Category Science

What’s in a spacesuit?

Spacesuits are considered to be ‘personal spacecraft’ designed to keep a human alive in the harsh environment of space. Inside spacesuits, astronauts have the oxygen they need to breathe and the water they need to drink. Astronauts put on their spacesuits several hours before a spacewalk.

NASA astronauts wear what’s called an EMU (extravehicular mobility unit), which includes a protective white suit and a strap-on pack that provides oxygen and other life support necessities.

The suit consists of about 14 layers, within which there are three assemblies- (1) the liquid cooling garment which protects the astronauts from overheating; (2) the pressure garment to retain air pressure within the suit and (3) the thermal micrometeoroid garment to protect them from the sun’s radiation and to deflect space debris.

 

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What is spacewalk? And why is a spacesuit important for spacefaring astronauts?

The U.S. Space Agency, NASA, is all set to conduct a marathon of spacewalks in the coming months, including one by an all-female crew.

Does this information give you a deja vu feeling? NASA announced a similar attempt in March 2019 with astronauts Christina Koch and Anne McClain. But it scrapped the plan later, citing spacesuit shortage. Both the astronauts needed medium-size torso component, but only one was available at the International Space Station (ISS) at that time.

Now that another medium hard upper torso (HUT), the part of the spacesuit shaped like a T-shirt, is ready, the first all-female spacewalk plan is back on track. However, this time astronaut Christian Koch will be paired with Jessica Meir and they are expected to conduct the spacewalk on October 21.

What is a spacewalk?

A spacewalk is any activity done by an astronaut outside a space vehicle, such as the ISS, while in space. It is also called the Extra-vehicular Activity (EVA). Astronauts go on a spacewalk to install new equipment, conduct experiments, and to carry out repairs.

Spacewalks usually last between five and eight hours, depending on the job undertaken. By going on spacewalks, astronauts can fix things by themselves instead of bringing them back to Earth to fix.

What is the current mission all about?

The spacewalk by Koch and Meir is one of ten spacewalks that NASA has planned for the rest of the year. The agency has set such an aggressive schedule in order to replace ageing nickel-hydrogen batteries on the ISS with newer lithium-ion ones. NASA astronauts started replacing these batteries in 2017, and they will complete the task this year.

What did the March all-female spacewalk fall through?

On March 29 Christian Koch and Anne McClain were to step out of the ISS and upgrade the space station’s power system.

But during her spacewalk on March 22, McClain discovered that her best spacesuit torso fit was medium, not large as the team previously thought.

There are no male or female versions for spacesuits, but only a mix-and-match collection of parts – torso, arms, gloves, etc. – in different sizes to ensure proper fit. In the past, missions have been all-male or male-female and hence this problem did not arise earlier.

So, NASA had to scrap the plan and conduct a male-female spacewalk instead on March 29. McClain was replaced by astronaut Nick Hague.

But this time around, NASA has the spacesuits ready for both the astronauts, as a new medium size configuration spacesuit was launched to the ISS earlier this year.

 

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What were the initial studies about moonlight?

 

          Ancient scientists and astronomers were fascinated by moonlight. The ancient Greek philosopher Anaxagoras was one of the first scholars to understand the nature of moonlight. His investigations suggested that the Sun and the Moon were both giant spherical rocks, and that the Moon reflected the light of the Sun.

          The Chinese of the Han dynasty believed in the ‘radiating influence’ of the Moon. They recognized that the light of the Moon was merely a reflection of the Sun. Jing Fang of the Han dynasty studied further about the spherical nature of the Moon.

          Indian astronomer Aryabhatta studied about the physical characteristics of the Moon. In Aryabhatiya, he notes that reflected sunlight is the cause of the shining of the Moon. The Arab astronomer Alhazen threw more light on the way the Moon reflected sunlight. He found that sunlight was not merely reflected from the Moon like a mirror, rather it was emitted from every part of the Moon’s sunlit surface in all directions.

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What do we know of the ancient studies about the Moon?

           The journey to the Moon had to be somehow made possible. This thought was the driving force behind all the studies about the Moon.

           The early developments were crucial in moulding the later growth. It all began thousands of years ago with sketching the Moon; humans began drawing pictures to track the changes of the Moon. Later, their observations of the Moon led to creating calendars.

           Understanding the Moon’s cycles was the earliest development in astronomy. Astronomers from India studied the monthly elongation of the Moon while the Babylonian astronomers worked towards finding formulas to predict the lunar eclipse. The Chinese astronomer Shi Shen is noted for his instructions for predicting solar and lunar eclipses. The Chinese also studied the physical form of the Moon, including moonlight and gravitational pull. There were also efforts to calculate the distance between the Earth and the Moon. However, the Moon was believed to be a sphere with a smooth surface before the invention of the telescope.

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Does the Moon influence animal behaviour?

 

          We are familiar with the word lunacy, which means madness. Did you know that this word comes from Luna, the Latin word for the Moon?

          There are many stories about mysterious events that happen during the full moon. This includes strange and violent behaviour of animals including wolves and dogs. It is believed that the full moon brings out the worst in humans and animals. However, there are no satisfactory scientific explanations for any of this, though there are some evidences about the lunar phases affecting the behaviour of birds, fish, insects and even mammals. It’s a growing research area now.

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Can the Moon slow down the speed of the Earth?

          About 350 million years ago, a day on the Earth was around three hours shorter than today. The Earth slowed down because of the Moon. Aren’t you surprised?

          The Moon can slow down the Earth, even with its weak gravitational and magnetic field. This happens when there’s a force of friction between the surface of the Earth and the tidal bulges.

          During its rotation, the Earth drags the tidal bulge directly under the Moon. This causes friction between the Earth’s surface and the tidal bulge. The friction generated during this action slows down the rotation of the Earth on its axis. This results in a longer day and even a longer month.

Picture Credit : Google