Opportunity (rover)

Opportunity (English for opportunity ) is a started in July 2003 U.S. space probe for geological exploration of Mars. The probe was originally called by its full name Mars Exploration Rover B ( MER -B) and was then renamed Opportunity. It landed on January 25, 2004 successfully in a small crater ( in the lowlands Meridiani Planum ), the NASA later christened Eagle Crater, and is active on the surface of Mars for a decade. The sister rover Spirit ( MER -A) landed on January 4, 2004 at Gusev Crater.

• 5.1 evidence of former liquid water on Mars
• 5.2 evidence of formerly open standing water in motion

Objectives of the mission

Target of the probe Opportunity ( MER -B) and its sister rover Spirit ( MER -A) was the landing and geological (actually areologische ) exploration in areas of previous Mars orbiters NASA after the follow- the-water strategy ( " were detected follow the water " ) as possible, formerly water-bearing areas. They pointed to line structures or minerals that were on the influence of liquid water or perhaps even close to formerly open water. For an Opportunity landing site was selected near the planetary equator on the plains of Meridiani Planum, because there were recognizable extensive deposits of hematite on the surface. Hematite may arise, among others, in open water or hydrothermal. Another interesting aspect for the selection of this area was well aware that an orbiter there discovered a nearly flat -lying, obviously very finely layered bright rock formation, although this was never officially confirmed in advance. Constitute Whether these rocks, however aeolian ( windabgelagerte ) or aquatic ( wasserabgelagerte ) sediments or whether they are tuffites ( volcanic ash ), bright Vulkanitdecken ( lava) or special impactites ( stratified deposits of so-called " rock clouds" from meteorite impacts ), was before the examination at the Martian soil still completely open.

The mission duration should initially be guaranteed 90 days, but Opportunity has far exceeded this long. The mission has been extended regularly. Currently ( as at 1st January 2014), the rover traveled a total distance of 38.73 km on Mars and is located near the " Solander Point". Less than 3 km before he had completed the investigation of the " Cape York " segment of Endeavour crater, where it was hoped that access to older layers of the Martian surface.

Technique of probe

The two rovers Spirit and Opportunity are identical. Therefore, there is a detailed description of the technique, Mars Exploration Rover.

Unlike Mars Pathfinder Opportunity is called no fixed ground station, but a wheeled robot, " Rover ". It is 1.6 m long, 1.5 m high and 185 kg. According to the specification, he should be able, depending on the surface condition on the day of about 100 m, a total of about 3 km before and up to six months to remain operational on the planet's surface. This exceeds the capabilities of its predecessor Sojourner of the Mars Pathfinder mission in 1997 by about a factor of 60 The rover is NASA itself as a " robot geologist " ( robotic geologist ) referred to and has six independently driven wheels on stilts shaped telescopic legs. He carries in addition to various panoramic ( Pancam ), navigation ( navcam ) and danger recognition cameras ( hazcams - hazard recognition cameras ) a pivoting arm with a rock microscope (also with camera ), several spectrometers ( Mössbauer, alpha particles, infrared ) and a mechanical tool that is able to brush off rock surfaces and deep to drill on a few square centimeters to several millimeters in order to examine the interior accessible rocks can (RAT - rock - abrasion tool ). The wheels are moved individually and not used solely for locomotion, but can also be used as mining equipment to dig up the ground and thus to examine a few centimeters of the soil profile mechanically and photographically. The rover has about solar panels and rechargeable batteries is to save energy before sunset brought into a state of rest and again " awakened" after sunrise by a radio signal. With the help of his antennas, the device images and measurement results can either send the used as intermediate stations for earth orbiting Orbiter NASA and the ESA or directly to earth and receive commands from there. Because of the relatively high running time of the signals from the earth (depending on planets distance up to 20 minutes ), the rover must with its on-board computers to some extent can act autonomously.

Course of the mission

Opportunity successfully launched on 8 July 2003 with a Delta II 7925H launch vehicle and landed in the early morning of 25 January 2004 ( 6:05 clock CET) in the Meridiani Planum - Great Plain of Mars. Unlike previous missions of the lander was not withdrawn from orbit, but drilled directly from its trajectory out with an error tolerance of a few kilometers on the planet, which required the utmost accuracy in the approach. The probe was protected by a heat shield, first decelerated in the atmosphere down to the speed of sound. Then a parachute on its lines a missile system was installed above the probe, which should compensate for horizontal movements in the atmosphere unfolded. Shortly before touchdown protectively around the probe set airbags were inflated abruptly. After touchdown, the lander bounced on the air bag or several times over the surface until it came to a halt in a small crater. After deflating the airbags and opening the landing capsule, the first photos of the Rovers never disclosed structures seen at the edge of the small crater, which should be one of the main objects of observation for Opportunity. They showed that the probe had their goal, against many expectations, just hit and possible favorable position just a few meters had landed next to a overt bleed the targeted light rock formation.

