Perhaps the most important Mars mission from the perspective of determining whether life ever existed on Mars goes. It will also significantly speed up our endeavor of human exploration.
Back in 2013, NASA laid out its grand plan to send a new rover to Mars in 2020. This mission’s primary focus is to discover evidence of past microbial life on the Martian planet, collect samples that can eventually be brought back to Earth, and conduct experiments to verify technologies enabling human exploration of Mars in the future. Previous rover missions have already achieved their objectives, with Spirit and Opportunity discovering signs of water on the planet, and Curiosity confirming the presence of environmental conditions in the past that could have supported life on Mars. Now, scientists want to go out and actually look for signs of life on the barren planet. The Mars 2020 rover will introduce new instruments dedicated towards achieving its objectives.
The Mars 2020 mission is part of NASA’s Mars Exploration Program (MEP). The program consists of four long-term science goals – determining whether life ever existed on Mars, characterising the climate, studying the geology, and finally preparing for human exploration. Most of the goals are based on surface exploration, and although it’s highly improbable we will find anything alive on the surface, efforts will be made to search for preserved signs in rock and soil samples.
The first objective will be to find out how the environment used to be and how it changed. The next objective is to search for locations or materials that could have potentially possessed microbial life in the past. Then, if such material is found, the rover will document its findings by storing samples from the site that can be sent back to Earth later. Thus far, we’ve never brought back any samples from Mars to be studied here on Earth. The Science Definition Team, which is behind outlining the entire mission, has proposed the collection of about 31 samples of rock cores and soil.
The fourth and final objective is to carry out research so that we are fully prepared to send humans to Mars. We hope that once this is accomplished, future missions will not have to worry about certain supplies being sent from earth. One such experiment hopes to be able to scrub oxygen out of the carbon dioxide in the Martian atmosphere, for respiration and also as an oxidiser for rocket fuel. Studying the atmospheric dust size and morphology will provide data on whether surface systems can function in such harsh conditions. More data about the planet’s atmospheric model will also be acquired with this study. This will help us observe the effects of the external conditions on human health as well. Few of the last objectives would be to measure data on aerothermal conditions, thermal protection system, and aerodynamic performance on entry vehicles. These data sets are necessary since they will enable scientists to design spacecraft for a safe entry and descent into the Martian atmosphere.
The new rover will be based on the fundamental design of Curiosity. This ensures lower mission costs and even lower risks. However, several upgrades have been made to ensure it delivers the required objectives. Curiosity had an arm which was used to collect rock and soil samples from the surface and now Mars 2020 adds a drill. Having a drill makes it easier to penetrate Martian rocks and soil to collect samples for analysis. These samples will be stored in tubes on the surface through a process called “depot caching”. Essentially, the rover will directly collect or drill down rocks and store these samples into tubes. The tubes will be sealed and placed on storage racks right on the surface of Mars, waiting to be picked up in a future retrieval mission. Another improvement applied to the Curiosity design is an upgraded wheel design which will probably favour easier traversal over different terrains of the Martian surface.
Mars 2020 will employ the same method applied by Curiosity for its entry, descent and landing (EDL) on Mars. The spacecraft will use a three-stage system including a parachute, descent vehicle, and “skycrane maneuver”. The third final stage is an approach to ensure the spacecraft stabilises over the surface before the rover is lowered using tethers. In this way, a more precise landing is achieved. Mars 2020 uses a new system called Terrain-Relative Navigation (TRN) so that the rover detects unfavourable and hazardous terrain below, and looks for a safer landing spot.
To meet the objectives of the mission, several instruments were proposed to be installed on the Mars 2020. Out of all of them, seven instruments have been selected that will carry out the necessary research.
