Human Space Exploration
Humanity's interest in the heavens has been universal and enduring. Humans are driven to explore the unknown, discover new worlds, push the boundaries of our scientific and technical limits, and then push further. The intangible desire to explore and challenge the boundaries of what we know and where we have been has provided benefits to our society for centuries.
Human space exploration helps to address fundamental questions about our place in the Universe and the history of our solar system. Through addressing the challenges related to human space exploration we expand technology, create new industries, and help to foster a peaceful connection with other nations. Curiosity and exploration are vital to the human spirit and accepting the challenge of going deeper into space will invite the citizens of the world today and the generations of tomorrow to join NASA on this exciting journey.
A Flexible Path
This is the beginning of a new era in space exploration in which NASA has been challenged to develop systems and capabilities required to explore beyond low-Earth orbit, including destinations such as translunar space, near-Earth asteroids and eventually Mars.
NASA will use the International Space Station as a test-bed and stepping stone for the challenging journey ahead. By building upon what we learn there we will prepare astronauts for the challenges of long-duration flight and the permanent expansion of human exploration beyond where we have been before. Explorers may visit near-Earth asteroids where we may get answers to the questions humans have always asked. Visiting an asteroid will provide valuable mission experience and prepare us for the next steps–possibly for the first humans to step on Mars.
Robotic exploration continues to deliver profound answers about our Universe by visiting far-off destinations, providing reconnaissance and collecting scientific data. When combining both human and robotic exploration methods we will use technology and our senses to increase our ability to observe, adapt, and uncover new knowledge.
Why the International Space Station?
The first step in embarking on a long and challenging journey involves laying solid groundwork for a successful endeavor. The International Space Station serves as a national laboratory for human health, biological, and materials research, as a technology test-bed, and as a stepping stone for going further into the solar system. On the International Space Station we will improve and learn new ways to ensure astronauts are safe, healthy and productive while exploring, and we will continue expand our knowledge about how materials and biological systems behave outside of the influence of gravity.
NASA will continue its unprecedented work with the commercial industry and expand an entire industry as private companies develop and operate safe, reliable and affordable commercial systems to transport crew and cargo to and from the International Space Station and low Earth orbit.
Why Translunar Space?
Translunar space is vast expanse surrounding the Earth-moon system, extending far beyond the moon’s orbit and dominated by the two bodies’ gravity fields. Exploring in translunar space, beyond the protection of the Earth’s geomagnetic field, will provide unprecedented experience in deep-space operations. Operating in translunar space, NASA can research galactic cosmic radiation–potentially the most threatening element to humans exploring deep space–and develop mitigation strategies that may also lead to medical advancements on Earth.
The Lagrange points–places in cislunar space where the gravitational influences of the Earth and moon cancel each other out–are advantageous areas for exploration and research in which almost no propulsion is required to keep an object or spacecraft stationary. The Lagrange point on the far side of the Earth-Moon system, called L2, also provides a “radio silence” zone for astronomical observations.
Missions to translunar space will give NASA and its partners the opportunity to develop tools and operational techniques to support decades of future exploration, while remaining in relative proximity to Earth.
Why Asteroids?
Asteroids are believed to have formed early in our solar system's history–about 4.5 billion years ago–when a cloud of gas and dust called the solar nebula collapsed and formed our sun and the planets. By visiting these near Earth objects to study the material that came from the solar nebula, we can look for answers to some of humankind's most compelling questions, such as: how did the solar system form and where did the Earth's water and other organic materials such as carbon come from?
In addition to unlocking clues about our solar system, asteroids may provide clues about our Earth. By understanding more about asteroids we may learn more about past Earth impacts and possibly find ways to reduce the threat of future impacts.
Future robotic missions to asteroids will prepare humans for long-duration space travel and the eventual journey to Mars. Robotic missions will provide reconnaissance information about asteroid orbits, surface composition, and even return samples to Earth for further evaluation. These robotic missions are a critical step in preparing humans to visit asteroids where we will learn about the valuable resources available in space, and further develop ways to use them in our quest for more efficient and affordable exploration.
Why Mars?
Mars has always been a source of inspiration for explorers and scientists. Robotic missions have found evidence of water, but if life exists beyond Earth still remains a mystery. Robotic and scientific robotic missions have shown that Mars has characteristics and a history similar to Earth's, but we know that there are striking differences that we have yet to begin to understand. Humans can build upon this knowledge and look for signs of life and investigate Mars' geological evolution, resulting in research and methods that could be applied here on Earth.
A mission to our nearest planetary neighbor provides the best opportunity to demonstrate that humans can live for extended, even permanent, stays beyond low Earth orbit. The technology and space systems required to transport and sustain explorers will drive innovation and encourage creative ways to address challenges. As previous space endeavors have demonstrated, the resulting ingenuity and technologies will have long lasting benefits and applications.