As the first decade of the twenty-first century comes to a close—I know that one could make the case that the first decade ended in 2009 but we had this argument during Y2K and I’m not going to rehash it here—what might we consider the ten most important events in space exploration and discovery? Everyone is free to come up with their own lists, but here is mine. These are in no particular order, at least it is not a countdown, and it is weighted toward recent acquisitions at the National Air and Space Museum. What would your list look like?

SpaceShipOne, June 21, 2004, September 29, 2004, and October 4, 2004

 Launched from its White Knight mothership, the rocket-powered SpaceShipOne and its pilot ascended just beyond the atmosphere, arced through space (but not into orbit), then glided safely back to Earth. The three flights of SpaceShipOne represented the first times in which a privately-developed spacecraft reached space. The flights were part of the Ansari X-Prize competition to develop a robust and reliable piloted space vehicle that could offer space tourism to a broad set of participants. Based on this success, prospects for suborbital space tourism are expanding as successor vehicles are being built. SpaceShipOne is on display in the National Air and Space Museum’s “Milestones of Flight” exhibition.

 Mars Exploration Rovers, 2004-Present

On January 3, 2004, the “Spirit” rover landed on Mars in Gusev crater, followed on January 25 by “Opportunity” reaching the Sinus Meridiani region, halfway around the planet from its twin. Since that time, both rovers have been operating on the Martian surface and returning stunning scientific findings that are restructuring our knowledge of the red planet. For one, we now know that Mars was once a watery world, and that water may yet be under its surface. This discovery has profound consequences for the possibilities of life having once been there. A mockup of the Mars Exploration Rover is on display in the National Air and Space Museum’s “Exploring the Planets” exhibition.

Stardust Comet Sample Return Mission, 1999-2006, extended mission, on-going

 Stardust was the first U.S. space mission dedicated solely to returning extraterrestrial material from beyond the Moon. It collected samples from Comet Wild 2 and interstellar dust. Launched in 1999, it returned to Earth seven years later, parachuting to a landing in the Utah desert in 2006. The Stardust canister containing samples was sealed in an exterior shell that protected them from the heat of reentry. The material Stardust returned may date from the formation of the solar system. Scientific studies of the samples are altering our understanding of the universe. One major discovery is that ice-rich comets, the coldest and most distant bodies in the solar system, also contain fragments of materials. This return capsule is on display in the National Air and Space Museum’s “Milestones of Flight” exhibition.

Columbia Accident, 2003, and return to flight, 2005

The tragedy of STS-107 on February 1, 2003, cannot be overemphasized. It led to a stand down of the Space Shuttle program for more than two years, a hiatus on most construction for the International Space Station, and the decision to retire the shuttle by the end of the decade. The loss of the crew of seven, including international astronauts, was traumatic. The return to flight with STS-114 on July 26, 2005, brought a return to activity for the U.S. human spaceflight program, but the imminent retirement of the Space Shuttle opens questions about how the U.S. will undertake human activities in space. The Space Shuttle program is a major focus of the “Moving Beyond Earth” exhibition at the National Air and Space Museum.

 Building of International Space Station (ISS), 1998-2009

With the first elements launched and joined in orbit in 1998, the building of ISS has consumed most of the human space missions of both the United States and Russia for the last decade. Since the occupation of the Expedition One crew to ISS—William M. (Bill) Shepherd, Yuri Pavlovich Gidzenko, and Sergei K. Krikalev—in 2001 there has been a crew of between two and six aboard the station throughout the decade. The ISS is a major focus of the “Moving Beyond Earth” exhibition at the National Air and Space Museum.

Discovery of Extrasolar Planets, 1995-present

 The first planet discovered around another star was announced on October 6, 1995, and since that time 358 extrasolar planets have been discovered. Although no Earth-like planets have been discovered yet, the prospects seem good for discovery in the next few years. Imagine the excitement of such a discovery? Information about cosmology, astronomy, and astrophysics is available in the National Air and Space Museum’s “Explore the Universe” exhibition.

Near Earth Asteroid Rendezvous (NEAR) Shoemaker Mission, 1996-2001

 NEAR Shoemaker was launched on February 17, 1996, journeyed to the Mathilde asteroid for a flyby, and then landed on the Asteroid 433 Eros on February 12, 2001, while transmitting 69 close-up images of the surface during its final descent. It was the first spacecraft mission specifically designed to study an asteroid. We would really like to collect NEAR Shoemaker for the National Air and Space Museum, but that will have to await a return to Asteroid 433 Eros with capability to return cargo. I probably won’t see this in my lifetime. There is more information on asteroids and their exploration in the National Air and Space Museum’s “Exploring the Planets” exhibition.

Chandra X-Ray Observatory, 1999-Present

 Since its launch on July 23, 1999, the Chandra X-ray Observatory has engaged in X-ray astronomy of the universe, taking its place in the fleet of what NASA calls its “Great Observatories” program. Designed to observe X-rays from high-energy regions of the universe, such as the remnants of exploded stars and even particles up to the last second before they fall into a black hole, Chandra has greatly enhanced our understanding of the origin and evolution of the universe. There is a Chandra 1/5-scale model in the National Air and Space Museum’s “Explore the Universe” exhibition.

Hubble Servicing Missions, STS-109 (2002), STS-125 (2009)

 The Hubble Space Telescope is acclaimed as one of the most significant astronomical instruments in history. First deployed in 1990, it has been serviced five times by astronauts visiting it aboard the Space Shuttle. These missions have extended its service life, and the most recent in 2009 appears to have extended its capabilities for the better part of the next decade. The structural dynamics test article for the Hubble Space Telescope is on display in the “Space Race” exhibition at the National Air and Space Museum. During that last servicing mission, NASA removed the Corrective Optics Space Telescope Axial Replacement (COSTAR) and it is on display in the National Air and Space Museum’s “Moving Beyond Earth” exhibition.

Shenzou V, 2003

 Until 2003 only two nations had sent humans into space. On October 15-16, 2003, China joined Russia and United States in that exclusive club when taikonaut Yang Liwei completed 14 orbits of the Earth. The trip into space started when the Long March rocket carrying Yang in the Shenzhou V capsule blasted off from the Jiuquan launch center. The National Air and Space Museum looks forward to the prospect of displaying objects associated with the Chinese space program. I could have offered several other events for this list—the completion of the Milstar constellation, the advance of GPS into everyday life, the launch of Falcon 9 with its Dragon capsule, and the recognition of John Mather and George Smoot with the Nobel Prize for their elucidation of the Big Bang theory with data from the Cosmic Background Explore—all come to mind. I invite others to offer their own lists of significant space events in the first decade of the twenty-first century
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