Space exploration is one of the most difficult endeavors we undertake, and from Apollo 1 to Challenger to Columbia, brave Americans have made the ultimate sacrifice in our quest to push new boundaries, and explore new frontiers. On this annual Day of Remembrance, the American people pause to honor the men and women of NASA who gave their lives in service to their country and the world.

Yet, despite the dangers, we continue to reach for the stars, study the wonders of the universe, and learn more about the planet we call home. As a country, we support the innovators hard at work on the next generation of cutting-edge research and innovation. We seek to inspire the young people pursuing careers in science, technology, engineering, and mathematics. From new partnerships with private industry to the development of groundbreaking inventions that Americans will take with them into the Solar System and eventually to Mars, we will continue our journey of discovery.

With every challenge overcome, with every mission safely accomplished, we honor those who gave their lives for the cause of exploration. We will continue to build on their discoveries and their technical achievements, and guided by their courage and determination, to lead the world in exploring the mysteries of space.

Today we remember and give thanks for the lives and contributions of those who gave all trying to push the boundaries of human achievement. On this solemn occasion, we pause in our normal routines and remember the STS-107 Columbia crew; the STS-51L Challenger crew; the Apollo 1 crew; Mike Adams, the first in-flight fatality of the space program as he piloted the X-15 No. 3 on a research flight; and those lost in test flights and aeronautics research throughout our history.

These men and women were our friends, family and colleagues. They still are. As we undertake a journey to Mars, they will be with us. They have our eternal respect, love and gratitude.

Today, their legacy lives on as the International Space Station fulfills its promise as a symbol of hope for the world and a springboard to missions farther into the solar system. Our lost friends are with us in the strivings of all of our missions to take humans to new destinations and to unlock the secrets of our universe. We honor them by making our dreams of a better tomorrow reality and taking advantage of the fruits of exploration to improve life for people everywhere.

Let us join together as one NASA Family, along with the entire world, in paying our respects, and honoring the memories of our dear friends. They will never be forgotten. Godspeed to every one of them.

Charlie B.

Just 73 seconds after launch on the morning of Jan. 28, 1986, a booster engine failed and caused the Shuttle Challenger to break apart, taking the lives of all seven crewmembers.

President Ronald Reagan eulogized the crew, quoting from the poem "High Flight": "We will never forget them, nor the last time we saw them, this morning, as they prepared for the journey and waved goodbye and 'slipped the surly bonds of earth' to 'touch the face of God.'"

The seven-member crew of the STS-107 mission was just 16 minutes from landing on the morning of Feb. 1, 2003, when Mission Control lost contact with the shuttle Columbia. A piece of foam, falling from the external tank during launch, had opened a hole in one of the shuttle's wings, leading to the breakup of the orbiter upon re-entry.

Addressing the nation, President Bush said, "mankind is led into the darkness beyond our world by the inspiration of discovery and the longing to understand. Our journey into space will go on."