1st half of 2004 - Primary Mission

After several days, the rover was on its landing platform (now designated as Challenger Memorial Station ) unfolded and was able to leave on a folded-down ramp. The floor of the crater, the Eagle crater was named, was littered with small beads, called Blueberries. In the crater were also the prints of the landing airbags clearly seen. A recording of the infrared spectrometer minites showed the Hämatitverteilung inside the crater. Where the airbag was impinged, no hematite was found. Apparently the Blueberries were pushed by the airbag into the ground and so could not be found by minites. A subsequent examination of a collection of Blueberries with the Mössbauer spectrometer also showed that these beads are made of hematite.

In just a few meters from stratified rock was found on the crater rim, in which the individual layers were only a few millimeters thick. This meant the advantage to investigate rock where it was written for geologists. In these strata the Blueberries were partially embedded therein or were previously scattered. This indicates the formation of the Blueberries within the rock. In the investigation of the rock with the APXS and the Mössbauer spectrometer evidence was found that it contains jarosite. This potassium -iron sulfate hydroxide normally develops in an aquatic environment. Some of the layers could be grooved and cross-over (cross- bedding ) structures make up, which usually form in running water. In a shed called El Capitain narrow elongated voids were found. These spaces are formed when crystals form in the rock and then eroded out. In addition, a 50 cm long and 10 cm deep trench was to examine the ground, dug with the right front wheel. Again, the Blueberries have been found. It was also noted that the soil has a very clumpy structure.

After a two- month investigation Opportunity left the crater. To find out whether the found evidence of liquid water were only locally due or to find in the whole region, a 750 m distant crater was determined as the next target. This was named after the research ship Endurance, which under the leadership of the British polar explorer Ernest Shackleton was used at the Imperial Trans- Antarctic Expedition. Other examined craters were named after famous research vessels.

On the way there is a stone called Bounce rock could be examined. This was accidentally hit by the impact of the landing, and the airbag has been loosened. The stone has a volcanic nature and strong resemblance to the Shergottites, a subset of the so-called Martian meteorites. It was assumed that he was thrown out by an impact from a relatively fresh impact crater 75 km southwest of Eagle Crater. The rover could partially distances up to 100 meters per Martian day cover and came so very well in the flat plane ahead. The Move were discovered at a point called Anatolia splits or cracks, which could be attributed either tectonically or were formed by a series of impact craters. Even with a smaller crater called Fram sulfur, chlorine and bromreiches bedrock could be detected. This was an indication that it must have once been a great deal of surface water, which covered the entire Meridiani Planum.

End of April 2004 reached Opportunity to Endurance Crater. In order to observe the crater interior and discover a possible entry point, the rover went first along the crater rim. Inside there were the expected deeper layers, the ground itself was covered by sand dunes. Therefore it was decided at NASA, the rover into send into the crater, even at the risk that he could not get out. On June 10, NASA engineers began to make some descent experiments with the Rover, because it was not clear whether and how well Opportunity could handle the ground. Therefore, at first only two driving tests were into the crater and made ​​out again. After these attempts were successful, drove the rover on Sol 133 at a place called Karatepe deeper into the crater into it.

Second half of 2004 - Endurance Crater

Now the study of the layers of Endurance Crater, which is about 12 m deep began. Each layer was photographed, and in several places holes have been with the stone grinding tool drilled into the rock. This enabled a stratigraphy of the bottom of Meridiani Planum are created. By mid-August ( Sol 192), the rover analyzed the individual layers almost to the dunes on the floor. The study of the dune itself was considered too dangerous, as the wheels of the rover could get stuck in the dunes. While driving on the slopes of the crater, the wheels of the rover slip partly strong, so that the precise positioning of interesting objects very difficult.

A stone formation called Escher on the southwestern slope of the crater was examined more closely. This stone contained fault lines that divided the surface into polygons. These faults could have originated either in the forest or by the influence of water and subsequent dehydration. Mid-September 2004 entered the solar conjunction, that is, the sun was between Mars and Earth. During about two weeks can not be communicated with the probe. On the way to Burns Cliff, a steep slope on the crater rim, the rock was Wopmay, with a diameter of nearly a meter, examined. Its unusual surface had, like Escher, the possibility of strong water influence. The layers of Burns Cliff could not be reached due to the steep environment. Instead, a wide panorama of it produced. After this examination, the Rover ( Sol 318) went below by Burns Cliff back to the entry point Karatepe and from there on 21 December 2004 back out.

The investigations in Endurance crater revealed that the region was not only once covered by shallow, salty water, but often covered with water and was dried again. To confirm these results, a crater named Victoria was chosen in 5.6 km distance as a new long-term goal.

First half of 2005 - incident at the dune

The first stop after Endurance was the investigation of its own heat shield, which had sprung up just south of the crater on landing. Here you did on the unique opportunity to investigate this component according to its use, including how the refractory material had changed during re-entry. It was found, among other things, that the inside had turned inside out upon impact. A few meters away from the heat shield Opportunity discovered its first iron meteorite called Heat Shield rock.

After the examination of the heat shield, the rover began its way to Victoria Crater. Since the area was very flat and monotonous, the rover moved forward quickly, so about 400 m were partly driven per day. A first intermediate target was reached on sol 399 (March 8, 2005) at Vostok crater. The crater, however, was completely filled with sand and therefore not suitable for an in-depth investigation. Therefore, it was further down to the south to an area called Etched Terrain, which consists of large-scale structures from bedrock. During the next rides the dunes were the Opportunity crossed higher. After the April 17, 2005 blocked the engine of the right front wheel, the rover was instructed by now to go backwards in order to relieve this wheel.

