How Hydrogen Has Advanced Humanity’s Reach for 250 Years
The familiar image of mythological hero Icarus and his father falling from the sky as the sun melted the wax wings they constructed to escape from Crete symbolizes mankind’s many failed attempts at flying throughout the millennia. The air and space travel we now take for granted was once a dream that took thousands of years to materialize. It was hydrogen that first made human flight possible.
The history of the discovery and use of hydrogen is closely coupled with the rich history of flying machines that pioneering scientists and entrepreneurs have built to leverage the many unique properties of the universe’s most abundant element. This “inflammable air,” as some of the early scientists called it, defied common sense in many ways. For example, Henry Cavendish, who’s credited with discovering hydrogen as an element in 1766, showed that it produced water when burned, thereby, ending the centuries-old belief that water itself was an element. Another way hydrogen defied common sense was the realization that hydrogen gas was lighter than air. This fact captured the imagination of ingenious inventors throughout the centuries who have looked to the sky to advance our understanding and relationship with the physical world.
This week, we explore three machines that have used hydrogen in novel ways to help humanity soar. The number one element is responsible for lifting the balloons that took us to the skies for the first time in the 19th century, to powering the rockets that allowed us to see far into the cosmos in the 20th century (and still today), to making air travel more sustainable in the 21st century.
The element of the stars make it possible to take us there.
Hydrogen Balloons: The First Flying Machines that Worked
A hundred years before the invention of the airplane, humans took flight using hydrogen. The History of Balloons provides a vivid tale of how the idea of using hydrogen to fly came about:
“The idea to use a gas lighter than air began with Henry Cavendish’s 1766 work on hydrogen, and Robert Boyle’s Law [of gas and pressure] from 1662. Joseph Black also proposed that a balloon filled with hydrogen would rise in the air. Professor Jacques Charles studied them and decided to try these ideas in practice. He designed the hydrogen balloon, while the Robert brothers [Anne-Jean and Nicolas-Louis Robert] invented the way to construct the lightweight, airtight gas bag―a balloon. They used the sheets of silk which were varnished with rubber dissolved in turpentine. That made silk airtight. The world’s first hydrogen-filled balloon was launched on August 27, 1783, from the Champ de Mars, Paris. It was a relatively small balloon that could lift some 9kg, but it was the first. The hydrogen needed for the balloon was made by pouring nearly a quarter of a ton of sulphuric acid onto half a ton of scrap iron and fed into a balloon via lead pipes. The balloon flew 21km for 45-minutes and landed in the village of Gonesse. It was there welcomed by frightened villagers that attacked it with pitchforks and knives and destroyed it.”
A few months later, the Robert Brothers launched the first manned hydrogen balloon, just ten days after the same was done using a hot air balloon. Hydrogen balloons, because they allowed for greater altitudes and longer distances than hot air balloons, dominated the skies for 120 years before airplanes took over at the beginning of the 20th century.
Hydrogen Rockets: The First Vehicles Powerful Enough to Take Humans and Cargo to Space
“Voyager 1 Fires Up Thrusters After 37 Years.” This is how NASA announced last December that the Voyager 1, the first man-made object to reach interstellar space, woke up after four decades of silent space travel. These thrusters use hydrogen in the form of a fuel called hydrazine, comprising a tiny portion of the hydrogen that put the Voyager 1 in space in the first place.
The element that first lifted us to the skies also took us beyond them. The first rockets tested in the 1950s did not use hydrogen as a propellant, as the technology to make it usable was also evolving. A powerful and energetic fuel was needed to take things into Earth’s orbit and beyond. NASA answered this call by making liquid hydrogen the fuel of choice for the Space Program. Hydrogen made possible the Saturn rocket, the largest rocket ever built, which was used for the later stages that sped up the capsules that took us to the moon in the 1960s and 70s. Since then, hydrogen continues to propel our exploration of space, powering most of the rockets that have taken probes to every planet in our solar system. Just a couple of weeks ago, hydrogen put a Tesla Roadster into orbit around the sun with the SpaceX Falcon Heavy rocket launch. You can read our post about it here.
According to NASA, “Today, liquid hydrogen is the signature fuel of the American space program and is used by other countries in the business of launching satellites.” They further explain, “Hydrogen is a light and extremely powerful rocket propellant―has the lowest molecular weight of any known substance and burns with extreme intensity (2,800°C or 5,100°F). In combination with an oxidizer such as liquid oxygen, liquid hydrogen yields the highest specific impulse, or efficiency in relation to the amount of propellant consumed, of any known rocket propellant.”
Hydrogen Planes: A Successful Alternative for Clean Air Travel
The Environmental Protection Agency (EPA) indicates that aircraft account for 12% of all U.S transportation greenhouse emissions. That is a significant number and most large aircraft manufacturers―from Boeing and Lockheed in the U.S., Airbus in Europe, and Tupolev in Russia―are experimenting with hydrogen-powered airplanes to decarbonize the industry and make air travel more sustainable.
One of these experimental hydrogen-powered aircraft is called “HY4.” According to CNN, “The HY4 is the result of a collaborative effort in Europe between aircraft manufacturer Pipistrel, fuel cell specialists Hydrogenics, the University of Ulm, and the German Aerospace Center (DLR)’s Institute of Engineering and Thermodynamics,” adding that “it runs on fuel cells―devices producing an electrical current from a supply of hydrogen and oxygen―aided by a battery for extra oomph during takeoff.”
The HY4 made its successful debut experimental flight in September 2016, adding aircraft to the list of flying machines powered by hydrogen. Unlike rockets, these aircraft emit only water vapor, which at scale, can help the industry lower its carbon footprint.
Future Hydrogen Machines
In the 250 years since its discovery, significant breakthroughs in the history of flight have been aided by hydrogen. Despite hydrogen’s stellar position in taking us to the skies, there remain important issues to solve to fully capture the enormous energy potential of the number one element. For instance, our work on Hydrogen 2.0 technology is focused on solving the traditional barriers to widespread adoption such as availability and affordability.
Throughout history, scientists have relied on hydrogen, the simplest of all atoms, as a way to push the boundaries of understanding of our natural world. Through the application of hydrogen in flight, we have broadened our understanding of our physical world. The latest applications of hydrogen in flight aim to help us continue to soar without negatively impacting our world.
As the Hydrogen 2.0 ecosystem gains momentum, we’ll be sharing our views and insights on the new Hydrogen 2.0 Economy. We also update our blog every week with insightful and current knowledge in this growing energy field.