Color mosaic image of Mars, taken by the HRSC instrument aboard the ESA's Mars Express orbiter. Credit: ESA/DLR/FU Berlin (G. Michael)
Check any container of over-the-counter medicine, and you’ll see its expiration date. Prescription medicines have similar lifetimes, and we’re told to discard old medications rather than hold on to them. Most of them lose their effectiveness over time, and some can even become toxic. We’re discouraged from disposing of them in our wastewater because they can find their way into other organisms, sometimes with deleterious effects.
We can replace them relatively easily on Earth, but not on a space mission beyond Low Earth Orbit.
Martian dust could be a serious health hazard for future missions to Mars. Credit: NASA/AI. SpaceFactory
To quote NASA associate administrator Jim Reuter, sending crewed missions to Mars by 2040 is an “audacious goal.” The challenges include the distance involved, which can take up to six months to traverse using conventional propulsion methods. Then there’s the hazard posed by radiation, which includes increased exposure to solar particles, flares, and galactic cosmic rays (GCRs). And then there’s the time the crews will spend in microgravity during transits, which can take a serious toll on human health, physiology, and psychology.
But what about the challenges of living and working on Mars for several months at a time? While elevated radiation and lower gravity are a concern, so is Martian regolith. Like lunar regolith, dust on Mars will adhere to astronauts’ spacesuits and inflict wear on their equipment. However, it also contains harmful particles that must be removed to prevent contaminating habitats. In a recent study, a team of aerospace engineers tested a new electrostatic system for removing Martian regolith from spacesuits that could potentially remove harmful dust with up to 98% efficiency.
In 2033, NASA hopes to make the next great leap in space exploration by sending the first crewed mission to Mars. Additional missions will launch every two years, coinciding with when Mars is in “Opposition” (closest to Earth), to establish a research outpost on the Martian surface. Naturally, many challenges need to be dealt with first, such as logistics, radiation protection, and ensuring enough food, water, and air for the astronauts.
This raises another all-important question: what to do with all the waste this generates? To address this, NASA has once again teamed up with the crowdsourcing platform HeroX to foster solutions. Having already launched competitions for new ideas on how to convert space waste into building materials and jettison the unrecyclable waste, HeroX has launched the Trash-to-Gas Challenge – on behalf of the NASA Tournament Lab (NTL).
With a prize purse of $30,000, NASA wants to hear your best ideas on how to maintain trash-to-gas reactors that may be used on long-duration missions.
Space agencies worldwide have some very ambitious plans that will take place in this decade and the next. For starters, NASA and its agency and commercial partners plan to return to the Moon for the first time since the Apollo Era. Beyond that, they also intend to build the infrastructure that will allow for a “sustained program of lunar exploration,” such as bases on the surface and the Lunar Gateway. Once all of that is in place, NASA will be contemplating sending crewed missions to Mars.
This raises many challenges, including logistics, energy requirements, and the health and safety of astronauts. One crucial concern that is not often thought of by the general public is what to do about the waste generated along the way. To address this, the NASA Tournament Lab (NTL) has partnered with HeroX once again to launch the NASA Waste Jettison Mechanism Challenge. With a prize purse of $30,000, NASA is seeking solutions for safely and effectively jettisoning waste that cannot be recycled.
In the coming years, NASA will be making the long-awaited return to the Moon, where they will be joined by multiple space agencies and commercial partners. This will be followed by NASA and China sending the first crewed missions to Mars and other locations in deep space in the next decade. This presents numerous challenges, not the least of which involves providing for astronauts’ basic needs while in flight. In keeping with Dr. Sian Proctor’s motto, “solving for space solves for Earth,” dedicated to addressing air-quality problems and Climate Change here at home.
To help NASA address these problems, the leading crowdsourcing platform HeroX has launched two new incentive challenges. First, there’s the “Waste to Base Materials Challenge: Sustainable Reprocessing in Space,” which seeks innovative solutions for what to do about all the waste that’s generated during long-duration spaceflights. (human and otherwise). Second, there’s the “NASA Air-athon Challenge,” which is looking to foster high-resolution air quality information to improve public health and safety.
