Space One KAIROS

The KAIROS rocket (カイロスロケット), or Kii-based Advanced & Instant Rocket System,  is a Japanese solid-fuel rocket designed to launch small satellites of mass up to 250 kg to low Earth orbit and up to 150 kg to sun-synchronous orbit by the private spaceflight company Space One. It consists of 3 solid fuel powered stages and a liquid propellant upper stage.

Namesake
The namesake of the KAIROS rocket is the Greek word Kairos, which means the subjective 'right time' as contrasted with Chronos which is the objective clock time. Kairos is also an alternate spelling of the name of Caerus, the Greek deity of luck and opportunity.

Manufacture
IHI Aerospace manufactures the KAIROS rocket at Tomioka Plant in the city of Tomioka, Gunma Prefecture.

Launch site
Launches are planned from Spaceport Kii in Kushimoto, Wakayama, Japan, a dedicated launch site built by Shimizu Corporation. This spaceport is accessible from Tokyo International Airport (Haneda Airport) via Nanki–Shirahama Airport in approximately 2 hours and 20 minutes, and from Kansai International Airport in approximately 2 hours and 30 minutes.

First launch
The first launch was planned on 9 March 2024 but was postponed because a ship was spotted in the "maritime warning area" set up in waters near the launch pad. The launch eventually took place on 13 March 2024, but the vehicle exploded five seconds after liftoff. The remains of the rocket fell close to the launch pad, but no substantial damage was found. Space One announced that the autonomous flight termination system could have activated and ended the mission. The launch failure is still under investigation.