Title:

The Mars Challenge: The Past, Present, and Future of Human Spaceflight

Author:

Benjamin A. Wilgus

Artist:

Wyeth Yates

Category:

Non Fiction

Rating:

Date Reviewed:

February 4, 2024

he Mars Challenge: The Past, Present, and Future of Human Spaceflight is a short explanation of the difficulties of traveling to Mars, presented in a graphic novel format. While I was aware of most of these challenges already, to see them assembled in one place and explained in a concise, clear manner drove home just how difficult and dangerous a trip to Mars would be for humans. It is hard enough to send rovers on one way trips to the red planet, but humans, with their pesky need for life support systems, plus the requirement that they be returned safely to Earth, dramatically increases the scope of such a trip.

The Mars Challenge imagines an enthusiastic young woman named Nadia who wants to be the first woman to walk on the surface of Mars. Her friend Eleanor is a scientist who is well versed in all of the hazards of space travel. But before they discuss the obstacles, Nadia and Eleanor first talk about the justification for sending humans in the first place. A scientist on the surface of Mars can survey his environment, and spot something interesting and immediately go investigate. A rover must carefully navigate even short distances, a rover can be thwarted by the simplest obstacles, such as a boulder field or a ditch, which a human could traverse without thinking. A human could dig into mountainsides or dried lake bottoms, and immediately pursue new lines of investigation if something curious pops up. There is no doubt a trained scientist could do 100x the field work of even our best rovers.

But getting a small crew to Mars is hard. First big challenge is building a spaceship large enough to contain a small crew for the long journey. Humans need food, air, and gravity. Humans need shielding from cosmic rays. Humans need instruments and systems to handle our biological functions. All of this takes weight. Which means a lot of flights from Earth into space carrying all of the required supplies. Once the ship is built, what propels it? Humans exposed to space are at risk, so the shortest journey to Mars is the best journey. But a chemical rocket would take an incredible amount of fuel. Do we launch a nuclear generator? Hydrazine is an excellent rocket fuel, and also incredibly toxic and dangerous. Ion engines might be efficient, but they are slow and unproven.

No human has spent a sustained amount of time in deep space - the space station is in low Earth orbit, and so is protected by the Van Allen belts. But once the Mars ship leaves Earth orbit the crew will be vulnerable to cosmic particles. Mars does not have a magnetic field, so being on the Martian surface offers no protection. The human body degrades in zero-G, so even if they stick to a vigorous exercise schedule, the astronauts might arrive at Mars too weak to do anything!

The psychological challenges of such a long trip are also serious. Confined to a small space, could the crew maintain their focus? The astronauts who spend a long term on the space station say that the best way to de-stress is to stare out the window at the Earth below. On a trip to Mars, Earth would soon be lost in the distance. They would be entirely on their own, once the rocket launches them toward Mars, there is no aborting the mission and flying back. Any Apollo-13 style catastrophe would have to be solved on their own.

Landing on Mars is equally hard, the atmosphere is too thin for parachutes to be of much use. But it takes a lot of fuel to land a rocket, even if Mars gravity is much less than Earth's. Of course, the crew will need the rocket to return them to Mars orbit for the journey home. There are suggestions to send an advanced automated factory to Mars ahead of the arrival of the humans; this factory could process the CO2 in Mars' atmosphere to make hydrazine - but of course this idea is entirely unproven.

The dust on Mars is super sharp and corrosive - as is the dust on the moon. Without water or humidity, Martian dust is super fine grains ground down to tiny particles by eons of wind and exposure. Dust so fine that it would get into every crevice; inhaling it would scar the lungs. Without water, the dust is sharp. On the moon, the astronauts space suits were damaged by the lunar dust, and the Apollo astronauts were on the surface just 3 days.

When I finished The Mars Challenge, my first thought was: "Rats. Looks like humans won't be landing on Mars any time soon." These obstacles make the probability of going to Mars in my lifetime seem remote. Even getting back to moon is a monster challenge. I hope to live long enough to witness humans return to the lunar surface, seeing us build a permanent lunar base is perhaps too much to wish.