China’s largest rocket apparently wasn’t big enough to launch the country’s newest spy satellite, so engineers gave the rocket an upgrade.

The Long March 5 launcher flew with a payload fairing some 20 feet (6.2 meters) taller than its usual nose cone when it took off on Friday with a Chinese military spy satellite. This made the Long March 5, with a height of some 200 feet, the tallest rocket China has ever flown.

Adding to the intrigue, the Chinese government claimed the spacecraft aboard the Long March 5 rocket, named Yaogan-41, is a high-altitude optical remote sensing satellite. These types of surveillance satellites usually fly much closer to Earth to obtain the sharpest images possible of an adversary’s military forces and strategically important sites.