The space race officially ended in 1972 when NASA sent a final crew of astronauts to the surface of the moon (Apollo 17). This was the brass ring that both the US and Soviets reached for, the “moon shot” that would determine who was in control of space. In the current age of space re-exploration, the next big leap will clearly be sending astronauts to Mars.
This will bring many challenges that need to be addressed beforehand, many of which will have to do with just getting the astronauts there in one piece! These challenges were the subject of a presentation by two Indian researchers at SciTech Forum 2020, an annual event organized by the International Academy of Astronautics (IAA), RUDN University, and the American Astronomical Society (AAS).
The study describing their research findings was recently published online and accepted for publication by Advances in Aeronautical Sciences (pending publication date). Both it and the presentation at SciTech Forum 2020 were conducted by Malaya Kumar Biswal and Ramesh Naidu Annavarapua – a graduate researcher and Associate Professor of Physics at Pondicherry University, India.
Her research was also the subject of a presentation (video above) given during the 7th session of the Lunar Planetary Institute (LPI) virtual space biology workshop between January 20-21. As Biswal and Annavarapua have indicated in their studies and presentations, Mars holds a special place in the hearts and minds of scientists and astrobiological researchers.
Along with Earth, Mars is the most habitable place in the solar system (by terrestrial standards). Several lines of evidence, gathered over the decades, have also shown that they may have assisted life all at once. Unfortunately, sending astronauts to Mars will inevitably pose a number of different challenges arising from logistics and technology to human factors and the distances involved.
Resolving these issues early is of paramount importance if NASA and other space agencies hope to conduct their first crewed missions to Mars in the next decade and beyond. Based on their analysis, Biswal and Annavarapu identified 14 different challenges including (but not limited to):
- The flight path for Mars and corrective maneuvers
- Spacecraft and fuel management
- Radiation, Microgravity, and Astronaut Health
- Isolation and psychological problems
- Communication (on the move and on Mars)
- The Martian Approach and Orbital Insertion (see Martian Curse)
All of these challenges overlap to some extent with one or more of the other challenges listed. For example, an obvious problem with planning missions to Mars is the sheer distance. For this reason, launch windows between Earth and Mars only occur every two years when our planets are closest in their orbits (ie when Mars is in “opposition” relative to the sun).
During these windows, a spaceship can make the journey from Earth to Mars in 150 to 300 days (about five to ten months). This makes replenishment missions impractical because astronauts cannot wait long to receive much-needed supplies of fuel, food, and other supplies. As Biswal emailed Universe Today, the distances also cause problems when it comes to astronaut safety and power generation:
“[I]We cannot bring astronauts back from Mars in an emergency [as we could] in the case of LEO or lunar missions … Similarly, the distance reduces the solar flux from Earth orbit to Mars orbit, resulting in a deficit in power generation, which is of great importance for propelling the vehicle and maintaining thermal stability (there again the distance to a low environment can lead to temperature causing hypothermia and freezing (especially in the mouth). “
In other words, simply reaching Mars presents several specific challenges that Biswal and Annavarapu included in their analysis. When it comes to healthy and safe astronauts, there are some specific challenges here too. For example, the fact that astronauts will spend several months in space poses all possible risks to their physical and mental health.
Artist’s impression of the Mars base camp in orbit around Mars. When missions to Mars begin, one of the greatest risks is space radiation. Photo credit: Lockheed Martin
For starters, there is the psychological toll of being confined to a spacecraft cabin with other astronauts. There is also the physical toll of long-term exposure to a microgravity environment. As research on board the International Space Station (ISS) has shown – especially NASA’s twin study – spending up to a year in space puts a significant strain on the human body.
In addition to loss of muscle and bone density, astronauts who spent long periods on board the ISS also experienced loss of vision, genetic changes, and long-term problems with their cardiovascular and circulatory systems. There have also been cases of psychological effects with astronauts experiencing high levels of anxiety, insomnia, and depression.
