Mars, Ho!

NASA's 2001 Mars Odyssey probe is poised to enter orbit around the Red Planet.

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October 18, 2001: After more than six months cruising through interplanetary space, NASA's 2001 Mars Odyssey is nearing its destination. On October 23rd the spacecraft will fire its main engine for the first and only time and put itself into orbit around the Red Planet.

Right: An artist's rendition of 2001 Mars Odyssey as it enters orbit around the Red Planet. Credit: JPL

"The spacecraft, ground system and flight team are ready for Mars orbit insertion," said Matthew Landano, Odyssey project manager at NASA's Jet Propulsion Laboratory. "We uplinked the sequence of commands that control the orbit insertion on Oct. 15th. Now we will closely monitor the spacecraft's progress as it approaches Mars and executes the orbit insertion burn."

Odyssey was launched April 7, 2001, from Cape Canaveral Air Force Station in Florida. Since then it has traveled 460 million kilometers -- an interplanetary journey that has gone "flawlessly."

Other than our Moon, Mars has attracted more spacecraft than any other object in the solar system -- and no other planet has proved as daunting to success. Of the 30 missions sent to Mars by three countries over 40 years, less than one-third have been successful.

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Scientists, mission controllers, and Mars enthusiasts everywhere hope Odyssey will become one of the exceptional spacecraft that make it.

To enter orbit, Odyssey's propellant tanks -- the size of big beachballs -- must first be pressurized, plumbing lines heated, and the system primed before 262.8 kilograms of propellant is burned in exactly the right direction for 19.7 minutes. Flight controllers at JPL will see the main engine burn begin a few seconds after 7:26 p.m. Pacific time (PDT) on the evening of Oct. 23rd.

(Events in space are usually measured in Universal Time or "UT" -- formerly called Greenwich Mean Time. Odyssey will arrive at Mars on Oct. 24th Universal Time. In the United States, however, the arrival will take place on Oct. 23rd.)

The spacecraft will pass behind the planet 10 minutes later and remain out of contact for about 20 minutes. The burn is expected to end at 7:46 p.m. PDT, but controllers will not receive confirmation until a few minutes later when the spacecraft emerges from behind Mars and reestablishes contact with Earth at about 8 p.m PDT.

Below: Click on this artist's rendering of 2001 Mars Odyssey to view simulated videos of the coming Mars Orbit Insertion. [more]

The firing of the main engine will brake the spacecraft's speed, slowing and curving its trajectory into an egg-shaped elliptical orbit around the planet. In the weeks and months ahead, Odyssey will repeatedly brush against the top of Mars' atmosphere in a process called aerobraking, which will circularize the craft's orbit. At first Odyssey will loop around Mars in a 19-hour long ellipse. Aerobraking will transform that path into a shorter, 2-hour circular orbit approximately 400 kilometers above the planet. Such an orbit is better suited to the mission's science data collection activities.

Odyssey carries a suite of scientific instruments designed to seek out evidence of near-surface water, to probe the planet's radiation environment (vital information for possible future human missions to Mars), and to map interesting minerals on the planet's surface. See the recent Science@NASA story "2001 Mars Odyssey" for an overview of the craft's science objectives.

And stay tuned to NASA TV, which will begin coverage of Odyssey's orbit insertion at 7 p.m. PDT on October 23rd.

The Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C.

2001 Mars Odyssey -(JPL) mission home page

2001 Mars Odyssey Video -- (JPL) This collection of video clips illustrates Odyssey's journey to Mars. Topics include aerobraking, telecommunications, orbit insertion, and the interplanetary cruise.

The Challenge of getting to Mars: Orbit Insertion -- (JPL) Mission scientists and engineers describe what's tricky about traveling to the Red Planet.

More Science@NASA stories about Mars and 2001 Mars Odyssey:

Planet Gobbling Dust Storms -(Science@NASA) An enormous dust storm exploded on Mars earlier this year, shrouding the planet in haze and substantially raising the temperature of its atmosphere.

The Perfect Storm Strikes Mars -(Science@NASA) 2001 Mars Odyssey mission controllers will be keeping a close eye on a Martian dust storm as Odyssey enters the critical aerobraking phase of its mission.

2001 Mars Odyssey -(Science@NASA) Learn more about the science objectives of the 2001 Mars Odyssey mission.

Space Weather on Mars -(Science@NASA) Future human explorers of Mars can leave their umbrellas back on Earth, but perhaps they shouldn't forget their Geiger counters!

The Lure of Hematite -(Science@NASA) On rusty-red Mars, a curious deposit of gray-colored hematite (a mineral cousin of common household rust) could hold the key to the mystery of elusive Martian water.

Carbonated Mars -(Science@NASA) Here on Earth the only way to make carbonate rocks is with the aid of liquid water. Finding such rocks on Mars might prove, once and for all, that the barren Red Planet was once warm and wet.