Timeline of Mars Science Laboratory

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.

[2][4] 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.

[62] 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).

[72] 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.

[77][78][79][80][81] 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.

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.

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.

[103] 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.

[105][106][107] 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.

[120] On 9 December 2013, NASA reported that the planet Mars had a large freshwater lake (which could have been a hospitable environment for microbial life) based on evidence from the Curiosity rover studying Aeolis Palus near Mount Sharp in Gale Crater.

These measurements are necessary for human missions to the surface of Mars, to provide microbial survival times of any possible extant or past life, and to determine how long potential organic biosignatures can be preserved.

[128][130] The two samples, John Klein and Cumberland, contain basaltic minerals, Ca-sulfates, Fe oxide/hydroxides, Fe-sulfides, amorphous material, and trioctahedral smectites (a type of clay).

[138] A Late Noachian/Early Hesperian or younger age indicates that clay mineral formation on Mars extended beyond Noachian time; therefore, in this location neutral pH lasted longer than previously thought.

[103] Curiosity had traveled an estimated linear distance of 6.9 km (4.3 mi)[145] to the mountain slopes since leaving its "start" point in Yellowknife Bay on 4 July 2013.

[146][147] On 6 February 2014, the Curiosity rover, in order to reduce wear on its wheels by avoiding rougher terrain,[148] successfully crossed (image) the "Dingo Gap" sand dune and is now expected to travel a smoother route to Mount Sharp.

[152] On 27 June 2014, Curiosity crossed the boundary line of its "3-sigma safe-to-land ellipse" and is now in territory that may get even more interesting, especially in terms of Martian geology and landscape (view from space).

On 8 December 2014, a panel of NASA scientists discussed (archive 62:03) the latest observations of Curiosity, including findings about how water may have helped shape the landscape of Mars and had a climate long ago that could have produced long-lasting lakes at many Martian locations.

[146][147][158] On 21 January 2015, NASA announced a collaborative effort with Microsoft that developed a software project called OnSight which allows scientists to perform virtual work on Mars based on data from the Curiosity rover.

[159] On 6 March 2015, NASA reported performing tests on the rover to help uncover the reason for intermittent problems with the robotic arm used for rock drilling and analysis.

On 4 April 2015, NASA reported studies, based on measurements by the Sample Analysis at Mars (SAM) instrument on the Curiosity rover, of the Martian atmosphere using xenon and argon isotopes.

[163]On 19 August 2015, NASA scientists reported that the Dynamic Albedo of Neutrons (DAN) instrument on the Curiosity rover detected an unusual hydrogen-rich area, at "Marias Pass," on Mars.

[166] On 8 October 2015, NASA confirmed that lakes and streams existed in Gale crater 3.3 - 3.8 billion years ago delivering sediments to build up the lower layers of Mount Sharp.

[172] On 13 December 2016, NASA reported further evidence supporting habitability on Mars as the Curiosity rover climbed higher, studying younger layers, on Mount Sharp.

[185] On 30 September 2017, NASA reported radiation levels on the surface of the planet Mars were temporarily doubled, and were associated with an aurora 25-times brighter than any observed earlier, due to a massive, and unexpected, solar storm in the middle of the month.

The organic compounds were from mudstone rocks aged approximately 3.5 billion years old, sampled from two distinct sites in a dry lake in the Pahrump Hills of the Gale crater.

On 1 February 2019, NASA scientists reported that the Mars Curiosity rover determined, for the first time, the density of Mount Sharp in Gale crater, thereby establishing a clearer understanding of how the mountain was formed.

[217] In October 2019, evidence in the form of magnesium sulfate deposits left behind in ways that suggested evaporation, uncovered by the Curiosity rover on Mount Sharp, was reported of a 150 km (93 mi) wide ancient basin in Gale crater that once may have contained a salty lake.

[223] On 29 August 2020, NASA released several videos taken by the Curiosity rover, including those involving dust devils, as well as very high resolution images of the related local martian terrain.

On 1 November 2021, astronomers reported detecting, in a "first-of-its-kind" process based on SAM instruments, organic molecules, including benzoic acid, ammonia and other related unknown compounds, on the planet Mars by the Curiosity rover.

[237][238] In October 2024, the science team behind the SAM experiment onboard the rover announced the results of three years of sampling, which suggested that based on high carbon-13 and oxygen-18 levels in the regolith, the early Martian atmosphere was unlikely to be stable enough to support surface water hospitable to life, with rapid wetting-drying cycles and very high-salinity cryogenic brines providing an explanation.