ZERO is a two-stage, small orbital launch vehicle being developed by Japan's Interstellar Technologies to carry up to 1,000 kg to low Earth orbit, succeeding the company's MOMO suborbital sounding rocket.
ZERO
ZERO is a two-stage, small orbital launch vehicle being developed by Japan's Interstellar Technologies to carry up to 1,000 kg to low Earth orbit, succeeding the company's MOMO suborbital sounding rocket.
Description
ZERO is an expendable, two-stage small-satellite launch vehicle developed by Interstellar Technologies Inc. (IST), a Japanese private space company based in Taiki, Hokkaido, the follow-on to the company's MOMO sounding rocket. ZERO stands roughly 32 m tall with a vehicle mass around 71 t and a body diameter of approximately 1.7 m. The first stage clusters nine of IST's own 'Cosmos' engines, while the second stage uses a single vacuum-optimized Cosmos engine; both burn liquid biomethane and liquid oxygen. ZERO targets payloads of up to about 1,000 kg to LEO, and will fly from IST's own Hokkaido Spaceport in Taiki. As of mid-2026, ZERO has not yet flown its maiden orbital mission; IST has been conducting engine and vehicle qualification tests, has raised roughly $130 million to fund development, and has signed multiple commercial customers for its debut flight, publicly targeted for around 2027. MOMO, ZERO's suborbital predecessor, flew seven times between 2017 and 2021, becoming Japan's first privately developed rocket to reach space on its third flight in 2019.
Specifications
| Height | 32 m |
|---|---|
| Diameter | 1.7 m |
| Mass | 71 t |
| Stages | 2 (expendable) |
| 1st stage engines | 9x Cosmos engine |
| 2nd stage engines | 1x Cosmos engine (vacuum optimized) |
| Propellants | Liquid biomethane and liquid oxygen |
| Payload to LEO | ~1,000 kg (42.2° inclination) |
| Payload to SSO | ~250 kg |
| Launch site | Hokkaido Spaceport (HOSPO), Taiki, Japan |
| Flight heritage/status (mid-2026) | Has not yet flown; qualification testing underway; maiden orbital flight publicly targeted for ~2027 |
| Predecessor | MOMO suborbital sounding rocket - flew 7 times (2017-2021), reached space on 3rd flight in 2019, Japan's first privately developed rocket to reach space |