South Dakota museum reveals America’s secret pre-NASA space program

Explorer II’s Record-Breaking Stratosphere Flight from Black Hills

In 1934, a quiet bowl-shaped canyon in South Dakota’s Black Hills made history.

The Army Air Corps and National Geographic picked this spot, called the Stratobowl, to launch giant balloons into the stratosphere.

Their first try with Explorer I ended when the balloon tore at 60,613 feet, forcing three men to jump as their craft burst into flames. Yet they tried again.

On November 11, 1935, Captains Stevens and Anderson soared to 72,395 feet in Explorer II, a world record that stood for twenty years. From that height, they took the first photos ever showing Earth’s curve.

The South Dakota Air and Space Museum now tells this amazing story of America’s first steps toward space.

Nature’s Perfect Bowl Kept Airmen Safe From Wind

The Stratobowl sits tucked away in South Dakota’s Black Hills near Rapid City.

This natural dip looks like someone scooped out part of the forest floor, making a round valley with rocky edges all around.

In the 1930s, the National Geographic Society and US Army Air Corps got excited about this spot. They needed a place where giant balloons could fill up without wind tearing them apart.

The bowl-shaped canyon worked great – tall ridges blocked wind while the flat grassy bottom gave crews plenty of room.

A Mining Engineer Wanted to Touch the Stars

Captain Albert Stevens first came up with the idea of flying balloons to the upper sky. Before joining the Army Air Corps, he worked finding minerals, but he really loved taking pictures from the air.

Stevens thought balloons could carry men and tools higher than any plane could fly. He wanted to measure cosmic rays and study what happens where the air gets very thin.

The National Geographic Society liked his plan and joined forces with the Army Air Corps in 1933.

Three Brave Men Got Into a Metal Ball

Major William Kepner led the Explorer I mission, with Captain Stevens handling the science work and Captain Orvil Anderson running balloon operations.

They didn’t ride in a typical balloon basket – workers built them a sealed metal ball to keep air pressure normal and heat bearable at extreme heights.

The crew packed the ball with tools to measure radiation, air pressure, and heat. Their hydrogen-filled balloon stood taller than a 30-story building when full.

Thousands Watched the Giant Bubble Go Up

On July 28, 1934, people flooded into the Black Hills to see history happen.

About 30,000 folks lined the ridges around the Stratobowl, making a human ring around the launch site. NBC radio set up gear to broadcast the event live across America.

At dawn, ground crews started filling the huge balloon with hydrogen gas. By mid-morning, the balloon towered over the trees, pulling at its ropes.

When let go, Explorer I shot upward as the crowd cheered.

The First Flight Ended With Fire

Explorer I climbed steadily for hours, finally reaching 60,613 feet – nearly twice as high as today’s airplanes fly. The crew sent radio messages and gathered data until they spotted a problem.

Their balloon had a tear, letting hydrogen leak out. They started coming down fast, but at 5,000 feet, disaster struck.

The leaking hydrogen caught fire, causing a big explosion. The ball fell toward the ground as the balloon broke apart.

All three men jumped out with parachutes and lived.

Helium Replaced Hydrogen After the Big Bang

After figuring out what went wrong with Explorer I, the team made big changes. They switched from easy-to-burn hydrogen to much safer helium gas for their next try.

Workers redesigned the ball with better seals and improved air systems to keep the crew comfy for longer flights. They also added better radios so the balloon could talk to ground stations throughout its trip.

Launch steps got fixed too, with improved ways for filling and letting go of the giant balloon.

Two Airmen Got Ready for a Second Try

Explorer II came together in fall 1935 with many improvements. This time, only two men would make the trip – Captain Stevens and Captain Anderson.

The smaller crew allowed for more science gear and extra safety stuff. Their new balloon used stronger materials and could lift more than the first version.

Stevens packed special cameras to capture Earth’s curve from very high up. The team picked November for launch, hoping the cooler fall air would help the balloon rise higher.

A Balloon Took Men Higher Than Anyone Had Gone Before

Explorer II took off on November 11, 1935, with about 20,000 people watching from the Stratobowl ridges.

The balloon worked perfectly, carrying Stevens and Anderson to an amazing 72,395 feet – nearly 14 miles above Earth. This world height record lasted for twenty years.

From their spot near space, the men saw the clear curve of our planet against the black sky.

Their eight-hour flight went as planned, with a smooth landing in a White River field about 225 miles from where they started.

Scientists Saw the Edge of Space for the First Time

The Explorer II mission brought back lots of valuable information. Stevens and Anderson collected measurements showing how cosmic rays get stronger at higher heights.

Their tools recorded how temperature drops to minus 70 degrees in the upper sky. They mapped changes in the ozone layer that shields Earth from harmful rays.

Their cameras took amazing photos showing the atmosphere as a thin blue line against the darkness of space.

The Hubbard Medal Honored Their Bravery

President Roosevelt personally congratulated Stevens and Anderson for what they did.

The National Geographic Society gave both men its highest award – the Hubbard Medal – previously given to explorers like Charles Lindbergh and Admiral Richard Byrd.

Their flight data appeared in science journals worldwide and filled a special issue of National Geographic Magazine. The men traveled around the country giving talks about their trip and what they learned.

Space Travel Got Its Start in a South Dakota Valley

The Stratobowl flights directly shaped the future of aviation and space travel. Aircraft designers used the mission data to create pressurized cabins for high-altitude planes.

Military programs adopted the crew’s oxygen systems and cold-weather gear for pilot training. NASA later borrowed techniques from these balloon flights when planning early space missions.

Today, the Stratobowl remains much as it looked in the 1930s. Visitors can hike to overlooks with informational signs explaining the historic flights.

The South Dakota Air and Space Museum in Rapid City displays artifacts from the missions, including instruments and photos from mankind’s first journey to the edge of space.

Visiting South Dakota Air and Space Museum

The South Dakota Air and Space Museum at 2890 Davis Dr in Box Elder showcases the famous Stratobowl balloon launches from the 1930s that first reached the stratosphere and captured Earth’s curvature.

You can visit Wednesday through Friday 9am-4pm and Saturday 10am-2pm for free admission.

The museum has four galleries with interactive displays and flight simulators, plus indoor and outdoor aircraft exhibits featuring historic military planes from different eras.

This article was created with AI assistance and human editing.

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