On April 26, 2005, after 5346 m travel distance, the wheels of the rover dug firmly while crossing a dune in the loose sand. Since the software was not prepared for such a situation, the wheels turned to the programmed end on. All six wheels now stuck up to its axles in sand. After trying to find a way NASA technicians using simulations on earth to free the rover again. Pessimists feared a premature end to the mobile mission. On May 13, the attempt to gently retract the rover in small steps began. Until June 3, 2005 Opportunity has already been moved out to 93 cm from the dune. The wheel rotations required for this would have been enough on the open road for 177.2 m distance. On June 4, finally succeeded hinauszumanövrieren the rover from the dune. After this five-week breakdown could now move all the wheels again. Subsequently, the name Purgatory ( " Purgatory ") was baptized dune examined to determine what differentiates them from numerous problems so far crossed dunes. Since July 5, 2005 Opportunity was back on the road in the direction of the crater Erebus.

2nd half of 2005 - Erebus

After the liberation from the sand dune no longer travel long distances have now been moved, so the rover was not progressing as quickly as before. Since the orientation of the dunes was mainly in North-South direction, the spacecraft could usually drive along between the dunes and had only now and then to cross a dune. The Etched Terrain -called terrain has been achieved and it turned out they had more bedrock was revealed between the dunes. This was positive for the ride, because the rover to fight on solid rock with fewer problems had as if he drives on a sandy bottom. On August 21 there was a computer crash. This problem has been studied during the next sol, so the ride was taken in September to Erebus crater only again.

On October 5, an image of the rover could be included in the dunes of Mars, Mars Mars Global Surveyor. These recordings were important aids to navigation. On November 2, the Erebus crater was reached. He was surrounded on the eastern edge, as there was the rocky ground. The crater itself was filled with sand, but smaller cliffs were open at the edges, which were later examined.

On 20 November 2005, the instrument arm should be extended as planned, however, blocked a problem with the shoulder joint motor command. One reason for this could be the now often longer operating time of the Rovers. In the next few weeks the problem has been studied by the engineers. Meanwhile, the rover remained at that position and took on the Erebus Rim called Panorama, which consists of over 1300 individual images.

H1 2006 - Leave for Victoria Crater

The instrument arm absolutely had to be retracted again, because the ride with extended arm was hardly possible. On January 20 (sol 695 ) continued the Rover on again after the instrument arm at a different location could be stored on the machine. Opportunity also conducted coordinated examinations of the atmosphere with his minites spectrometer in combination with the Mars probe Mars Express of the European Space Agency and photographed by crossings of the Martian moon Phobos by the solar disk. This allows, for example, the path of the moon to be determined even more accurately.

From the crater Erebus a cliff called Payson and the Mogollon Rim escarpment, which were still visible from the crater rim were then further investigated. Again, again showed stratified rock layers that have been interpreted as sedimentary rocks.

On March 17, Opportunity finished the investigation of Erebus, and began the journey to Victoria Crater, which is located 2 km south-east from the hotel. The next few weeks came the Rover again a more advanced level, partly because the dunes were low again, and had covered a total of 8392 meters on Mars until 27 June 2006. Despite all precautions, the Rover ( 833 Sol ) drove on May 29 in a small dune fixedly but could be freed from it again after a week.

2nd half of 2006 - arrival at Victoria Crater

In the first half of July, the software of the Rovers has been updated. He received greater autonomy while driving, and improved energy management thereby. Beginning of August, the vehicle the about 35 meters in diameter crater Beagle, which is only about 500 meters away from the edge of Victoria; a month later the car was only 200 meters from the crater rim. During the trip also came back to a clean up event, was blown down in the dust of the solar panels, which improved the power supply strong. It is through these events, the lifetime of the robot extended again and again.

The rover reached at 28-29. September 2006 after several short trips to the three preceding sol ( 30.2, 26.4 and 3.5m ) deep the edge of the 60 m and 800 m wide crater at an indentation, which was called Duck Bay. The study of rock strata of the crater should allow even more detailed information about the existence of water on the red planet. At first shots of the crater inside the hoped rock layers have been discovered that towered up in up to 6 m high cliffs. Now it was time to find the best entry into the crater. Therefore, the rover drove first to the north, to circumnavigate the crater in the next few months clockwise partially. In each case, images of approximately 10 m distant locations were combined into stereo images to create a three-dimensional map of the crater.

The Mars Reconnaissance Orbiter arrived at Mars in March 2006 and then took the end of November the scientific operation. Since the camera resolution of this orbiter surpassed the previous quality of previous missions by far, the environment could be taken up in great detail of Opportunity. Beginning of October 2006 published NASA photographs of the Mars Reconnaissance Orbiter, on which the crater and the rover can be seen itself.

1st half of 2007 - Crater circumnavigation

In January 2007, Opportunity was further down on the northern edge of the crater and photographed the cliffs from different perspectives. These showed that these were formed from sand dunes that were piled by north-south winds and then fossilized. Another meteorite called Santa Catarina was found here on the northern edge of the crater and examined. On 9 February, the 10 - km mark was achieved.

