In 1972, the Space Race officially ended when NASA sent a last crew of astronauts to the lunar surface (Apollo 17). It was the copper ring that the US as well as the Soviets aspired to, the “Moonshot” that would determine who had the supremacy in space. In the current era of renewed space exploration, the next big leap will clearly involve astronauts being sent to Mars.
It will present many challenges that need to be addressed in advance, many of which have to do with simply getting the astronauts there in one piece! These challenges were the subject of a presentation by two Indian researchers at the SciTech Forum 2020, an annual event hosted by the International Academy of Astronautics (IAA), RUDN University and the American Astronomical Society (AAS).
The study describing their research findings recently appeared online and was accepted by publication Advances in Aviation Sciences (publication date pending). Both this and the presentation presented during the SciTech Forum 2020 was given by Malaya Kumar Biswal and Ramesh Naidu Annavarapua – a postgraduate researcher and associate professor of physics from Pondicherry University, India respectively.
Their research was also the subject of a presentation (video above) presented during the 7th Session of the Virtual Workshop for Space Biology, presented by the Lunar Planetary Institute (LPI) – which took place between 20 and 21 January. As Biswal and Annavarapua indicated in their study and presentations, Mars takes a special place in the hearts and minds of scientists and astrobiological researchers.
Next to Earth, Mars is the most habitable place in the solar system (by earthly standards). Several pieces of evidence built up over the decades have also shown that it may have supported life at the same time. Unfortunately, sending astronauts to Mars will inevitably pose a number of obvious challenges ranging from logistics and technology to human factors and the distances involved.
It is of utmost importance to address these issues in advance as NASA and other space agencies hope to conduct the first crew missions to Mars in the next decade and beyond. Based on their analysis, Biswal and Annavarapu identified 14 different challenges, which include (but are not limited to):
- The runway for Mars and corrective maneuvers
- Spacecraft and fuel management
- Radiation, microgravity and astronaut health
- Isolation and psychological issues
- Communication (in transport and on Mars)
- The Mars approach and orbital insertion (see Mars Curse)
All of these challenges experience some overlap with one or more of the others listed. For example, a clear issue when it comes to planning missions to Mars is the great distance. As a result, launch windows between Earth and Mars occur only every two years when our planets are closest in their orbit to each other (ie when Mars is in an “opposition” to the sun).
During these windows, a spacecraft can travel from Earth to Mars within 150 to 300 days (about five to ten months). This makes the supply of missions impractical, as astronauts can not wait so long to receive much-needed transportation of fuel, food and other necessities. As Biswal emailed Universe Today, the distances also create problems for the astronaut’s safety and power generation:
‘[I]in case of emergency, we can not bring back astronauts from Mars [as we could] in the case of LEO or Lunar missions … Distance also reduces the solar current of the earth around the Mars orbit, leading to the lack of power production which is very important for the motor vehicle and it maintains the thermal stability (as well as the distant distance to a low environment can lead to temperatures that cause hypothermia and frostbite (especially in the mouth). ”
In other words, just getting to Mars presents very specific challenges that Biswal and Annavarapu include in their analysis. When we talk about astronaut health and safety, there are also several specific challenges that come up here. The fact that astronauts will spend several months in space, for example, creates all sorts of risks to their physical and mental health.
To begin with, there is the psychological toll of a spacecraft cabin along with other astronauts. There is also the physical toll of prolonged exposure to a micro-gravity environment. As research aboard the International Space Station (ISS) has shown, especially NASA’s Twin Study, the human body costs up to a year in space.
In addition to loss of muscle and bone density, astronauts who spent long periods aboard the ISS also experienced a loss of vision, genetic changes, and long-term problems with their cardiovascular and circulatory systems. There were also cases of psychological consequences, where astronauts experienced high levels of anxiety, insomnia and depression.
