NASA's Human Landing System (HLS) Program


NASA’s Lunar Loo Challenge - Junior Category

Help astronauts go back to the Moon in 2024! NASA seeks new designs for a toilet that will work both in microgravity and lunar gravity.
Official NASA Swag & Bragging Rights

Challenge Overview

This challenge is for anyone under the age of 18. If you are 18 years of age or older, please go here.

If you are 12 years old or younger, please have your parent/guardian register on your behalf.


We are going back to the Moon.  

Artemis is NASA’s program to land the first woman and the next man on the Moon by 2024.  Humanity is going back to the Moon to establish a presence that will enable eventual crewed journeys to Mars.  As we prepare for our return to the Moon, innumerable activities to equip, shelter, and otherwise support future astronauts are underway.  These astronauts will be eating and drinking, and subsequently urinating and defecating in microgravity and lunar gravity.  While astronauts are in the cabin and out of their spacesuits, they will need a toilet that has all the same capabilities as ones here on Earth.

NASA is calling on the global community for their novel design concepts for compact toilets that can operate in both microgravity and lunar gravity.  These designs may be adapted for use in the Artemis lunar landers that take us back to the Moon.  Although space toilets already exist and are in use (at the International Space Station, for example), they are designed for microgravity only.  NASA is looking for a next-generation device that is smaller, more efficient, and capable of working in both microgravity and lunar gravity.  Getting back to the Moon by 2024 is an ambitious goal, and NASA is already working on approaches to miniaturize and streamline the existing toilets.  But they are also inviting ideas from the global community, knowing that they will approach the problem with a mindset different from traditional aerospace engineering.  This challenge hopes to attract radically new and different approaches to the problem of human waste capture and containment.

We want to encourage the next generation of space explorers, engineers, and scientists, and we know that students may think about this design problem without the same constraints as adults.  So in addition to the main Technical category, this challenge will have a Junior category.  

The goal of this category is to get our younger participants excited and thinking about STEM projects, and specifically about lunar toilets.  If you are 15 or over and believe that you have an idea with technical merit, we encourage you to have your parent or guardian submit your design concept on your behalf in the main Technical category.

To submit to the Junior category, you must be less than 18.   If you are younger than 12 years old, you must have a parent register and submit on your behalf.

The top three participants in the Junior category will each receive public recognition and an item of official NASA-logoed merchandise.


Challenge Guidelines

This challenge is for anyone under the age of 18. If you are 18 years of age or older, please go here.

If you are 12 years old or younger, please have your parent/guardian register on your behalf.



With the Artemis program, NASA will land the first woman and the next man on the Moon in 2024, and the goal is to do this in a way that uses less mass, occupies less volume, is more energy efficient, and has streamlined processes.  This massive effort is able to stay on track thanks to intensive collaboration between NASA and its commercial partners.  These partners are designing and developing different elements that are part of the overall program, including lunar landers and rovers.  Toilets will be integrated into landers developed by commercial partners. Due to the parallel development of components, the exact dimensions and performance specifications of lunar toilets are still unknown.  Nonetheless, there are general specifications and constraints for these toilets, and they are discussed below.  Designing and developing new lunar toilets may not be as exciting or intriguing as developing tools to support the exploration of the lunar surface, but the need is just as important.

Lunar toilet design concepts should allow astronauts to urinate and defecate in both microgravity and lunar gravity.  Microgravity is what is generally considered “zero-g” and is experienced as weightlessness.  The g-force is not actually zero in microgravity; it is just very small.   Lunar gravity is approximately one sixth of Earth’s gravity, so urine and feces will fall down.  

The process for using proposed toilet designs must be relatively straightforward.  Anything that is very time intensive or complicated to use will generally be less attractive to NASA.   Toilets will operate in a nominal spacecraft environment with an air pressure of 14.7 psia (sea level like on Earth) or 8.2 psia, and the toilet storage systems could experience 0 psia (vacuum) during Extra-Vehicular Activities (EVA).  Additionally, toilet designs should conserve water and help maintain a pristine environment inside the lander that is free of odors and other contaminants.  Complete solutions will be ones that can support a crew of two astronauts for 14 days, while controlling odor, accommodating different types of waste (urine, feces, vomit, diarrhea, menses), and different gender users (female and male). 

Additionally, toilet designs must be able to accommodate sick crew members dealing with vomiting and diarrhea.  Although the preferred method for capturing vomit will be emesis bags (“throw up” bags), bonus points will be awarded to designs that can capture vomit without requiring the crew member to put his/her head in the toilet.