The APXS was now for the first time used to determine the content of the inert gas argon in the Martian atmosphere. To this end, the instrument was directed toward the sky and then made ​​about three hours measurements. These studies were also carried out by the twin rover Spirit on the other side of Mars. Thus it was hoped that a better understanding of how varying the mixing ratio of argon to carbon dioxide during the seasons when the carbon dioxide is reflected at the poles.

In March, the Valley was achieved without peril, which was considered as a possible entry point into the crater. Here it was found that the slope had a strong tendency to order into it down safely at this point. After two more clip projections were examined, it was decided that all the way back 600 meters to go to the original destination, to descend into the crater there. On the way back, the solar cells were purified by some wind gusts. Thus, the available energy increased to nearly 800 watt-hours per day. This was almost as much as after landing three and a half years earlier. On June 15, Opportunity reached again Duck Bay and prepared for entry into the crater.

On January 4, 2007, both Rover new control software were given for their computers. The new system gave the Rover more freedom of choice as to whether an image is to be transferred, or if the instrument arm should be extended. This saved the scientists time, as they no longer have to review hundreds of images.

2nd half of 2007 - The Sandstorm

However, the entry had to be postponed because as of end of July 2007 a ​​sandstorm disabled the probe, which covered large parts of Mars soon. The whirling sand darkened the sky almost completely, so that the solar panels, the batteries could no longer be recharged. To save power, all activities were stopped. The probe should wait for the end of the storm with the lowest possible power consumption. However, this waiting proved to be very difficult because the probe was constructed (also due to their short life expectancy) not for such situations. The probe generates enough heat, than that they might keep the operating temperature electronics in power saving mode. If the temperature of the electronics under a certain value, so jump on automatic heaters to prevent cold damage to the electronic components (below -37 ° C). However, this use more energy than the probe during the storm ( down to -80 ° C) could still produce. The heaters would therefore the batteries very quickly empty, which would lead to a definitive closure of the probe. Since the end of July, the Rover was therefore a little longer actively maintained to prevent initiation of the heaters.

The probe automatically switches on when a critical charge status of the batteries itself, and only checked every Sol once again whether enough energy would be available for re- intervention is available. Also at large sand deposits on the panels were feared, so the probe would not be able to gain enough energy to get back fully on.

In mid-August, the storm was weaker and the transparency of the atmosphere rose again. Opportunity had survived the six-week dust storm. The next problem was that the dust stirred up by the storm was deposited on the solar cells.

On September 11, Opportunity could then drive into the crater. Here we first explored a lighter rock layer (bright band), which was discovered in the crater bypass. This layer is visible everywhere on the crater rim. The investigations showed that these lighter rock layer was formed by diagenesis. This rock layer separates the bedrock of the material that was ejected by the impact.

1st half of 2008 - Victoria Crater

Opportunity examined the next few weeks this geologically interesting rock layer and worked his way deeper into the crater interior. Among other things, a narrow, projecting Gesteinsgrat was discovered at a location called Gilbert. This ridge consists of minerals that were originally deposited in crevices and then remained after the surrounding rock was eroded away. Analysis with the APXS and the Mössbauer spectrometer showed that the ridge is just like the Blueberries from hematite.

End of April, the measurements were then completed, and now the cliff Cape Verde should be further explored. The ride there turned out to be problematic: The rover slipped on the sandy and 25 ° steep rock bottom very strong and mid-May, the middle right wheel dug itself even in the sandy bottom one. In addition, in April were again problems with the instrument arm. This could not be expanded because of the shoulder joint motor. Only after several attempts could move him again. The other routes, however, had to be carefully planned, because the ride with an extended delivery arm is difficult.

On Sol 1565, June 19, 2008, Opportunity had approached to within 10 m of the lower area of Cape Verde. Called From this position, Cape St. Mary, then a detailed panoramic image of the cliffs was created. Near the cliff had to be also paid to the shadow of the cliffs, so as not to endanger the power supply. The cliffs themselves could not be reached because the floor in front was too steep and sandy.

Second half of 2008 - Farewell to Victoria

In July it was then attempted to reach some geologically interesting rocks in the vicinity of Cape Verde. However, the terrain turned out to be too difficult to navigate. On July 24 (sol 1600) an unusually high current was measured at the motor of the right front wheel. When Rover Spirit one wheel fell off after a similar current peak and could not be reactivated. Since Opportunity could never leave with a broken wheel the crater again, it was decided to discontinue the investigation of the crater and out down the fastest way out of the crater. On 24 August 2008, the rover drove back out to the spot Duck Bay from the crater.

After Opportunity had reached level ground again, in early September was tested, as can be driven and worked with the defective instrument arm. Following the tests, the rover drove on the southern edge of Victoria Crater on to take pictures of the town is home to cliffs. In the flat area routes could be operated more than 200 meters per day.

End of October, then the journey to the crater Endeavour began. This crater is about 12 km away and has a diameter of 22 km and a depth of 300 m. Here, too, hopes to regain access to deeper rock layers and thus insight into the early history of Mars. However, since there are on a direct path to high dune fields, the rover must make a detour of about 19 km. Therefore, the rover drove first in a southwesterly direction. Due to the high resolution, the Mars Reconnaissance Orbiter, on which even individual rocks and the dune crests are seen, the route can be very well planned in advance.

