Sending humans to Mars is one of the most ambitious and challenging endeavors ever contemplated by humankind. A crewed mission to the red planet has been the subject of science fiction for over a century, but in recent years, it has become an increasingly serious goal for space agencies and private companies around the world. NASA plans to send astronauts to Mars orbit by the 2030s, while SpaceX founder Elon Musk has outlined even more aggressive timelines.
However, the immense difficulties and dangers of a human mission to Mars cannot be overstated. The red planet lies an average of 140 million miles from Earth, necessitating a round-trip journey of up to three years. During this time, the crew would face unprecedented hazards and challenges, from the physiological effects of prolonged weightlessness and radiation exposure to the psychological strain of isolation and confinement.
Moreover, the spacecraft and surface systems required to keep the astronauts alive must function flawlessly in an unforgiving environment never before encountered by humans. Even a small equipment malfunction or human error could spell disaster when Earth is many months away.
In this article, we will examine the myriad ways that a crewed mission to Mars could go catastrophically wrong, from launch to landing to the long journey home. By understanding these risks, we can better appreciate the monumental challenge that lies ahead – and the bravery of those who will ultimately attempt this next giant leap for humanity. While a successful human mission to Mars may one day inspire the world, a failure could set back space exploration for generations. The stakes could not be higher.
Launch Failures
A crewed mission to Mars faces risks from the very beginning during the launch phase. The powerful rockets needed to propel a spacecraft holding crew and supplies to Mars have many potential points of failure. An engine malfunction, guidance system glitch, or problem with the launch abort system during ascent could spell disaster for the crew. Even if the launch vehicle performs flawlessly, there is always the possibility of a catastrophic failure of the spacecraft itself that would prevent it from reaching orbit or functioning as intended. History has shown that launch is one of the most dangerous phases of any space mission.
Spacecraft Malfunctions
Once safely in space, the Mars-bound spacecraft must operate reliably for months during the long journey to the red planet. Any major malfunction or failure of a critical system could endanger the crew. Life support systems must provide breathable air, clean water, proper temperature control, and remove carbon dioxide – a tall order for a small spacecraft far from home. Other vital systems like navigation, communications, power generation and storage, thermal control, etc. will all need to function continuously. Unanticipated glitches or breakdowns in any number of spacecraft components could put the crew at risk.
Radiation Exposure
A flight to Mars will expose the crew to dangerous levels of cosmic radiation for a prolonged period. Without the protection of Earth’s magnetic field, galactic cosmic rays and energetic particles from solar flares become a serious health hazard. High-energy cosmic radiation can damage DNA and increase cancer risk. It may also harm the central nervous system, leading to cognitive impairment. Solar particle events can deliver extremely high radiation doses in a short time. Spacecraft will need to be heavily shielded, but some exposure is still unavoidable. Radiation sickness and long-term health consequences are a major concern.
Microgravity Effects
During the multi-month transit to Mars, the crew will live in microgravity which takes a heavy toll on the human body. Bone density and muscle mass are lost at an accelerated rate. The heart becomes deconditioned. Vision problems may develop due to changes in intracranial pressure. The immune system is weakened. Body fluids shift toward the head, causing a puffy face and congestion. There are concerns that the crew will be in a significantly weakened state by the time they reach Mars and may have trouble functioning in gravity again. Some effects of long-duration microgravity may even be irreversible.
Supply Shortages
A Mars mission must carry all the necessary supplies for the round-trip journey since there are no resupply opportunities. If any miscalculation is made in terms of food, water, oxygen, medicine, or other essentials, the crew could be faced with severe shortages. There is little margin for error. Even if supplies are adequate, failures in the storage or recycling systems could deplete reserves faster than anticipated. Rationing supplies to dangerously low levels may become necessary. Depending on when a shortage occurs in the mission, there may be no way to rectify the situation, dooming the crew.
Medical Emergencies
Astronauts on a Mars mission will be isolated from advanced medical care for years, a dangerous prospect if a severe illness or injury occurs. The crew medical officer will have limited diagnostic tools, treatment options, and supplies onboard the spacecraft. A medical emergency such as a heart attack, stroke, appendicitis, serious infection, or major trauma may not be treatable en route. Chronic conditions could also deteriorate over the course of the long mission. In the worst case, an astronaut could die and endanger the rest of the crew both physically and psychologically. Medical issues are a major threat.
Human Factors and Psychology
The mental well-being of the crew is of utmost importance on a long-duration Mars mission. Astronauts will be living in a confined space under stressful conditions with no way to return home. Interpersonal conflicts, loneliness, homesickness, boredom, and depression could set in and seriously impact crew morale and performance. Prolonged isolation may lead to mental health problems and erratic behavior. The crew will need to maintain a demanding workload while dealing with the ever-present danger of the mission. Keeping the crew psychologically healthy and motivated will be a constant challenge with no easy solutions if problems arise.
Landing Risks
After surviving the long journey to Mars, the crew must still land safely on the surface. Mars has a thin atmosphere that makes landing large, heavy spacecraft tricky. Parachutes are of limited use, so propulsive deceleration with retrorockets is required. However, rocket engines can kick up dust and debris which may damage the spacecraft. The landing sequence must be executed autonomously due to the time delay in communications with Earth. Any failure during this critical phase would likely be fatal for the crew. In addition, the landing zone will only be preliminarily scouted by satellites and robotic probes, so there is a possibility of encountering unexpected hazards that could complicate the landing.
System Failures on the Surface
Once on the surface of Mars, the crew will be dependent on their surface habitat and life support systems to keep them alive. Like the spacecraft, these systems must operate continuously and reliably in the harsh Martian environment. System redundancy and spare parts can only go so far. A major failure in power generation, water recycling, temperature control, airlock mechanisms, etc. could quickly become life-threatening. Dust storms could clog vital components. Radiation shielding could be inadequate. The crew will be extraordinarily vulnerable to equipment malfunctions.
Martian Environment Hazards
Mars is a dangerous place for humans. The surface radiation is intense and protection is vital whenever astronauts are outside their habitat. Dust and wind could hamper visibility, damage equipment, and may be toxic if inhaled. The reduced gravity could cause astronauts to be more prone to falls and injury. Temperatures are extremely cold and frostbite is a concern. The lack of atmospheric pressure means a punctured spacesuit would be fatal in minutes. Astronauts will need to exercise extreme caution whenever they venture out to explore. An accident or suit malfunction while away from the habitat could easily turn deadly.
Ascent and Return Voyage Risks
Getting off of Mars and back to Earth may be even riskier than landing. The Mars ascent vehicle must launch and reach orbit autonomously and dock with the waiting Earth return vehicle. Any failures during this critical rendezvous and docking would strand the crew on Mars with no hope of rescue. If the ascent is successful, the crew must still survive another multi-month voyage through deep space to return home, facing the same hazards and issues they encountered on the outbound journey, but in a likely weakened physical and psychological state. Re-entry and landing on Earth also presents a final risk of failure at the end of the mission.
Conclusion
While a human mission to Mars is technologically feasible, it involves enormous risks and challenges that cannot be fully mitigated. Spacecraft systems and the human body will be pushed to their limits. Unknown and unanticipated problems are bound to occur. But great rewards require great risks. With extensive planning, smart spacecraft and mission design, rigorous testing, and a healthy dose of luck, humankind may one day walk on the red planet. However, mission planners and the public must acknowledge and accept the very real possibility of mission failure and crew loss as we reach for this next giant leap.
