The United States has embarked upon a bold, new journey of space exploration and discovery – one that extends far beyond our first cautious yet daring steps into space and one which drives us beyond accomplishments long past.
‘s continued success as a leader in space, however, requires our sustained commitment, perseverance, ingenuity and confidence.

As an engineer by training, I have been honored to be part of
‘s civil and military space programs for more than 30 years. Like many of my peers, I have learned that the rewards are many, but so are the challenges associated with harnessing complex technologies and powerful forces to ensure our nation’s continued leadership in space.

We cannot achieve goals worthy of a great nation if we reverse course or constantly reassess and delay our plan at every step. Unfortunately, some argue we should do exactly that, just as
prepares to explore the Moon and ultimately send men and women to Mars where newly discovered frozen lakes of water await us.

Some question our nation’s goals for space exploration and the specific means chosen to accomplish them. We are told that it would be better to pursue alternative options and pathways to NASA’s Constellation program. I realize that intelligent people who care passionately about space can and will differ from time to time on how best to achieve our objectives. That said, I respectfully disagree with those who believe we are off track and feel we need to chart a new direction.

The journey upward and onward can never be made foolproof or easy. Hesitation and lack of commitment to keep Constellation moving forward is a prescription for wasted investment, a widening gap in
‘s human space transportation capability and a squandered opportunity to advance
‘s technological leadership on a global scale as well as inspire future generations of
scientists and engineers.

Nations and civilizations progress when they set ambitious goals, choose a path and follow through with determination – unshaken by temporary setbacks and challenges. In that spirit,
answered President John F. Kennedy’s call to send a man to the Moon and return him safely before the decade’s end. Today, we have set our sights upon equally bold missions of discovery. With strong public support and the overwhelming bipartisan endorsement of Congress, we are once again reaching out beyond low Earth orbit.

We already have made significant strides forward on a path to explore the Moon, Mars and beyond. Despite what naysayers claim, engineers, scientists and technicians representing a cross section of disciplines working day and night across
are making solid progress. They are developing the spacecraft, launch vehicles and supporting infrastructure needed to ensure our future success in space. In the case of the Orion Crew Exploration Vehicle, we are working with NASA to implement requirements, fine-tune the design, test fire motors and prepare for production of the world’s first interplanetary human spacecraft.

Our industry colleagues also are moving forward with the Ares 1 crew launch vehicle. Ares 1 is designed to carry Orion into space where it will rendezvous with an Earth Departure Stage and the Altair lunar lander carried aboard an Ares 5 cargo launch vehicle on its way to the Moon.

These hardware elements are tied together by an overall architecture established by NASA as a result of extensive evaluation and recommendations by independent advisers and advisory boards representing a broad range of critical skills and expertise across the
United States
. That architecture provides the enabling capabilities that support our nation’s long-term exploration and space science goals for beyond low Earth orbit and lunar missions, and the international space station in the near-term. Bottom-line: NASA’s Constellation program effectively builds upon
‘s more than 50 years of operational space experience while leveraging new technologies, mitigating risks, enhancing crew safety and ensuring mission success.

Now, I am not naive enough to believe that having gotten this far the rest of the journey will be easy. This actually is rocket science, as many new to the endeavors of space have learned. Nor is any feat more exacting than safe human spaceflight. We undoubtedly will face performance, budget and schedule pressures. We also will have new leadership in the White House and changes in Congress – all the more reason to build upon our progress and maintain momentum for the future.

Our nation’s space exploration policy is both achievable and affordable. We must, however, press forward with disciplined plans, effective execution and operational agility to complete the milestones before us.

Courage and the spirit of exploration formed our nation, shaped our history and will surely define our future. For
‘s space program, the opportunities are too great and the stakes too high to reverse course at this critical juncture.

John Karas is vice president and general manager of Human Space Flight at Lockheed Martin Space Systems, Littleton, Colo.