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