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.
This competition complements NASA’s Waste to Base Challenge, which launched on January 18th, 2021. This incentive prize will award $24,000 to teams that offer “circular economy” proposals that could lead to spacecraft systems capable of converting human waste, packaging, and assorted trash into products astronauts can use for the mission. But even with a robust waste-management system, deep-space missions will still generate some waste that cannot be reused, repurposed, or recycled.
Artist’s impression of NASA’s Crew Transfer Vehicle (CTV) using its nuclear-thermal rocket engines to accelerate away from Low Earth Orbit (LEO). Credit: NASA
For this Challenge, NASA is looking for detailed designs for jettison mechanisms that can efficiently eject non-recyclable material from a spacecraft during crewed missions to Mars. Controlled jettison operations are an effective means for mitigating risks to spacecraft and crew. Unchecked waste can take up crucial volumes in a spacecraft, pose potential hazards for the crew, and release contaminants that threaten astronaut health.
“This challenge requires creativity, and there is no doubt that our network of problem solvers will come up with something ingenious,” said HeroX CEO Kal K. Sahota in an official press release. “I look forward to seeing the thoughtful and sustainable solutions designed by our community of innovators.”
Jettison mechanisms refer to controlled means for disposing waste materials and objects that (as the name suggests) consist of ejecting them via airlock into space. These objects will then assume an orbit around the Sun but are extremely unlikely to interfere with future operations given the huge distances involved. In addition, ejecting waste mass has benefits as far as spacecraft performance, and fuel requirements are concerned.
Steve Sepka, the project manager for the Trash Compaction and Processing System at NASA’s Ames Research Center, is also part of NASA’s Waste Jettison Mechanism Challenge team. As Sepka explained to Universe Today via email:
“Carrying unneeded mass results in a substantial need for extra fuel for planetary ascent, descent, and transition between planets. So much so that reducing waste mass is considered Mars mission enabling. If the mass is biodegradable, then keeping it onboard poses a significant risk as a biohazard for crew health. Also keeping a viable living space for crew is also a concern. NASA is developing different technologies to remove or repurpose waste: Waste-to-Base, Trash-to-Gas, and Jettison are some of them.”
The Crew Transfer Vehicle (CTV) using its nuclear-thermal rocket engines to slow down and establish orbit around Mars. Credit: NASA
Some examples of material generated during long-duration spaceflights include biological waste from astronauts, spent components, protective packaging, and damaged parts. While much of this can be recycled or reused with the right technology, NASA anticipates that a four-person crew traveling to Mars will create a significant volume of non-recyclable waste. This waste will measure approximately 0.2 m3 (7 cu ft) in volume and weigh 50 kg (110 lbs), enough to fill a standard 55-gallon drum.
Given that it takes 6 to 9 months for a one-way trip to Mars, that works out to 1,200 to 1,800 kg (2,645 to 3,968 lbs) of excess mass generated along the way. In terms of volume, the garbage will grow to occupy 4.8 to 7.2 m3 (169.5 to 254 cu ft) of space. Considering that the interior volume of an Orion spacecraft is 9 m3 (316 cu ft), this means that a separate module will need to be added to the spacecraft, so the crews are not buried in it by the time they reach their destination!
As the NTL and HeroX highlight, jettison operations are complex and potentially risky. During the long-duration transit phases of a crewed mission to Mars, there are no opportunities to rendezvous with resupply or repair craft, or return to Earth early. Therefore, the Challenge is complex and requires some truly innovative thinking that will help ensure mission success. As with so many other aspects of missions beyond Earth, the main focuses are sustainability In-Situ Resource Utilization (ISRU). Said Sepka:
“We consider the Waste-to-Base and Jettison Challenges to be complimentary. There are materials that will likely need to be jettisoned, but as we develop ways to repurpose materials the list of jettisoned materials decreases. Eventually, we’d like to repurpose all materials to create a circular economy. We’re not there yet.”
Some potential crewed Mars mission profiles and the time they would take. Credit: NTL/HeroX
To participate, competitors must consider several different crewed mission profiles (shown in the illustration above) that will require mechanical jettison operations at some point. The longest of these mission profiles is a round-trip to Mars that would last a total of 3 years. This would consist of 6 to 9 months in transit between Earth and Mars, 18 to 24 months of science operations on or near the Martian surface, and a 6 to 9 moth return flight to Earth.
For this Challenge, the jettison mechanism refers specifically to the transit phases, where crews travel from Earth to Mars and then return. While surface operations are not technically included, the solution must still be available for the return journey, so consideration must be given to how the system will be stored and kept in working order for the many months that the crews are on the surface. As Sepka explained, this Challenge will be a first for his team, but something that NASA is very accustomed to:
“Our team is new to crowdsourcing, but NASA has used this method for hundreds of challenges. We’re at the early steps of developing new technologies, so CrowdSourcing is an ideal way to start because of its ability to come up with creative and novel ideas, or to confirm more traditional approaches. It will be exciting to see what innovative solutions will be offered using this method. Crowdsourcing also allows us to reach a wider audience.”
The Challenged launched earlier today (February 1st) and was accompanied by a statement from HeroX Project Manager Shane Jenkins:
“And so it begins! As of today, you now have access to the full guidelines so you can begin working on your solutions. To begin, click the orange “Solve this Challenge” button. Once you’ve accepted the legal agreement, you’ll be officially signed up as a competitor.
“If you’re ever feeling stuck, the challenge forum is the first place to go. The forum is there for you to ask questions and seek advice. Bounce ideas around, get to know your fellow innovators, and maybe even form a team (more on that later). Now get cracking! We can’t wait to see what you come up with.”
An artist’s conception shows a Mars transit habitat with a nuclear propulsion system. Credit: NASA
The Challenge will remain open until April 12th, 2021. The winning concepts – to be announced on June 14th, 2022 – may be considered for further development by NASA. The competition is open to anyone aged 18 or older (participating as individuals or teams) from anywhere in the world, provided U.S. federal sanctions do not prohibit participation. For more information on how you can participate, check out the registration page.
Further Reading: HeroX
