NASA is about six months from preliminary design review (PDR) for its Mars 2020 rover, according to a key NASA official.

NASA Director of Mars Exploration Program Jim Watzin told sister publication Defense Daily Aug. 13 the agency is “well ahead of the game” with the subsystems NASA is not redesigning, but instead is  leaning on from the Mars Science Laboratory (MSL) Curiosity rover and the two Mars Exploration Rovers: Spirit and Opportunity. Watzin said on these systems, some hardware is already being built, which he called outside the norm for PDR. Curiosity, which landed two years ago, is currently operating on Mars, according to an agency statement.

The rover body and other major hardware (such as the cruise stage, aeroshell and heat shield) would be near-duplicates of the systems of the MSL to take maximum advantage of engineering heritage, according to a NASA fact sheet. The rover’s baseline power source is a Multi-Mission Radioisotope Thermoelectric Generator (MMRTG) provided by the Energy Department. It uses the heat from the natural decay of plutonium-238 to generate electricity.

Other new systems that involve flying and the drilling and the caching of the Mars surface sample are “more classic” in terms of progress, Watzin said at the 18th Annual International Mars Society Convention in Washington. These, he said, are still in the preliminary design phase and their details are still being worked out.

The Mars 2020 rover will carry seven instruments to conduct geological assessments of its landing site, determine the potential habitability of the environment and directly search for signs of ancient Martian life. NASA, last summer, selected seven proposals and issued contracts totaling $130 million for the development of the instruments. Scientists will use the rover to identify and select a collection of rock and soil samples that will be stored for potential return to Earth by a future mission.

Watzin said sample caching is one key technology NASA is working on to ensure a successful Mars 2020 rover mission. He said once NASA drills and obtains the Mars sample, it will put the sample into a tube and seal it in order to prepare it for return back to Earth. Watzin said the tube must be sealed such that the sample is not contaminated with whatever the rover picks up on its journey to Mars. This would ensure the scientific integrity of the sample for when it returns to Earth, he said.

Thought the tubes themselves will be dirty with Martian dust and debris on the outside, Watzin said once they are launched from the Mars surface and orbit, they will be encapsulated, yet again, into a container that will completely seal and prepare the sample for return back to Earth. Ensuring the scientific integrity of the samples is requiring some technology development, Watzin said.

The Mars 2020 rover will also help advance United States knowledge of how future human explorers could use natural resources available on the surface of the Red Planet. Designers of future human expeditions can use this mission to understand the hazards posed by Martian dust and demonstrate technology to process carbon dioxide from the atmosphere to produce oxygen. These experiments will help engineers learn how to use Martian resources to produce oxygen for human respiration and, potentially, as an oxidizer for rocket fuel.

NASA has not selected a launch vehicle for the rover. Watzin said the agency was “another year or two” away from issuing a solicitation for the launch vehicle. NASA spokeswoman Mary Ann Chevalier said Aug. 13 there is no date for the request for proposal (RFP) release for the Mars 2020 rover launch vehicle. She added a RFP is typically put out three years prior to the anticipated launch date of the spacecraft.

Launch is estimated for July-August 2020 with landing on Mars in February 2021 at a site to be determined. A workshop was held the week of Aug 3 in California to narrow down candidate landing sites to eight from the roughly 30 candidate landing sites raised in a previous workshop and eight new candidate sites.

The seven instruments selected last summer were:

* Mastcam-Z, an advanced camera system with panoramic and stereoscopic imaging capability with the ability to zoom;

* SuperCam, an instrument that can provide imaging, chemical composition analysis and mineralogy. It will also be able to detect the presence of organic compounds in rocks and regolith from a distance. France is contributing to SuperCam;

* Planetary Instrument for X-ray Lithochemistry (PIXL), an X-ray fluorescence spectrometer that will also contain an imager with high resolution to determine the fine scale elemental composition of Martian surface materials;

* Scanning Habitable Environments with Raman & Luminescence for Organics and Chemicals (SHERLOC), a spectrometer that will provide fine-scale imaging and uses an ultraviolet (UV) laser to determine fine-scale mineralogy and detect organic compounds;

* Mars Oxygen ISRU Experiment (MOXIE), an exploration technology investigation that will produce oxygen from Martian atmospheric carbon dioxide;

* Mars Environmental Dynamics Analyzer (MEDA), a set of sensors that will provide measurements of temperature, wind speed and direction, pressure, relative humidity and dust size and shape. Spain is the principal investigator for MEDA;

* Radar Imager for Mars’ Subsurface Experiment (RIMFAX), a ground-penetrating radar that will provide centimeter-scale resolution of the geologic structure of the subsurface. Norway is the principal investigator for RIMFAX.

NASA requested $228 million for Mars 2020 rover in its fiscal year 2016 budget request. NASA’s Jet Propulsion Laboratory (JPL) will build and manage operations of the Mars 2020 rover.