But as Biswal has indicated, the biggest and most obvious challenge is all of the radiation (sun and cosmos) that the astronauts will be exposed to throughout the course of the mission:
“[The] The greatest dangers include the risk of prolonged cancer and its effects from exposure to interplanetary radiation (during Mars transit) and surface radiation (during prolonged surface stay). Then the effects of radiation cause poor brain coordination and other brain-related diseases; then the psychological impact of the crew during complete isolation. Since the crew and crew is based on the performance of an astronaut, the astronaut has more health problems. “
An illustration of a moon base that could be created using 3D printing and ISRU (In-Situ Resource Utilization). Photo credit: RegoLight, visualization: Liquifer Systems Group, 2018
In developed countries, people on earth are exposed to an average of 620 millirem (62 mSv) per year or 1.7 millirem (0.17 mSv) per day. Meanwhile, NASA has been conducting studies showing how a mission to Mars over a two and a half year period would result in a total exposure of about 1,000 mSv. This would consist of 600 mSv during a year round trip plus 400 mSv during an 18 month stay (while the planets realigned).
This means that astronauts are exposed to 1.64 mSv daily during transport and 0.73 mSv every day they are on Mars – that’s more than 9.5 and 4.3 times, respectively of the daily average. The associated health risks could mean astronauts are suffering from radiation-related health problems even before they even arrive on Mars, not to mention surface surgery or the return journey.
Fortunately, mitigation strategies exist for the transit and surface portions of the mission, some of which recommend Biswal and Annavarapua. “We are currently developing a Mars underground habitat that can solve any health issue related to the extended mission or permanent colonization of Mars,” Biswal said. “[T]The crewed mission should include faster production of crew supplies from in situ resources [utilization] (ISRU). “
This proposal is in line with the many mission profiles NASA and other space agencies are developing for future lunar and Mars explorations. There are already many strategies in place to protect crews from radiation in space. In alien environments, all concepts involve the use of local resources (such as regolith or ice) to create a natural shield.
The local availability of ice is also seen as a must to ensure a steady supply of water for human consumption and irrigation (as astronauts have to grow much of their own food on long-term missions). That being said, Biswal and Annavarapu emphasized how maintaining a fast flight path and return flight path can help reduce travel time.
There is also the option of using advanced technologies such as nuclear thermal and nuclear electric propulsion (NTP / NEP). NASA and other space agencies are actively researching nuclear missiles, as an NTP or NEP-equipped spacecraft could make the trip to Mars in just 100 days! But as Bisawl and Annavarapu have suggested, this presents the challenge of dealing with nuclear systems and exposing them to more radiation.
Unfortunately, all of these challenges can be addressed with the right combination of innovation and preparation. And when you consider how sending crewed missions to Mars pays off, the challenges seem a lot less daunting. As Biswal offered, this includes the proximity, the opportunity to examine Martian soil samples in an earth laboratory, the expansion of our horizons and the ability to answer fundamental questions about life:
“We have always been fascinated to know where we come from and whether there is a life like us in other astronomical bodies? [W]Due to the mission risk and management, a crewed mission cannot be carried out to any other interplanetary destination.
“Mars is the only neighboring planet in our solar system that we can explore [has] a good geological record to answer all of them [of] our unresolved questions and [we can] Bring samples [back] to analyze in our terrestrial laboratory? ‘And finally, it would be interesting to do a human mission to Mars to demonstrate the extent of current technology and advancement in aerospace. “
Artist’s concept of a bimodal nuclear missile on its way to the moon, Mars and other targets in the solar system. Photo credit: NASA
Space agencies have been sending robotic missions to Mars since the early 1960s. Since the 1970s, some of these missions have been landers that have settled on the surface. With over forty years of data and expertise, NASA and other space agencies want to apply what they have learned to send the first astronauts to Mars.
The first attempts may still be more than a decade (or more) away, but only if significant preparation has been made beforehand. Not only do many mission-related components and infrastructures have to be developed, but a lot of research still needs to be done. Fortunately, these efforts benefit from the thorough evaluations we see here, where all potential risks and hazards are investigated (and countermeasures suggested).
All of this will hopefully lead to the creation of a sustainable program for the exploration of Mars. It could even enable the long-term human occupation of Mars and the creation of a permanent colony. Thanks to the efforts of many researchers and scientists, the day may finally come when there will be such a thing as “Martians”.
This year’s SciTech Forum was a virtual event where the speakers exchanged their results at two conferences from December 8th to 10th. Further information can be found on the website of the IAA-AAS SciTech Forum 2020.
Further reading: arXiv
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