JAXA’s mission are far more ambitious than its budget would suggest.
The agency has no manned missions and operated on 339 billion yen (four billion dollars) this fiscal year — less than one-tenth of the NASA budget, and less than half the annual cost of Europe’s space programme.
Space officials are now fighting back against any further government belt tightening as they plan a follow-up probe to Hayabusa in 2014, which would explore an asteroid named 1999JU3.
JAXA says it hopes its probe would find "organic or hydrated materials" on the asteroid, and to find out whether "there is any relation to life on Earth".
The science and technology minister, Yoshiaki Takagi, last month vowed that "we will strive to secure the budget so that we can offer maximum support" for the Hayabusa-2 project.
His ministry has requested a 100-fold boost to the research budget for Hayabusa-2 to some three billion yen next year.
Prime Minister Naoto Kan sounded sympathetic when he said last month that Japan "must be committed" to space projects.
In future the space agency may take on an even more ambitious task.
An expert panel advising the minister for space development has called for sending a wheeled robot to the Moon in five years — having first considered a two-legged humanoid, which was rejected because of the Moon’s bumpy surface.
It envisions building the first lunar base by 2020, which could be staffed by advanced robots, as a key stepping stone for Japan’s space exploration, a field where Asian competition is heating up.
"It is extremely important to probe the Moon… as we now see the dawn of ‘the Age of Great Voyages’ in the solar system," the panel said, pointing out that "China, India and other countries are aiming to probe the Moon."
The government’s Strategic Headquarters for Space Policy believes a successful space programme does much to lift Japan’s profile on Earth.
"Our country’s space technology, its achievements and human resources are truly diplomatic resources that would boost our influence and position in the international community," it said in a policy report.
"We will promote them as a source of our soft power."