in October 1947, and it went into production the next year. Various models of the F-86 would see a good deal of combat in the Korean War, notably including aerial matchups against MiG-15 aircraft flown by Soviet pilots. Some models served in a ground attack role.
October 1947 also brought an incredible achievement by Air Force pilot Capt. Chuck Yeager. Midway through that month, he became the first person to fly faster than the speed of sound, a feat he accomplished in the Air Force's Bell-built X-1. The achievement was classified as top secret -- the Air Force didn't confirm the supersonic flight until March 1948.
For more than 15 months from 1948 into 1949, the Air Force ferried supplies in the Berlin Airlift, one of the first big confrontations of the Cold War. Lined up for unloading at Tempelhof Airfield in Berlin are Douglas C-47 Skytrain aircraft, derived from the civilian DC-3. They were later superseded by the larger, faster, four-engine Douglas C-54 Skymaster.
A few years later, this is a Fairchild C-119 Flying Boxcar -- what a great name! -- on a supply mission to drop rations and gasoline to UN troops on a battlefield near Chungju, Korea. Look close, and you can see a second Boxcar in the far background. The C-119 entered service late in 1949.
Cold War muscle-flexing often involved bombers and the ability to project force a long way from home. In 1949 this Boeing B-50A Superfortress, known as the Lucky Lady II, carried out the first-ever nonstop round-the-world flight. The circumnavigation by the Air Force aircraft took 94 hours, 1 minute -- 2 hours less than four full days -- from Feb. 26 to March 2, and required the assistance of four pairs of KB-29M tankers, which carried out an unspecified number of refuelings.
This was one of the more intimidating aircraft of the 1950s, the Convair B-36 Peacemaker. Throughout that decade, it was the Strategic Air Command's primary delivery system for nuclear weapons, and it was said to have the range to reach any target and return without refueling. It was huge, too -- 163 feet long, with a 230-foot wingspan and a bomb bay the size of four railroad freight cars.
The distinctive look came from the B-36's rear-facing pusher propellers (an echo of the very earliest planes from the likes of the Wright Brothers). Beginning with the D model, this brute added a pair of jet engines toward the outer reaches of the wings, to provide bursts of speed. After this point, all new designs for strategic bombers would be just jet-powered.
Just like bombers, cargo aircraft were getting bigger, too. This is a Douglas C-124C Globemaster at the National Museum of the United States Air Force in Dayton, Ohio. Back in the day -- the C-124 went into service around the start of the Korean War -- this 48-foot-tall aircraft could carry tanks, bulldozers and artillery pieces, 200 fully equipped soldiers, or 127 wounded on stretchers (along with medical personnel). Its nickname of "Old Shaky" makes you wonder how comfortable -- or queasy -- a ride it was.
But size wasn't the only sign of progress. So too were speed and power. This is a Boeing B-47B Stratojet, in a rocket-assisted take-off in April 1954. (This aircraft needed the rocket boost to supplement the jet engines to get off the ground when fully loaded.) Besides serving as a bomber, the B-47 -- which had a maximum speed of about 600 mph -- also pulled duty as a reconnaissance aircraft.
Now we're getting supersonic. The Convair F-102, an interceptor, served as the Air Force's first operational delta-wing aircraft -- see the shape of the wings in the overhead view -- hence the name Delta Dagger. The F-102 flew for the first time in 1953, became operational in 1956 and was a mainstay of the Air Force into the 1960s.
Faster still was the Lockheed-built F-104 Starfighter, also an interceptor, which became operational in the mid-1950s. In May 1958 an F-104A set a world speed record for the time of 1,404 mph, and in December 1959 an F-104C set an altitude record of 103,395 feet. The F-104C seen here is at at the National Museum of the US Air Force.
If there's one Air Force aircraft that everyone knows, it's the Boeing B-52 Stratofortress, one of the most potent symbols of American military might for more than six decades. The first production model made its maiden flight on Aug. 5, 1954, and although the Air Force took its final delivery of the heavy bomber in 1962, more than 70 of the H model aircraft -- all regularly updated -- are still in active service or on reserve duty.
The B-52 hasn't just carried and dropped bombs. It's also served as a mothership for other aircraft, as in this 1959 photo showing an X-15 just after its release from a wing mount. These airborne launches took place at about 45,000 feet with the planes moving at 500 miles per hour or better. The X-15 typically was propelled by its rocket engine for about 1 to 2 minutes, then flew for 8 to 12 minutes without power before coming to Earth in a 200-mph glide landing.
An amazingly versatile aircraft, the Lockheed C-130 Hercules continues to serve more than 60 years after its debut flight. A cargo aircraft in its primary role, it has variants that work as gunship or aerial tanker or in jobs ranging from weather reconnaissance to electronic warfare. This one is dropping supplies somewhere in Southeast Asia during the Vietnam War.
