NASA's Asteroid Initiative consists of two separate but related activities: the Asteroid Redirect Mission (ARM), and the Asteroid Grand Challenge (AGC). NASA is developing concepts for the ARM, which would use a robotic spacecraft to capture a small near-Earth asteroid (7 to 10 meters), or remove a boulder (1 to 10 meters) from the surface of a larger asteroid, and redirect it into a stable orbit around the moon. Astronauts launched aboard the Orion spacecraft would rendezvous with the captured asteroid material in lunar orbit, and collect samples for return to Earth. The AGC is seeking the...

Welcome to "Risk and Exploration-Earth, Sea, and the Stars." Today's session is entitled "Why We Explore," but I'm hoping that, mostly, we can make it a dialogue, up close and personal. I'm John Grunsfeld. I'm the NASA chief scientist and an astronaut. I think we have started getting into the discussions on risk and exploration, into some of the thorny questions about how do we make decisions. How do we use our judgment? How do we, as institutional managers of a public institution, make decisions on behalf of the American people, and with oversight of the Congress, that can stand the test of...

Ellington Field in Houston, Texas, has a unique heritage that mirrors the course of 20th century American military history. For 81 years, Ellington Field served the United States Army and Air Force through times of war, cold war, and peace. Over the past 8 decades the airfield has functioned in variety of operational roles: as an active duty base, an Air Force Reserve base, and an Air National Guard base. Overall, Ellington Field's economic, political, and technological impact on the development of south Texas cannot be underestimated. While most military facilities built in 1917 to train...