General, Research, Technology

Why are satellites made of metal rather than wood?

According to the March 2019 nonprofit Union of Concerned Scientists, there is more than 2000 active satellites... Thanks to them, scientists can conduct scientificactivities, and ordinary people - watching TV and using mobile communications. All of these spacecraft are made of alloys of aluminum or titanium, but in the 21st century, carbon fiber, which is a material of woven carbon fiber strands, has become very popular. Engineers use metals and CFRP due to their strength and relative cheapness, but they have one drawback. When satellites fail, they burn up in the atmosphere of our planet, resulting in the release of many relatively harmful substances. To make satellites safer, Japanese scientists decided to create satellites out of wood. But is it really possible and how safe is it?

It is unlikely that wooden satellites would look like this, but foreign publications use this particular picture.

Interesting fact: There are now more than 2,000 working satellites in Earth orbit. In total, more than 9000 of them were created and launched, and most of them burned out in the atmosphere, or turned into space debris.


  • 1 What are satellites made of?
    • 1.1 Aluminum satellites
    • 1.2 Titanium satellites
    • 1.3 CFRP satellites
  • 2 Companion made of wood

What are satellites made of?

At the moment, aluminum, titanium and carbon fiber are considered the best materials for making satellites.

Aluminum satellites

The very first satellite in the world was launched into spaceOctober 4, 1957. The Soviet "Sputnik-1", 58 centimeters in diameter and 83.6 kilograms in weight, was made of an aluminum-magnesium alloy. The use of this material was something a hundred self-evident, because the space environment is very harsh and the vehicles must be as protected as possible. And this metal alloy was very widespread, so engineers hardly thought long about the choice of material - it was obvious. The Soviet satellite worked in orbit for 3 months and managed to make 1440 orbits around our planet, and the material showed itself from the best side. It has withstood both vacuum and cosmic radiation.

Soviet "Sputnik-1"

More interesting facts about "Sputnik-1" can be read in this article. But read this material first.

Titanium satellites

Over time, there were more satellites, soEarth's orbit has become an even more dangerous place. Orbiters crashed and fell apart, becoming space debris. According to data for 2019, about 1.25 billion fragments of failed devices are circling around our planet and their speed reaches 30,000 kilometers per hour. In a collision, they can cause irreparable damage to working satellites, so engineers had to make them from a more durable material - titanium. But even he is not perfect, because it is expensive and weighs a lot. But the greater the mass of the satellite, the more expensive it is to put it into Earth's orbit.

Debris of old satellites are flying around our planet right now

CFRP satellites

The cost of sending a satellite into space depends onwhat company is doing this. For several years now, SpaceX has been filling many orders, but similar services are provided by Rocket Lab and a number of other aerospace companies. Prices are different for everyone, but on average, you have to pay about 50 thousand dollars for each kilogram of cargo. And this, by the way, is more than 3.5 million rubles. To reduce the cost of sending satellites, engineers have recently decided to make them from carbon fiber, which reduces the mass of the devices by about 35%.

Another good property of CFRP is that it can withstand the load during orbit.

See also: How do satellites prevent astronomers from studying the Universe?

Wooden satellite

But scientists continue to look for better materials.Over time, satellites disintegrate in the Earth's atmosphere and if they are made of metal, solid particles of aluminum oxide are formed. They can be in the air for tens of years, so scientists admit their potential danger to earthly nature and even human health. We need a safer alternative, and recently the employees of the Japanese company Sumitomo Forestry found it - this is a tree. At least this was reported by Tech Xplore.

Japanese scientists want to put electronics in a wooden box. It looks strange, but why not?

Space satellites must necessarily burn out inthe planet's atmosphere, because otherwise they will turn into space debris, of which there is so much in orbit. According to Japanese researchers, the combustion of wood produces much less harmful substances than the destruction of metal. Yes, the resulting carbon dioxide is also harmful, but the satellites are small and the emissions should be harmless. The tree has another important advantage - it perfectly transmits radio waves, which can greatly simplify the communication system and reduce the cost of satellites.

The first wooden satellite will be assembled around 2023. Probably, something similar to this awaits us

But there is a question - can wood withstandharsh space conditions? I have already mentioned above that in the Earth's orbit, the devices are affected by extreme temperatures, vacuum and cosmic radiation. Scientists intend to assess the strength of wood during tests. A prototype of a wooden satellite is planned to be created as early as 2023. It sounds interesting, even if the potential of wood in the space industry is hard to believe. After all, this is also a rather expensive material, for which there is already a great demand. It is unlikely that in the near future there will be something better than carbon fiber, because there is still no evidence of its harmfulness - you can safely use it and not reinvent the wheel. What do you think?

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And if you have time, I highly recommendread material about the satellite Capella 2, which allows you to follow people even through walls. It is owned by Capella Space, which provides espionage services to everyone.