From the late 1950s onward, the Lockheed U-2 flew high-altitude reconnaissance missions. In October 1962, US Air Force pilots flying U-2 aircraft (commandeered from the CIA) featured in significant moments of the Cuban Missile Crisis, one of the tensest standoffs in the long confrontation between the US and the Soviet Union. One took photos that revealed the presence of Soviet missile bases in Cuba; just over a week later, a second pilot on a similar mission died when his U-2 was shot down.
When the delta-winged Convair B-58 Hustler came into service in 1960, it was the first operational supersonic bomber for the Air Force. This one, parked at the National Museum of the US Air Force, set speed records in 1962, flying from Los Angeles to New York in 2 hours, 57 seconds, at an average speed of 1,214 mph, and then again for the return trip and the round trip.
In the early 1960s, the Mercury Seven astronauts were the first Americans to venture into space Three members of the group were Air Force pilots: Gordon Cooper (second from left), Gus Grissom (fourth from left) and Deke Slayton (at right). Because of a health issue, Slayton didn't fly in those Mercury missions, but he did get to orbit in the 1970s in the Apollo-Soyuz project. The seven are posing here in front of an F-106 Delta Dart.
This Air Force officer, Joe Kittinger, took a balloon into the stratosphere -- and jumped. Researchers wanted to know how astronauts and high-flying aircraft pilots would deal with ejecting from their vehicles at extreme altitudes. On Aug. 16, 1960, at an altitude of 102,800 feet (19.5 miles), he jumped from the gondola of his balloon -- the plaque on the threshold says, "This is the highest step in the world" -- and on the way down reached a speed of 614 mph. Kittinger's achievement remained unmatched until Felix Baumgartner's much more famous jump in October 2012.
The Vietnam War entered a heavier phase in 1965 when the Air Force began striking targets in North Vietnam during Operation Rolling Thunder, which would last three years. The aircraft dropping bombs here are Republic F-105 Thunderchiefs.
Here you see all of a KC-135 Stratotanker as it fuels a Douglas EB-66 in an undated photo. The KC-135, built on the same design as the Boeing 707 commercial aircraft, entered service in 1957, and even though the Air Force last took delivery of this tanker in the mid-1960s, dozens are still in service today. The Douglas EB-66 was an electronic warfare variant of the B-66 Destroyer bomber, which itself was derived from the Navy's A-3 Skywarrior and which flew for the Air Force from 1954 to 1973. The first electronic warfare B-66s went to Southeast Asia in the spring of 1965, according to the National Museum of the US Air Force.
A long-range strategic reconnaissance aircraft, the Lockheed SR-71 began its Air Force career in 1966. In July 1976, an SR-71 set two world records -- for speed (2,193 mph) and for altitude (85,069 feet).
That's a big mouth on a big plane: The Lockheed Martin C-5 Galaxy, the largest "airlifter" in the US Air Force inventory, is one of the largest aircraft in the world, period. It has five sets of landing gear, with a total of 28 wheels, which helps when you can pack in up to 270,000 pounds (122,470 kilograms) of cargo. It also holds up to 51,150 gallons of fuel, which itself weighs 332,500 pounds. The first operational C-5 flew for the Air Force in 1970. This one is being loaded with cargo for troops in the desert in 1991 during Operation Desert Storm.
The Air Force took delivery of its first A-10 Thunderbolt II in late 1975, and the ground-attack planes -- better known as "Warthogs" -- remain in service. How much longer, though, remains in question. For months now, the Air Force has talked of axing the budget for them and retiring the fleet, but at last check, it plans to keep the Warthogs going for the foreseeable future.
The E-3 Sentry also goes by the name of AWACS, for airborne warning and control system. Think of it as the Air Force's eye in the sky. Its distinguishing feature is the rotating radar dome on top, but the aircraft -- a modified Boeing 707 -- is packed with sensors, computers and communications systems that provide detailed information on the terrain below and the other aircraft in the area. E-3 aircraft have been in service since the late 1970s.
This looks like a fighter but it's actually a specialist in electronic warfare. The supersonic EF-111A Raven packed high-powered transmitter antennas (in that black bulge on the bottom of the fuselage) that could jam enemy signals, along with receiver antennas (in the pod on top of the tail structure) for picking up on incoming radar waves. All that gear required a dedicated electronic warfare officer on board. EF-111A aircraft served through the 1980s and 1990s. And you weren't wrong to think of it as a fighter -- it was a modification of the F-111 Aardvark, a long-range strike aircraft (which also served as a bomber) that had been around since the late 1960s.
