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European researchers will be allowed to propose experiments using laboratory animals for the International Space Station, following an 11 to 1 vote last month by European Space Agency (ESA) partners in the project.

Learning experience: a Neurolab crew member is shown how to operate one of its rodent habitats. Credit: NASA

The move follows acceptance by Germany, the largest European contributor to the space station, that animals are essential for certain experiments in space. Work with higher mammals such as dogs and primates will still be forbidden. But researchers will be able to experiment with rodents, which ESA had prohibited in the past.

Many European scientists had seen the space agency's unwritten rule against rat and mice studies as a competitive disadvantage when proposing experiments in developmental biology, muscle deterioration and other areas of space research (see Nature 391, 733; 1998). The other major station partners — the United States, Japan, Canada and Russia — have no such prohibition.

Germany's long opposition to animal studies has been the main factor behind ESA policy. But the agency's life science working group, which gives advice on space biology research, lobbied over the past two years to have the ban removed.

“The real work was done country by country,” says Didier Schmitt, head of life science research at ESA's ESTEC research centre in the Netherlands.

The German space agency DLR concluded in February that “animal experiments are unavoidable” for certain kinds of space research, says Günter Ruyters, head of the agency's life and microgravity sciences programme.

The German science ministry agreed, but stipulated that such experiments should be conducted only when there is no alternative, and when the scientific return is high. That cleared the way for Germany to vote ‘yes’ at a meeting last month of ESA space station partners to consider allowing animal studies.

Sweden cast the only ‘no’ vote, out of concern over possible political damage to the space station project. Per Magnusson of the Swedish National Space Board says European partners are taking a risk by approving experiments that a large fraction of the population opposes. Ruyters acknowledges that animal experiments are still “a very touchy issue” in Germany, where an already strong animal rights movement is gaining ground (see Nature 397, 461; 1999).

ESA's Schmitt says there is now an “urgent need” for an international committee to set ethical guidelines for animal experiments in space. That topic will be on the agenda at an international space life science working group meeting in Italy next week, which will also include a workshop on habitat design for rodents in microgravity.

Biologists learned hard lessons about how not to design such a habitat after dozens of newborn rats — more than half of those on board — died on last year's Neurolab Space Shuttle mission (see Nature 393, 4; 1998).

Before the flight, a plan to build a special cage for Neurolab was scrapped, and engineers modified an earlier design that had successfully housed adult rats, but not newborns. Problems with the young rats moving around on smooth (as opposed to mesh) surfaces in the cage in weightlessness may have contributed to the high death rate.

Visibility into the cage was also limited, which made it difficult to monitor the animals. A panel set up by the US space agency NASA and the National Institutes of Health to consider developmental biology research in space recommends that communications be improved among cage designers, scientists, astronauts and NASA managers to avoid such mishaps. And animals may need to be monitored more closely in orbit — either by astronauts or by ground investigators through a video system — to ensure their health.

But such problems should be surmountable, according to the panel. Despite the loss of the Neurolab rats, the panel concludes that scientific results from the flight clearly demonstrate that complex animal studies are possible in space.