I’ve belatedly read Daniel R. Adamo’s op-ed, “Humans to Mars in 20 Years: A Faster, Better, Cheaper Sequel?” He is exactly half correct.

It is true that today, going from a base in low Earth orbit directly to the Martian surface is a step too far. Visits to Martian orbit, and to Phobos and Deimos, should be done first, to practice interplanetary flight without the added complication (and mass) of getting to the Martian surface — and because it will cost a lot less. Likewise, a lunar base is highly desirable to practice living off the land on a regolith-dominated surface while still relatively close to home. We also need to experiment with precommercial trade in raw materials, like delivering lunar water to the International Space Station and applications satellites: In the long term, only trade can pay for exploration.

However, in arguing that, ethically, safety should come first, Mr. Adamo is dead wrong. If humanity ever wants to send people to any deep-space destination in the solar system at any price, let alone one the nation or world can afford, we must be prepared to take risks and lose astronauts. Our own world never could have been explored, let alone colonized, without loss of life. Every year, hundreds of people die in deep-sea shipping accidents: Preventing all of those, as we insist on doing in space, would raise costs so high that no ship would ever traverse the world’s oceans — let alone allow a privately funded and profitable industry. We tolerate untold civilian slaughter in private automobiles for no better purpose than convenience.

Why are we unwilling to accept comparable costs in the far riskier activity of traveling to the planets?

The real lesson of the Apollo 1 fire and the lost shuttle orbiters is that mistakes and failures are inevitable. While not excusing bad decisions, there will always be schedule and financial pressure: These are inevitable facts of life in any large project, and without them the project will never proceed to completion. If we send expeditions into the wilds of the solar system, astronauts will die, and probably a lot of them. If we are not willing to pay that price, we should immediately stop unethically risking lives and wasting money pretending that we will ever go to Mars or anywhere else.

None of that means that we should needlessly lose astronauts, but early Mars missions should be just safe enough to allow a positive chance of success. Trying to guarantee success and absolute safety only guarantees that we will never go.

Donald F. Robertson
San Francisco

Donald F. Robertson is a retired space industry journalist and technical writer based in San Francisco.

Brian Berger is editor in chief of SpaceNews.com and the SpaceNews magazine. He joined SpaceNews.com in 1998, spending his first decade with the publication covering NASA. His reporting on the 2003 Space Shuttle Columbia accident was...