NASA rescheduled the launch of Mars Science Laboratory for 2011, 2 years later than previously planned. The mission will send a next-generation rover with unprecedented research tools to study the early environmental history of Mars.

A launch date of October 2009 no longer is feasible because of testing and hardware challenges that must be addressed to ensure mission success. The window for a 2009 launch ends in late October. The relative positions of Earth and Mars are favorable for flights to Mars only a few weeks every 2 years. The next launch opportunity after 2009 is in 2011.

"We will not lessen our standards for testing the mission's complex flight systems, so we are choosing the more responsible option of changing the launch date," said Doug McCuistion, director of the Mars Exploration Program at NASA Headquarters in Washington. "Up to this point, efforts have focused on launching next year, both to begin the exciting science and because the delay will increase taxpayers' investment in the mission. However, we've reached the point where we can not condense the schedule further without compromising vital testing."

The Mars Science Laboratory team recently completed an assessment of the progress it has made in the past 3 months. As a result of the team's findings, the launch date was changed.

"Despite exhaustive work in multiple shifts by a dedicated team, the progress in recent weeks has not come fast enough on solving technical challenges and pulling hardware together," said Charles Elachi, director of NASA's Jet Propulsion Laboratory in Pasadena, California. "The right and smart course now for a successful mission is to launch in 2011."

The advanced rover is one of the most technologically challenging interplanetary missions ever designed. It will use new technologies to adjust its flight while descending through the martian atmosphere and to set the rover on the surface by lowering it on a tether from a hovering descent stage. Advanced research instruments make up a science payload 10 times the mass of instruments on NASA's Spirit and Opportunity Mars rovers.

The Mars Science Laboratory is engineered to drive longer distances over rougher terrain than previous rovers. It will employ a new surface propulsion system.

Rigorous testing of components and systems is essential to develop such a complex mission and prepare it for launch. Tests during the middle phases of development resulted in decisions to re-engineer key parts of the spacecraft.

"Costs and schedules are taken very seriously on any science mission," said Ed Weiler, associate administrator for NASA's Science Mission Directorate at NASA Headquarters. "However, when it's all said and done, the passing grade is mission success."

The mission will explore a Mars site where images taken by NASA's orbiting spacecraft indicate there were wet conditions in the past. Four candidate landing sites are under consideration. The rover will check for evidence of whether ancient Mars environments had conditions favorable for supporting microbial life and preserving evidence of that life if it existed there.

NASA is officially moving forward on a mission to conduct an in-depth study of Jupiter.

Juno will be the first mission in which a spacecraft enters a highly elliptical polar orbit around the giant planet to understand its formation, evolution, and structure. Underneath its dense cloud cover, Jupiter safeguards secrets to the fundamental processes and conditions that governed our early solar system.

"Jupiter is the archetype of giant planets in our solar system and formed very early, capturing most of the material left after the Sun formed," said Scott Bolton, Juno principal investigator from the Southwest Research Institute in San Antonio. "Unlike Earth, Jupiter's giant mass allowed it to hold onto its original composition, providing us with a way of tracing our solar system's history."

The spacecraft is scheduled to launch aboard an Atlas rocket from Cape Canaveral, Florida, August 2011, reaching Jupiter in 2016. The spacecraft will orbit Jupiter 32 times, skimming about 3,000 miles (4,828 kilometers) over the planet's cloud tops for approximately 1 year. The mission will be the first solar-powered spacecraft designed to operate despite the great distance from the Sun.

"Jupiter is more than 400 million miles from the Sun, or five times further than Earth," Bolton said. "Juno is engineered to be extremely energy efficient."

The spacecraft will use a camera and nine science instruments to study the hidden world beneath Jupiter's colorful clouds. The suite of science instruments will investigate the existence of an ice-rock core, Jupiter's intense magnetic field, water and ammonia clouds in the deep atmosphere, and explore the planet's aurorae.

Understanding Jupiter's formation is essential to discovering the processes that led to the development of the rest of our solar system and what conditions led to Earth. Similar to the Sun, Jupiter is composed mostly of hydrogen and helium. A small percentage of the planet is composed of heavier elements. However, Jupiter has a larger percentage of these heavier elements than the Sun.

"Juno's extraordinarily accurate determination of the gravity and magnetic fields of Jupiter will enable us to understand what is going on deep down in the planet," said Dave Stevenson, co-investigator at the California Institute of Technology in Pasadena, California. "These and other measurements will inform us about how Jupiter's constituents are distributed, how Jupiter formed and how it evolved, which is a central part of our growing understanding of the nature of our solar system."

Deep in Jupiter's atmosphere, under great pressure, hydrogen gas is squeezed into a fluid known as metallic hydrogen. At these great depths, the hydrogen acts like an electrically conducting metal, which is believed to be the source of the planet's intense magnetic field. Jupiter also may have a rocky solid core at the center.

"Juno gives us a fantastic opportunity to get a picture of the structure of Jupiter in a way never before possible," said James Green, director of NASA's Planetary Division at NASA Headquarters in Washington. "It will allow us to take a giant step forward in our understanding on how giant planets form and the role that plays in putting the rest of the solar system together. "