Curiosity (rover)
Curiosity is a car-sized rover designed to explore Gale Crater on Mars as part of NASA's Mars Science Laboratory mission. Curiosity was launched from Cape Canaveral on November 26th, 2011, at 15:02 UTC and landed on Aeolis Palus inside Gale on Mars on August 6th, 2012, 05:17 UTC. The Bradbury Landing site was less than from the center of the rover's touchdown target after a journey. The rover's [|goals] include an investigation of the Martian climate and geology; assessment of whether the selected field site inside Gale has ever offered environmental conditions favorable for microbial life, including investigation of the role of water; and planetary habitability studies in preparation for human exploration.
In December 2012, Curiosity two-year mission was extended indefinitely, and on August 5th, 2017, NASA celebrated the fifth anniversary of the Curiosity rover landing. The rover is still operational, and as of ,, Curiosity has been on the planet Mars for sols since landing on August 6th, 2012. The NASA/JPL Mars Science Laboratory/Curiosity Project Team was awarded the 2012 Robert J. Collier Trophy by the National Aeronautic Association "In recognition of the extraordinary achievements of successfully landing Curiosity on Mars, advancing the nation's technological and engineering capabilities, and significantly improving humanity's understanding of ancient Martian habitable environments."
Curiosity rover design will serve as the basis for NASA's 2021 Perseverance mission which will carry different scientific instruments.
Mission
Goals and objectives
As established by the Mars Exploration Program, the main scientific goals of the MSL mission are to help determine whether Mars could ever have supported life, as well as determining the role of water, and to study the climate and geology of Mars. The mission results will also help prepare for human exploration. To contribute to these goals, MSL has eight main scientific objectives:;Biological:
- Determine the nature and inventory of organic carbon compounds
- Investigate the chemical building blocks of life
- Identify features that may represent the effects of biological processes
- Investigate the chemical, isotopic, and mineralogical composition of the Martian surface and near-surface geological materials
- Interpret the processes that have formed and modified rocks and soils
- Assess long-timescale Martian atmospheric evolution processes
- Determine present state, distribution, and cycling of water and carbon dioxide
- Characterize the broad spectrum of surface radiation, including galactic and cosmic radiation, solar proton events and secondary neutrons. As part of its exploration, it also measured the radiation exposure in the interior of the spacecraft as it traveled to Mars, and it is continuing radiation measurements as it explores the surface of Mars. This data would be important for a future crewed mission.
Name
A NASA panel selected the name Curiosity following a nationwide student contest that attracted more than 9,000 proposals via the Internet and mail. A sixth-grade student from Kansas, 12-year-old Clara Ma from Sunflower Elementary School in Lenexa, Kansas, submitted the winning entry. As her prize, Ma won a trip to NASA's Jet Propulsion Laboratory in Pasadena, California, where she signed her name directly onto the rover as it was being assembled.Ma wrote in her winning essay:
Rover and lander specifications
Curiosity is long by wide by in height, larger than Mars Exploration Rovers, which are long and have a mass of including of scientific instruments. In comparison to Pancam on the Mars Exploration Rovers, the MastCam-34 has 1.25× higher spatial resolution and the MastCam-100 has 3.67× higher spatial resolution.Curiosity has an advanced payload of scientific equipment on Mars. It is the fourth NASA robotic rover sent to Mars since 1996. Previous successful Mars rovers are Sojourner from the Mars Pathfinder mission, and Spirit and Opportunity rovers from the Mars Exploration Rover mission.
Curiosity comprised 23% of the mass of the spacecraft at launch. The remaining mass was discarded in the process of transport and landing.
- Dimensions: Curiosity has a mass of including of scientific instruments. The rover is long by wide by in height.
- Power source: Curiosity is powered by a radioisotope thermoelectric generator, like the successful Viking 1 and Viking 2 Mars landers in 1976.
- Heat rejection system: The temperatures at the landing site can vary from ; therefore, the thermal system warms the rover for most of the Martian year. The thermal system does so in several ways: passively, through the dissipation to internal components; by electrical heaters strategically placed on key components; and by using the rover heat rejection system. It uses fluid pumped through of tubing in the rover body so that sensitive components are kept at optimal temperatures. The fluid loop serves the additional purpose of rejecting heat when the rover has become too warm, and it can also gather waste heat from the power source by pumping fluid through two heat exchangers that are mounted alongside the RTG. The HRS also has the ability to cool components if necessary.
