Behind the sky-high price of the toilet is an astronaut’s bitter toilet history
In early October, the National Aeronautics and Space Administration (NASA) used the Cygnus cargo spacecraft to deliver approximately 3.6 tons of materials and equipment to the International Space Station.
Among them is a new toilet.
That's right, even tall astronauts need to face the "three vulgarities" problem of "shit, urine, and ass".
But to put it another way, even if it is a toilet, it has to become sophisticated equipment to enter space.
Pang Zhihao, chief science communication expert of national space exploration technology, introduced to a reporter from Science and Technology Daily that this new type of space toilet called the "universal waste management system" cost 23 million U.S. dollars and took more than 6 years to develop, making it the most expensive toilet in history.
Why are space toilets so expensive and how difficult is it for astronauts to use the toilet?
Let's talk about it.
What is so good about the sky-high price of a space toilet?
The new space toilet weighs 45 kg and is 71 cm high.
Pang Zhihao said that its volume is 65% less than the toilet currently used in the space station, and its weight is reduced by 40%. It can reduce the occupation of valuable space on the International Space Station and can be integrated into the life support systems of different spacecraft.
In the past, toilets on the International Space Station were designed to be more suitable for men.
In order to better suit female astronauts, the new toilet has been improved in design and is more ergonomic.
The seat is higher and slightly inclined.
This allows female astronauts to sit on the toilet to urinate and suck urine with a special-shaped funnel and hose.
Previously, female astronauts needed other special equipment to urinate.
The new toilet uses a 3D printed titanium alloy fan separator, which can generate a strong suction force to suck the excrement into the toilet to ensure that they will not flutter.
Compared with the old-fashioned space toilet, the new toilet has another feature. After opening the toilet lid, the airflow will automatically spray out, thereby controlling the spread of odor.
Titanium alloy material also greatly improves the corrosion resistance and durability of the toilet, which can save more cleaning and maintenance time, allowing astronauts to devote more energy to scientific research and exploration tasks, instead of cleaning the toilet. Overworked.
In space, water resources need a lot of recycling.
It is estimated that if an astronaut lives in space for a year, he will drink more than 700 liters of processed urine.
The urine recovery efficiency of the new toilet has been further improved, and the proportion of urine that can be converted into drinking water after treatment has increased.
The urine purification function is realized by the electrochemical system of the urea bioreactor, which can effectively convert the urea in the urine into ammonia, and then decompose the ammonia into water and energy.
It is said that the purified water obtained by recycling and filtering the urine discharged by the astronauts is cleaner than any water on earth.
Pang Zhihao introduced that the annual transportation cost of providing 2,200 liters of drinking water to the International Space Station is as high as 22 million US dollars, and the space station's drinking water storage capacity is also limited.
If humans want to leave low-Earth orbit and further explore interstellar space, water supply will be more difficult.
The design goal of the new space toilet is to achieve a 98% liquid recovery rate before humans go to Mars. This time it was shipped to the International Space Station for testing purposes.
Special training is needed to use the toilet well
To use the space toilet proficiently, astronauts need to carry out special training.
When defecation, they must ensure that the buttocks are close to the edge of the cushion to completely seal the toilet. At the same time, they must keep in mind the relative position of the buttocks and the toilet cushion so that the anus can accurately aim at the central hole with a diameter of 10 cm.
All this is to ensure that the stool can be sucked away smoothly, and will not float out of the toilet gap.
For this reason, the Johnson Space Center in the United States has specially designed a toilet trainer. A camera is installed in the toilet. Astronauts can observe and adjust their buttocks through the screen to find the posture with the highest aiming accuracy.
Although the Soviet Union lost to the United States in the moon landing race, it has since focused on space station research and development. It has rich experience in long-term on-orbit and environmental control and life support systems, and it has built more sophisticated space toilets.
Although the United States has also developed a space toilet, the effect is not satisfactory.
In 2007, the United States simply spent 19 million US dollars to order a space toilet from Russia, and said it was more cost-effective than its own research and development.
But later, the United States restarted the development of the space toilet at a cost of more than 100 million US dollars.
Those toilet failures that can't bear to look back
Is such an expensive space toilet necessarily safe and reliable?
Do not.
