Posted by Ask when will humans go to Mars and you will get a date, and the date will usually be about fifteen years away. That has been true for a remarkably long time. Wernher von Braun drew up a detailed Mars expedition in the late 1940s, published as Das Marsprojekt in 1952, with a fleet of ten ships and around seventy crew. In 1969, fresh from Apollo 11, he pitched a landing in the early 1980s. Neither happened, and the pattern repeated with almost comic regularity over the following decades.
So it’s worth being blunt at the start. There is no confirmed launch date for a crewed Mars mission, from any country or company. What exists is a set of goals, a hard orbital calendar and a short list of technical milestones that would tell you a mission is genuinely getting close.
A short history of “fifteen years from now”
In July 1989, on the twentieth anniversary of the first Moon landing, President George H. W. Bush announced the Space Exploration Initiative: back to the Moon, then on to Mars. NASA’s internal study came back with a price tag widely reported at around $500 billion, and Congress lost interest almost immediately. In 2004, the Vision for Space Exploration set similar goals and produced the Constellation program, which was cancelled in 2010. That same year, President Obama said he expected humans to orbit Mars by the mid-2030s and land after that.
Private industry joined the forecasting game later. At the 2016 International Astronautical Congress in Guadalajara, Elon Musk presented a plan that showed a first crewed flight to Mars launching in 2024. That year came and went. The company has since talked about sending uncrewed Starships in an early launch window, with crews following in a later one, and Musk himself has described his timelines as aspirational. China’s space industry has sketched crewed Mars missions starting in the 2030s, again as a target rather than a scheduled flight.
None of this means the people involved were lying. It means a Mars landing is the kind of project where every unknown turns out to cost money and time, and every political change resets priorities.
The calendar nobody can negotiate with
Whatever the budget, Mars imposes its own timetable. Efficient transfers between Earth and Mars open roughly every 26 months, when the two planets are positioned so a spacecraft can coast from one orbit to the other on a minimum-energy path. Miss a window and you wait more than two years for the next one.
Looking ahead, those openings fall around the end of 2026, then at the turn of 2028 into 2029, then in 2031, 2033 and so on. That rhythm is why mission announcements cluster around specific years and why one slipped test campaign can push a landing back by a full cycle rather than a few months. It also shapes the mission itself. A typical crewed plan takes six to nine months out, spends over a year on the surface waiting for the return window, and comes home roughly two and a half years after leaving. Faster, more energetic trajectories exist on paper. They cost far more propellant.
Robots first, and cargo before crew
Almost every serious architecture sends machinery ahead of people. Cargo landers would arrive one or two windows early carrying habitats, power systems and, ideally, the equipment to make return propellant from Martian ice and carbon dioxide. Only once those systems are on the ground and confirmed working would a crew launch.
This is good engineering, and it also stretches the schedule. If the first uncrewed heavy lander arrives in a given window, a crew probably can’t follow until at least one window later, and realistically two, after the hardware has proven it can survive a Martian winter and a dust season. Each round of robots buys knowledge at the price of another 26 months.
Choosing where to land is its own slow process. In 2015 NASA held its first workshop on so-called exploration zones for human crews, and scientists and engineers pitched dozens of candidate regions, each a circle about 100 kilometers across that had to offer interesting geology, a safe landing ellipse and, crucially, accessible water ice. Orbiters have been refining that shortlist ever since, mapping buried ice in the mid-latitudes and photographing boulder fields at sub-meter resolution. A crew will not go anywhere that hasn’t been studied from orbit for years. That work is largely done in the background, and it rarely makes headlines, but it is one of the few parts of the schedule that is genuinely on track.
The Moon as a rehearsal, and a bottleneck
NASA’s current approach runs through the Moon. The Artemis program is meant to put astronauts back on the lunar surface, build experience with long stays, new spacesuits and surface power, and use all of that as a stepping stone to Mars. The logic is reasonable. The Moon is three days away rather than months, so a failed experiment there is survivable.
The downside is that Mars timelines inherit every lunar delay. Artemis I, the uncrewed test flight around the Moon, launched in November 2022 after years of slips, and the crewed missions that followed it have moved too. If you want to forecast when NASA might fly people to Mars, the most honest approach is to watch how quickly it can sustain operations on the Moon, then add a decade or so.
Milestones that would actually change the forecast
Instead of trusting announced years, look for demonstrations. A few would move the needle more than any press release.
The first is a heavy landing on Mars. Everything landed there so far weighs about a tonne or less, while a crewed mission needs vehicles that land tens of tonnes. An uncrewed spacecraft of that size touching down intact would be a genuine turning point.
The second is refuelling in orbit at scale. Starship-based plans depend on transferring large quantities of cryogenic propellant between vehicles in Earth orbit, something nobody has done routinely. NASA’s lunar lander plans depend on it too, which means you’ll hear about it well before any Mars launch.
Third: making propellant or large quantities of oxygen on Mars itself, beyond the small MOXIE experiment on Perseverance. Fourth: a long-duration crewed flight beyond low Earth orbit, ideally a year or more, that shows life support and crew health holding up far from home. Fifth, and least glamorous, is money committed by a government to a specific crewed Mars program with hardware contracts, rather than studies and roadmaps.
When three or four of those are done, a date starts to mean something.
So, when will humans go to Mars?
Honestly, nobody knows. A crewed landing in the early 2030s would require nearly everything to go right, quickly. The late 2030s or the 2040s are far more common guesses among people who work on the problem, though they would be the first to admit how unreliable such guesses have been. A breakthrough in propulsion or a sudden political commitment could pull the date forward. A serious accident, on the Moon or in low Earth orbit, could push it back by years.
That uncertainty isn’t a reason for cynicism. Since von Braun’s era, we have learned where the water is, measured the radiation on the way there, landed rovers with a sky crane and flown a helicopter, Ingenuity, through Martian air. The pieces are much more real than they were. Putting them together, and paying for it, is what’s left.
If you’d rather track the milestones than the headlines, SETIworld follows Mars missions, test flights and the science behind them. Keep reading with us and decide for yourself when will humans go to Mars, or at least which launch window you’d bet on.