Toilet Design Specifications

The specifications listed below represent the maximum allowed values.  Proposed designs should at least meet them and will preferentially be lower than them.  The toilet design should:

  • Function in both microgravity and lunar gravity
  • Have a mass of less than 15 Kg in Earth’s gravity
  • Occupy a volume no greater than 0.12 m3
  • Consume less than 70 Watts of power
  • Operate with a noise level less than 60 decibels (no louder than an average bathroom fan)
  • Accommodate both female and male users
  • Accommodate users ranging from 58 to 77 inches tall and 107 to 290 lbs in weight

Toilet Performance Specifications

We are looking for a design that captures all the functionality of a toilet on Earth.  At a minimum, crew using lunar toilets should not be exposed to vacuum during use, and toilet designs should be able to:

  • Accommodate simultaneous urination and defecation
  • Collect 1 liter of urine per use, with an average of 6 uses per crew per day
  • Accommodate 500g of fecal matter per defecation, with an average of 2 uses per crew per day
  • Accommodate 500g of diarrhea per event
  • Accommodate an average of 114g of female menses, per crew per day
  • Stabilize urine to avoid the generation of gas and particulates
  • Accommodate crew use of toilet hygiene products, like toilet paper, wipes, and gloves
  • Be clear of previous user’s urine and feces in preparation for the next use
  • Allow for transfer of collected waste to storage  and/or provide for external vehicle disposal. Minimal Lander volume requires regularly minimizing waste storage or removing it from the vehicle
  • Allow for easy cleaning and maintenance, with 5 minute turnaround time or less between uses

Additionally, in the event of a system failure, the toilet designs will ensure that:

  • All waste materials collected remain safely stored
  • The crew is not exposed to urine, feces, or other collected materials
  • The crew is not exposed to vacuum


This challenge has two categories: Technical and Junior.  Submissions to both categories are due no later than 5pm ET on August 17, 2020.  The winners for the Technical category will be announced on September 30, and the winners for the Junior category will be announced on October 20, 2020.

In the Junior category, this challenge will recognize the top three submissions, one per age group.  The authors of these three submissions will each receive: public recognition from NASA and from HeroX, a winner’s certificate, and an item of official NASA-logoed merchandise.  Additional “mystery” prizes may also be awarded to winners of the Junior category.  Such prizes could include a video call between the winner’s science class and an astronaut, or NASA-logoed specialty items (patches, pins, etc).  To submit to this category, you must be less than 18 years of age.  




Ages 15-17


Public recognition,

Official NASA-logoed merchandise

Additional “mystery” prizes!

Ages 11-14
Under 11



Open to submissions June 25, 2020
Submission deadline August 17, 2020 @ 5pm ET
Junior category judging and evaluation August 18 - October 13, 2020
Junior category winners announced October 20, 2020


How do I win?

Submissions to the Junior Category must contain at least one of the following elements to be eligible for an award:

  • A drawing of your idea for a Lunar Toilet
  • A paragraph that explains how your toilet would work
  • A 30-90 second video clip of you explaining your toilet design

Eligible submissions will be reviewed by a NASA evaluation panel and one winner per age category will be selected based on the Judging Criteria listed below.


Judging Criteria



Overall Weight


How well does the submission present your toilet design?  Is it clear and easy to understand?


Design - creativity and innovation

How creatively and innovatively does your design address the challenge requirements for dealing with bathroom needs?


Design - completeness

How many different challenge requirements are met by your design?



How does your design protect the safety of astronauts?


Your submission

Questions marked with an asterisk (*) are required. Character limits include spaces.

  1. Please enter your name and tell us a little about yourself. If you are submitting on behalf of a child, please enter the child’s name and a little bit about them. This field is optional. (2000 characters)
  2. If you are a parent/guardian completing this form, please enter the parent's name and email address.
  3. How old are you? (or the age of the child you are submitting on behalf of.) *
  4. Lunar toilet design: Please upload a drawing, photo, diagram, or schematic of your lunar toilet design. *
  5. Lunar toilet description: Please describe your lunar toilet design. How does it work? Why will it work in both “zero-gravity” and lunar gravity? * (5000 characters)
  6. Video: Please link a 30-90 second video of yourself describing your lunar toilet design. Upload your video to Youtube or Vimeo and share the link here. Ensure the share settings are set to public or unlisted.
  7. Safety: Please describe how your lunar toilet design will protect the astronauts’ safety. * (5000 characters)


The Prize is open to anyone under the age of 18, participating as an individual or as a team.  If you are 12 years old or younger, you will need to have a parent or guardian register and submit on your behalf. Individual competitors and teams may originate from any country, as long as United States federal sanctions do not prohibit participation (see: If you are a NASA employee, a Government contractor, or employed by a Government Contractor, your participation in this challenge may be restricted.

Submissions must be made in English. All challenge-related communication will be in English.

No specific qualifications or expertise in the field of waste management  is required. NASA encourages outside individuals and non-expert teams to compete and propose new solutions.

Registration and Submissions:

Submissions must be made online (only), via upload to the website, on or before August 17th , 2020, at 5:00 pm ET. No late submissions will be accepted.

All submissions become NASA's property and will not be returned.

Selection of Winners:

Based on the winning criteria, prizes will be awarded per the weighted Judging Criteria section above.

Judging Panel:

The determination of the winners will be made by HeroX based on evaluation by relevant NASA specialists.

