By means of orbiters, landers, rovers and sample return missions, NASA's revamped campaign to explore Mars, announced today, is poised to unravel the secrets of the Red Planet 's past environments, the history of its rocks, the many roles of water and, possibly, evidence of past or present life.

This artist's concept shows NASA's Mars rover program - past, present and future. The rover on the left is Sojourner, which landed as part of the Mars Pathfinder mission in 1997. The image in the middle is the Mars Exploration Rover that is planned for launch in 2003 and the image on the right is a proposed concept of a future mobile science laboratory that is under consideration for a launch in 2007. Photo: NASA/JPL

Six major missions are planned in this decade as part of a scientific tapestry that will weave a tale of new understanding of Earth's sometimes enigmatic and surprising neighbor.

The missions are part of a long-term Mars exploration program which has been developed over the past six months. The new program incorporates the lessons learned from previous mission successes and failures, and builds on scientific discoveries from past missions. The NASA-led effort to define the program well into the next decade focused on the science goals, management strategies, technology development and resource availability in an effort to design and implement missions which would be successful and provide a balanced program of discoveries. International participation, especially from Italy and France, will add significantly to the plan. The next step will be an 18-month programmatic systems engineering study to refine the costs and technology needs.

In addition to the previously announced 2001 Mars Odyssey orbiter mission and the twin Mars Exploration Rovers in 2003, NASA plans to launch a powerful scientific orbiter in 2005. This mission, the Mars Reconnaissance Orbiter, will focus on analyzing the surface at new scales in an effort to follow the tantalizing hints of water from the Mars Global Surveyor images and to bridge the gap between surface observations and measurements from orbit. For example, the Reconnaissance Orbiter will measure thousands of Martian landscapes at 8-to-12-inch (20-to-30-cm) resolution, good enough to observe rocks the size of beach balls.

NASA proposes to create a new line of small "Scout" missions that would be selected from proposals from the science community, and might involve a small lander such as the one depicted in this artist's concept. The first Scout mission launch is proposed for 2007. Photo: NASA/JPL

NASA proposes to develop and to launch a long-range, long-duration mobile science laboratory that will be a major leap in surface measurements and pave the way for a future sample return mission. NASA is studying options to launch this mobile science labroatory mission as early as 2007. This capability will also demonstrate the technology for accurate landing and hazard avoidance in order to reach what may be very promising but difficult-to-reach scientific sites.

NASA also proposes to create a new line of small "Scout" missions which would be selected from proposals from the science community, and might involve airborne vehicles or small landers, as an investigation platform. Exciting new vistas could be opened up by this approach either through the airborne scale of observation or by increasing the number of sites visited. The first Scout mission launch is planned for 2007.

In the second decade, NASA plans additional science orbiters, rovers and landers, and the first mission to return the most promising Martian samples to Earth. Current plans call for the first sample return mission to be launched in 2014 and a second in 2016. Options which would significantly increase the rate of mission launch and/or accelerate the schedule of exploration are under study, including launching the first sample return mission as early as 2011. Technology development for advanced capabilities such as miniaturized surface science instruments and deep drilling to several hundred feet will also be carried out in this period.

An illustration of Mars "Scout" balloon. Photo: NASA/JPL

Mars missions can be launched every 26 months during advantageous alignments -- called launch opportunities -- of the Earth and Mars, which facilitate the minimum amount of fuel needed to make the long trip.

The agency's Mars Exploration Program envisions significant international participation, particularly by France and Italy. In cooperation with NASA, the French and Italian Space Agencies plan to conduct collaborative scientific orbital and surface investigations and to make other major contributions to sample collection/return systems, telecommunications assets and launch services. Other nations also have expressed interest in participating in the program.

"We have developed a campaign to explore Mars unparalleled in the history of space exploration. It will change and adapt over time in response to what we find with each mission. It's meant to be a robust, flexible, long-term program that will give us the highest chances for success," said Scott Hubbard, Mars Program Director at NASA Headquarters, Washington, DC. "We're moving from the early era of global mapping and limited surface exploration to a much more intensive approach. We will establish a sustained presence in orbit around Mars and on the surface with long-duration exploration of some of the most scientifically promising and intriguing places on the planet."

An artist's concept of "Scout" airplane. Photo: NASA/JPL

"The scientific strategy developed for the new program is that of first seeking the most compelling places from above, before moving to the surface to investigate Mars," said Dr. Jim Garvin, NASA Mars Exploration Program Scientist at Headquarters. "The new program offers opportunities for competitively selected instruments and investigations at every step, and endeavors to keep the public informed on each mission via higher bandwidth telecommunication on the web."

"NASA's new Mars Exploration Program may well prove to be a watershed in the history of Mars exploration," said Dr. Ed Weiler, NASA's Associate Administrator for Space Science. "With this new strategy, we're going to dig deep into the details of Mars' mineralogy, geology and climate history in a way we've never been able to do before. We also plan to 'follow the water' so that in the not-to-distant future we may finally know the answers to the most far-reaching questions about the Red Planet we humans have asked over the generations: Did life ever arise there, and does life exist there now?"