Garbage in Human Spaceflight Missions

The last few months have been busy with the big move to Germany. Having almost grasped the garbage sorting algorithms of Deutschland (Umweltbundesamt – Federal Environment Agency), I got curious about the garbage scene in space. Since I couldn’t find a one-stop-online info website for space garbage, this article gives a short summary of historical and current garbage scenes in Human Space Flight missions.

Brief History

During the initial days of the human spaceflight, space agencies did not foresee the large importance of garbage disposal in space. Since most of the initial flights were for either 15 minutes (in case of Allen Shepard) and a few orbits by Yuri Gagarin, the focus was primarily on the safety systems and the data collection. The first instance of the challenge of tackling the problem of human waste came up during the Redstone mission (launch on May 5, 1961) when Alan Shepard infamously wet himself. Since the mission supposed to last only 15 minutes, mission managers thought that he would be able to off.

This problem that a space agency like NASA did not foresee was then corrected in the later missions of Freedom 7 with a primitive urine collection methods on board by using simple bags to store urine. Urine from these bags was then easy to be ejected from the side of spacecraft. Containment of fecal matter was the next big challenge which was posed during the longer duration Gemini missions in spite of the low fiber diet designed for astronauts.

The Gemini missions had a fecal kit that basically comprised a plastic bag with adhesives, wet wipes, and chemical bacteria to neutralize odors. Also, there was an extension the plastic bag, to enable the astronauts to separate the fecal matter from their body, given the absence of gravity in space.

Typically, an astronaut would strip naked, attach the fecal bag to his body to complete the action, with the whole exercise taking usually more than an hour. In spite of this elaborate routine, Apollo 10 astronauts had fecal particles floating around during their return trip from the Moon. No literature could be found for waste disposal for female astronauts since there were very few initial recruits. It could simply be that they used a diaper for urine during the initial missions.

Soyuz (by the Russians) was the first spacecraft that had the first toilet instead of the primitive bags. This may be a measure taken to accommodate for the waste generated by the larger three-person occupied spacecraft. Urine and fecal matter collection system was basically a funnel that was based on air flow so that urine and fecal matter would be suctioned out.

Given their duration of not more than few days, all these missions only undertook measures to handle human waste. Other waste such as defunct electronics, paper, etc. did not constitute as much and was simply brought back to the earth.

Then came the manned space stations beginning with the Russian Salyut in 1971 which were occupied for longer durations with more than 3 people at the same time. This Salyut and the next space station which was the American Skylab both had simple toilets similar to the ones on the Russian Soyuz. The waste collected from these toilets were simply packed away and brought back to Earth. Skylab introduced the concept of exposing the bio-waste as well as its garbage to the harsh outer space via the airlock (Skylab Trash Airlock) so as to kill the microorganisms and prevent any decomposition reactions and also to evaporate the water content.



Human Waste Disposal Unit from the Mir Space Station


The next advancement in space toilets came with the American Space Shuttle in 1981 with its Waste Collection System that is slightly more complex and sophisticated than the simple toilets used so far. It is an automated system comprising the human waste collection, processing, airlock exposure, ejection (urine only) from craft and storage. It also accommodated female astronauts. It’s dual urine and fecal collection mode was perhaps the first of its kind to be present in a space toilet wherein an astronaut can urinate and expel feces in the same toilet cycle without having to change settings on the toilet. However, this sophisticated system required more elaborate maintenance and needed to be cleaned and flushed with water every day.

All the space toilets so far though slightly different in construction and operation, disposed of the waste in a similar manner. The liquid urine was jettisoned out of the rocket/station and the fecal matter was brought back to the Earth after chemical treatment. The Russian MIR was the first to come up with an alternate of disposing of the solid waste – which is by burning it up in the atmosphere. This act of throwing garbage out in space was not technically the first, given the fact that Apollo 11 had left a jettison bag (trash bag) on the moon’s surface and the Apollo 16 crew throwing a jettison bag out during an EVA but these were one-time events and not really a part of their overall waste disposal strategy.