- Computers: The two identical on-board rover computers, called Rover Compute Element contain radiation hardened memory to tolerate the extreme radiation from space and to safeguard against power-off cycles. The computers run the VxWorks real-time operating system. Each computer's memory includes 256 kB of EEPROM, 256 MB of DRAM, and 2 GB of flash memory. For comparison, the Mars Exploration Rovers used 3 MB of EEPROM, 128 MB of DRAM, and 256 MB of flash memory.
- Communications: Curiosity is equipped with significant telecommunication redundancy by several means: an X band transmitter and receiver that can communicate directly with Earth, and a UHF Electra-Lite software-defined radio for communicating with Mars orbiters. Communication with orbiters is the main path for data return to Earth, since the orbiters have both more power and larger antennas than the lander, allowing for faster transmission speeds. Telecommunication included a small deep space transponder on the descent stage and a solid-state power amplifier on the rover for X band. The rover also has two UHF radios, the signals of which orbiting relay satellites are capable of relaying back to Earth. Signals between Earth and Mars take an average of 14 minutes, 6 seconds. Curiosity can communicate with Earth directly at speeds up to 32 kbit/s, but the bulk of the data transfer is being relayed through the Mars Reconnaissance Orbiter and Odyssey orbiter. Data transfer speeds between Curiosity and each orbiter may reach 2000 kbit/s and 256 kbit/s, respectively, but each orbiter is able to communicate with Curiosity for only about eight minutes per day. Communication from and to Curiosity relies on internationally agreed space data communications protocols as defined by the Consultative Committee for Space Data Systems.
- Mobility systems: Curiosity is equipped with six diameter wheels in a rocker-bogie suspension. The suspension system also served as landing gear for the vehicle, unlike its smaller predecessors. Each wheel has cleats and is independently actuated and geared, providing for climbing in soft sand and scrambling over rocks. Each front and rear wheel can be independently steered, allowing the vehicle to turn in place as well as execute arcing turns. Each wheel has a pattern that helps it maintain traction but also leaves patterned tracks in the sandy surface of Mars. That pattern is used by on-board cameras to estimate the distance traveled. The pattern itself is Morse code for "JPL". The rover is capable of climbing sand dunes with slopes up to 12.5°. Based on the center of mass, the vehicle can withstand a tilt of at least 50° in any direction without overturning, but automatic sensors limit the rover from exceeding 30° tilts. After six years of use, the wheels are visibly worn with punctures and tears.
Landing
According to NASA, an estimated 20,000 to 40,000 heat-resistant bacterial spores were on Curiosity at launch, and as much as 1,000 times that number may not have been counted.
Rover's landing system
Previous NASA Mars rovers became active only after the successful entry, descent and landing on the Martian surface. Curiosity, on the other hand, was active when it touched down on the surface of Mars, employing the rover suspension system for the final set-down.Curiosity transformed from its stowed flight configuration to a landing configuration while the MSL spacecraft simultaneously lowered it beneath the spacecraft descent stage with a tether from the "sky crane" system to a soft landing—wheels down—on the surface of Mars. After the rover touched down it waited 2 seconds to confirm that it was on solid ground then fired several pyrotechnic fasteners activating cable cutters on the bridle to free itself from the spacecraft descent stage. The descent stage then flew away to a crash landing, and the rover prepared itself to begin the science portion of the mission.
Daily operations
The rover spends a lot of its time idle because it will stop and spend extended periods of time at major science waypoints.Communication with the rover is not instantaneous. There is a delay in transmitting commands to the rover, and there is a delay receiving imagery back from the rover. Depending on the distance between Earth and Mars, the delay is between 4 to 24 minutes, and averages 14 minutes. As a result, navigation is done by sending a command such as "drive forward X distance" or "drive toward X place", and the rover will use its cameras and computers to drive to those locations autonomously.
See : Timeline of Mars Science Laboratory
Travel status
On April 16, 2020, the rover is now 13.66 miles away from its landing site. As of April 17, 2020, the rover has been driven on less than 800 out of 2736 sols.Scientific instruments
The general sample analysis strategy begins with high-resolution cameras to look for features of interest. If a particular surface is of interest, Curiosity can vaporize a small portion of it with an infrared laser and examine the resulting spectra signature to query the rock's elemental composition. If that signature is intriguing, the rover uses its long arm to swing over a microscope and an [|X-ray spectrometer] to take a closer look. If the specimen warrants further analysis, Curiosity can drill into the boulder and deliver a powdered sample to either the SAM or the CheMin analytical laboratories inside the rover. The MastCam, Mars Hand Lens Imager, and Mars Descent Imager cameras were developed by Malin Space Science Systems and they all share common design components, such as on-board electronic imaging processing boxes, 1600×1200 CCDs, and an RGB Bayer pattern filter.In total, the rover carries 17 cameras: HazCams, NavCams, MastCams, MAHLI, MARDI, and ChemCam.
