\n<\/p>\n
Back in 2007, I talked with Rob Manning, engineer extraordinaire at the Jet Propulsion Laboratory, and he told me something shocking. Even though he had successfully led the entry, descent, and landing (EDL) teams for three Mars rover missions, he said the prospect of landing a human mission on the Red Planet might be impossible.<\/p>\n
But now, after nearly 20 years of work and research \u2014 as well as more successful Mars rover landings \u2014 Manning says the outlook has vastly improved.<\/p>\n
\u201cWe\u2019ve made huge progress since 2007,\u201d Manning told me when we chatted a few weeks ago in 2024. \u201cIt\u2019s interesting how its evolved, but the fundamental challenges we had in 2007 haven\u2019t gone away, they\u2019ve just morphed.\u201d<\/p>\n
<\/p>\n The problems arise from the combination of Mars\u2019 ultra-thin atmosphere\u2014which is over 100 times thinner than Earth\u2019s \u2014 and the ultra-large size of spacecraft needed for human missions, likely between 20 \u2013 100 metric tons.<\/p>\n \u201cMany people immediately conclude that landing humans on Mars should be easy,\u201d Manning said back in 2007, \u201csince we\u2019ve landed successfully on the Moon and we routinely land human-carrying vehicles from space to Earth. And since Mars falls between the Earth and the Moon in size and in the amount of atmosphere, then the middle ground of Mars should be easy.\u201d<\/p>\n But Mars\u2019 atmosphere provides challenges not found on Earth or the Moon. A large, heavy spacecraft \u00a0streaking through Mars\u2019 thin, volatile atmosphere only has just a few minutes to slow from incoming interplanetary speeds (for example, the Perseverance rover was traveling 12,100 mph [19,500 kph] when it reached Mars) to under Mach 1, and then quickly transition to a lander to slow to be able to touch down gently.<\/p>\n \n