A team of scientists from China grew mouse embryos in space. The research is the first one to successfully push past the biological barriers surrounding mammalian embryo reproduction while in orbit.

The scientists grew the mouse embryos on board the SJ-10 recoverable satellite, China's first microgravity satellite that launched on April 6. A few days after the launch, onboard images showed how the two-cell mouse embryos developed while in orbit.

Duan Enkui from the Institute of Zoology in China said that human space colonization still has a long way to go, as humans first need to analyze if survival and reproduction in space are possible.

"Now, we finally proved that the most crucial step in our reproduction - the early embryo development - is possible in the outer space," said Enkui.

The SJ-10 satellite launched with 20 experiments on board, including 6,000 mouse embryos. During the launch, the embryos were still in their early stages of development. They were kept in a nutrient-providing solution that can help them mature.

The embryos' enclosed chamber included a camera that takes images of the development progress every 4 hours. The earthbound team analyzed the photos and found that within 80 hours, several embryos developed into blastocysts, marked by complex differentiation of the cells.

The blastocysts are the first sign that mouse embryos are capable of normal development while in zero gravity. From this stage, the cells will further divide. SJ-10 will remain in orbit for several more days before reentering the planet.

Of course, the question remains if the same can be said for human embryos. Nevertheless, the research is the first in overcoming the biological hurdles that surround reproduction in space.

In comparison, NASA tried the same approach in 1996 with 49 mouse embryos on board the STS-80 spacecraft. It was the first time that scientists attempted to develop embryos in orbit. However, none of the embryos succeeded in developing in zero gravity.

"This represents an important milestone in human space exploration. One small step for mouse embryos, one giant leap for human reproduction," commented Stanford University professor Aaron Hsueh, who specializes in reproductive biology.