- Human waste can be used as rocket propellant by future Mars astronauts https://interestingengineering.com/human-waste-to-rocket-propellant 195 comments space
- Human waste can be used as rocket propellant by future Mars astronauts https://factinworld.com/human-waste-can-be-used-as-rocket-propellant-by-future-mars-astronauts/ 2 comments astronomy