According to a new study, EDLS hardware that has been jettisoned on Mars could create problems for future missions to the same landing sites. Credit: NASA
At one time, the idea of sending humans to Mars either seemed like a distant prospect or something out of science fiction. But with multiple space agencies and even commercial space companies planning to mount missions in the coming decade, the day when humans will go to Mars is fast approaching the point of realization. Before this can happen, several issues need to be resolved first, including a myriad of technical and human factors.
In any discussion about crewed missions to Mars, there are recurring questions about whether or not we can mitigate the threat of radiation. In a new study, an international team of space scientists addressed the question of whether particle radiation would be too great a threat and if radiation could be mitigating through careful timing. In the end, they found that a mission to Mars is doable but that it could not exceed a duration of four years.
An artist's conception shows a Mars transit habitat with a nuclear propulsion system. Credit: NASA
In 1972, the Space Race officially ended as NASA sent one last crew of astronauts to the surface of the Moon (Apollo 17). This was the brass ring that both the US and the Soviets were reaching for, the “Moonshot” that would determine who had supremacy in space. In the current age of renewed space exploration, the next great leap will clearly involve sending astronauts to Mars.
This will present many challenges that will 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 made 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).
Deceleration of Mars Science Laboratory in Martian Atmosphere. Artist's Concept depicts the interaction of NASA's Mars Science Laboratory spacecraft with the upper atmosphere of Mars during the entry, descent and landing (EDL) of the Curiosity rover onto the Martian surface. EDL begins when the spacecraft reaches the top of Martian atmosphere, about 81 miles (131 kilometers) above the surface of the Gale crater landing area, and ends with the rover safe and sound on the surface of Mars some 7 minutes later. During EDL, the spacecraft decelerates from a velocity of about 13,200 miles per hour (5,900 meters per second) at the top of the atmosphere, to stationary on the surface. Credit: NASA/JPL-Caltech
In the coming decades, a number of missions are planned for Mars, which include proposals to send astronauts there for the first time. This presents numerous logistical and technical challenges, ranging from the sheer distance to the need for increased protection against radiation. At the same time, there is also the difficulty of landing on the Red Planet, or what is referred to as the “Mars Curse“.
To complicate matters more, the size and mass of future missions (especially crewed spacecraft) will be beyond the capacity of current entry, descent, and landing (EDL) technology. To address this, a team of aerospace scientists released a study that shows how a trade-off between lower-altitude braking thrust and flight-path angle could allow for heavy missions to safely land on Mars.
The International Space Station (ISS), seen here with Earth as a backdrop. Credit: NASA
For years, scientists have been conducting studies aboard the International Space Station (ISS) to determine the effects of living in space on humans and micro-organisms. In addition to the high levels of radiation, there are also worries that long-term exposure to microgravity could cause genetic mutations. Understanding these, and coming up with counter-measures, is essential if humanity is to become a truly space-faring species.
Interestingly enough, a team of researchers from Northwestern University recently conducted a study with bacteria that was kept aboard the ISS. Contrary to what many suspected, the bacteria did not mutate into a drug-resistant super strain, but instead mutated to adapt to its environment. These results could be vital when it comes to understanding how living beings will adapt to the stressful environment of space.
A prototype Hall-effect thruster being tested at NASA's Glenn Research Center. Credit: NASA
When it comes to the future of space exploration, a number of new technologies are being investigated. Foremost among these are new forms of propulsion that will be able to balance fuel-efficiency with power. Not only would engines that are capable of achieving a great deal of thrust using less fuel be cost-effective, they will be able to ferry astronauts to destinations like Mars and beyond in less time.
This is where engines like the X3 Hall-effect thruster comes into play. This thruster, which is being developed by NASA’s Glenn Research Center in conjunction with the US Air Force and the University of Michigan, is a scaled-up model of the kinds of thrusters used by the Dawn spacecraft. During a recent test, this thruster shattered the previous record for a Hall-effect thruster, achieving higher power and superior thrust.