But as Biswal has indicated, the biggest and most obvious challenge is all the radiation (solar and cosmic) to which the astronauts will be exposed throughout the mission:
‘[The] The greatest dangers include the risk of long-term cancer and its consequences due to exposure to both interplanetary radiation (during Mars transit) and surface radiation (during long-term surface stay). The effect of radiation then causes improper brain coordination function and other brain-related diseases; then the psychological effect of the crew during complete isolation. Since the mission with crew is dependent on the performance of astronaut, the astronaut experiences more health-related problems. ”
In developed countries, people on earth are exposed to approximately 620 millirem (62 mSv) annually, or 1.7 millirem (0.17 mSv) per day. Meanwhile, NASA conducted studies that showed how a mission to Mars would result in a total exposure of about 1000 mSv over a period of two and a half years. It would consist of 600 mSv during a round trip, plus 400 mSv during an 18-month stay (while the planets re-aligned).
What this means is that astronauts are exposed to 1.64 mSv per day during transport and 0.73 mSv for each day they stay on Mars – this is more than 9.5 and 4.3 times the daily average, respectively. The health risks it poses can mean that astronauts suffer from radiation-related health problems before they even arrive on Mars, let alone the surface operations or return flight.
Fortunately, there are mitigation strategies for the passage and surface portions of the mission, some of which Biswal and Annavarapua recommend. “We are currently developing a Mars subterranean habitat that can address all the health-related issues regarding the extended mission or permanent settlement on Mars,” Biswal said. ‘[T]the mission with a crew must produce faster crew requirements from the in-situ resource [utilization] (ISRU). ”
This proposal is in line with the many mission profiles that NASA and other space agencies are developing for future lunar and Mars exploration. There are already many strategies to keep crews protected from radiation while in space, but in extraterrestrial environments, all concepts include the use of local resources (such as regolith or ice) to create natural shielding.
The local availability of ice is also considered a must for the sake of a stable water supply for human consumption and irrigation (since astronauts on long missions will have to grow much of their own food). Apart from all this, Biswal and Annavarapu emphasized how maintaining a fast flight and return route can reduce travel time.
There is also the possibility of utilizing advanced technologies such as nuclear thermal and nuclear electric propulsion (NTP / NEP). NASA and other space agencies are actively investigating nuclear missiles, as a spacecraft equipped with NTP or NEP can make the journey to Mars in just 100 days! But as Bisawl and Annavarapu have pointed out, it increases the challenge of dealing with nuclear systems and more exposure to radiation.
Unfortunately, all of these challenges can be addressed with the right combination of innovation and preparation. And when you think about the payoff of sending crews to Mars, the challenges seem far less daunting. As Biswal presented, this includes the proximity, the opportunities to study Mars soil samples in an Earth laboratory, the expansion of our horizons and the ability to answer fundamental life questions:
‘We have always been fascinated to know where we come from and whether there is a life like ours in other astronomical bodies? [W]e cannot carry out a mission with crew to any other interplanetary destination due to mission risk and management.
‘Mars is the only neighboring planet in our solar system that we can explore [has] a good geological record to answer all [of] our unresolved questions, and [we can] bring samples [back] to analyze in our country laboratory? ‘And lastly, it would be interesting to carry out a human mission to Mars to demonstrate the extent of current technology and advances in space. ‘
Since the early 1960s, space agencies have been sending robotic missions to Mars. Since the 1970s, some of these missions have been landers who have sunk to the surface. With the forty years of data and expertise that has resulted from it, NASA and other space agencies now want to apply what they have learned so that they can send the first astronauts to Mars.
The first attempts may be over more than a decade (or more), but only if important preparations are made in advance. Not only do many mission-related components and infrastructure need to be developed, but much research still needs to be done. Fortunately, these efforts benefit from the kinds of thorough assessments we see here, where all possible risks and dangers are investigated (and countermeasures are suggested).
All of this will hopefully lead to the creation of a sustainable Mars exploration program. It could even enable the long-term occupation of Mars and the creation of a permanent colony. Thanks to the efforts of many researchers and scientists, the day may finally dawn when there is such a thing as ‘Martians’.
This year’s SciTech Forum was a virtual event, where presenters shared their findings at two conferences that took place from December 8de up to 10de. For more information, visit the IAA-AAS SciTech Forum 2020 website.
Further reading: arXiv