Mars 2020

Mars 2020 is a Mars rover mission by NASA's Mars Exploration Program with a planned launch in July 2020. It will investigate an astrobiologically relevant ancient environment on Mars, investigate its surface geological processes and history, including the assessment of its past habitability, the possibility of past life on Mars, and the potential for preservation of biosignatures within accessible geological materials.

The as-yet unnamed Mars 2020 mission was announced by NASA on 4 December 2012 at the fall meeting of the American Geophysical Union in San Francisco. The rover's design is derived from the Curiosity rover, and will use many components already fabricated and tested, but it will carry different scientific instruments and a core drill.

Mission overview


The mission will seek signs of habitable conditions on Mars in the ancient past, and will also search for evidence —or biosignatures— of past microbial life. The rover is planned for launch in 2020 on an Atlas V-541, and the Jet Propulsion Laboratory will manage the mission. The mission is part of NASA's Mars Exploration Program.

The Science Definition Team proposed that the rover collect and package as many as 31 samples of rock cores and surface soil for a later mission to bring back for definitive analysis on Earth. In 2015, however, they expanded the concept, planning to collect even more samples and distribute the tubes in small piles or caches across the surface of Mars.

In September 2013 NASA launched an Announcement of Opportunity for researchers to propose and develop the instruments needed, including the Sample Caching System. The science instruments for the mission were selected in July 2014 after an open competition based on the scientific objectives set one year earlier. The science conducted by the rover's instruments will provide the context needed for detailed analyses of the returned samples. The chairman of the Science Definition Team stated that NASA does not presume that life ever existed on Mars, but given the recent Curiosity rover findings, past Martian life seems possible.

Objectives
The Mars 2020 rover will explore a site likely to have been habitable. It will seek signs of past life, set aside a returnable cache with the most compelling rock core and soil samples, and demonstrate technology needed for the future human and robotic exploration of Mars.

A key mission requirement is that it must help prepare NASA for its long-term Mars sample-return mission and crewed mission efforts. The rover will make measurements and technology demonstrations to help designers of a future human expedition understand any hazards posed by Martian dust, and will test technology to produce a small amount of pure oxygen (O2) from Martian atmospheric carbon dioxide (CO2). Improved precision landing technology that enhances the scientific value of robotic missions also will be critical for eventual human exploration on the surface. Based on input from the Science Definition Team, NASA defined the final objectives for the 2020 rover. Those become the basis for soliciting proposals to provide instruments for the rover's science payload in the spring 2014.

The mission will also attempt to identify subsurface water, improve landing techniques, and characterize weather, dust, and other potential environmental conditions that could affect future astronauts living and working on Mars.

Design


The rover is based on the design of Curiosity. While there are differences in scientific instruments and the engineering required to support them, the entire landing system (including the sky crane and heat shield) and rover chassis can essentially be recreated without any additional engineering or research. This reduces overall technical risk for the mission, while saving funds and time on development. One of the upgrades is a guidance and control technique called "Terrain Relative Navigation" to fine-tune steering in the final moments of landing. In October 2016, NASA reported using the Xombie rocket to test the Lander Vision System (LVS), as part of the Autonomous Descent and Ascent Powered-flight Testbed (ADAPT) experimental technologies, for the Mars 2020 mission landing.

A Multi-Mission Radioisotope Thermoelectric Generator (MMRTG), left over as a backup part for Curiosity during its construction, will power the rover. The generator has a mass of 45 kg and uses 4.8 kg of plutonium dioxide as the source of steady supply of heat that is converted to electricity; the electrical power generated is approximately 110 watts at launch with little decrease over the mission time. Two lithium-ion rechargeable batteries are included to meet peak demands of rover activities when the demand temporarily exceeds the MMRTG's steady electrical output levels. The MMRTG offers a 14-year operational lifetime, and it was provided to NASA by the US Department of Energy. Unlike solar panels, the MMRTG provides engineers with significant flexibility in operating the rover's instruments even at night and during dust storms, and through the winter season.

The three major components of the Mars 2020 spacecraft are the cruise stage for travel between Earth and Mars; the Entry, Descent, and Landing System (EDLS) that includes the aeroshell, parachute, descent vehicle, and sky crane; and the rover. Engineers redesigned the Mars 2020 rover wheels to be more robust than Curiosity wheels, which have sustained some damage. The rover will have thicker, more durable aluminium wheels, with reduced width and a greater diameter (52.5 cm) than Curiosity 50 cm wheels. The aluminium wheels are covered with cleats for traction and curved titanium spokes for springy support. The combination of the larger instrument suite, new Sampling and Caching System, and modified wheels makes Mars 2020 heavier than its predecessor, Curiosity.