The most up to date space toilet today is present on the ISS (International Space Station) that designed its toilet and its waste management strategy by studying the human waste management methods employed not only on MIR, Skylab but also from the US Navy’s Submarines. All along the evolution of the space toilet from the initial space age days to the current ISS, there have been several instances of critical problems arising directly because of human waste. For instance, near the end of Gordon Cooper’s 34-hour Mercury mission in 1963, a urine bag leakage resulted in multiple system failures and Cooper had to manually control the re-entry. At the time of MIR space station’s retirement in 2001, all the urine that had been ejected reduced the efficiency of the solar panels by 40%.

While it’s obvious that the primitive fecal bags were a rather time-consuming and messy affair, the later space toilets though more sophisticated required special positional training for the astronauts to be able to effectively use them. Though there weren’t any such critical issues with the ISS’s toilet, it was very expensive and had cost NASA $19M to replace their broken toilet on their ISS module.

The toilet scene on all the human spaceflight missions so far (rockets and space stations) is compiled in Table 1 and Table 2. The space stations, owing to their longer occupancy times and nature of activities onboard, also generated a comparatively greater amount of non-human garbage. Salyut and Skylab brought their garbage back to earth along with the human solid waste while MIR and ISS burned up their garbage together the human solid waste.

The Chinese Shenzhou rocket also includes a simple toilet but there isn’t much literature to be found on it. The Chinese space stations Tiangong-1 and Tiangong-2 have their toilets on the docked Shenzhou rocket and they dispose of their human solid waste and garbage via burnup in the Earth’s atmosphere.

A summary of the toilet scenes so far in crafts and space stations is given in the following tables. Both tables compiled from various sources indexed in the text above.


Country Capacity Period Active Toilet Scene


Russia 1 person 1961 – 1963 Bag


USA 1 person 1961 – 1963 Bag
Voskhod Russia 2-3 person 1964 – 1965


Gemini USA 2 persons 1965 – 1966



Russian 3 persons 1967 – present Simple Toilet


USA 3 persons 1968 – 1975


Space Shuttle 1981 – 2011

Waste Collection System


Chinese 3 persons 2003 – present Simple Toilet
X-15* US 1 person 1963

No toilet

SpaceShipOne* 1 person 2004

No toilet

* Sub-orbital


Space Station

Country Capacity Period Active Toilet Scene Garbage Scene

Salyut series

Russia 2-4 person 1971 – 1991 Simple Toilet Earth bound
Skylab US 3 persons 1973 – 1974 Simple Toilet

Earth bound (after airlock exposure)


Russia 3/(>) persons 1986 – 2001 Toilet System Burnup


US 6 persons 2000 – present Waste Collection System

EAS burnup

Tiangong-1 Chinese 2 persons 2011 – 2012 Toilet on Shenzhou


Tiangong-2 Chinese 2 persons 2016 – present Toilet on Shenzhou

Tiangong-1 burnup


Current Garbage Scene

The most sophisticated garbage management plan is now being implemented on the International Space Station. Given the increased astronaut presence and also the numerous activities and experiments being performed on the ISS, human waste is no longer the biggest aspect of garbage. As per the ISS’s “Non-Recoverable Cargo Management Plan”, garbage is classified as Trash and Waste. Trash refers to all that garbage that doesn’t significantly contribute to the decay of the habitable environment and typically comprises expired consumables, payload generated items or used/defective hardware. Waste comprises of chemicals, radioactive materials, biologically active products, etc. Every item discarded is labeled according to the extensive classification scheme and disposed of accordingly. ISS also seems to be the only space station that has a recycling system in place. It is not clear if Tiangong 1 or 2 has a recycling system onboard due to limited literature available on them.

In summary, the current garbage scene on the ISS is that about 80% of the water collected from the toilets, showers, and water vapor from the air is recycled. All the other garbage is exposed to the outer space in the airlock to kill microbial growth. Of this airlock exposed garbage, the toxic part it brought back to earth while the rest is burned up in the atmosphere. Figure 4: ATV-4 (Albert Einstein) Re-entry shows 1.6 tons of astronaut waste and other garbage being burned up during re-entry of the fourth Automated Transfer Vehicle named Albert Einstein in 2013.


ATV-4 reentry in 2013
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