Mars Odyssey Mission Status July 16, 2001

At 8:30 a.m. Pacific time today, NASA’s 2001 Mars Odyssey spacecraft passed
the halfway point on its journey to Mars. It has been 100 days since Odyssey’s launch
and 100 days remain until it arrives at the red planet.

“Odyssey is now closer to Mars than Earth. The spacecraft is healthy and all
systems are looking good,” said David A. Spencer, the Odyssey mission manager at
NASA’s Jet Propulsion Laboratory. “Planning for Mars approach and orbit insertion in
October is our primary focus right now.”

The navigation team reports the spacecraft is right on course. To date, the Deep
Space Network has taken 11 separate measurements using the so-called delta differential
one-way range measurement, a technique that uses two ground stations to determine the
angular position of the spacecraft relative to the known position of a quasar. The
measurements provide the navigation team with an additional source of information,
adding confidence to their estimates of the Odyssey flight path.

Today, Odyssey is 45.8 million kilometers (about 28.5 million miles) from Earth
and 30 million kilometers (about 19 million miles) from Mars, traveling at a velocity of
26 kilometers per second (58,000 miles per hour) relative to the Sun.

The Mars Odyssey mission is managed by JPL for NASA’s Office of Space
Science, Washington, D.C. JPL is a division of the California Institute of Technology in
Pasadena. The Odyssey spacecraft was built by Lockheed Martin Astronautics, Denver.