Since time immemorial, humans have been observing their environment to gain knowledge and advance civilization. Space observation is difficult and requires good tools, and nanosatellites have recently gained traction. Nanosatellites are a low-cost way to observe the universe and validate technologies. Nanosatellites, such as CubeSats, are used for a variety of experiments and are likely to become more popular in the future due to their affordability and convenience.
Since time immemorial, humans have been constantly observing their surroundings, gaining new knowledge from these observations and using that knowledge to advance civilization and improve their quality of life. Human observations have extended beyond the Earth they live on to the universe that surrounds them, including the constellations and the motions of the sun and moon. These observations have deepened our understanding of natural phenomena and led to revolutionary advances in agriculture, navigation, architecture, and many other fields. However, because the universe is so vast compared to Earth, observing it is much more difficult than observing the environment on Earth’s surface. For this reason, we need good observational tools to observe the universe. In the past, we used to look at the universe with telescopes like Galilei’s, and now we look at the universe with satellites, which are much better tools than telescopes.
But the universe is big, and many people might assume that the satellites that observe it are all big. That’s what I and my classmates in the School of Mechanical and Aerospace Engineering thought until we took an introductory aerospace engineering class. However, there are small satellites called “nanosatellites” that seem out of place in the vastness of space. What are these nanosatellites, and how do they observe the universe?
A satellite is a celestial body that revolves around a planet due to its gravitational attraction to it, so a satellite is an artificial satellite launched by humans. These satellites are generally categorized according to their size, and their functions vary. Depending on their size, satellites can be categorized into large satellites (over 1000 kilograms), medium-sized satellites (500-1000 kilograms), small satellites (100-500 kilograms), and nanosatellites, which we’ll discuss in this article. Large satellites are mostly used for communications, meteorology, and military applications, while medium-sized satellites are used for practical Earth observation and technology validation. Small satellites are mostly orbiting in low-Earth orbit and are used for lunar and planetary exploration.
So what are these nanosatellites? There’s no clear definition of a nanosatellite, but in general, it’s a satellite that weighs 10 kilograms or less. Due to their small size, nanosatellites have several advantages and features that take advantage of this. The biggest advantage is that they cost less money. A typical satellite costs between $100 million and $300 million to launch once. Considering that South Korea’s space industry budget for 2023 is about $450 million, it’s a huge financial burden to launch a satellite once. However, nanosatellites cost about $1 million to $3 million per launch, which means that you can launch many nanosatellites for the price of one conventional satellite.
In science, when observing something or making a claim, the more data you have, the more reliable you are, so the ability to launch nanosatellites multiple times at a lower cost is an advantage because it increases the reliability of your observations. For example, the main task of nanosatellites is to investigate the thermosphere, especially the lower thermosphere, which is between 90 and 300 kilometers in altitude. When observing the atmosphere, satellites, regardless of their size, generate heat due to friction with the air, which can cause them to burn out after a period of time. Therefore, by using inexpensive nanosatellites instead of expensive conventional satellites, it is possible to obtain a greater amount of data more economically.
Also, because of their low cost, they are less prone to failure than conventional satellites, which is favorable for developing and validating technologies. For example, let’s say you develop a technology for another satellite. On Earth, gravity is a factor, so you can’t test the technology in zero gravity to see if it works. This is where nanosatellites come into play, as they are inexpensive, and you can put the technology on a nanosatellite and fly it into space to test it. Nanosatellites are also small and lightweight, so they don’t have complex structures, making them easy to assemble. Currently, the components of nanosatellites are already available on the market in kit form, making them accessible to both experts and non-experts. With these advantages, you can use nanosatellites yourself to obtain data when it is difficult to obtain results from ordinary satellites.
One of the representative nanosatellites is CubeSat. CubeSat is a satellite with a size of about 10 centimeters in width, length, and height. Currently, many countries around the world, such as the United States, Germany, and Japan, are using CubeSats because of their small size and the ability to conduct various space experiments at low cost, and are also focusing on their development. One such example is the U.S. Air Force’s Space Weather Observation CubeSat program. The Space Weather Observation CubeSat Program is a program that uses two CubeSats to observe the weather in space, with the United States taking the lead in observing the weather in space, as the weather in space (the top of the atmosphere) has become increasingly important due to the large number of spacecraft and satellites traveling in space in modern times. In addition to the U.S. Air Force, CubeSats are actively used in research at universities such as Arizona, Stanford, and MIT. The CubeSat XI-IV program at the University of Tokyo in Japan is a successful program where the CubeSat launched in 2003 is still alive and functioning. In Korea, CubeSats, or nanosatellites, are currently being researched by Korea Aerospace University, Kyung Hee University, and others.
Nowadays, the aerospace industry is becoming more and more important all over the world, and most developed countries are investing heavily in the aerospace industry. In this space-critical era, nanosatellites will become more prominent in the future because they are economical and convenient for observing the universe. This article aims to show that nanosatellites are indeed important in the modern space age, and to give a basic explanation of them at the level of common sense to the average person living in this era.
