Odyssey Spacecraft Looks to Be in Mars Orbit

NASA’s 2001 Mars Odyssey spacecraft appeared to successfully enter orbit late Tuesday around the Red Planet, where the space agency suffered back-to-back failures on its previous two tries.

Engineers and scientists at NASA’s Jet Propulsion Laboratory in Pasadena received preliminary indication shortly before 8 p.m. that a programmed engine firing had slowed the spacecraft and allowed Mars to capture it into an egg-shaped orbit.

Mission control at the lab erupted in cheers.

“It’s great. It’s wonderful. We’re back at Mars,” said Daniel McCleese, chief scientist of the JPL Mars program. “The orbit looks even better than the predictions. It’s really good.”

Odyssey slipped over Mars’ north pole and dipped behind the planet after the burn began, leaving mission team members waiting anxiously. About 20 minutes later the probe reappeared and transmitted a signal to Earth across 93 million miles of space.

Scientists did not expect to know for up to three hours the exact orbital path the boxy spacecraft was traveling around Mars.

The Mars Odyssey, which reached Mars after a six-month, 286-million-mile journey from Earth, is the first mission to the planet since two NASA failures in 1999. For the space agency, the project represented a shot at redemption.

A spacecraft’s transition from interplanetary cruising to arrival has proved to be one of the most challenging phases in the exploration of Mars.

In 1993, contact with NASA’s Mars Observer was lost as the satellite neared Mars, probably after a fuel-system explosion. Six years later, a mix-up between English and metric units in calculating trajectory put the Climate Orbiter too close to Mars, causing it to burn up in the atmosphere. The Polar Lander vanished three months later, probably because a software error caused it to plunge to the surface.

The back-to-back losses in 1999 underscored the difficulty of getting to Mars: Fewer than one-third of the 30 missions launched to the planet by the U.S. and other countries since 1960 have succeeded.

The two botched missions also forced the space agency to scale back what had been an ambitious program to explore the planet.

Originally, Odyssey was supposed to be joined by a spacecraft that would put a rover on the surface of Mars. But the lander was scrapped, leaving Odyssey to wend its way alone to Mars after its launch last April.

To avoid another fiasco, NASA added staff, did extra checks on software and took precautions to prevent a repeat of the English-metric mix-up.