Event timeline of the NASA Mars Science Laboratory mission
The Mars Science Laboratory and its rover, "Curiosity", were launched from Earth on 26 November 2011. As of 19, 2025, "Curiosity" has been on the planet Mars for sols ( total days; ) since landing on 6 August 2012. "(See Current status.)"
Prelaunch (2004–2011).
In April 2004, the United States National Aeronautics and Space Administration (NASA) called for scientific experiments and instruments proposals for the Mars Science Laboratory and rover mission. Launch was proposed for September 2009. By 14 December 2004, eight proposals were selected, including instruments from Russia and Spain.
Testing of components also began in late 2004, including Aerojet's monopropellant engine with the ability to throttle from 15 to 100 percent thrust with a fixed propellant inlet pressure. By November 2008 most hardware and software development was complete, and testing continued. At this point, cost overruns were approximately $400 million. In December 2008, lift-off was delayed to November 2011 due to insufficient time for testing and integration.
Between 23–29 March 2009, the general public ranked nine finalist rover names ("Adventure, Amelia, Journey, Perception, Pursuit, Sunrise, Vision, Wonder", and "Curiosity") through a public poll on the NASA website. On 27 May 2009, the winning name was announced to be "Curiosity". The name had been submitted in an essay contest by Clara Ma, a then sixth-grader from Kansas.
Landing site selection.
At the first MSL Landing Site workshop, 33 potential landing sites were identified. By the second workshop in late 2007, the list had grown to include almost 50 sites, and by the end of the workshop, the list was reduced to six; in November 2008, project leaders at a third workshop reduced the list to these four landing sites:
A fourth landing site workshop was held in late September 2010, and the fifth and final workshop 16–18 May 2011. On 22 July 2011, it was announced that Gale Crater had been selected as the landing site of the Mars Science Laboratory mission.
Launch (2011).
MSL was launched from Cape Canaveral Air Force Station Space Launch Complex 41 on 26 November 2011, at 10:02 EST (15:02 UTC) aboard an Atlas V 541 provided by United Launch Alliance. The first and second rocket stages, along with the rocket motors, were stacked on 9 October 2011, near the launch pad. The fairing containing the spacecraft was transported to the launch pad on 3 November 2011.
On 13 December 2011, the rover began monitoring space radiation to aid in planning for future crewed missions to Mars.
The interplanetary journey to Mars took more than eight months, time during which, the spacecraft performed four trajectory corrections: on 11 January, 26 March, 26 June and on 28 July. Mission design had allowed for a maximum of 6 trajectory correction opportunities.
Landing (2012).
"Curiosity" landed in the Gale Crater at 05:17 UTC on 6 August 2012. Upon reaching Mars, an automated precision landing sequence took over the entire landing events. A cable cutter separated the cruise stage from the aeroshell and then the cruise stage was diverted into a trajectory for burn-up in the atmosphere. Landing was confirmed simultaneously by 3 monitoring Mars orbiters. "Curiosity" landed on target and only from its center. The coordinates of the landing site (named "Bradbury Landing") are: .
Some low resolution Hazcam images were beamed to Earth by relay orbiters confirming the rover's wheels were deployed correctly and on the ground. Three hours later, the rover begins to beam detailed data on its systems' status as well as on its entry, descent and landing experience. Aerial 3-D images of the landing site are available and include: the "Curiosity" rover and related Parachute (HiRISE, 10 October 2012).
On 8 August 2012, Mission Control began upgrading the rover's dual computers by deleting the entry-descent-landing software, then uploading and installing the surface operation software; the switchover was completed by 15 August.
Prime mission (2012 - September 2014).
On 15 August 2012, the rover began several days of instrument checks and mobility tests. The first laser testing of the ChemCam by "Curiosity" on Mars was performed on a rock, N165 ("Coronation" rock), near Bradbury Landing on 19 August 2012.