On May 21, 2008, the toilet in the Russian compartment of the International Space Station malfunctioned and could only store solid excrement, but liquid could not be handled.
The Russian Space Agency urgently manufactured a substitute, and asked the United States to pick it up with the space shuttle Discovery launched in early June.
On July 19, 2009, the toilet in the U.S. compartment was also broken. The reason was that the 6 liters of water used to flush the toilet erroneously flowed into the separator and other places.
Fortunately, the space shuttle Endeavour docked on the space station.
The 13 astronauts, including the space station watchmen and the Endeavour crew, had to line up to go to the shuttle to use the toilet.
However, the toilet on the space shuttle is not designed for frequent use.
In order to protect this precious "single seedling", the ground command center has imposed strict restrictions on the astronauts' defecation: the interval between two visits to the toilet must be more than 6 minutes; after 3 uses, it must be disabled for more than 30 minutes to allow the system to cool down.
The astronauts persisted for a month, and finally looked forward to the next shuttle to deliver the new toilet.
The worst toilet failure in history occurred during the first flight of the Columbia Space Shuttle in 1981.
During the mission, the toilet was blocked.
In the face of adversity, the astronauts firmly put on the stool collection bag.
However, on the return journey, the excrement stored in the discarded toilet was transferred to the ventilation system, and it spewed out like a flower, floating everywhere in the cabin, and the scene was extremely tragic.
For the removal of debris in the cabin, the astronauts have received special training.
For example, for large solids, you can directly "catch"; liquids need to be absorbed with absorbent paper and other materials.
The fine particles or fragments are more troublesome. They can only be cleaned up after they are concentrated on the air vent filter along with the airflow circulating in the cabin.
Everyone fully practiced the training content during this cleaning, but what they were faced with was a cleanup goal that they never thought of during training.
The failure of the space toilet brings not only hygiene problems and sensory stimulation, but also threatens the health of astronauts.
Pang Zhihao introduced that the United States has discovered bacterial strains with high resistance to antibiotics in the toilets of the space station. They may evolve into pathogenic bacteria and cause astronauts to get sick.
In order to design a better space toilet, in June this year, the United States launched a "Moon Toilet Challenge" event, soliciting "Moon Toilet" design proposals from all over the world for the moon landing plan in 2024.
"Lunar toilets" must meet a number of design requirements, such as being able to operate normally in both microgravity and lunar gravity, compatible with male and female users, and capable of urinating and defecation at the same time.
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How can astronauts "convenient" when there is no space toilet
When humans are exploring space, they will inevitably face the problem of excretion.
How can astronauts "convenient" when there is no space toilet?
If the mission time is not long, it would be better to say.
For example, when my country’s space hero Yang Liwei performed the Shenzhou V mission in 2003, he used a diaper-like urine collection device in the space suit to defecate during a 21-hour 23-minute flight.
The device can turn urine into flocculent solids through water-absorbing materials, and can deodorize, but it can't do anything about stool.
With the gradual extension of space travel time, astronauts' excretion problem is no longer solved by diapers.
Although the astronaut’s food has been specially processed to ensure nutrition while minimizing the residue after digestion to reduce the frequency and volume of stool, there will always be something.
In the early manned space activities, astronauts handled excrement in a more unrestrained manner.
In the 1960s, when the United States implemented the Apollo program, the astronauts had not used the toilet in space, and had to use separate collection devices for urine and feces.
Among them, the stool collection bag has a circular bag opening similar to a funnel. When in use, it should be used to cover the buttocks tightly, discharge the stool, and then pour the fungicide, seal the bag mouth and shake and knead to make the internal substances fully mixed.
Once, an unknown astronaut in the Apollo 10 crew had a problem with the operation, so that a stool floated into the capsule gorgeously, frightening the astronauts.
With such a painful experience, the Apollo astronauts who completed the moon landing later threw the stool collection bags on the moon.
The handling of urine by astronauts is simpler and more straightforward.
For a long time, they all discharged waste water directly into space.
This behavior was later stopped, not only for environmental protection, but also for the cost.
When the Mir space station was decommissioned in 2001, due to the use of drain-type bathrooms and toilets, the solar panels were wrapped in layers of urine and bath water, and the efficiency was lost by 40%.
The urine even formed ice cubes and hit the battery panels at high speed, causing considerable losses.