Mast Camera (MastCam)
The MastCam system provides multiple spectra and true-color imaging with two cameras. The cameras can take true-color images at 1600×1200 pixels and up to 10 frames per second hardware-compressed video at 720p.One MastCam camera is the Medium Angle Camera, which has a focal length, a 15° field of view, and can yield 22 cm/pixel scale at. The other camera in the MastCam is the Narrow Angle Camera, which has a focal length, a 5.1° field of view, and can yield 7.4 cm/pixel scale at. Malin also developed a pair of MastCams with zoom lenses, but these were not included in the rover because of the time required to test the new hardware and the looming November 2011 launch date. However, the improved zoom version was selected to be incorporated on the upcoming Mars 2020 mission as Mastcam-Z.
Each camera has eight gigabytes of flash memory, which is capable of storing over 5,500 raw images, and can apply real time lossless data compression. The cameras have an autofocus capability that allows them to focus on objects from to infinity. In addition to the fixed RGBG Bayer pattern filter, each camera has an eight-position filter wheel. While the Bayer filter reduces visible light throughput, all three colors are mostly transparent at wavelengths longer than 700 nm, and have minimal effect on such infrared observations.
Chemistry and Camera complex (ChemCam)
ChemCam is a suite of two remote sensing instruments combined as one: a laser-induced breakdown spectroscopy and a Remote Micro Imager telescope. The ChemCam instrument suite was developed by the French CESR laboratory and the Los Alamos National Laboratory. The flight model of the mast unit was delivered from the French CNES to Los Alamos National Laboratory. The purpose of the LIBS instrument is to provide elemental compositions of rock and soil, while the RMI gives ChemCam scientists high-resolution images of the sampling areas of the rocks and soil that LIBS targets. The LIBS instrument can target a rock or soil sample up to away, vaporizing a small amount of it with about 50 to 75 5-nanosecond pulses from a 1067 nm infrared laser and then observes the spectrum of the light emitted by the vaporized rock.s from ChemCam on Curiosity
ChemCam has the ability to record up to 6,144 different wavelengths of ultraviolet, visible, and infrared light. Detection of the ball of luminous plasma is done in the visible, near-UV and near-infrared ranges, between 240 nm and 800 nm. The first initial laser testing of the ChemCam by Curiosity on Mars was performed on a rock, N165, near Bradbury Landing on August 19, 2012. The ChemCam team expects to take approximately one dozen compositional measurements of rocks per day.
Using the same collection optics, the RMI provides context images of the LIBS analysis spots. The RMI resolves objects at distance, and has a field of view covering at that distance.
Navigation cameras (navcams)
The rover has two pairs of black and white navigation cameras mounted on the mast to support ground navigation. The cameras have a 45° angle of view and use visible light to capture stereoscopic 3-D imagery.Rover Environmental Monitoring Station (REMS)
REMS comprises instruments to measure the Mars environment: humidity, pressure, temperatures, wind speeds, and ultraviolet radiation. It is a meteorological package that includes an ultraviolet sensor provided by the Spanish Ministry of Education and Science. The investigative team is led by Javier Gómez-Elvira of the Spanish Astrobiology Center and includes the Finnish Meteorological Institute as a partner. All sensors are located around three elements: two booms attached to the rover's mast, the Ultraviolet Sensor assembly located on the rover top deck, and the Instrument Control Unit inside the rover body. REMS provides new clues about the Martian general circulation, micro scale weather systems, local hydrological cycle, destructive potential of UV radiation, and subsurface habitability based on ground-atmosphere interaction.Hazard avoidance cameras (hazcams)
The rover has four pairs of black and white navigation cameras called hazcams, two pairs in the front and two pairs in the back. They are used for autonomous hazard avoidance during rover drives and for safe positioning of the robotic arm on rocks and soils. Each camera in a pair is hardlinked to one of two identical main computers for redundancy; only four out of the eight cameras are in use at any one time. The cameras use visible light to capture stereoscopic three-dimensional imagery. The cameras have a 120° field of view and map the terrain at up to in front of the rover. This imagery safeguards against the rover crashing into unexpected obstacles, and works in tandem with software that allows the rover to make its own safety choices.Mars Hand Lens Imager (MAHLI)
MAHLI is a camera on the rover's robotic arm, and acquires microscopic images of rock and soil. MAHLI can take true-color images at 1600×1200 pixels with a resolution as high as 14.5 micrometers per pixel. MAHLI has an focal length and a 33.8–38.5° field of view. MAHLI has both white and ultraviolet LED illumination for imaging in darkness or fluorescence imaging. MAHLI also has mechanical focusing in a range from infinite to millimeter distances. This system can make some images with focus stacking processing. MAHLI can store either the raw images or do real time lossless predictive or JPEG compression. The calibration target for MAHLI includes color references, a metric bar graphic, a 1909 VDB Lincoln penny, and a stair-step pattern for depth calibration.Alpha Particle X-ray Spectrometer (APXS)
