The Future Opened by the Greenhouse Gases Observing Satellite "GOSAT-GW"
I recently took some time off and visited Tanegashima. June is the season for loggerhead sea turtles to come ashore to lay eggs, and my main purpose was to participate in a "loggerhead sea turtle nesting survey." However, I saw a poster at a local convenience store announcing the launch of the H-IIA Rocket No. 50 (its final flight) and learned that it would be carrying a satellite related to greenhouse gases, so I decided to join a facility tour at the Tanegashima Space Center.
What is the H-IIA rocket?
The H-IIA rocket is Japan's flagship launch vehicle that has been in operation for over 20 years since the launch of the No. 1 test flight in 2001. It was developed based on technology cultivated through the H-II rocket, Japan's first purely domestic rocket, and has launched a variety of satellites and probes. The No. 50 vehicle carries the Global Observing SATellite for Greenhouse gases and Water cycle (GOSAT-GW). The H-IIA will conclude its mission with this 50th flight, passing the baton to Japan's new flagship rocket, the "H3".
What is GOSAT?
GOSAT is an acronym for "Greenhouse Gases Observing SATellite," and is the nickname for the greenhouse gas observation satellites launched by Japan.
The first "Ibuki" (GOSAT) was launched in 2009, followed by its successor "Ibuki-2" (GOSAT-2) in 2018, and they continue to "observe" the Earth from orbit to this day.
This H-IIA Rocket No. 50 carries the Global Observing SATellite for Greenhouse gases and Water cycle (GOSAT-GW, officially nicknamed Ibuki GW).
The satellite's main mission is to precisely measure the concentrations of carbon dioxide (CO2) and methane (CH4) on Earth, but Ibuki GW will also be able to observe nitrogen dioxide (NOx), precipitation, and sea ice distribution.
Furthermore, Ibuki GW changes the observation method from "point to area," allowing it to acquire data from an overwhelmingly larger number of observation points compared to the conventional GOSAT series. It is amazing that it will be possible to conduct observations at the city level and identify large-scale emission sources such as power plants and gas/oil facilities.
Prospects for Corporate Climate Change Measures
The data provided by Ibuki GW has the potential to take corporate climate change measures to the "next level."
For example, while many companies are currently working on calculating greenhouse gas emissions, most of these are "estimates" based on activity levels.
Since the data from Ibuki GW consists of actual measured values directly observing gas concentrations on Earth, once this data can be utilized, we may no longer need to rely on calculations using emission factors. It is exciting to think that it will become possible to formulate management strategies based on more concrete and scientific evidence.
The H-IIA Rocket No. 50 was launched at 1:33 AM on June 29, 2025, and Ibuki GW successfully reached its intended orbit. I also watched the real-time live stream (YouTube) of the rocket launch, and it was quite good.
References
Press Release Launch time and launch window for the Global Observing SATellite for Greenhouse gases and Water cycle (GOSAT-GW)
SatNavi https://www.satnavi.jaxa.jp/ja/project/gosat-gw/index.html
Ministry of the Environment About the GOSAT series of greenhouse gas observation satellites