Additional Information

  • By participating in the challenge, each competitor agrees to submit only their original idea. Any indication of "copying" amongst competitors is grounds for disqualification.
  • All applications will go through a process of due diligence; any application found to be misrepresentative, plagiarized, or sharing an idea that is not their own will be automatically disqualified.
  • All ineligible applicants will be automatically removed from the competition with no recourse or reimbursement.
  • No purchase or payment of any kind is necessary to enter or win the competition.
  • Void wherever restricted or prohibited by law.
Updates 15

Challenge Updates

Recording: Meet the Winners of the Lunar Loo Junior Challenge

Oct. 29, 2020, 1:10 p.m. PDT by Liz Treadwell

Thank you to everyone that tuned in to our "Meet the Winners" Webinar on Wednesday! If you were unable to join, you can watch the recording below to meet the winners, learn more about their solutions, and how they developed them.  

In order to respect the hard work the submitters put in, we will not be releasing the entries to the public. The recording of the webinar is the best place to learn more about them. Please note that additional rankings or judges' scores will not be released either.

While we were only able to award three winners in each age category, we would like to commend and recognize the nearly 900 submissions that were received. The creative solutions submitted by these brilliant, young minds were extremely impressive.  We look forward to seeing what everyone accomplishes in the future!

Congratulations again to our winners and to everyone who contributed to NASA's Lunar Loo Junior Challenge!

Meet the Lunar Loo Junior Winners!

Oct. 22, 2020, 6:13 a.m. PDT by Liz Treadwell

Greetings space enthusiasts, future engineers and innovative thinkers!

Thank you again for taking the time to submit your brilliant space toilet designs to the Lunar Loo Challenge - Junior Category! The NASA team had a wonderful time reviewing the nearly 900 submissions we received from individuals and teams around the world. After many weeks of discussion, we have narrowed down all of your creative solutions to the top 3 from each age category that will receive the awards:

Under 11 category:

  1. Tied:
    1. Artemis Easy Loo (AEL) - submitted by Arun George John's son, Joel John Arun
    2. Spacesuit Lunar Toilet - Pei Yong Tan
  2. The Cosmic Loo - Grace Hespenheide
  3. The Lavabo Throne - Moon Scientists

Runner Ups:

Ages 11 to 14 category:

  1. The UniPump System - Junior team
  2. L∞P - Infinity LOO-P team
  3. The CosmoCommode-An Artificial Gravity Toilet - Bodhi Chiravuri

Runner Ups:

Ages 15 to 17 category

  1. A bladed toilet. - Edison Yau Yik Hang
  2. Earth-Based Space Toilet (EBST) - Justin Hagen
  3. AutoLETs with Hygiene & Cleanliness - TECHNO-NERDS team

Runner Ups:

Congratulations to the winners! We wish we could have awarded all of the submissions received, but we are confident that all of you will go on to do amazing things in your futures. Never give up on your dreams!

We look forward to highlighting these winners further and seeing you all at the winners’ webinar on October 28th!

Webinar Reminder + Winner Announcement Update

Oct. 20, 2020, 3:10 p.m. PDT by Liz Treadwell

Hello Lunar Loo Junior community!

Don't forget to join us next Wednesday, October 28th @ 9am PDT to meet the winners of the Lunar Loo Junior Category! You can register your attendance here.

Another important update: NASA is excited to promote the winners announcement through their channels and for this reason we'll have to delay the announcement until the following day. Winners will now be announced on October 22nd @ 6am PDT. You can view the exact date and time for your location in the Timeline here.  

We understand everyone is eagerly awaiting the results so we appreciate your patience!

Register now for the Lunar Loo Challenge - Junior Category Winner Webinar!

Oct. 16, 2020, 12:30 p.m. PDT by Liz Treadwell

Hey everyone!

Thanks again for sending us your awesome toilet designs. The judges have really enjoyed reviewing them and we’re excited to announce the winners in each age category on October 21st.

We also wanted to let you know that on Wednesday, October 28th, we will be hosting a webinar highlighting the winning designs and the creative minds who submitted them!

It will be hosted by HeroX's Kal Sahota and include the following guests:

  • Michael Interbartolo, NASA Human Lunar Lander Crew Module SE&I Team
  • Steve Rader, NASA Tournament Lab
  • Diane DeTroye, NASA STEM Portfolio Integration
  • Christian Cotichini, HeroX CEO
  • The challenge winners
  • A special guest appearance!

If you’re under 13 years old, please have your parent or guardian save your virtual seat at the webinar by registering here. If you’re 13 or older, you can register for it yourself. Don’t delay since space is limited!

8 Hours Remaining to Submit!

Aug. 17, 2020, 6 a.m. PDT by Lulu


Submissions are due today at 5:00 pm Eastern Daylight Time. You can see the deadline in your local timezone here.

Be sure to complete your submission form well before the exact cut-off time. At exactly 5:00 pm ET, we can no longer accept new submissions!  

Here's a Tip: HeroX recommends innovators plan to submit with at least a 3-hour window of time before the true deadline. Last-minute technical problems and unforeseen roadblocks have been the cause of many headaches. Don't let that be you!

Forum 184
Community 4K