Two huge red flags flying at 180 km per hour over Beijing's Tian'anmen Square Thursday opened China's grand parade to commemorate the 70th anniversary of the end of World War Two.

Thousands of visitors, including 30 foreign leaders on the Tian'anmen Rostrum, applauded when the 9-meter-long national flag and 7.5-meter-long Chinese army flag hanging from two helicopters flew overhead.

But the spectacle would have been impossible without China's advanced space technology.

"The flag would have been torn into pieces at such a speed," said Jiang Changhong, an expert with Beijing Institute of Space Mechanics and Electricity, "as it had to withstand winds as powerful as a typhoon."

After numerous experiments, scientists discovered that they could do it using same special material used to make the Shenzhou spacecraft parachute.

"The special material enabled the parachute to bear up to 3 tonnes and be folded into a big suitcase." Jiang said it was also light, easily carried and durable.

Scientists also used a special paint that made the flag brighter and more waterproof to prevent fading in the elements.

Each flag was made up of seven pieces, requiring master sewing skills.

And while the cost was high, scientists said, the quality and peace of mind were priceless.