Ten-year-old Claudia Cowen stood nervously in front of the microphone. A disembodied woman's voice filled the room: "This is WH6PN Honolulu calling for a scheduled contact. Do you copy?"

The message was repeated three times more as a packed Michael Sobell Sinai School hall hung on every word. Then, suddenly, through noisy static, came the voice they were waiting to hear - and a bit of history was made.

The hushed hall heard the voice of Jewish astronaut Greg Chamitoff, currently circling the world in the International Space Station: "WH6PN, this is station NSA1SS, receiving you loud and clear."

The nervous pupil asked: "This is Claudia Cowen. What training do you do to become an astronaut?"

Greg Chamitoff replied: "Hi, Claudia, and welcome on board everyone at Sinai School. I want to say hello to my cousins. It's great to have you on board the space station today."

Thus began arguably the most exciting 10 minutes in Europe's biggest Jewish primary school - the first school in London to speak directly to an astronaut in space.

In May, two of the Kenton-based school's younger pupils, Jessica and Amelia Diamond, six and four, were taken by their parents, Karen and Julian, to Florida, to watch the launch of the space shuttle. For on board was Mrs Diamond's first cousin, Greg Chamitoff.

Mrs Diamond said: "Since then, Julian has kept track of the space station on the internet. He noticed in June that the National Aeronautical and Space Administration (Nasa) had organised a link-up between Greg and a radio ham.

"We have been in email contact with Greg, so Julian asked him if he would be interested in speaking to the school. He said it was great and to get in touch with Nasa to organise it. So we did."

Once Nasa said yes, the Diamonds got in touch with Sinai head Vivienne Orloff to begin organising the link-up.

Deputy head Joanna Walker explained that the timing of the link-up was very specific. "The space station orbits the Earth every 90 minutes and we booked a 10-minute slot at 12.34pm when it was directly above Hawaii. Originally it had been booked the previous week, but it was called off because of Hurricane Ike," said Mrs Walker.

The school's Year Five, who are studying the planets, and Year Six, who are revising them, were in the hall along with many of the teaching staff. "As Year Five is studying it now, they got to ask the questions," said Mrs Walker.

"There was huge excitement in the hall. It was touch and go whether or not we would make contact until the last minute. You could feel the tension as the radio operator in Honolulu tried to make contact, and there was great relief when she got through."

The children had 20 one-line questions written down and managed to get through 15 before the static returned and the connection came to an end.

They asked how an astronaut can observe religion in space; what was the purpose of his trip; what the food was like; what the Earth looks like from space - and, inevitably, how astronauts go to the toilet. (Carefully, apparently.)

Mrs Walker said: "We thought they might get through 10 questions so they did extremely well to get in so many."

Mrs Diamond added: "It was unbelievable. It was almost as exciting as being at the launch, because this was for the children. You could see in their faces that they couldn't believe they were talking to him." She revealed that her cousin had also given her a surprise.

"On my birthday in July, the phone rang and I got a birthday phone-call from my cousin in space. How cool is that?"