Record-Breaking Aircraft That Were Lighter than Air

Today, most people encounter lighter-than-air vehicles only in special situations. Helium-filled blimps provide aerial shots of stadiums for television broadcasts, and some passengers may enjoy hot-air balloon excursions over game preserves in East Africa or tethered over fairgrounds. But balloons and airships offer several advantages over heavier-than-air vehicles even if they can’t provide the commercially important value of speed.
 
Here are some examples of lighter-than-air vehicles that have pushed important boundaries.
 

First powered flight 

The Wright Brothers justly claim credit for the first airplane flight, which launched several industries and remade the world. But the first powered flight occurred more than 50 years earlier. A young French engineer named Baptiste Jules Henri Jacques Giffard designed and built a hydrogen-filled airship powered by a 250-pound, 3 horsepower steam engine. Unlike hot-air balloons (another French invention), Giffard’s airship had a propeller for forward propulsion and a rudder that allowed the pilot to change direction.
 
Giffard first flew his airship on September 24, 1852, travelling about 17 miles. While the design enabled the airship to maneuver and even fly in circles, the engine was not powerful enough to fly against the wind.
  

First trip to the North Pole 

During the Age of Exploration, adventurers risked life and limb to reach arbitrary points on the map—the source of the Nile, the top of Mount Everest, the bottom of the ocean. But no feat was as sought-after and dangerous as becoming the first person to reach the North Pole. A 1909 expedition over the surface of the polar icepack by Robert Peary was long credited with reaching 90 degrees latitude, but in recent decades, his claim has become discredited. 
 
Instead, the semi-rigid airship Norge is now believed to have carried the first people to the North Pole. Built in 1923, the flexible, fabric-covered hydrogen envelope was capped by metal frames on either end. Three 260-horsepower engines could propel the Norge to 70 miles per hour. An expedition, led by Roald Amundsen, who was the first person to reach the South Pole, set off in the spring of 1926 with a crew of 16. On May 12, 1926, the airship reached the pole and the international crew dropped Norwegian, Italian, and American flags on the spot to mark their achievement. 
 
Ice build-up on the propellers damaged the fabric envelope and Norge limped to a village in Alaska. The airship never flew again.
 

First non-stop flight around the world without refueling

Circumnavigations are a major achievement, but because they take so long to accomplish, airplanes need to refuel their engines. Prior to the Cold War, refueling required planes to land, but by the late 1940s, the U.S. Air Force perfected in-air refueling so that its bombers could circle the globe non-stop.
 
Balloons don’t have the refueling restriction, since the lighter than air envelope keeps the craft airborne without power. In 1999, pilots Bertrand Piccard and Brian Jones set out in the Breitling Orbiter 3, an 18-story balloon that carried a two-ton, pressurized gondola. Rather than a combustion engine, the solar panels and a battery pack provided power during the flight. Starting from a village in Switzerland, the balloon headed southwest to the Sahara Desert before catching winds that carried it east. Reaching altitudes as great as 38,500 feet, Piccard and Jones spent more than 19 days aloft before landing in Egypt. The gondola now resides at a National Air and Space Museum site in Virginia.
 

Record for highest skydive

Sometimes, an extreme feat isn’t possible without a good ride. For Alan Eustace, that meant hitching a ride on a high-altitude balloon.
 
Eustace wasn’t a typical daredevil. He was the senior vice president for engineering at Google who had worked on the cutting edge of Silicon Valley computer science in the 1980s and 1990s. But Eustace also had a passion for high-altitude skydiving and wanted to break the record for longest freefall. To reach the prerequisite height—135,890 feet, or more than 25 miles—would require travelling farther up than can be reached by even a high-altitude reconnaissance airplane such as the SR-71 Blackbird. However, weather balloons can reach that height, so Eustace and an engineering team at Paragon Space Development Corp. developed a system that would connect a large, helium-filled balloon to a pressure suit similar to what astronauts wear. (That suit was necessary as at the altitude Eustace would reach, air pressure is low enough that his blood would boil.) When filled, the balloon was more than 40 stories tall and enveloped 11 cubic feet. 
 
The record-setting freefall lasted nearly four and a half minutes, and at one point, he reached an astonishing speed of 822 miles per hour.
 

The future 

One longstanding dream has been to use airships for transporting cargo to islands or other remote areas without the need for infrastructure. In the 2010, the United States military’s Long Endurance Multi-intelligence Vehicle program looked to develop an airship that could transport as much as 20 tons of equipment or personnel to battlefields thousands of miles away. While the program disbanded after the construction of a few protypes, private companies are continuing to develop the technology, with the hope of launching the distinctively shaped airships before the end of the decade.
 
Farther in the future, NASA is looking at the potential to build a space station that would float in the atmosphere of Venus. While the surface is hot enough to boil melt lead and features crushing atmospheric pressure, at an altitude of 34 miles, the temperature is similar to the Earth’s tropics and the air pressure is not much lower than what’s found in Tibet. Because that atmosphere is made up of carbon dioxide, however, it’s unbreathable, but it would support an airship or station filled with oxygen and nitrogen. In the mid-2010s, engineers at NASA’s Langley Research Center developed a plan, the High Altitude Venus Operational Concept, for housing astronauts on a buoyant station in Venus’s atmosphere. While it is no longer funded, the concept did prove to be viable.
 
Jeffrey Winters is editor in chief of Mechanical Engineering magazine.