Hall-effect thrusters have garnered favor with mission planners in recent years because of their extreme efficiency. They function by turning small amounts of propellant (usually inert gases like xenon) into charged plasma with electrical fields, which is then accelerated very quickly using a magnetic field. Compared to chemical rockets, they can achieve top speeds using a tiny fraction of their fuel.
Artist’s concept of Dawn mission using its blue ion engine to reach Ceres in the distance. Credit: NASA/JPL
However, a major challenge so far has been building a Hall-effect thruster that is capable of achieving high levels of thrust as well. While fuel efficient, conventional ion engines typically produce only a fraction of the thrust produced by rockets that rely on solid-chemical propellants. Hence why NASA has been developing the scaled-up model X3 thruster in conjunction with its partners.
The development of the thruster has been overseen by Alec Gallimore, a professor of aerospace engineering and the Robert J. Vlasic Dean of Engineering at the University of Michigan. As he indicated in a recent Michigan News press statement:
“Mars missions are just on the horizon, and we already know that Hall thrusters work well in space. They can be optimized either for carrying equipment with minimal energy and propellant over the course of a year or so, or for speed—carrying the crew to Mars much more quickly.”
In recent tests, the X3 shattered the previous thrust record set by a Hall thruster, achieving 5.4 newtons of force compared with the old record of 3.3 newtons. The X3 also more than doubled the operating current (250 amperes vs. 112 amperes) and ran at a slightly higher power than the previous record-holder (102 kilowatts vs. 98 kilowatts). This was encouraging news, since it means that the engine can offer faster acceleration, which means shorter travel times.
Scott Hall makes some final adjustments on the thruster before the test begins. Credit: NASA
The test was carried about by Scott Hall and Hani Kamhawi at the NASA Glenn Research Center in Cleveland. Whereas Hall is a doctoral student in aerospace engineering at U-M, Kamhawi is NASA Glenn research scientist who has been heavily involved in the development of the X3. In addition, Kamhawi is also Hall’s NASA mentor, as part of the NASA Space Technology Research Fellowship (NSTRF).
This test was the culmination of more than five years of research which sought to improve upon current Hall-effect designs. To conduct the test, the team relied on NASA Glenn’s vacuum chamber, which is currently the only chamber in the US that can handle the X3 thruster. This is due to the sheer amount of exhaust the thruster produces, which can result in ionized xenon drifting back into the plasma plume, thus skewing the test results.
NASA Glenn’s setup is the only one with a vacuum pump powerful enough to create the conditions necessary to keep the exhaust clean. Hall and Kamhawi also had to build a custom thrust stand to support the X3’s 227 kg (500 pound) frame and withstand the force it generates, since existing stands were not up to the task. After securing a test window, the team spent four weeks prepping the stand, the thruster, and setting up all the necessary connections.
All the while, NASA researchers, engineers and technicians were on hand to provide support. After 20 hours of pumping to achieve a space-like vacuum inside the chamber, Hall and Kamhawi conducted a series of tests where the engine would be fired for 12-hours straight. Over the course of 25 days, the team brought the X3 up to its record-breaking power, current and thrust levels.
A side shot of the X3 firing at 50 kilowatts. Credit: NASA
Looking ahead, the team plans to conduct more tests in Gallimore’s lab at U-M using an upgraded vacuum chamber. These upgrades will are schedules to be completed by January of 2018, and will enable the team to conduct future tests in-house. This upgrade was made possible thanks to a $1 million USD grant, contributed in part by the Air Force Office of Scientific Research, with additional support provided by the Jet Propulsion Laboratory and U-M.
The X3’s power supplies are also being developed by Aerojet Rocketdyne, the Sacramento-based rocket and missile propulsion manufacturer that is also the lead on the propulsion system grant from NASA. By Spring of 2018, the engine is expected to be integrated with these power systems; at which point, a series of 100-hour tests that will once again be conducted at the Glenn Research Center.
The X3 is one of three prototypes that NASA is investigating for future crewed missions to Mars, all of which are intended to reduce travel times and reduce the amount of fuel needed. Beyond making such missions more cost-effective, the reduced transit times are also intended to reduce the amount of radiation astronauts will be exposed to as they travel between Earth and Mars.
