Milestones of Flight

Celebrate some of the most significant, airplanes, rockets and spacecraft in history on this tour through the Smithsonian's National Air and Space Museum.

Capsule, Gemini IV Capsule, Gemini IVSmithsonian's National Air and Space Museum

Objects with a history

They tell tales of ingenuity and courage, war and peace, politics and power, as well as society and culture. These milestones have made our planet smaller and the universe larger. 

Lunar Module LM-2

The Apollo Lunar Module (LM) was a two-stage vehicle designed by Grumman to ferry two astronauts from lunar orbit to the lunar surface and back. LM 2 was built for a second unmanned Earth-orbit test flight. Because the test flight of LM 1, was so successful, a second test mission was deemed unnecessary. LM-2 was used for ground testing prior to the first successful Moon-landing mission.

Upper ascent stage

The upper ascent stage consisted of a pressurized crew compartment, equipment areas, and an ascent rocket engine. In 1970 the ascent stage of LM-2 spent several months on display at the "Expo '70" in Osaka, Japan.

Lower descent stage

The lower descent stage had the landing gear and contained the descent rocket engine and lunar surface experiments. When the LM-2 ascent stage returned to the United States, it was modified to appear like the Apollo 11 Lunar Module "Eagle".

LM-2 Rocket

LM-2 Rocket - NASA chose a craft that had only to land and take off -- the separate command module handled the aerodynamics of the return to earth. The lander rendezvoused with the command module in lunar orbit.

Ryan NYP Spirit of St. Louis

Charles Lindbergh made the first solo nonstop transatlantic flight from New York to Paris in the modified Ryan M-2. To accommodate the flight, the wingspan was increased by 10 feet and the structural members of the fuselage and wing cellule were designed to accommodate the greater fuel load. Other structural modifications were made to handle the additional weight and balance the aircraft.


After his historic nonstop solo transatlantic flight, Lindbergh took the aircraft first on a US tour and then on a goodwill flight to Central and South America. Flags of the countries he visited were painted on the cowling.


The Spirit of St. Louis had no windscreen. Lindbergh used a periscope on the left side of the aircraft to see ahead of him.

Flare tubes

Two flare tubes project from the underside of the “Spirit of St. Louis” that helped Charles Lindbergh land at night during his Latin American tour in late 1927, early 1928.

Glamorous Glennis

In 1947, the Bell X-1 Glamorous Glennis became the first airplane to fly faster than the speed of sound. Piloted by U.S. Air Force Capt. Charles E. "Chuck" Yeager, the X-1 reached a speed of 1,127 kilometers (700 miles) per hour, Mach 1.06, at an altitude of 45,000 feet (13,716 meters). In 1948, it attained a speed of 1,540 kilometers (957 miles) per hour, Mach 1.45, at an altitude of 21,900 meters (71,900 feet). This was the highest velocity and altitude reached by a manned airplane at that time.

High visibility

Yeager named the airplane "Glamorous Glennis" in tribute to his wife. The bright orange paint helped observers track the aircraft while it was in flight.


The fuselage is shaped like a .50 caliber machine gun bullet because the designers knew that high-powered bullets were stable in supersonic flight.


This was the United States' first successful orbiting satellite. The Explorer-1 satellite was successfully launched and placed into Earth orbit on January 31, 1958. Also known unofficially as Satellite 1958 alpha, transmitted data on micrometeorites and cosmic radiation for 105 days. Data from this and two subsequent Explorer satellites led to the discovery by James Van Allen of a belt of intense radiation surrounding the earth. 

Cosmic ray detection

The front section of Explorer contained the payload, which included a cosmic ray detector radio transmitter, and temperature and micrometeoroid sensors. Explorer’s light and dark stripes helped control its temperature. As Explorer spun about its long axis, four flexible antennas extended.

The rear section of Explorer was a solid-fuel rocket motor.


Launched from its White Knight mothership, the rocket-powered SpaceShipOne ascended just beyond the atmosphere, arced through space (but not into orbit), then glided safely back to Earth. The flight lasted 24 minutes, with 3 minutes of weightlessness. SpaceShipOne won the Ansari X Prize as the first privately-design and -flown space vehicle capable of carrying three people into suborbital spaceflight, the Collier Trophy for greatest achievement in aeronautics in 2004, and the National Air and Space Museum Trophy for Current Achievement.

SpaceShipOne has no heat shield or retro-rockets for reentry because it doesn’t need them, unlike earlier spacecraft.


With a unique design feature of jointed “feathered” wings, SpaceShipOne operated much like a badminton shuttlecock. Upon reaching top altitude, it tipped over for a smoother, more efficient reentry.


Rainbow striping painted on the wings and fuselage of SpaceShipOne. This temperature-sensitive paint was a low-cost, reliable way to determine the temperatures endured by the spacecraft.

Viking Mars Lander

This is the proof test article of the Viking Mars Lander. The Viking mission used two identical spacecraft, each consisting of a lander and an orbiter. Launched in August, 1975, Viking 1 spent nearly a year cruising to Mars, placed an orbiter in operation around the planet, and landed on the Golden Plains. Viking 2 was launched in September 1975 and landed on September 3, 1976. The Viking project's primary mission ended in November 1976, although the Viking spacecraft continued to operate for six years after first reaching Mars. The last transmission from the planet reached Earth on November 11, 1982.

