As space shuttle astronauts, each of us has sat high atop a magnificent U.S.-built spaceship loaded with 725,700 kilograms of liquid hydrogen and oxygen, waiting for the shuttle’s solid-rocket motors and engines to ignite and propel us from zero to 28,000 kilometers per hour into orbit around the Earth. We understand the importance and significance of having a safe and well-funded space program, as we personally accepted the risk worth taking with every mission. With each flight, we entrusted our lives to experienced, innovative men and women on the ground, dedicated to our safety and passionately committed to our nation’s space program.

As America prepares to embark upon a new era of human space exploration, U.S. President Barack Obama has commissioned a review of the nation’s human spaceflight plans. Known as the Augustine Committee, this panel has the important charter of evaluating the current NASA plan and offering options for the future. We urge this panel, along with the president, Congress and the American people to consider that:

(1) exploration must be recognized as a national imperative that sustains U.S. leadership in space;

(2) a significant increase in human spaceflight safety should be accomplished under government leadership;

(3) we must leave low Earth orbit and explore destinations beyond; and

(4) sustaining robust funding and staying the course is imperative to implementing a safe, reliable and meaningful space exploration program worthy of our nation.

Exploration is a National Imperative

Over the past 50 years, our country has profoundly benefited from the space program in more ways than most people are even aware. In a recent report, the value of the world space economy is estimated at $250 billion. Many industries — telecommunications, agriculture, medicine, Earth observation, public health and safety, to name a few — have advanced and grown due to development of space technologies. Our aerospace industry is the envy of the world, employing 650,000 Americans in high-wage, high-skill jobs. It is one of the few industries that actually enjoys a trade surplus with our foreign competition.

Every time NASA accomplishes a great achievement, the interest of our young people in pursuing a career in science and engineering spikes upward. When they graduate from college, not all will end up working in the space program, but many of them will join leading technology companies all over America.

We believe that America’s space exploration program has positively impacted the world perhaps more than any single national endeavor during the last half century.

Our space leadership is a projection of this country’s technical capability leveraged to foster peaceful cooperation among nations in a politically uncertain world. Each of us has been part of this great space legacy — and continues to be committed to ensuring the safety, vitality, sustainability and excitement of the future space program. United States investment in space and technology generates tens of thousands of jobs, stimulates small businesses and entrepreneurship, drives innovation and inspires the next generation of engineers, scientists and explorers so critical to America’s future.

Crew Safety

Our top concern as the country moves forward in human spaceflight is to ensure the safest possible system is utilized and regulated through government leadership. This requires a proven track record, building on important lessons learned to ensure crew safety and mission success. NASA’s Constellation program is exactly that type of effort — infused with generational lessons learned, well planned and scrutinized by multiple stakeholders to provide a safe and reliable system for our nation.

New entrants to the aerospace community have been provided a pathway and government funding to pursue opportunities to support international space station operations — starting with cargo and possibly progressing to crew operations, if those companies successfully demonstrate vehicle performance and meet NASA’s crew safety requirements. This is a sensible, milestone-driven approach that ensures appropriate measures are being taken to protect our assets while allowing NASA to focus on its current program.

Breaking the Bonds of Low Earth Orbit After a Four-Decade Hiatus

We recently celebrated the 40th anniversary of one of humankind’s greatest achievements — the landing of people on the surface of the Moon. We are proud of our association with the space shuttle and space station, and are excited about NASA’s space exploration plans. Using the knowledge and heritage from previous human spaceflight programs, we must prepare for the next giant leap in space exploration. It is now time to move on and push the boundaries of human discovery beyond low Earth orbit to the Moon, asteroids, Mars and beyond.

Sustained Robust Funding is Imperative

During Apollo, America allocated almost 5 percent of the federal budget to achieve President John F. Kennedy’s vision to land people on the Moon and return them safely to Earth. Today, that number has dropped to only about 0.5 percent, while at the same time the range of space, science and aeronautics missions conducted by NASA is much more diverse than it was 40 years ago. We are convinced that an increased investment today of only 0.1 percent of the federal budget annually would support a healthy, safe exploration program as well as a robust science and aeronautic program ensuring U.S. leadership and opportunities for international collaboration.

Underfunding and start-stop investment practices during the past decade have undermined the cause of exploration, wasted resources and delayed the development of new systems. This has led to an overall strain on political support and public enthusiasm. We can do better as a nation and we must.

In conclusion, we stand united in our advocacy of a strong U.S. space exploration program that is fully funded, values and maintains safety, and pushes our horizons beyond low Earth orbit. To date, our space program has earned the support of the American public and our elected officials. What we need now is a stable policy and the resources necessary to create a future space program that truly reflects the pride and capabilities of our great nation.

Steve Hawley, Ph.D., a former astronaut, is a professor of physics and astronomy at the University of Kansas. Fellow astronaut Ken Reightler is vice president of NASA program integration at Lockheed Martin Space Systems. Their coauthors on this Commentary piece are NASA astronauts Jeff Ashby, Michael Bloomfield, Bob Crippen, Roger Crouch, Jan Davis, Brian Duffy, Jim Halsell, Rick Hieb, Scott “Doc” Horowitz, Bruce McCandless II, Don McMonagle, Pam Melroy, Charlie Precourt and Kent Roming