The rover mission and launch are estimated to cost about US$2.1 billion. The mission's predecessor, the Mars Science Laboratory, cost US$2.5 billion in total. The availability of spare parts make the new rover somewhat more affordable. Curiosity engineering team are also involved in the rover's design.

Scientific instruments


Based on the scientific objectives, nearly 60 proposals for rover instrumentation were evaluated and, on 31 July 2014, NASA announced the payload for the rover.


 * Planetary Instrument for X-Ray Lithochemistry (PIXL), an X-ray fluorescence spectrometer to determine the fine scale elemental composition of Martian surface materials.
 * Radar Imager for Mars' subsurface experiment (RIMFAX), a ground-penetrating radar to image different ground densities, structural layers, buried rocks, meteorites, and detect underground water ice and salty brine at 10 m depth.
 * Mars Environmental Dynamics Analyzer (MEDA), a set of sensors that measure temperature, wind speed and direction, pressure, relative humidity, radiation, and dust size and shape. It will be provided by Spain's Centro de Astrobiología.
 * Mars Oxygen ISRU Experiment (MOXIE), an exploration technology investigation that will produce a small amount of oxygen (O2) from Martian atmospheric carbon dioxide (CO2). This technology could be scaled up in the future for human life support or make rocket fuel for return missions.
 * SuperCam, an instrument suite that can provide imaging, chemical composition analysis and mineralogy in rocks and regolith from a distance. It is an upgraded version of the ChemCam on the Curiosity rover but with two lasers and four spectrometers that will allow it to remotely identify biosignatures and assess the past habitability.
 * Mastcam-Z, a stereoscopic imaging system with the ability to zoom.
 * Scanning Habitable Environments with Raman and Luminescence for Organics and Chemicals (SHERLOC), an ultraviolet Raman spectrometer that uses fine-scale imaging and an ultraviolet (UV) laser to determine fine-scale mineralogy and detect organic compounds.
 * Mars Helicopter Scout (MHS) is a planned solar powered helicopter drone with a mass of 1.8 kg that is expected to help pinpoint interesting targets for study and plan the best driving route for the rover. The small helicopter is expected to fly up to five times during its 30-day testing, and will fly no more than 3 minutes per day. It is a technology demonstrator that will form the foundation on which more capable helicopters can be developed for aerial exploration of Mars and other planetary targets with an atmosphere.
 * Microphones will be used during the landing event, while driving, and when collecting samples.
 * 23 cameras in total are included in the Mars 2020 rover.

Proposed landing sites
In May 2017, evidence of the earliest known life on land may have been found in 3.48-billion-year-old geyserite, a mineral deposit often found around hot springs and geysers, uncovered in the Pilbara Craton of Western Australia. These findings may be helpful in deciding where best to search for early signs of life on the planet Mars. The following locations are the eight landing sites that were under consideration for Mars 2020.


 * Columbia Hills, in Gusev Crater
 * Eberswalde Crater
 * Holden Crater
 * Jezero Crater
 * Mawrth Vallis
 * Northeastern region of Syrtis Major Planum
 * Nili Fossae
 * Southwestern region of Melas Chasma

A workshop was held on 8–10 February 2017 in Pasadena, California, to discuss these sites, with the goal of narrowing down the list to three sites for further consideration. The selected sites are:


 * Jezero Crater
 * Northeastern region of Syrtis Major Planum
 * Columbia Hills, in Gusev Crater, where the Spirit rover landed

Proposed sample-return
A key mission requirement for this rover is that it must help prepare NASA for its Mars sample-return mission (MSR) campaign, which is needed before any crewed mission takes place. Such effort would require three additional vehicles: an orbiter, a fetch rover, and a Mars ascent vehicle (MAV).

Dozens of samples would be collected and cached by the Mars 2020 rover, and would be left on the surface of Mars for possible later retrieval. A "fetch rover" would retrieve the sample caches and deliver them to a Mars ascent vehicle (MAV). In July 2018 NASA contracted Airbus to produce a "fetch rover" concept. The MAV would launch from Mars and enter a 500 km orbit and rendezvous with a new Mars orbiter. The sample container would be transferred to an Earth entry vehicle (EEV) which would bring it to Earth, enter the atmosphere under a parachute and hard-land for retrieval and analyses in specially designed safe laboratories.