The longest serving spacecraft at Mars
Today is the anniversary of 2001 Mars Odissey spacecraft’s Mars orbit insertion. The veteran probe was launched on April 7, 2001, but only seven months later, on October 24, 2001, Mars Odyssey arrived at its destination, firing its main engine to enter Martian orbit. As a consequence today is basically the 15th birthday for its full operating life. It is quite obvious that the orbiter was named in honor of Arthur C. Clarke’s popular science fiction novel 2001: A Space Odyssey, but the story behind the choice of the name is more tormented. Originally, the committee appointed for the mission’s name choice, decided for Astrobiological Reconnaissance and Elemental Surveyor, abbreviated ARES (a tribute to Ares, the Greek god of war). Faced with criticism that this name was not very charming and definitely too aggressive, the naming committee reconvened and while the candidate name “2001 Mars Odyssey” had earlier been rejected because of copyright and trademark concerns, there was the chance to email Arthur C. Clark about the possibility of naming the orbiter after his book. He responded that he would be delighted to have the mission named with that title, and having no objections, NASA approved the name change.
Also the mission general idea was not completely clear from the beginning. The spacecraft was supposed to have a a companion known as Mars Surveyor 2001 Lander, but the lander mission was canceled in May 2000 following the failures of Mars Climate Orbiter and Mars Polar Lander in late 1999.
Odyssey’s primary mission was completed in three years only and multiple mission extensions have kept it active for a decade and a half. By December 15, 2010 it broke the record for longest serving spacecraft at Mars, claiming the title from NASA’s Mars Global Surveyor. Being in a polar orbit around Mars with an altitude of about 3,800 km, it currently holds the record for the longest-surviving continually active spacecraft in orbit around a planet other than Earth, ahead of the Pioneer Venus Orbiter, which operated for 13 years and ten months.
The communication relay support is probably one of the most important role the orbiter had in the last 15 years. Both the Mars Exploration Rovers, Spirit and Opportunity, relied on Odyssey to transmit more than 90 percent of the data they collected back to Earth and the same Curiosity, on the Red Planet since 2012, still relays its data through Odyssey, together with the Mars Reconnaissance Orbiter.
The three primary instruments Odyssey uses are the:
- Thermal Emission Imaging System (THEMIS)
- Gamma Ray Spectrometer (GRS)
- Mars Radiation Environment Experiment (MARIE)
In particular, THEMIS is probably the instrument that returned the most visible results from Odyssey. It images Mars in the visible and infrared parts of the electromagnetic spectrum to determine the thermal properties of the surface and to refine the distribution of minerals on the surface of Mars as determined by the Thermal Emission Spectrometer (TES).
The payload’s MARIE radiation experiment stopped taking measurements after a large solar event bombarded the Odyssey spacecraft on October 28, 2003. Engineers believe the most likely cause is that a computer chip was damaged by a solar particle smashing into the MARIE computer board. Despite this, the spacecraft is remarkably healthy, and it has enough fuel to last for several more years.
The orbiter has observed in total more than six full changes of Martian seasons, enabling it to discern cyclical weather patterns that repeat seasonally though may be somewhat different each year. It also mapped the distribution of water in the surface of the red planet and it has not only been used to relay Mars Curiosity communication, but it was also used to help select a landing site for the Mars Science Laboratory (MSL) rover.
The project was developed by NASA, and contracted out to Lockheed Martin, with an expected cost for the entire mission of US $297 million. Odyssey was designed for a four-year mission: we’re now in the 16th year, and it keeps counting from around a planet millions of kilometers away from home.