The science and operations teams have identified at least six possible routes to the base of Mount Sharp, and estimate about a year studying the rocks and soil of the crater floor while "Curiosity" slowly makes its way to the base of the mountain. The ChemCam team expects to take approximately one dozen compositional measurements of rocks per day.
Having completed its mobility tests, the rover's first drive began on 29 August 2012, to a place called Glenelg about to the east. Glenelg is a location where three types of terrain intersect, and is the mission's first major driving destination. The drive across may take up to two months, after which "Curiosity" will stay at Glenelg for a month.
On the way, "Curiosity" studied a pyramidal rock dubbed "Jake Matijevic" after a mathematician-turned-rover-engineer who played a critical role in the design of the six-wheeled rover, but died just days after "Curiosity" landed in August.
 The "Jake rock" measures about tall and wide. It is an igneous rock and may be a mugearite, a sodium rich oligoclase-bearing basaltic trachyandesite. Afterwards, on 30 September 2012, a finely-grained rock, named "Bathurst Inlet", was examined by "Curiosity"'s Mars Hand Lens Imager (MAHLI) and Alpha particle X-ray spectrometer (APXS). The rock was named after Bathurst Inlet, a deep inlet located along the northern coast of the Canadian mainland. Also, a sand patch, named "Rocknest", is a test target for the first use of the scoop on the arm of the "Curiosity rover".
Evidence for ancient water.
On 27 September 2012, NASA scientists announced that the "Curiosity" rover found evidence for an ancient streambed suggesting a "vigorous flow" of water on Mars.
On 7 October 2012, a mysterious "bright object" (), discovered in the sand at "Rocknest", drew scientific interest. Several close-up pictures (close-up 1) (close-up 2) were taken of the object and preliminary interpretations by scientists suggest the object to be "debris from the spacecraft". Nonetheless, further images in the nearby sand have detected other "bright particles" (image) (close-up 1). These newly discovered objects are presently thought to be "native Martian material".
On 17 October 2012, at "Rocknest", the first X-ray diffraction analysis of Martian soil was performed. The results revealed the presence of several minerals, including feldspar, pyroxenes and olivine, and suggested that the Martian soil in the sample was similar to the weathered basaltic soils of Hawaiian volcanoes. The sample used is composed of dust distributed from global dust storms and local fine sand. So far, the materials "Curiosity" has analyzed are consistent with the initial ideas of deposits in Gale Crater recording a transition through time from a wet to dry environment.
On 22 November 2012, the "Curiosity" rover analyzed a rock named "Rocknest 3" with the APXS and then resumed traveling toward "Point Lake" overlook on its way to Glenelg Intrigue.
On 3 December 2012, NASA reported that "Curiosity" performed its first extensive soil analysis, revealing the presence of water molecules, sulfur and chlorine in the Martian soil. The presence of perchlorates in the sample seems highly likely. The presence of sulfate and sulfide is also likely because sulfur dioxide and hydrogen sulfide were detected. Small amounts of chloromethane, dichloromethane and trichloromethane were detected. The source of the carbon in these molecules is unclear. Possible sources include contamination of the instrument, organics in the sample and inorganic carbonates.
Evidence for ancient habitability.
In February 2013, the rover used its drill for the first time.
In March 2013, NASA reported "Curiosity" found evidence that geochemical conditions in Gale Crater were once suitable for microbial life after analyzing the first drilled sample of Martian rock, "John Klein" rock at "Yellowknife Bay" in Gale Crater. The rover detected water, carbon dioxide, oxygen, sulfur dioxide and hydrogen sulfide. Chloromethane and dichloromethane were also detected. Related tests found results consistent with the presence of smectite clay minerals. In addition, sandstone beds associated with the Gillespie Lake Member of "Yellowknife Bay" seem similar to microbially induced sedimentary structures (MISS) found on Earth, according to one study.
Evidence for atmospheric loss.
