Water on Mars of these salts". NASA also reported that Jake M rock, a rock encountered by "Curiosity" on the way to Glenelg, was a mugearite and very similar to terrestrial mugearite rocks. On December 9, 2013, NASA reported that Mars once had a large freshwater lake inside Gale Crater, that could have been a hospitable environment for microbial life. On December 16, 2014, NASA reported detecting an unusual increase, then decrease, in the amounts of methane in the atmosphere of the planet Mars; in addition, organic chemicals were detected in powder drilled from a rock by the "Curiosity" rover. Also, based on
Human mission to Mars considerations for using aerocapture on crewed missions is a maximum G-limit to experience, for which it was noted 5-g's (5 times Earth gravity) was a common limit to be planned for. There may be several landers, for example, separate ones for the crew, a habitat, rover, supplies, ascent vehicle, etc. Landed spacecraft on the surface of Mars: One of the big challenges to landing on Mars was overcome by Mariner 4, when it showed the properties of the atmosphere. Another was a basic survey of the planet, to know what place might be suitable to land. This has been overcome