{"id":13946,"date":"2018-03-08T00:01:32","date_gmt":"2018-03-07T16:01:32","guid":{"rendered":"https:\/\/wp-productionenv-bjg9h2g2bgg5b8aa.southeastasia-01.azurewebsites.net\/news\/europes-exomars-orbiter-nears-start-of-methane-sniffing-science-mission\/"},"modified":"2018-03-08T00:01:32","modified_gmt":"2018-03-07T16:01:32","slug":"europes-exomars-orbiter-nears-start-of-methane-sniffing-science-mission","status":"publish","type":"post","link":"https:\/\/starpath.global\/news\/europes-exomars-orbiter-nears-start-of-methane-sniffing-science-mission\/","title":{"rendered":"Europe\u2019s ExoMars orbiter nears start of methane-sniffing science mission"},"content":{"rendered":"
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Artist\u2019s concept of the ExoMars Trace Gas Orbiter during aerobraking at Mars. Credit: ESA\/ATG medialab<\/figcaption><\/figure>\n

Nearly a year-and-a-half after arriving at the red planet, Europe\u2019s ExoMars orbiter is finally approaching a planned perch around 250 miles over the rust-colored world after repeatedly dipping into the Martian atmosphere to lower its orbit.<\/p>\n

The end of a year-long \u201caerobraking\u201d campaign moves the ExoMars Trace Gas Orbiter closer to starting regular science observations, a transition expected in April, when the mission will begin measuring how much methane is in the Martian atmosphere, an indicator of potential ongoing biological or geological activity.<\/p>\n

Built in Europe and launched by a Russian Proton rocket in March 2016, the Trace Gas Orbiter is the first mission in the two-part ExoMars program, a partnership between the European Space Agency and Roscosmos, Russia\u2019s space agency. An ExoMars lander and rover are scheduled for launch to the red planet in 2020.<\/p>\n

The robotic spacecraft zoomed through the planet\u2019s outer atmosphere nearly 1,000 times since it looped into orbit around Mars in October 2016, using gentle nudges of aerodynamic drag to gradually slow down. In response, the high point of ExoMars\u2019 orbit was reduced from an altitude of 20,500 miles (33,000 kilometers) to 650 miles (1,050 kilometers).<\/p>\n

The Trace Gas Orbiter fired its main engine to slow down and enter orbit around Mars. The spacecraft used thrusters for two more major maneuvers in early 2017, first to change the inclination, or tilt, of its orbit from 7 degrees to 74 degrees with respect to the planet\u2019s equator, then to lower its peak altitude from 61,000 miles (98,000 kilometers) down to 20,500 miles in preparation for the start of aerobraking.<\/p>\n

Further rocket firings moved the low point of the probe\u2019s orbit into the high-altitude layers of the Martian atmosphere.<\/p>\n

\u201cSince March 2017, we\u2019ve been conducting a terrifically delicate \u2018aerobraking\u2019 campaign, during which we commanded it to dip into the wispy, uppermost tendrils of the atmosphere once per revolution, slowing the craft and lowering its orbit,\u201d said Michel Denis, the European Space Agency\u2019s flight director for the ExoMars mission.<\/p>\n

\u201cThis took advantage of the faint drag on the solar wings, steadily transforming the orbit,\u201d Denis said in a statement. \u201cIt\u2019s been a major challenge for the mission teams supported by European industry, but they\u2019ve done an excellent job and we\u2019ve reached our initial goal.\u201d<\/p>\n

The drag exposed parts of the spacecraft, especially its solar panels, to elevated temperatures near 200 degrees Fahrenheit (100 degrees Celsius).<\/p>\n

Assembled and tested in France by Thales Alenia Space, the Trace Gas Orbiter flew as low as 64 miles (103 kilometers) on some orbits. Cumulatively, more than 950 passes through the atmosphere changed the orbiter\u2019s velocity by more than 2,200 mph (3,600 kilometers per hour), according to ESA.<\/p>\n

ESA controllers paused the aerobraking campaign between late June and early September when Mars \u2014 and the Trace Gas Orbiter \u2014 flew behind the sun as viewed from Earth. The event, known as solar conjunction, occurs regularly as the planets march around the sun, disrupting reliable communications with spacecraft at the red planet.<\/p>\n

The aerobraking technique saves fuel, reducing the mass of a spacecraft at launch. In TGO\u2019s case, the tradeoff saved around 1,300 pounds (600 kilograms) of fuel, according to ESA.<\/p>\n

That saved manufacturing and launch costs for the mission.<\/p>\n

Ground controllers at the European Space Operations Center in Darmstadt, Germany, sent commands for TGO to fire thrusters Feb. 20 to boost the craft\u2019s orbit out of the Martian atmosphere to an altitude of approximately 120 miles (200 kilometers), ending the aerobraking phase of the mission.<\/p>\n