On 8 April 2013, NASA reported that much of the atmosphere of Mars has been lost based on argon isotope ratios studies.
On 19 July 2013, NASA scientists published the results of a new analysis of the atmosphere of Mars, reporting a lack of methane around the landing site of the "Curiosity" rover. In addition, the scientists found evidence that Mars "has lost a good deal of its atmosphere over time", based on the abundance of isotopic compositions of gases, particularly those related to argon and carbon.
Other 2013 events.
On 28 February 2013, NASA was forced to switch to the backup computer due to an issue with the then active computer's flash memory which resulted in the computer continuously rebooting in a loop. The backup computer was turned on in safe mode and was converted to operational status on 19 March 2013.
On 18 March 2013, NASA reported evidence of mineral hydration, likely hydrated calcium sulfate, in several rock samples including the broken fragments of "Tintina" rock and "Sutton Inlier" rock as well as in veins and nodules in other rocks like "Knorr" rock and "Wernicke" rock. Analysis using the rover's DAN instrument provided evidence of subsurface water, amounting to as much as 4% water content, down to a depth of , in the rover's traverse from the "Bradbury Landing" site to the "Yellowknife Bay" area in the "Glenelg" terrain.
Between 4 April – 1 May 2013, "Curiosity" operated autonomously due to a Martian solar conjunction with Earth. While "Curiosity" transmitted a beep to Earth each day and the "Odyssey "spacecraft continued to relay information from the rover, no commands were sent from mission control since there was a possibility of data corruption due to interference from the Sun. "Curiosity" continued to perform stationary science at Yellowknife Bay for the duration of the conjunction.
On 5 June 2013, NASA announced that "Curiosity" will soon begin a journey from the Glenelg area to the base of Mount Sharp. The trip is expected to take nine months to a year with stops along the way to study the local terrain.
On 16 July 2013, the "Curiosity" rover reached a milestone in its journey across Mars, having traveled , since its landing in 2012; on 1 August 2013, the rover traveled over one mile: .
On 6 August 2013, NASA celebrated "Curiosity"'s first year on Mars (6 August 2012 to 5 August 2013) by programming the rover to perform the "Happy Birthday" song to itself. NASA also released several videos (video-1, video-2) summarizing the rover's accomplishments over the year. Primarily, the mission found evidence of "ancient environments suitable for life" on Mars. The rover drove over one-mile across the Martian terrain, transmitted more than 190 gigabits of data to Earth, including 70,000 images (36,700 full images and 35,000 thumbnails), and the rover's laser fired more than 75,000 times at 2,000 targets.
On 27 August 2013, "Curiosity" used autonomous navigation (or "autonav"- the ability of the rover to decide for itself how to drive safely) over unknown Martian ground for the first time.
On 19 September 2013, NASA scientists, on the basis of further measurements by "Curiosity", reported no detection of atmospheric methane with a measured value of ppbv corresponding to an upper limit of only 1.3 ppbv (95% confidence limit) and, as a result, conclude that the probability of current methanogenic microbial activity on Mars is reduced.
On 26 September 2013, NASA scientists reported the Mars "Curiosity" rover detected "abundant, easily accessible" water (1.5 to 3 weight percent) in soil samples at the Rocknest region of Aeolis Palus in Gale Crater. In addition, NASA reported that the "Curiosity" rover found two principal soil types: a fine-grained mafic type and a locally derived, coarse-grained felsic type. The mafic type, similar to other Martian soils and Martian dust, was associated with hydration of the amorphous phases of the soil. Also, perchlorates, the presence of which may make detection of life-related organic molecules difficult, were found at the "Curiosity" rover landing site (and earlier at the more polar site of the Phoenix lander) suggesting a "global distribution of these salts". NASA also reported that Jake M rock, a rock encountered by "Curiosity" on the way to Glenelg, was a mugearite and very similar to terrestrial mugearite rocks.
On 17 October 2013, NASA reported, based on analysis of argon in the