The Japanese military looks likely to be allowed to operate in space for the first time, in response to growing domestic concern over the threat posed by North Korea and China.
North Korea now has a ballistic-missile system capable of striking Japan and the west coast of the US, and China rattled nerves in the region last year by destroying one of its orbiting weather satellites using a ground-based missile.
Japan has responded by developing an anti-missile capability of its own, based on US technology.
In December 2007, it successfully destroyed a missile in flight over the Pacific Ocean using a ship-launched interceptor. It has also built and launched a number of spy satellites to monitor the region.
Until now, the programme has been kept under civilian control because of Japanese laws governing the use of space. That could soon change, following a decision by a committee of Japanese MPs to revise the legislation to give the military access to space.
The new bill will allow the Japanese defence ministry to deploy satellites for non-aggressive missions, including communications, surveillance and weather observations, as other countries' military agencies do. The use of weapons in space will still be banned under Japanese law.
"This is a major change in Japanese space policy," says John Logsdon, a space policy expert at George Washington University in Washington DC. It will also dramatically raise the profile of the Japanese space programme, he says.