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.

Craft

Country Capacity Period Active Toilet Scene

Vostok

Russia 1 person 1961 – 1963 Bag

Mercury

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

Bag

Gemini USA 2 persons 1965 – 1966

Bag

Soyuz

Russian 3 persons 1967 – present Simple Toilet

Apollo

USA 3 persons 1968 – 1975

Bag

Space Shuttle 1981 – 2011

Waste Collection System

Shenzhou

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)

Mir

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

ISS

US 6 persons 2000 – present Waste Collection System

EAS burnup

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

Burnup

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

Role of International Entities: Inception of the Indian Space Program

A brief history of the satellite, launch vehicle and application programs of ISRO to shed some light on the important role played by international entities especially from the Soviet Union, the USA, France and Germany in kickstarting the Indian Space Program.

Satellite Systems

The success of the satellite programmes Aryabhatta, Bhaskara, Rohini and Apple in the 70s led to the operational programmes INSAT for communication, broadcasting and meteorology and IRS for earth observation in the 80s, which are currently the major programmes of ISRO. The first satellite ‘Aryabhata’ was developed and launched using a Soviet Launcher. Bhaskara-I & II missions pioneered the future remote sensing satellite series. ‘Ariane Passenger Payload Experiment (APPLE)’ was ISRO’s first indigenous, experimental communication satellite launched by ESA’a Ariane vehicle from Kourou on June 19, 1981

The INSAT-1 was built by the American Ford Aerospace while the INSAT-2 was indigenously developed. The IRS-1A, IRS-1B and IRS 1-C were launched in March 1988, August 1988 and December 1995 respectively using Russian launch vehicles. From IRS-1D onwards, ISRO’s PSLV was used.

Launch Services

Even though ISRO had acquired the baseline technologies before the establishment of the MTCR, technology denial regimes had delayed ISRO’s progress by increasing costs of materials & subsystems and deliberately delaying deliveries. However, these restrictions enabled indigenous developments in the areas of guidance & inertial systems, propellants, materials engineering, manufacture and mechanical & electrical design.

Satellite Launch Vehicle-3 (SLV-3) in 1980 was the first experimental satellite launch vehicle. Development of the complex Augmented Satellite Launch Vehicle (ASLV) demonstrated newer technologies and paved the way for realisation of operational launch vehicles such as PSLV and GSLV.

Application Programmes

In 1967 itself, the first ‘Experimental Satellite Communication Earth Station (ESCES)’ was set up in Ahmedabad that also acted as a training centre for Indian and International scientists and engineers. However, before developing and operating a full-fledged satellite system of its own for national needs, a TV program ‘Krishi Darshan’ using foreign satellites was started, to provided information on agriculture for farmers of the country, that received a wide response.

After this came ‘the largest sociological experiment in the world’ during 1975-76, that benefitted about 200000 people from 2400 villages across six states. This was the Satellite Instructional Television Experiment (SITE) that used the American Technology Satellite (ATS-6) to transmit development oriented programs. For this purpose, fifty thousand science teachers from primary schools were trained in a surprisingly short period of one year, by the SITE team.

Following SITE was the joint project of ISRO-and Post and Telegraphs Department (P&T) known as the Satellite Telecommunication Experiments Project (STEP), during 1977-79. This used the Franco-German Symphonie satellite, and focused on telecommunication experiments with the objectives of – testing the use of geosynchronous satellites for domestic communication; enhancing capabilities and experience in various ground segment facilities including their design, manufacture, installation, operation and maintenance; building up of indigenous competence for the proposed INSAT domestic satellite system. Then came the ‘Kheda Communications Project (KCP)’ for testing need-based and locale specific programme transmission, which was awarded the UNESCO-IPDC (International Programme for the Development of Communication) award for rural communication efficiency in the 1984.

Now, nearly six decades after its inception, ISRO has drawn global attention by the thrifty innovations of its Moon and Mars missions. Unlike in other major space faring countries, ISRO is the major space manufacturer in India. The 500 small, medium and large scale domestic industries that participate in the space program have only been supplying satellite and launch vehicle components and ground equipment to ISRO since the 1970s, while ISRO was solely responsible for the sub-system assembly and integration and launch activities. Its commercial arm Antrix has been responsible for the sale of remote sensing data, ground station services, satellite launches, transponder leases and export of satellite components. However, with the global demand for PSLV launches surpassing ISRO’s current production capacity and to nurture the domestic industrial capabilities, ISRO has announced plans towards privatisation of its workhorse PSLV and transfer of the AIT (Assembly, Integration and Testing) activities of its satellites to the domestic private players. Moreover, the Indian space industry is getting an additional boost from the handful of newspace startups that are eager to experiment with the downstream as well as upstream space activities, such as Astrome Technologies, SatSure, Bellatrix aerospace, among others.