Astronauts in space just got a tasty delivery（投递）. It came from students in Melbourne, Australia. They are starting a test on space yogurt. The 40 high school students are working with the scientists from Swinburne University. Together, they are studying bacteria（细菌）that make yogurt.
A rocket delivered the bacteria to the International Space Station（ISS）. The students are hoping to learn what will happen to bacteria on the ISS.
"On Earth, you feel gravity（重力）. But this does not happen on the ISS." said Mike, who studies at Swinburne University. They want to know what conditions the astronauts need to make yogurt.
But how exactly do bacteria make yogurt? It all starts with the bacteria that live in milk. These bacteria eat the sugar in milk. Then they make a kind of acid（酸）. The acid turns the milk thick and sour.
The students filled 36 boxes with milk and bacteria. Then, they sent the boxes to the ISS. The astronauts will use different kinds of milk and bacteria and run tests for 6 weeks. Then, they will send the yogurts back to Australia.
The students will study the yogurts when they come back to Earth. They want to look at the nutrients（营养物）in the yogurts.
"We even might get to taste them. It is pretty exciting" Linda, a student at Swinburne University, said. The students also want to compare the space yogurts to the ones they grow on Earth.
Dr. Sara Webb works with the students on this project. She hopes they can send astronauts to space with bacteria and milk. Then they can easily make their own tasty yogurts in space.
