KOROLYOV (Moscow region), May 21 (RIA Novosti) - A technical glitch caused the ballistic landing of Russia's Soyuz TMA-11 capsule in April this year, the head of the Federal Space Agency's department for manned flights said on Wednesday.

On April 19, the Soyuz-TMA-11 capsule, carrying U.S. astronaut Peggy Whitson, Russian flight engineer Yuri Malenchenko, and Korean bioengineer Yi So-yeon from the International Space Station, made a bumpy re-entry, landing 420 km (260 miles) off-target in the steppes of northern Kazakhstan.

"The cause has been established," said Alexei Krasnov. "The equipment bay failed to separate from the capsule in the designated time, causing a ballistic landing of the spacecraft."

The spacecraft should have landed to the north of the town of Artalyk, but it came down near the Kazakh-Russian border, to the southeast of the Russian town of Orsk, due to a "ballistic re-entry."

During ballistic re-entry, the capsule follows a much steeper descent trajectory, and the crew is subjected to much higher G-forces than normally experienced.

However, the official stressed that a ballistic re-entry, although uncommon, is not classed as an emergency landing.

In October 2007, a Soyuz capsule carrying Malaysia's first astronaut also landed off course and in 2003, the crew had to wait for several hours until rescuers located them.