How Long Does It Take to Get to Mars? Days, Months, or Years?

Traveling to Mars

Exploring is in our nature. Even in early childhood, we all had the itch to discover. We explored the attic, and if we found some big old heavy chest up there, we couldn’t wait to see what was inside. As teenagers, we rode our bikes ever farther. After college, many of us went overseas. 

When it comes to off-Earth travel, we are limited. Mercury and Venus are too hot, way too hot. From Jupiter on outward, no planet has a surface, at least not a solid surface. Nowhere to land. Your rocket would just keep descending into thicker and thicker layers of gases and then gooey liquids. That leaves Mars alone. Mars is on average 142 million miles away from Earth according to NASA.

Its temperatures are not too crazy. The surface of Mars can even reach 40°F at times. Probes show a sandy, rocky terrain that resembles the deserts of the southwestern US. Though half our own planet’s diameter, it’s got the same land area as our world since it has no oceans. And our landers, starting with the twin Vikings in 1976, revealed no poisonous gases or flimsy surfaces incapable of supporting a landing spacecraft. Of course, we’ll go!

Beyond the romance are practical reasons. What if we badly mess up our own world? Shouldn’t we have a backup? There’s even some water ice buried in deep-shadowed Martian crevices. We already have the technology to turn that into oxygen for breathing and hydrogen for fuel. It’s starting to sound like Shangri-La or at least summer camp.

How Would We Get to Mars?

Unmanned Martian probes are now almost routine. But the great number of mission failures show it’s not exactly easy. You can’t just aim a rocket at it; that wouldn’t work because Mars, orbiting at 15 miles a second, wouldn’t be in that spot when we arrived. Instead, you use something called a Hohman Transfer Orbit. It gets you there using minimum fuel and granting you maximum payload.

Have you not heard of the Hohmann Transfer Orbit? It’s a simple concept. Johannes Kepler told us in the 17th century that every planet moves in a path that’s not a circle but an ellipse. Orbital ellipses make each planet regularly arrive at the perihelion or near the point to the Sun, which Earth annually reaches in the first week of January. 

Then, on the opposite side of its oval-shaped orbit, planets reach a far point, which we hit every July 4, give or take a day. So when we send any rocket to Mars, we actually blast it more or less forward a bit in Earth’s orbit but at a higher speed, which sends the rocket into a new orbit around the Sun. The spacecraft’s orbit is an ellipse of the right shape and size so that it reaches its far point from the Sun at the Martian orbit’s distance. 

If both Earth and Mars magically disappeared, the rocket, using no additional fuel, would continue in this orbit forever, coming back to Earth’s distance from the Sun at its perihelion point, whipping around, and then heading outward again to reach its aphelion position at the Martian orbit distance.

How Long Does It Take to Get to Mars?

The tricky part of knowing how long it will take to travel is calculating exactly when to launch. That’s because when your spacecraft reaches Martian orbit, you want Mars to be arriving at that exact spot at the same time. 

Then, the Red Planet’s gravity can help you slow down, capture your craft, and, with a few engine burns, let you enter its thin atmosphere for a nice, soft parachute landing. 

This Hohmann transfer orbit requires 259 days to reach Mars from Earth (or around 8 ½ months). You can choose to burn more fuel or carry a lighter payload and get there a bit faster, but figure at least half a year at best.

We could have done this already if we only needed a one-way trip without returning home. Say you get some volunteers, maybe people with serious credit card debt. Depressive types who think Earth is overrated and are willing to stake out a permanent new home. The Alaska mentality. So you’d send an advance rocket stocked with food, medical supplies, a bunch of MP3 files and movies, and a disassembled, modular-type shelter so that all such stuff is awaiting the incoming visitors. Now you send your colonists. There, done.

Of course, if the astronauts do want to come home, that changes things eventually. Now, you need to start with a rocket having enough fuel and air for the almost 1 ½-year roundtrip. This is big and expensive, and we’re not quite there yet. 

Unfortunately, rescue or return missions to Mars can only happen when the planets align, which occurs every 26 months. At an absolute minimum, that’s more than two years between visits.

But there are other considerations, too.

What Other Factors Affect a Journey to Mars?

The biggest issue is that too many people over-romanticize the Mars thing. Maybe the Red Planet brochure needs to offer a more realistic picture.