The APXS instrument irradiates samples with alpha particles and maps the spectra of X-rays that are re-emitted for determining the elemental composition of samples. Curiosity APXS was developed by the Canadian Space Agency. MacDonald Dettwiler, the Canadian aerospace company that built the Canadarm and RADARSAT, were responsible for the engineering design and building of the APXS. The APXS science team includes members from the University of Guelph, the University of New Brunswick, the University of Western Ontario, NASA, the University of California, San Diego and Cornell University. The APXS instrument takes advantage of particle-induced X-ray emission and X-ray fluorescence, previously exploited by the Mars Pathfinder and the two Mars Exploration Rovers.Chemistry and Mineralogy (CheMin)
is the Chemistry and Mineralogy X-ray powder diffraction and fluorescence instrument. CheMin is one of four spectrometers. It can identify and quantify the abundance of the minerals on Mars. It was developed by David Blake at NASA Ames Research Center and the Jet Propulsion Laboratory, and won the 2013 NASA Government Invention of the year award. The rover can drill samples from rocks and the resulting fine powder is poured into the instrument via a sample inlet tube on the top of the vehicle. A beam of X-rays is then directed at the powder and the crystal structure of the minerals deflects it at characteristic angles, allowing scientists to identify the minerals being analyzed.On October 17, 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 paragonetic tephra from a Hawaiian cinder cone has been mined to create Martian regolith simulant for researchers to use since 1998.
Sample Analysis at Mars (SAM)
The SAM instrument suite analyzes organics and gases from both atmospheric and solid samples. It consists of instruments developed by the NASA Goddard Space Flight Center, the Laboratoire Inter-Universitaire des Systèmes Atmosphériques , and Honeybee Robotics, along with many additional external partners. The three main instruments are a Quadrupole Mass Spectrometer, a gas chromatograph and a tunable laser spectrometer. These instruments perform precision measurements of oxygen and carbon isotope ratios in carbon dioxide and methane in the atmosphere of Mars in order to distinguish between their geochemical or biological origin.Dust Removal Tool (DRT)
The Dust Removal Tool is a motorized, wire-bristle brush on the turret at the end of Curiosity arm. The DRT was first used on a rock target named Ekwir_1 on January 6, 2013. Honeybee Robotics built the DRT.Radiation assessment detector (RAD)
The role of the RAD instrument is to characterize the broad spectrum of radiation environment found inside the spacecraft during the cruise phase and while on Mars. These measurements have never been done before from the inside of a spacecraft in interplanetary space. Its primary purpose is to determine the viability and shielding needs for potential human explorers, as well as to characterize the radiation environment on the surface of Mars, which it started doing immediately after MSL landed in August 2012. Funded by the Exploration Systems Mission Directorate at NASA Headquarters and Germany's Space Agency, RAD was developed by Southwest Research Institute and the extraterrestrial physics group at Christian-Albrechts-Universität zu Kiel, Germany.Dynamic Albedo of Neutrons (DAN)
The DAN instrument employs a neutron source and detector for measuring the quantity and depth of hydrogen or ice and water at or near the Martian surface.The instrument consists of the detector element and a 14.1 MeV pulsing neutron generator. The die-away time of neutrons is measured by the DE after each neutron pulse from the PNG.
DAN was provided by the Russian Federal Space Agency and funded by Russia.
Mars Descent Imager (MARDI)
MARDI was fixed to the lower front left corner of the body of Curiosity. During the descent to the Martian surface, MARDI took color images at 1600×1200 pixels with a 1.3-millisecond exposure time starting at distances of about to near from the ground, at a rate of four frames per second for about two minutes. MARDI has a pixel scale of at to at and has a 90° circular field of view. MARDI has eight gigabytes of internal buffer memory that is capable of storing over 4,000 raw images. MARDI imaging allowed the mapping of surrounding terrain and the location of landing. JunoCam, built for the Juno spacecraft, is based on MARDI.Robotic arm
The rover has a long robotic arm with a cross-shaped turret holding five devices that can spin through a 350° turning range. The arm makes use of three joints to extend it forward and to stow it again while driving. It has a mass of and its diameter, including the tools mounted on it, is about. It was designed, built, and tested by MDA US Systems, building upon their prior robotic arm work on the Mars Surveyor 2001 Lander, the Phoenix lander, and the two Mars Exploration Rovers, Spirit and Opportunity.Two of the five devices are in-situ or contact instruments known as the X-ray spectrometer, and the Mars Hand Lens Imager. The remaining three are associated with sample acquisition and sample preparation functions: a percussion drill; a brush; and mechanisms for scooping, sieving, and portioning samples of powdered rock and soil. The diameter of the hole in a rock after drilling is and up to deep. The drill carries two spare bits. The rover's arm and turret system can place the APXS and MAHLI on their respective targets, and also obtain powdered sample from rock interiors, and deliver them to the SAM and CheMin analyzers inside the rover.