An Air Force HH-60 Pave Hawk helicopter lands near its cousin, a US Army UH-60 Blackhawk on a medevac pickup in Afghanistan in 2006. The Pave Hawk's main mission is combat search and rescue. This helicopter entered the Air Force inventory in 1982.
You probably don't think about the tires on an airplane, except when you bump down onto the runway for a landing. You would if you were a crew chief like the ones here dealing with a blown tire on a Boeing B-1B Lancer. This supersonic long-range heavy bomber joined the Air Force in the mid-1980s.
When it came along in the mid-1980s -- and finally was revealed to the public in 1988 -- the Lockheed F-117 Nighthawk was unlike anything we'd ever seen in the skies. The fuselage looked like a geometry exercise. Those angles, though, helped make the Nighthawk hard to detect by radar -- and thus the world's first operational stealth aircraft. That aerodynamically unstable design also required constant course corrections by flight control systems.
The B-2 Spirit bomber, a sleeker stealth aircraft also revealed in 1988, used a flying-wing design, combined with a body made of composite materials, special coatings and other technologies, to hide from radar. With aerial refueling, the B-2 can reach just about anyplace on the planet from the US. Over the last two decades, these stealth bombers have flown missions out of Missouri to places as far away as Kosovo, Afghanistan and South Korea, and back.
The Air Force lends its name to the aircraft that flies the president of the US. You know it best as Air Force One -- the radio call sign when the commander in chief is aboard -- but it also carries the military designation VC-25. There are just two of these converted Boeing 747-200B aircraft, the first of which took up the role in 1990. Though the Air Force One name dates back to the 1950s, it became well-known during the Kennedy administration, when the presidential aircraft was a Boeing C-137 Stratoliner.
The Air Force values the C-17 Globemaster III for its ability to handle any cargo or airlift mission, including operating in and out of "small, austere" airfields. The first squadron of C-17 aircraft became operational in 1995. This one's being guided along the tarmac at Al Udeid Air Base, Qatar, in 2016.
The Lockheed Martin F-22 Raptor became operational at the end of 2005. It features stealth characteristics and "supercruise" capabilities -- that is, the ability to fly supersonic without using an afterburner, which helps it conserve fuel at those hellacious speeds. The F-22 here is taking off from Ämari Air Base, Estonia, in 2015.
The Osprey flies like an airplane and like a helicopter, thanks to its tiltrotor design. With the engines in the propeller-forward position, as here, it moves through the air like an airplane. With the engines and propellers rotated up, it can lift off and land vertically, like a helicopter. A tag team creation of Boeing and Bell Aircraft, it began service in 2006 with the Air Force, which uses it on special operations missions. This photo shows a CV-22B from the vantage point of an MC-130 Combat Talon II aircraft that's refueling it off the coast of Greenland in 2013.
The story of the Air Force has been, in large part, the story of its pilots. What happens, though, when planes no longer need a pilot, or at least one in the cockpit and flying in harm's way? That's been an active question for the last decade as drones became a significant part of the Air Force arsenal. Pictured here is an MQ-9 Reaper, armed with GBU-12 Paveway II laser-guided munitions and AGM-114 Hellfire missiles, flying a combat mission over southern Afghanistan but piloted from the US, thousands of miles away. The Reaper came into the picture in 2007, two years after its sibling, the MQ-1 Predator.
Even more futuristic is the X-37B, the Boeing-built space plane that flies itself. The X-37B rides out of the atmosphere atop a rocket, then cruises in orbit for months at a time before guiding itself back to Earth, gliding home like the larger (and piloted) space shuttles it resembles. Since 2010, the Air Force's pair of X-37B Orbital Test Vehicles have completed a total of four trips into space, the most recent of which ended in May after a secret mission that lasted nearly two years. A new mission began on Sept. 7, lifted aloft by a SpaceX rocket. Seen here is OTV-1 after landing at Vandenberg Air Force Base, California, in December 2010.
The Air Force is now getting to know the F-35A Lightning II, which does need a pilot aboard. Referred to as a fifth-generation fighter, it's meant eventually to replace the Air Force's F-16 and A-10 aircraft. This one is taking off from Langley Air Force Base, Virginia, in 2016.
Don't look for this one in the sky just yet. It's an artist's rendering of what the planned B-21 Raider might look like (which, as it stands, is a lot like the existing B-2 bomber). In late 2015, the Air Force selected Northrop Grumman as the prime contractor for the future long-range strike bomber, but lots of details remain to be worked out -- how many of the aircraft the Air Force will acquire, what munitions it will carry, what other specific capabilities it will have, and whether it will be manned or unmanned.