• First, Mars has no air. Or at least nothing breathable. Its atmosphere is so thin that the surface pressure is less than what we have atop Mt. Everest.  See more facts about Earth’s neighbor, planet Mars.
• And even that super-skimpy vapor is almost pure carbon dioxide. No oxygen. This means you can’t just stroll around outside your spacecraft or sealed modular home. You’re permanently stuck in a spacesuit on the Martian surface. Wouldn’t that grow old pretty quickly?
• And you’d encounter no living creatures or plant life. And no water, Earth’s most magical compound. You’d never feel a breeze on your skin or hear birdsong or rustling leaves. This brings up an entire psychological issue: Does some basic part of us need earthly sensory experiences? Perhaps it even goes more deeply. Meaning, are we, in some sense, pieces of planet Earth itself? 

Are we children of our world, creatures of Earth with millions of years of genetic programming connected with all things earthlike? Bacteria come and go in our systems, and insects land on our skin. Is there some ultradeep connection without which we simply couldn’t live?

We look at zoo animals confined to a small, synthetic zone built to somewhat resemble their home region. What do they do? They pace restlessly, relentlessly. One senses that they feel some deep alienation, of being apart from their home. So, how would humans fare when they no longer receive the slightest aroma of anything? There are no mutating clouds overhead, no contact with strangers, and no life of any kind.

• Speaking of which, what if they send along the wrong companion for you? You’d be trapped with however many crew members are on the ship. What if you’ve come to hate any of them? Or, less dramatically, simply find a few of them annoying. Well, now you’re stuck with an irksome character day after day—for over two years before you can return. 

Added to that alienation thing and the total absence of earthly sensory experiences, might crew members get seriously nutty? Maybe even psychotic? 

Let’s not “go there.” Let’s keep it optimistic. Even so, we’ve already seen that you’re on a planet isolated from everything familiar, with day-to-day life a struggle. 

• You’ve got to find and melt ice to make water and create oxygen; you couldn’t possibly bring enough on board. 
• You’ve got to endure nonstop elevated radiation, which isn’t good for you. See more ways living on Mars would affect the human body.
• If you suddenly need extensive dental work or suffer appendicitis, there are no hospital facilities, and even if there were, they probably wouldn’t accept your plan.

Remember that woman researcher in the Antarctic a few years ago? A doctor herself, she recognized that the growing lump in her breast was probably cancer. But there are no facilities at the South Pole that could have helped her. Ultimately, our government flew in a risky rescue plane to land in the pitch-black conditions of the Antarctic winter. But if it was Mars? The nearest help would be a 17-month round-trip evacuation.

Another issue is the public reaction back home. Amid the current optimistic, Alaska-bound excitement of colonizing another planet, what would happen when actual struggles became widely recognized? Or, God forbid, one of the crew members, whom the world would have long gotten to know on a televised and Web first-name basis, the way everyone was familiar with Neil and Buzz on the Moon, what if they died? A stroke or appendicitis or something treatable had they been on Earth? Wouldn’t that instantly cool the popular ardor of wanting to try living off-planet?

Or consider: Many cite Mars as attractive because Earth’s population, now at around 8 billion, is making us increasingly crowded. Earth’s urban population surpassed its rural numbers in 2007. It again resurrected the Alaska mentality, the attraction for an uncrowded life. Yet there are many terrestrial places where no one wants to live even though they’d have it all to themselves. Why are virtually no habitations in the Sahara or Atacama? Or villages built on lofty mountain plateaus in the Himalayas? Sure, life would be tough in such spots, but at least you could breathe the air. 

Mars is incomparably more dangerous as a place to attempt simple survival. Such super-taxing everyday life is more than merely a totally synthetic environment surrounded by computers, LEDs, and the constant humming of air purifiers. 

What Would the Mars Journey Cost?

High technology also means astronomical costs. Round-trip transportation alone would amount to at least $25 million per colonist. 

When the world fully learns that such expense doesn’t necessarily buy anybody a good time, wouldn’t the queue of “I want to go next!” volunteers visibly shrink? This writer isn’t suggesting that this scenario is inevitable or even likely; it’s merely a possible side of the Mars-Colony dream that has perhaps received inadequate consideration.

It’s not hard to imagine a point when some psychologists publish papers suggesting that perhaps the Mars-colonization vogue isn’t borne of an innate human desire to explore. Rather, they may reason that its etiology could arise from a different human characteristic: restlessness. Or the compulsive need to always experience the “next new thing.” Ecologists would get their own turn chiming in, which is sometimes expressed even today: We’re fooling ourselves if we imagine that obtaining a “spare” planet if we totally mess up Earth might constitute a workable solution or bring human salvation.

Because—Earth is inside us. Our planet is unique and precious beyond words. There simply can be no true “spare.” Instead, a different focus is demanded. That we finally learn to be gentle and sensible with our home world. Because, in fact, there really is no other.