In the history of warfare, it has sometimes been the practice of armies to dress themselves in the uniforms of their adversaries and then commit atrocities in order to discredit the other side. Alternatively, such falsely uniformed war criminals have placed themselves among opposing forces, so that, posing as friends, they could misdirect them to their doom.

It is in this tradition that O. Glenn Smith and Paul Spudis, two die-hard opponents of Mars exploration, recently chose to costume themselves as advocates in their Commentary “Mars for Only $1.5 Trillion” [March 9, page 19], which is designed to make a feasible enterprise appear utterly unfeasible.

The mission plan claimed to be necessary by Smith and Spudis starts with the nonsensical idea that someone would use a monstrosity the size of the International Space Station for a disposable Mars mission transit vehicle, and continues with the conceit of saddling each and every Mars mission with the full development and several decades-long manufacturing, launch and on-orbit assembly program of the ISS. On the basis of this, they calculate that a “ballpark cost for the first human Mars mission in 2035 would total $230 billion” and “if we send nine crews to Mars, the total bill would be in the neighborhood of $1.5 trillion.”

To get a grasp of how absurd these estimates are, one need only point out that current and recent NASA budgets have been around $18 billion, including a human spaceflight budget of about $4 billion. So what Smith and Spudis are claiming is that sending nine flights to Mars would cost NASA’s full budget for the next 80 years, or the entirety of its human spaceflight budget for 375 years.

Nothing of the sort is necessary. Sending humans to Mars does not involve building fantastical, enormous interplanetary spaceships. Rather, it requires three flight elements of about 100 metric tons mass, comprising 30 tons of payload and 70 tons of trans-Mars propulsion, each of which could be delivered to orbit by two SpaceX Falcon Heavy rockets or one augmented NASA Space Launch System booster.

One of these flight elements would consist of an Earth return vehicle (ERV), which would be stationed in a highly elliptical Mars orbit from which it could easily take flight for Earth. Another would be a Mars ascent vehicle (MAV), which would be delivered to the Martian surface together with a 30-kilowatt-electric power system and an in-situ propellant manufacturing unit that would allow it to make most of its ascent propellant out of the local atmosphere.

Once this fueling operation is completed, the third flight element, consisting of a habitat spacecraft with a crew of four astronauts, would be sent on a six-month voyage to Mars, to be landed near the MAV. The astronauts would then use their habitat craft as their base on Mars for 18 months of exploration, after which they would use the MAV to ascend and rendezvous with the ERV. The ERV would then take them on a six-month transit back to Earth, at the end of which they would enter and land using a small bailout capsule such as a Dragon or downsized Orion. The habitat would remain behind on Mars, so that each mission could add another such unit to the base, rapidly building up the infrastructure of the first human settlement on a new world.

There is nothing in such a plan that is fundamentally beyond our technology.

Nor would it be beyond our financial means. The advertised price of the Falcon Heavy is $100 million. We would need six such launchers per mission, which would occur every other year, for an average program launch budget of $300 million per year, or less than 2 percent of the space agency’s current budget. NASA currently plans to spend $3 billion per year on the SLS to have it do nothing. The incremental cost of actually making good use of it to launch three boosters every other year (for a 1.5 launch-per-year average rate) would also be negligible. The cost of the modest payload elements required would be similarly two orders of magnitude less than the budgets for the “Battlestar Galactica” approach set out as a baseline by Smith and Spudis as well.

So, contrary to their claims, we really can have a space program worthy of the American pioneer spirit. We don’t need to just keep going nowhere, or returning to places we explored a half-century ago. We don’t need to disappoint yet another generation by failing to accept the challenge of attempting inspiring deeds. Rather than sending astronauts to the moon to date craters to gratify the scientifically trivial obsessions of lunar geologists such as Spudis, we can go to Mars to make fundamental discoveries about the potential prevalence and diversity of life in the universe. Rather than propose to dig in on the moon to make mindlessly make propellant for a space program that doesn’t go anywhere, we can actually go, and become the first explorers, pioneers and settlers of a new world filled with wonders waiting to be discovered and history waiting to be made.

The American human spaceflight program is in very bad shape right now. It is operating without a coherent and rational goal, and unless such a goal is embraced and an intelligent plan set forth to achieve it, the drift and waste will only continue until such time as the taxpayers, losing patience, put it out of its misery.

We need a real and honest debate about goals and means, and attempts to spread disinformation and confusion do not help. If Smith and Spudis have a case for a lunar base, they should just make it, without serving as patrons of ignorance with respect to the alternatives.

America is a can-do nation. Given the will, commitment and courage, we can certainly make it to Mars within less time than it took a much poorer United States to get to the moon a half-century ago. To say we can’t is to accept the idea that we have become much less than the people we used to be. That is what we cannot afford.

Robert Zubrin is president of Pioneer Astronautics and the Mars Society and the author of “The Case for Mars.” His latest work, “Mars Direct: Space Exploration, the Red Planet, and the Human Future,” was recently published by Penguin.