On 29 November, the solar conjunction, and thus again a phase began, could be communicated in the with no probe on Mars. During this time, Opportunity took a panoramic and analyzed the stone Santorini with the Mössbauer spectrometer. Santorini proved to be a Mesosiderite meteorite.

1st half of 2009 - ride in Meridiani Planum

After solar conjunction, the rover drove on in a southwesterly direction. Thanks to the autonomous control routes could be operated up to 150 m per day over again. But the age of the rover and its components made ​​itself felt: After some routes were covered on sandy soil, were again increased flows to the front motor. Therefore, some tracks were mastered riding backwards. The improved behavior of the motor, but the rover was slower in this mode above. In addition, rest breaks were repeatedly inserted, so that the wheel was able to recover. During the breaks, the lubricant distributed in the wheel bearing. This results in the next driving resistance will be less and less power consumption. Opportunity came to some smaller craters over, who have an estimated age of only 10,000 to 100,000 years. On Sol 1884 (May 12, 2009), the probe discovered her fifth meteorite: Kasos.

An unusual assistance gave his siblings Opportunity Rover on 19 May 2009. Spirit had dug in on the other side of Mars in sandy soil. In order to assess the situation better, it was necessary to get an accurate picture of the situation. The only camera that can look beneath the rover, the microscope camera on the instrument arm. However, this is only for close-ups, the captured image may be sharp subsequently calculated based on the known optics. Opportunity took this at some pictures of his underbody to see whether this technique provides the desired results.

By 29 June, the distance covered was increased to 16712 meters. While it was previously driven in a southerly direction, Opportunity now moved a few hundred meters in an easterly direction, to work around a field with high dunes.

2nd half of 2009 - meteorite finds

On July 19, it was discovered on older recordings a larger stone, was driven past the Opportunity previously in the distance. Since the stone appeared unusually large, the rover was decided to scale back the current cruising distance of approximately 200 m turn to examine this stone. Within a few days of the 0.7 m wide boulder was called Block Iceland reached. He stood out as previously Heat Shield rock, as another iron meteorite. Especially in this meteorite fell on the unusual wells must be formed by the weathering processes. To determine the most accurate three-dimensional model of the object, circled the rover the meteorite and recorded a total of six different positions. Shortly after block Iceland was left was in the plane of the end of September next meteorite, Shelter Iceland, in sight. This was also investigated in detail. On October 15, became the third meteorite, Mackinac discovered. Apparently this meteorite fragments of a larger meteorite that had come down in the area.

Opportunity then drove on solid rock in larger stages in the south to already to target one of the Mars orbit to be recognized more recent craters. Along the way, the rover in early November came to the next larger boulders, Marquette Iceland, where the origin was initially unclear. The stone grinding tool, which had become almost dull by years of use, could at least sanded the top layer and the stone be examined at this point with the remaining instruments. In addition, the stone itself had been broken apart at one edge, which facilitated access to their core. It turned out that Marquette Iceland had to be a basaltic rock from the interior of Mars, which was thrown out one day at a crater impact from the deep.

1st half of 2010 - Concepción

On Sol 2122, January 12, 2010 Opportunity finished its analysis of Marquette Iceland and continued his journey. The next destination was already visible on captured images of MRO: An apparently fresh impact crater called Concepcion, surrounded by dark eject rays. The researchers estimated his age in the order of 1000 years. This Concepción was the youngest ever examined crater. The rover circumnavigated the crater and took him into different perspectives. A rock called " Chocolate Hills " was examined in more detail, since a dark crust was discovered on its surface. This could be caused by Aufschmelzprozesse on impact. On March 9 ( Sol 2177 ) investigation of Concepción was completed and continued the journey to the south. Another software update was in March 2010, put into operation, which the Rover adds more autonomy: After a completed ride the system called " AEGIS " (Autonomous Exploration for Gathering Increased Science ) searches for striking objects and photographed them automatically.

The journey continued in a southerly direction past a double crater. Here, the Mars winter, it was noticeable. Due to the energy-intensive trips, the batteries need to be recharged, so the rover paused one or two sol between individual journeys. To abzubekommen as much solar energy, the rover was parked diagonally on the dunes slopes. In order to prevent that in the cold weather start the power-requiring heaters, the rover was kept awake longer.

In May, an attempt was made with the inertia measuring instrument to discover a Mars quake, which did not succeed.

On May 19, Opportunity had broken the record for the longest- operating on a planetary spacecraft, the Viking 1 had erected for a period of 6 years and 116 days.

Second half of 2010 - intermediate station Santa Maria

Through a time-intensive sunshine duration and wind events cleaning of the solar panels stand for the rides of opportunity again more energy. On July 28, the rover could take a photo of a dust devil for the first time, as he occasionally is responsible for cleaning the solar cells. This was previously only Spirit in Gusev Crater on the other side of Mars.

On the way to Endeavour crater, the automatic navigation of the rover, supported by the hazard avoidance cameras ( Hazcam ) is tested, which allows the rover to drive autonomously. Here, the rover is moving backwards, because the field of view of the forward -looking Hazcam is blocked by an inappropriately fitted antenna partially. On December 16 (sol 2450 ), the rover reached the 80 -meter crater " Santa Maria " and examined it more closely in the coming weeks.

