editorial Mars towards the future Three spacecraft from three diferent nations arrived at Mars in February 2021. Two of those nations are newcomers to Mars and the third successfully set out the path for a Mars sample return.

espite regular launch opportunities consisting of a full orbiter–lander–rover of being bypassed because of its high costs, every 26 months, every mission to package. The lander–rover composite is but now that it is in motion it will be much DMars invariably captures headlines in planned to land in Utopia Planitia in May harder to stop. the news and huge interest from the public. 2021 after a thorough reconnaissance of Perseverance’s look to the future goes The 2020 launch window, however, actually the area by the orbiter aimed at identifying beyond sample return, containing as it does had several novelties that distinguished it the best landing site according to scientific a rather unprecedented set of technology from the others — even without considering and technical criteria. Its scientific experiments. First, the Ingenuity helicopter that it happened in the midst of a global objectives are very different from — and will try to perform the first controlled pandemic. complementary to — Hope’s, focusing on flight on another planet as a standalone First of all, this year has been unusually surface and shallow sub-surface processes and autonomous system. Considering the busy. Mars has not seen so much incoming and environment. extremely thin and dust-laden atmosphere traffic since 2003. Moreover, all three Compared to the UAE and China, NASA of Mars, success is not a given and Ingenuity missions were successful, showing that we is the big veteran of Mars exploration. will be a crucial test for any future airborne are getting more confident in delivering However, the Perseverance rover marks a technology. In addition, the rover contains probes to Mars without glitches. Mars distinct change in perspective for the US MOXIE (the Mars Oxygen In-Situ Resource has long enjoyed the reputation of being space agency. The ‘follow the water’ mantra Utilization Experiment), which is designed a spacecraft-eating ghoul, but maybe it is that drove NASA’s Mars exploration since to release oxygen into the atmosphere of time to bury this cliché: only one of the 15 the 1990s is becoming obsolete, as we Mars after synthesizing it from locally missions sent to Mars since 2000 fully failed ‘follow habitability’ now. The Curiosity rover harvested CO2. This is the first attempt to by not leaving Earth’s orbit. started this new trend, and Perseverance consciously affect the environment of a One of the most significant features of is consolidating it. But above all, while planet. While MOXIE is just a technology the 2020 launch window is the appearance the science is surely going to be exciting, demonstrator and will not have any actual of new actors. The United Arab Emirates Perseverance has a clear forward-looking impact on the atmosphere of Mars, it is (UAE) and China have respectively become concept that distinguishes it from NASA’s a first test of how we could utilize local the fifth and sixth countries ever to reach previous rovers. The most important resources to support future human missions Mars. Like the European Space Agency innovation by far is the first step towards a and habitation. Resource utilization on (ESA) and India, they succeeded at the first Mars sample return. Mars is the next challenge and, in addition attempt. The widening of the exclusive club Actual projects for a Martian sample to Perseverance, there are already some of nations exploring beyond the Earth– return have struggled to materialize due to ongoing projects, in particular concerning Moon system is always welcome, although the magnitude of its technical challenges. water reservoirs. In this issue we present an we are far from the ‘democratization of Now we have a clear plan: a three-step effort to map the likelihood of water deep space’ that we are experiencing for sequence (of which Perseverance carries ice availability in the shallow subsurface Earth’s orbit and have started to glimpse for out the first) that spans the whole decade of Mars and just last month the US, the Moon. and involves a tight collaboration between Italian, Japanese and Canadian space Interestingly, the two nations opted for NASA and ESA. Much of Perseverance’s agencies announced a partnership for an very different approaches to their Mars design revolves around sample return. International Mars Ice Mapper orbiter that debut. The Mars Hope Probe from the The rover will drill and collect samples could fly as early as 2026. UAE was conceived to answer very specific that will be stored in cylinders and left on The 2020 launch window saw exciting scientific questions linked to the vertical the Martian surface. Cleverly, the rover new perspectives open up for Mars connections within the atmosphere, from will carry these samples from the different exploration, and this trend will continue the troposphere to atmospheric escape. acquisition points over to a single caching in the already busy next launch windows. In this sense, it has some overlap with area, ready for collection by the future ‘fetch’ Martian exploration has always been NASA’s Mars Atmosphere and Volatile rover. The scientific payload is also tailored fertile terrain for international scientific Evolution (MAVEN) orbiter, and indeed for this purpose: a suite of cameras and collaboration: we hope that these novelties the UAE has worked closely with members spectrometers will allow the identification will not change that and the way forward of the MAVEN team in the United States. of the most interesting rocks to sample, will be inclusive and concordant. ❐ International collaboration and knowledge and in situ sample analysis facilities were exchange have been key points of the Hope sacrificed to make space for the tube mission. Tianwen-1 is instead all Chinese collection and storage. Mars sample Published online: 16 March 2021 and also a very ambitious first attempt, return has always been considered at risk https://doi.org/10.1038/s41550-021-01337-9

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