Frequently Asked Questions

Space is generally considered to begin above the Kármán line at 100 km altitude. This is a conventional boundary set by the Fédération Aéronautique Internationale (FAI); 100 km is a distance a car travelling at 100 km/h would cover in one hour. Some organisations, such as the US Air Force, use 80 km instead — there is no sharp physical boundary.

The key to staying in space is sideways speed, not altitude. An object in orbit is continuously falling toward Earth, but it moves sideways fast enough that the ground curves away beneath it and it never reaches the surface. In low Earth orbit this speed is about 7.9 km per second (roughly 28,000 km/h), and most of a rocket's engine power goes into that horizontal acceleration.

With reusable rockets in routine service, the cost of delivering one kilogram to orbit has dropped by an order of magnitude in recent decades. That price collapse is what made previously unviable businesses — thousand-satellite constellations, smallsat ventures, space tourism — commercially possible.

LEO refers to Earth orbits below roughly 2,000 km altitude. It hosts communication satellite constellations, Earth observation satellites, and the International Space Station, making it by far the most economically active region of space today.

Cislunar space is the region between Earth and the Moon, including the lunar surface. Resource prospecting and building infrastructure for sustained human activity are accelerating there, making it the next frontier after low Earth orbit.

Japan is internationally recognised for pinpoint landing technology — placing a spacecraft precisely on a target site — and for deep-space mission operations, exemplified by its asteroid sample-return missions. It is modernising its flagship launch vehicles while private startups pursue lunar landers and on-orbit servicing.

The Artemis Accords are a US-led multilateral framework setting out principles for exploring and using the Moon and Mars. They cover transparency, emergency assistance, registration of space objects, and the public release of scientific data. The number of signatory nations continues to grow.

We aggregate official announcements from NASA, ESA, JAXA, and the National Astronomical Observatory of Japan, along with specialist media such as SpaceNews, sorae, and Space Media, via their RSS feeds and public APIs. Launch data comes from Launch Library 2 and research listings from arXiv. Copyright for each article remains with its original publisher; we provide headlines, summaries, and links.

They are generated automatically during collection, and translated items carry a "machine translated" badge. Because they are machine generated, wording may be inaccurate — always consult the linked original for authoritative content.