1st half of 2011 - Course on Cape York

Earlier this year circumnavigated the crater the rover in half and positioned at a point on the crater rim. In this place, hydrated sulfate minerals were discovered on images taken by the MRO probe. This forms only in conjunction with water. At this time began the solar conjunction again. This time was used to examine this rock with the Mössbauer spectrometer.

By 24 March, the investigations on the crater Santa Maria have been completed, and the rover took his journey to Endeavour Crater again. Distance between Cape York and Santa Maria is about 6.5 km.

Second half of 2011 - Endeavour Crater and Cape York

Until the 5th of July, the Rover had managed 18.0 km or 90% of the way to Endeavour crater. At this time, the Total Distance summed in Meridiani Planum at 31 km. There were photographed on the ride more (possible) meteorites, which were not analyzed further. Although Opportunity was just 1.8 km from Cape York station, this object was not yet in sight. Reason was that Cape York was on a slope on the crater rim of Endeavour crater, the rover and thus remained hidden. As a point of arrival at Cape York in the small crater 'Spirit Point' was (named after the twin rovers Spirit ) in the south of this structure announced.

After Opportunity had left on August 28, 2008 ( Sol 1634) Victoria Crater, the rover was in 1000 sol more than 21 km to cover and on 9 August 2011 ( Sol 2681 ), nearly three Earth years later, the Endurance Crater reach. Together with the already completed before August 28, 2008 there were 2011 33.4858 km route on August 9. In the one Earth year after he moved a little more than 1 km along the crater rim on. The low mileage is mainly explained by the Mars winter, which lasted about half of the 12 Erdmonate ( December 2011-June 2012 ).

The Endeavour crater has a diameter of 22 km - about the size of the Ries - and offers new opportunities for researchers to investigate older layers of rock. In particular, look out is kept by layer silicates, which can form only in conjunction with water. Into the interior of the crater is not to be retracted, since there the same rock layers are expected to have been previously studied in Meridiani Planum.

A rock named Tisdale was thrown out by a later strike from the edge of Endeavour crater. It lies on the southern edge of Odyssey crater. For him, a high concentration of the element zinc was found. This indicates that it has been altered by hydrothermal processes. After the impact, the gave rise to the Endeavour Crater, heat was released, the aufschmolz existing water ice in the subsurface. This water distributed the dissolved minerals in the surrounding rock.

In examining the area around Cape York conspicuous lighter rock veins were discovered. A closer examination of such a vein called " Homestake " with the X-ray spectrometer, it was found that this pure calcium sulfate ( gypsum) is. One explanation is that sooner of water has flowed through the ground. The dissolved calcium sulfate then put into the cavities. These two discoveries are further evidence that liquid water was at least temporarily available on Mars to provide a life-friendly environment.

Since the energy supply of the Rovers had become critical by deposited dust than in previous years, was looking for an overwintering spot where the rover to the sun inclined could survive the winter better. This point is found in the north of Cape York and approached until December 2011.

First half of 2012 - Greeley Haven

The place should overwinter on the Opportunity, was named after a deceased NASA scientist Greeley Haven. There is a rock outcrop was examined in more detail with the instrument arm at this point. As the rover was not moved during the winter months, an experiment was carried out with radio waves during this time: this was an attempt to discover, through radio signals of the Rovers smallest tilting the axis of rotation of Mars. Thus, knowledge about the internal structure of the planet core can be obtained. After a long winter break, Opportunity moved on 9 May 2012 the first 3.7 meters from his winter quarters away to continue the investigation of Cape York. First recordings of wintering position were made to assess the work carried out during the winter time measurements in context. The journey was continued from Cape York in northern direction order to carry out further investigations of the soil and other gypsum veins.

Second half of 2012 - Further investigation of the Cape York

On July 2, 2012 Opportunity has already celebrated his 3000th Martian day (equivalent to 3078 days on earth). NASA published on July 5, a new panorama of Cape York and the Endeavour Crater, which the rover had taken during his winter break in high resolution. The panoramic image is composed of over 800 individual images taken between 21 December 2011 and 8 May 2012.

The energy production of the rover climbed from Sol 2989 (June 20, 2012), due to better sunlight, clear skies and purified by wind solar cells again from under 400 to over 500 watt-hours per day.

A few days before the arrival of Curiosity opportunity has been programmed for 9 days in advance and then "parked" in order to keep clear of the arrival of the orbiter Curiosity and the radio network. The state of kilometers census was 7 August 2012 ( Sol 3035 ): 34.63945 kilometers.

On August 12 (sol 3040), the journey was continued and included the small crater " Sao Rafael " driving past with the panoramic camera.

Since the end of August, Opportunity had not moved very far. The 35 - kilometer mark had already been passed on 28 August, the 22 - mile mark only the beginning of November. After the 9 inches or 23 centimeters shortest movements of the state of kilometers enumeration appears on 4 December 2012 22.02 miles or 35.42986 kilometers.