Soil experiments

The digging arm on the Viking Lander collected soil for experiments. The biology experiments contained on the landers discovered unexpected and enigmatic chemical activity. They provided no clear evidence for the presence of living microorganisms in soil near the landing sites.

Viking dropped soil samples into three canisters for testing. Scientists concluded that the combination of solar ultraviolet radiation, the extreme dryness and oxidizing nature of the soil chemistry had prevented the formation of living organisms in the Martian soil.

Weather monitoring

The gas chromatograph -- mass spectrometer (GCMS) of the Viking Landers. The two landers continuously monitored weather at the landing sites and found both cyclical variations and exceptionally harsh climate that prohibited the possibility of life.

Historic capsule

In this historic capsule, John H. Glenn Jr. became the first American to orbit the Earth. Glenn's flight was the third manned mission of Project Mercury, following two suborbital flights by astronauts in 1961. Glenn's three-orbit mission on February 20, 1962, was a sterling success, as he overcame problems with the automatic control system that would have ended an unmanned flight. Glenn reentered successfully and splashed down in the Atlantic 4 hours, 55 minutes and 23 seconds after launch.

Mercury "Friendship 7"Smithsonian's National Air and Space Museum

The American Flag on Friendship 7 was one way to identify the capsule in the event it landed off course, but mostly it was a way of marking national pride.

Tense re-entry

Friendship 7’s re-entry was tense, as a faulty telemetry signal from the spacecraft indicated that the heat shield might be loose. Mission Control instructed Glenn not to jettison the retrorocket package after firing in order to better hold the heat shield in place.

Capsule, Mercury, MA-6 Capsule, Mercury, MA-6Smithsonian's National Air and Space Museum

The couch

The seat inside the Mercury Friendship 7 spacecraft was known as the couch. It was custom-made to fit John Glenn and his spacesuit during the mission.

X-15 rocket powered research

The North American X-15 rocket-powered research aircraft bridged the gap between manned flight within the atmosphere and manned flight beyond the atmosphere into space. After completing its initial test flights in 1959, the X-15 became the first winged aircraft to attain velocities of Mach 4, 5, and 6 (four, five, and six times the speed of sound). Three X-15 research aircraft were built and flown, completing a total of 199 research flights. The X-15 program gathered valuable data for the Mercury, Gemini, Apollo, and Space Shuttle programs.

Q-Ball nose

The “Q-Ball” in the nose of the X-15 served as an inertial flight data system capable of functioning in a highly dynamic pressure environment. The X-15 has a rounded nose to reduce aerodynamic heating.

Small wings

The X-15 has small wings because it flew very fast and didn’t need big wings to create enough lift. An alloy known as Inconel X (made of nickel with chromium, iron and columbium) gave the X-15 its black color and was highly resistant to heat.


The X-15 required conventional aerodynamic control surfaces to operate within the atmosphere and special “thruster” reaction control rocket located in the nose and wings kept the X-15 steady when flying out of the atmosphere.

Jet aircraft

The XP-59A is the first American jet aircraft. It did not see combat but it did give the U.S. Army Air Forces and the U.S. Navy  experience with jet aircraft technology and helped pave the way to more advanced designs. The United States was slow to enter the field of jet propulsion. Political and military leaders chose to forego rushing jet airplanes into service and concentrated instead on mass-producing and fielding more conventional designs that could contribute more quickly to the war effort.

Fake propeller

To confuse enemy spies from seeing America’s first jet aircraft, U.S. Army Air Forces’ personnel added a fake propeller to the Bell XP-59A Airacomet when it was on the ground during its flight tests into the fall of 1942.

Air for power

The two large air intakes for the jet engines under each wing make the XP-59 unique. Its jet engines “breathe” air to give it power.


Because the XP-59 was first intended to be a fighter, it was painted in standard US Army Air Forces olive drab and light gray camouflage paint.

Titan II

On June 3, 1965, a Titan II rocket launched this spacecraft, Gemini IV, carrying astronauts James McDivitt and Edward White into orbit. The flight lasted four days -- the first long-duration mission for the U.S. -- and included a historic space walk by White, the first by an American, early in the mission. The flight plan also included a rendezvous with the discarded second stage of the Titan II rocket. It was aborted, however, after pilot Jim McDivitt experienced unexpected difficulties reaching the booster.

Complicated manoeuvers

Unlike the Mercury program before it, astronauts piloted the Gemini spacecraft. This enabled more complicated manoeuvers in space, including rendezvous and docking. Like Mercury, it was very cramped inside the capsule and Gemini missions lasted much longer.

Capsule, Gemini IV Capsule, Gemini IVSmithsonian's National Air and Space Museum

Earth photography

Gemini had two windows. Other experiments during this flight included Earth photography. After being used by Mercury Astronaut Walter Schirra, the Hasselblad camera became the standard used by Gemini astronauts to photograph the earth and other objects in orbit.

Two by two

Gemini is a two-man capsule with two windows and two crew egress hatches.

SR-71 Blackbird SR-71 BlackbirdSmithsonian's National Air and Space Museum

Explore some more

To find out more about flight and space travel through the ages, visit the Smithsonian National Air and Space Museum page.

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