Since early 2015 the percussive mechanism in the drill that helps chisel into rock has had an intermittent electrical short. On December 1, 2016, the motor inside the drill caused a malfunction that prevented the rover from moving its robotic arm and driving to another location. The fault was isolated to the drill feed brake, and internal debris is suspected of causing the problem. By December 9, driving and robotic arm operations were cleared to continue, but drilling remained suspended indefinitely. The Curiosity team continued to perform diagnostics and testing on the drill mechanism throughout 2017, and resumed drilling operations on May 22, 2018.
Media, cultural impact and legacy
Live video showing the first footage from the surface of Mars was available at NASA TV, during the late hours of August 6, 2012 PDT, including interviews with the mission team. The NASA website momentarily became unavailable from the overwhelming number of people visiting it, and a 13-minute NASA excerpt of the landings on its YouTube channel was halted an hour after the landing by an automated DMCA takedown notice from Scripps Local News, which prevented access for several hours. Around 1,000 people gathered in New York City's Times Square, to watch NASA's live broadcast of Curiosity landing, as footage was being shown on the giant screen. Bobak Ferdowsi, Flight Director for the landing, became an Internet meme and attained Twitter celebrity status, with 45,000 new followers subscribing to his Twitter account, due to his Mohawk hairstyle with yellow stars that he wore during the televised broadcast.On August 13, 2012, U.S. President Barack Obama, calling from aboard Air Force One to congratulate the Curiosity team, said, "You guys are examples of American know-how and ingenuity. It's really an amazing accomplishment."
Scientists at the Getty Conservation Institute in Los Angeles, California, viewed the CheMin instrument aboard Curiosity as a potentially valuable means to examine ancient works of art without damaging them. Until recently, only a few instruments were available to determine the composition without cutting out physical samples large enough to potentially damage the artifacts. CheMin directs a beam of X-rays at particles as small as and reads the radiation scattered back to determine the composition of the artifact in minutes. Engineers created a smaller, portable version named the X-Duetto. Fitting into a few briefcase-sized boxes, it can examine objects on site, while preserving their physical integrity. It is now being used by Getty scientists to analyze a large collection of museum antiques and the Roman ruins of Herculaneum, Italy.
Prior to the landing, NASA and Microsoft released Mars Rover Landing, a free downloadable game on Xbox Live that uses Kinect to capture body motions, which allows users to simulate the landing sequence.
NASA gave the general public the opportunity from 2009 until 2011 to submit their names to be sent to Mars. More than 1.2 million people from the international community participated, and their names were etched into silicon using an electron-beam machine used for fabricating micro devices at JPL, and this plaque is now installed on the deck of Curiosity. In keeping with a 40-year tradition, a plaque with the signatures of President Barack Obama and Vice President Joe Biden was also installed. Elsewhere on the rover is the autograph of Clara Ma, the 12-year-old girl from Kansas who gave Curiosity its name in an essay contest, writing in part that "curiosity is the passion that drives us through our everyday lives."
On August 6, 2013, Curiosity audibly played "Happy Birthday to You" in honor of the one Earth year mark of its Martian landing, the first time for a song to be played on another planet. This was also the first time music was transmitted between two planets.
On June 24, 2014, Curiosity completed a Martian year—687 Earth days—after finding that Mars once had environmental conditions favorable for microbial life. Curiosity served as the basis for the design of the Perseverance rover for the Mars 2020 rover mission. Some spare parts from the build and ground test of Curiosity are being used in the new vehicle, but it will carry a different instrument payload.
On August 5, 2017, NASA celebrated the fifth anniversary of the Curiosity rover mission landing, and related exploratory accomplishments, on the planet Mars. ]; ; https://www.youtube.com/watch?v=Q-uAz82sH-E Curiosity Discoveries About Gale Crater
As reported in 2018, drill samples taken in 2015 uncovered organic molecules of [benzene and propane in 3 billion year old rock samples in Gale.