First half of 2013 - the end of the investigation of the Cape York

Although the exact location had changed ( Opportunity was located in early January at the " Copper Cliff " and the end of January at " Fullerton 1"), the rover moved very little (50 m in 2 months ). For the holidays at year investigation work had been programmed locally. In addition to the continuation of ground tests before Christmas the atmosphere (density and argon) was investigated. The day before the perihelion of Mars, Opportunity was the Sol 3200. Had so times the 35.5 its primary mission time and reached about 1 kilometers by 90 sol kilometer. In the period from January 7 to February 27 is not a " dementia " had shown problems with the flash file system.

On February 28, triggered by an error in the flash file system, an unexpected reset. Opportunity was then 2 days in so-called "Auto Mode ", which is a safe state with daily waking in which the rover only its own state ( in particular the excess temperature) monitored. On March 2, the command memory was targeted immediate command is cleared and installed new commands. After that, the rover worked for a week again properly. If problems would increase, a reformatting of the flash file system should be done in order to achieve a full recovery. On March 9, there was another minor problems with the flash file system, but not the same as before. Therefore, the system should first be observed further.

On March 11, the rover finished his local "walk" and looked again the " Newberries " for " Kirkwood ". After 10 days at the site, the rover began on March 21 in motion again and positioned himself at the "Big Nickel". He watched this place for about 3 weeks, because due to the conjunction on April 18, no communication with the Mars rovers and orbiters between 9 and 26 April was possible. For this reason, no rides, but only movements of the arm and analyzes the immediate area were planned from 9 to 26 April. When contact was recorded on April 27, again, it turned out that Opportunity had issued on April 21 because of a memory error in a standby mode. On May 1, the rover could be placed in the normal operating state. On May 16, 2013 Opportunity had a total of 35.760 kilometers traveled, which is more than the moon car of Apollo 17 the rover with the greatest distance traveled but still Lunokhod 2 at 42 km.

In June, the investigation of the rocks of Cape York have been completed and course taken on a new goal: Solander Point. This is hill south of the cape, which should be reached after a driving distance of 2.2 km. There are north facing slopes on which opportunity can survive the approaching Martian winter.

Second half of 2013 - Solander Point

On July 10, the energy production was as high as 435 Wh per day. It had continued to deposited dust on the panels, so that only 60 % of the incident light could be utilized to generate electricity.

When driving the rover progressed so well that it was decided to venture a little detour into the crater interior. After this detour the foot of the hill called Solander Point was reached around the 8th of August. For the climb up the hill a route has been chosen so that the angle of inclination of the solar panels was optimal. The slopes of the Solander Point provide insight into the time of the Noachian period. Rocks of early Mars period of history are usually hidden under the surface of Meridiani Planum. Only by the impact, in which the crater was formed, these layers were lifted up. Solander Point rises about 55 m above the Meridiani Planum. On October 1, was also trying to photograph the comet ISON. This failed because he was not bright enough for the rover's panoramic camera.

On December 6, the probe switched after transmission problems in the security mode. The solar energy production at this time was only 268 Wh per day. It occurred in the subsequent 3 days further transmission problems. However, a function testing showed no technical problems with the system. On December 10 ended Opportunity safe mode again. The mileage was now 38.7 km.

First half of 2014 - Murray Ridge

• This section presents the current situation

Early 2014, the rover had met a skew that best captured the translucent from the north sun. It is positioned on a rock digestion, in which observations of Mars probes small amounts of clay minerals suggest. So the more random dust from the solar panels by Martian winds - - Cleaning In addition, another event has been registered, in consequence of the energy production increased by 35 to 371 watt-hours ( per day).

Objects scanned

Since the Meridiani Planum, had landed in the opportunity, is very flat and uniform, boulders fall on already from afar. The age determination of meteorites is difficult because the fragments weather very slowly. The rocks bounce rock was hit during the landing of Opportunity from the airbag, hence its name. He was examined on 65 Sol. The study of the chemical composition showed a strong resemblance to the Shergottites, a subset of the so-called Martian meteorites. This is another strong indication that the Martian meteorites actually originate from Mars. The meteorite Heat Shield rock was near the heat shield encountered by Opportunity ( Sol 324) and is the first iron-nickel meteorite (93 % iron, 7% nickel), which was discovered on an alien planet.

The stone Santorini (examined Sol 1713-1749 ) proved to be an iron -rock meteorite ( Mesosiderite ). It has a size of 6 × 8 cm and a composition similar to the objects Barberton ( Sol 122 ) (3 cm diameter) and Santa Catarina ( Sol 1045, 14 cm diameter). It is possible that these three rocks were part of the object that had produced the Victoria Crater. The meteorite Kasos was investigated on Sol 1884 (May 12, 2009). Block Iceland was examined on Sol 1957. He is an iron meteorite and has a mass of about 900 kg. A body with this mass is too large to get through today's Martian atmosphere unchanged. Therefore, it is assumed that Mars previously had a denser atmosphere in which the meteorite was then landed. With the microscope camera triangular structures have been discovered that have similarities to structures of iron-nickel meteorites on Earth. These structures occur when the surface has been eroded by the wind. In addition, hole-like caves were found, based on the structure of the weathering history of the meteorite can be determined.

