Flight controllers for NASA’s 2001 Mars Odyssey spacecraft report that Odyssey has reduced its orbit period to just under 10 hours. The orbit period is the time it takes the spacecraft to make one revolution around the planet. During each aerobraking pass, when the spacecraft skims the atmosphere to alter its orbit, Odyssey’s closest approach, known as the periapsis, is just 103 kilometers (64 miles) above the Martian surface. Its farthest point from the planet, known as the apoapsis, is now 15,300 kilometers (9,500 miles).