In a Space News editorial titled “Cancel the GX” [Nov. 30, page 18], erroneous information was stated as fact that we believe needs correction. GX refers to Japan’s Galaxy Express launch vehicle program currently being developed, with assistance, to service the medium-class market. Japan is partnering with United Launch Alliance to use an Evolved Expendable Launch Vehicle booster launching from U.S. soil, where there are no launch restrictions for fishing season. In the future, GX will launch from a new restriction-free site in Japan as well.

The editorial stated the program should be canceled due to GX launch vehicle development schedule delays and cost growth. Many of these delays, however, were the result of failures incurred by other Japanese space programs. Subsequently, funds from GX were diverted to implement corrective actions for these programs. More important, the majority of GX funding to date was provided by Japanese industry partners, not government funding.

The editorial said Japan’s development of a liquefied natural gas (LNG) propulsion system for its second stage remains a challenge. Developing a new environmentally friendly propulsion system that provides unique technology leadership for Japan will have some developmental challenges. A series of hot-firing tests conducted this summer, however, clearly demonstrated this technological challenge was solved.

With GX specifically designed to service the medium-class market, it’s not a competitor to Japan’s H-2A intermediate and heavy-launch vehicle, as the editorial stated. Since GX is designed to launch from a U.S. site, it will not incur the limited launch window restrictions noted in the editorial and currently incurred by the H-2A.

Finally, the editorial stated GX does not have a mission. We respectfully disagree. As stated in several past Space News articles, there is clearly movement to consider medium-class satellites to provide more responsive commercial services to augment larger national systems. With budget constraints, technology improvements and a growing need for Earth-observing sensors for security and science, the medium-class GX will fit this need very well. The GX also sets the stage for Japanese-U.S. cooperation for a variety of space utilization efforts, including potential use of a new low-cost upper stage by a variety of U.S. and Japanese customers.

In conclusion, the Galaxy Express program is worth funding, and it will benefit the U.S. and Japanese space industry for decades to come.


Michael C. Gass, president and chief executive officer, United Launch


Kazuaki Kama, president and chief executive officer, IHI Corp.