From History to the Moon: Hydrogen and the Space Industry

Hydrogen has been a cornerstone of the space industry for decades, powering some of humanity's most iconic missions and continuing to play a critical role in advancing space exploration. Hydrogen's unique properties make it an excellent resource for the space industry, from rocket fuel to energy systems. Let's look closer at its fascinating history and current uses in space.

The Early Role of Hydrogen in Space Exploration

Hydrogen's journey in the space industry began with its discovery as a powerful and clean energy source. Its high energy-to-weight ratio—a crucial factor for rocket propulsion—made it an excellent candidate for powering spacecraft.

The Apollo Program (1960s–1970s)

NASA pioneered using liquid hydrogen (LH₂) as a rocket fuel during the Apollo program, which put the first humans on the Moon. Hydrogen was paired with liquid oxygen (LOX) to power the Saturn V rocket, the most powerful rocket ever built.

Why Hydrogen? Liquid hydrogen burns cleanly, producing only water vapor as a byproduct when combined with oxygen.

Challenges: Storing and handling liquid hydrogen required advanced cryogenic technology, as hydrogen must be kept at extremely low temperatures (-253°C / -423°F) to remain a liquid.

Hydrogen-powered fuel cells also provided electricity and drinking water for the Apollo spacecraft. By combining hydrogen and oxygen in fuel cells, astronauts had a reliable power source with the added benefit of producing water—an essential resource in space.

Hydrogen in the Space Shuttle Era (1981–2011)

The Space Shuttle program continued hydrogen's legacy in space exploration. Each Space Shuttle had three main engines fueled by liquid hydrogen and liquid oxygen.

Key Achievements:

The Space Shuttle Main Engine (SSME) was one of the most efficient and powerful rocket engines ever developed.

Liquid hydrogen fuel plays a major role in lifting payloads—such as satellites, space station modules, and astronauts—into orbit.

In addition to propulsion, hydrogen fuel cells generated onboard electricity for the Shuttle and provided water for the crew.

How Hydrogen is Used Today in Space Exploration

Hydrogen remains an essential part of modern space exploration, with applications in propulsion systems, power generation, and future technologies.

Rocket Propulsion

Hydrogen continues to be a preferred fuel for modern rockets due to its:

High Energy Efficiency: Hydrogen has the highest energy density per unit mass of any chemical fuel.

Clean Combustion: When burned with oxygen, hydrogen produces water as its only byproduct—ideal for sustainable missions.

Examples of Hydrogen-Powered Rockets Today:

NASA's Space Launch System (SLS): NASA's newest heavy-lift rocket, designed for the Artemis program to return humans to the Moon and beyond, uses liquid hydrogen in its core stage and upper stage engines.

Ariane 5 (European Space Agency): The Ariane 5 rocket, developed by the European Space Agency, relies on liquid hydrogen for its main-stage propulsion system.

Blue Origin's BE-3 Engine: Blue Origin uses liquid hydrogen to power its New Shepard rocket, a suborbital system designed for space tourism and research.

Hydrogen Fuel Cells for Power Generation

Hydrogen fuel cells continue to be used to provide electric power for spacecraft. In future long-term missions to the Moon, Mars, and beyond, hydrogen fuel cells are expected to play a critical role in:

Reliable Energy Storage: Storing energy for lunar or Martian habitats, where solar power may not always be available.

Producing Water: Fuel cells combine hydrogen and oxygen to generate water, which can support astronauts' needs on extended missions.

Example: NASA's Artemis missions plan to use hydrogen fuel cells to power lunar landers and habitats.

Future Applications: Hydrogen on the Moon and Mars

The future of space exploration will involve using in-situ resources (resources available in space) to produce hydrogen and oxygen on location:

Moon Missions: The Moon's regolith (soil) contains water ice, particularly in permanently shadowed craters. This ice can be harvested and split into hydrogen and oxygen through electrolysis, providing:

Rocket Fuel: To refuel lunar missions and return spacecraft to Earth.

Energy: Hydrogen fuel cells can power lunar habitats and rovers.

Life Support: Oxygen is used for breathing, and hydrogen is used for water production.

Mars Missions: Mars' thin atmosphere contains carbon dioxide (CO₂), which can be used to produce methane and water. Using electrolysis, astronauts could split water into hydrogen and oxygen, creating rocket fuel for return missions and providing a renewable power source.

The Challenges of Using Hydrogen in Space

While hydrogen is an exceptional fuel and energy source, its use in space comes with challenges:

Storage: Liquid hydrogen requires cryogenic tanks that maintain extremely low temperatures, increasing complexity and cost.

Leakage: Hydrogen is the lightest element and can easily escape through tiny gaps, requiring advanced containment systems.

Production in Space: Ideas for extracting and producing hydrogen on the Moon or Mars are still in their early stages and require new technologies to scale efficiently.

Hydrogen as the Future of Space Exploration

From powering the Saturn V to enabling modern rockets like the Space Launch System, hydrogen has played a pivotal role in advancing human spaceflight. Its clean-burning properties and high energy density make it ideal for propulsion, power generation, and life support in space missions.

Looking ahead, hydrogen will continue to be critical for long-term exploration:

Lunar Bases will rely on hydrogen for energy storage and fuel production.

Mars Missions will harness hydrogen to support habitats and enable return journeys to Earth.

Hydrogen's role in space is not just about exploration—it's about creating sustainable systems that mirror what's possible here on Earth. As we develop hydrogen technologies to support space missions, we're also building solutions for clean energy, transportation, and industry at home.

The sky is no longer the limit for hydrogen—it's the starting point.

Inspire the Next Generation with the H2GP Foundation

At the H2GP Foundation, we’re empowering the next generation of innovators to lead the hydrogen revolution. Our programs combine education and hands-on experience, helping students understand how hydrogen powers everything from spacecraft to sustainable energy solutions right here on Earth.

Through initiatives like H2GP XPR, Sprint and H2GP PRO, students learn to design, build, and test hydrogen-powered systems, gaining the skills and knowledge to solve real-world challenges.

Why It Matters: By engaging with hydrogen technology at an early stage, students prepare to contribute to the industries of the future, from space exploration to clean energy production.

How It Works: Students work collaboratively on hydrogen-powered projects, tackling challenges that mirror real-life applications, including renewable energy, transportation, and environmental sustainability.

Learn more about how we’re inspiring tomorrow’s clean energy pioneers and how you can get involved at H2GP Foundation.