Mars Reconnaissance Orbiter
A Mission to Study the History of Water on Mars
NASA's Mars Reconnaissance Orbiter, launched August 12, 2005, is on a search for evidence that water persisted on the surface of Mars for a long period of time. While other Mars missions have shown that water flowed across the surface in Mars' history, it remains a mystery whether water was ever around long enough to provide a habitat for life.
After a seven-month cruise to Mars and six months of aerobraking to reach its science orbit, Mars Reconnaissance Orbiter will seek to find out about the history of water on Mars with its science instruments. They will zoom in for extreme close-up photography of the martian surface, analyze minerals, look for subsurface water, trace how much dust and water are distributed in the atmosphere, and monitor daily global weather.
These studies will help determine if there are deposits of minerals that form in water over long periods of time, detect any shorelines of ancient seas and lakes, and analyze deposits placed in layers over time by flowing water. It will also be able to tell if the underground martian ice discovered by the Mars Odyssey orbiter is the top layer of a deep ice deposit or whether it is a shallow layer in equilibrium with the current atmosphere and its seasonal cycle of water vapor.
Looking at Small-Scale Features
In its survey of the red planet, Mars Reconnaissance will increase tenfold the number of spots surveyed close-up. One of the Mars Reconnaissance Orbiter's cameras is the largest ever flown on a planetary mission. While previous cameras on other Mars orbiters could identify objects no smaller than a school bus, this camera will be able to spot something as small as a dinner table. That capability will also allow the orbiter to identify obstacles like large rocks that could jeopardize the safety of future landers and rovers. Its imaging spectrometer will also be able to look at small-scale areas about five times smaller than a football field, at a scale perfect for identifying any hot springs or other small water features.
Powerful Communications and Navigation Link
The orbiter's telecommunications systems will also establish a crucial service for future spacecraft, becoming the first link in a communications bridge back to Earth, an "interplanetary Internet" that can be used by numerous international spacecraft in coming years. Testing the use of a radio frequency called Ka-band, Mars Reconnaissance Orbiter may demonstrate the potential for greater performance in communications using significantly less power.
The orbiter also carries an experimental navigation camera. If it performs well, similar cameras placed on orbiters of the future would be able to serve as high-precision interplanetary "eyes" to guide incoming landers to precise landings on Mars, opening up exciting - but otherwise dangerous - areas of the planet to exploration.
The orbiter's primary mission ends about five-and-a-half years after launch, on December 31, 2010.
Image Caption: This artist's concept of the Mars Reconnaissance Orbiter highlights the spacecraft's radar capability. The Shallow Radar (SHARAD) instrument is the long pole-like feature that extends horizontally from the spacecraft. The radar is pictured "beaming" down under the surface of Mars. The foreground of the image is a cross section of the planet, showing the crust, the layers below and, ultimately, reservoirs of ice or liquid water.
The SHARAD instrument will look into the first few hundreds of feet below the martian surface, up to 1 kilometer.
Image Credit: NASA/JPL