On Sol 2020 (2 October 2009), another iron meteorite called Shelter Iceland was investigated. It has a diameter of 47 inches and is just 700 meters from block Iceland. Also, this meteorite is heavily weathered, has a porous surface and also as block Iceland showing the Widmanstätten figures on its surface. The meteorite Mackinac was reached on Sol 2035 (October 16, 2009). Since this meteorite is an iron meteorite with similarities to the previous studied objects, it was not further investigated in detail.

The stone Marquette Iceland was investigated from November 2009 to January 2010. A lower nickel content than the other found meteorite is believed to Marquette Iceland is Martian origin. The stone contains more magnesium than the basaltic rocks that had examined Spirit. Marquette Iceland consists of coarse-grained rock and basalt. This composition suggests that the stone was formed from slowly cooling mode rocks, so that the crystals had time to grow. Therefore Geologists believe that the stone originated deep in the Martian crust.

Pinnacle Iceland is the name of a 2014 surprisingly encountered stone which is similar in size and shape of a Berlin and the twelve days Mars was not there before the Fund. He is believed to have been catapulted during a driving maneuver from one wheel of the rover there. The stone is externally whitish, reddish in the center. According to Spiegel Online Nasa scientist Steve Squyers said: "It is not like anything we have seen before ." The interior " was very sulfur and contains magnesium. The stone also contains twice as much manganese as the researchers have typically measured in the Martian samples. " Further investigation will take weeks.

Scientific Results

Evidence of former liquid water on Mars

Notes from the floor once liquid water on Mars was NASA first reported on 2 March 2004: Opportunity's instruments discovered high concentrations of sulfur in the rock, as they can be found under terrestrial conditions usually only in gypsum or anhydrite (both calcium sulphate ). Gypsum or anhydrithaltiges rock formed on Earth almost exclusively by evaporation of mineral- water and therefore is one of the evaporites. Furthermore, the instruments of the rover found jarosite, an iron -sulfur mineral that is also produced on Earth only with the cooperation of water. On Earth, the presence of these salts is at their given concentration, a clear indication that the rock was either precipitated in open standing water or over a longer period of time has been exposed to groundwater. These discoveries were developed with the two in Germany, only fist-sized and therefore extremely miniaturized instruments APXS ( Alpha Particle X - Ray Spectrometer) and MIMOS II become possible ( miniaturized Mössbauer spectrometer ). The APXS from the Max Planck Institute for Chemistry in Mainz is a radiation detector, the centerpieces, the alpha and X-ray semiconductor detectors have been developed and manufactured by the Munich-based company KETEK. The MIMOS II was developed at the Johannes Gutenberg University Mainz. High-resolution close-ups of finely layered sediments also showed centimeter-sized tabular cavities as they arise if water-soluble crystals, such as gypsum, dolomite or other sulfates are dissolved out of the rock mass. In addition, millimeter-sized and tubby mineral aggregates initially indeterminate composition in large numbers were regularly distributed, discovered in the rock, which could be interpreted as concretions soon as they arise in an aqueous medium. The fact that the beads in the rock are self- created, could be detected on the storage conditions: they lie in the rock, without in any way interfering with the millimeter- fine stratification recognizable, what would be the case, they would have been registered about as boulders or volcanic or meteoric precipitation from the outside. A little later, could be spectroscopically detected in these concretions high Hämatitkonzentrationen, which further corroborated the above interpretation. In light of these discoveries, NASA could from the formation as previously soaking wet ( dripping wet ) speak. First, it was unclear whether the water was involved in the original formation of the layers themselves, words, it was open at the location on the surface standing there, or whether the observed rock properties were due to the subsequent action of underground waters ( groundwater or hydrothermal solutions).

Evidence of formerly open standing water in motion

One of NASA's announcement of 23 March 2004 showed that may be reasonably ensured that existed at the landing site of a open flat salt lake or ocean. The rover could detect spatially in a series of over 200 photomicrographs at a part of digestion of the bedrock layers of sedimentary structures whose earthly equivalents only by moving water occur (cross- bedding cross bedding ). The researchers interpret these rocks as remnants of a former coastline and point out that exactly such deposits, such as those encountered here, would preserve any (micro-) fossils or other traces of biological activity, excellent. A return to the area for the purpose of automated or conventional sampling would thus be highly desirable and likely. Opportunity has discovered a hitherto the most interesting places in the solar system. On satellite images, it can be seen that the layers in question, a bright, finely stratified rock package, are apparently spread over at least several thousand square kilometers.

Discussion of previous discoveries

The dual mission of the Mars Exploration Rovers may already extraordinarily successfully apply before they graduate, as a technical and scientific point of view. It carries with it the greatest historical achievements of NASA and is in line with the manned moon landings, the Pioneer, Voyager and Viking probes and thus represents a technical achievement dar. It is the first time the evidence directly managed locally that on other planets, liquid water resources and the conditions for the possible emergence of life exist or have existed. It is the first time that sedimentary rocks of a strange planet could be studied. It is the first time that the data material was taken from approximately the exploration of a foreign celestial body over the Internet in real time to the public, even before the project participants themselves could evaluate it. The study of the chemical composition of Bounce Rock, a stone that would have been taken by Opportunity on landing almost show a strong resemblance to the Shergottites, a subset of the so-called Martian meteorites. This is another strong indication that the Martian meteorites actually come from Mars.