Guides

How to see the International Space Station with your own eyes

The ISS is easy to see without a telescope if you know when and where to look. When it is visible, what it looks like, and how to tell it from a plane.

Starlink train: what it is and when you can see it

A line of lights moving across the night sky is usually a fresh batch of Starlink satellites. Why they travel in a line, how long it lasts, and how to catch one.

Your first amateur radio satellite contact

With a dual-band handheld and a small directional antenna you can talk through a satellite overhead. What you need, how a pass works, and how to keep the contact short and clean.

How do satellites stay up? Orbits explained simply

A satellite is not floating: it is falling around Earth, fast enough that the ground curves away beneath it. What an orbit is, why speed matters, and why low satellites eventually come down.

Low, medium, geostationary: the kinds of orbit and what they are for

Why weather satellites, GPS and the ISS fly at such different heights. A guide to low Earth orbit, sun-synchronous orbit, medium orbit, geostationary orbit and highly elliptical orbits.

How to photograph the ISS and other satellites

A satellite pass makes a striking photo: a bright streak across the stars. What you need, the camera settings that work, and how to do it with a phone.

What is a TLE? Reading a satellite's two-line element set

Every tracked satellite's orbit is published as two lines of numbers. What those numbers mean, where they come from, and why predictions get less accurate as they age.

Why do Chollian and Koreasat never move? Geostationary satellites explained

Some satellites hang over the same spot all day. How the geostationary orbit works, what Korea uses it for, and where to look for these satellites in the sky.

How does GPS know where you are?

Your phone works out its position from signals sent by satellites 20,000 km away. How satellite navigation measures distance with time, why it needs four satellites, and why phones use several systems at once.

How weather satellites see the weather

From clouds at night to sea temperature and typhoons: what weather satellites measure, why some hover and others circle the poles, and how their images reach your forecast.

Korea in space: from Uribyol 1 to Nuri

A short history of the Korean space program: the first satellite in 1992, Arirang and Chollian, the Naro and Nuri rockets, the Danuri lunar orbiter, and the satellites in orbit today.

What you can see in the night sky without a telescope

Satellites, planets, the space station, meteors: what is visible to the naked eye even from a city, and how to tell a satellite from a plane, a star or a planet.

How Starlink works, and why there are so many satellites

SpaceX's Starlink provides internet from thousands of low satellites. Why it needs so many, how they talk to each other and to the ground, and why new ones look like a train of lights.

Space debris: how much junk is in orbit, and why it matters

Dead satellites, spent rocket stages and millions of fragments circle Earth. How much there is, where it came from, how it is tracked, and what the Kessler syndrome is.

What happens when a satellite falls back to Earth?

Every week old satellites and rocket stages re-enter the atmosphere. Why most burn up, what can survive, why the time and place are so hard to predict, and how risky it really is.

Tiangong: China's space station and how to see it

China's Tiangong space station has hosted crews since 2021. How it was built, who lives aboard, how it compares with the ISS, and how to spot it from Korea.

The Hubble Space Telescope: what it is and whether you can see it

Hubble has orbited Earth since 1990, above the blurring atmosphere. How it works, how astronauts repaired it, what it discovered, and whether it can be seen from Korea.

How do rockets reach orbit?

Getting to space is easy; staying there is hard. Why rockets turn sideways, why they drop stages, why launch sites are where they are, and how boosters land again.