Images from the Martian surface are always exciting to look at which will be made possible through the Mastcam-Z. Two units of this advanced camera system will allow the rover to take panoramic and stereoscopic images including the functionality to zoom. Not only pictures, the camera system will be able to measure the mineralogy of the rocks and soil on the surface, and assist with rover operations. SuperCam is another instrument that has imaging, chemical composition analysis and mineralogy functionalities. Hence, it will be able to determine the chemical composition of rocks and detect the presence of organic compounds without even touching them.
Among the two spectrometer instruments on the rover, the PIXL or Planetary Instrument For X-Ray Lithochemistry will be able to determine the elemental composition of materials to a finer scale. With its X-ray fluorescence spectrometer, this instrument essentially makes detection and analysis of the surface materials much more detailed compared to the previous instruments. The other spectrometer is the Scanning Habitable Environments with Raman and Luminescence for Organics and Chemicals (SHERLOC). Using an ultraviolet laser, it’s a finer spectrometer which will be used to detect organic compounds and also carry out fine-scale mineralogy. The imaging instruments and spectrometers makes it easier to study rock and soil composition. They could potentially provide evidence of microbial life if organic compounds are detected.
Studying the layers of rock formed on the Martian crust provides insight into past records of the environment on how they were formed and how they changed through time. This will be made possible with the Radar Imager for Mars’ Subsurface Experiment (RIMFAX). A centimeter-scale resolution of the geological structure of the crust and the subsurface will be recorded using this ground-penetrating radar.
The Mars Environmental Dynamics Analyzer (MEDA) contains several sensors working together to provide us with a lot of data on the climatic conditions. These include temperature, pressure, wind speed and direction, relative humidity, and dust size and shape.
Coming to one of the crucial instruments that will eventually enable humans to go to Mars is the Mars Oxygen ISRU Experiment (MOXIE). Mars’ atmosphere is about 96 per cent carbon dioxide. If this instrument works, we will not have to worry about producing Oxygen on Mars.
Where is it landing?
Mars is the second-smallest planet in the solar system (after Mercury), but it still has a surface area of about 144.8 million sq km – compare that to earth’s land surface area of 148.3 million sq km, and you understand why picking the right landing site is important. Extensive workshops have been conducted to look at the mission objectives, safe landing zones and maximising the rover’s exploring ability, and has been narrowed down to three sites. The three landing sites are called Columbia Hills, Jezero Crater and Northeast Syrtis. Columbia Hills/Gusev Crater could potentially harbour an ancient hot spring, Jezero Crater holds a dried-up Martian lake, and Northeast Syrtis is an interesting location that has a shield volcano right beside an impact crater. All three sites are on the Martian equator, and the rover will probably explore all three if all goes well.
Another interesting mission scientists at NASA are working on is Mars InSight (Interior Exploration using Seismic Investigations, Geodesy and Heat Transport). The primary objective of the lander is to study and understand the process of how rocky planets formed billions of years ago. The lander will investigate beyond the surface of the planet by studying the tectonic activity and meteorite impacts. This mission will give us an insight about the formation of planets in the solar system including our own. Initially slated for a 2016 launch, the Insight mission has been delayed for a 2018 launch due to a vacuum leak in one of its instruments.
The dream is to drop off astronauts on the red planet by the 2030s, because humans explore a lot better than robots or rovers. Sadly, NASA’s chief of human spaceflight, William H. Gerstenmaier, recently announced that they don’t have enough funding to “put a date on humans on Mars”. It’s going to be a long time before the world can once again sit glued to screens as they watch a human go farther than ever before in the bid to explore our solar system, and eventually the galaxy. It’s just sad that petty politics and a lack of international collaboration are holding us back from exploring space.
Hopefully, the Mars 2020 rover will be a success, and we will be able to conclude that Mars did indeed harbour life in the past (or maybe it still does?). If microbial life, or the traces of it from long ago, is actually discovered, perhaps that will be the final humbling our species needs, so that we can get our act together and start working together to preserve life instead of fighting amongst ourselves like squabbling siblings. Exciting times ahead, and Mars might still have important secrets to reveal. We can’t wait for the Mars 2020 mission!