The engine for a new flagship small Japanese rocket burst into flames Tuesday during a combustion test, causing no injury or damage to the outside but destroying the engine and extensively damaging its test facility, officials said.

The second failure in a row raises concern about the progress of the Epsilon S rocket, whose debut flight is expected by March.

The test was conducted inside of the restricted area at Japan’s Tanegashima Space Center in southwestern Japan, and the Japan Aerospace Exploration Agency is investigating, Chief Cabinet Secretary Yoshimasa Hayashi told reporters.

An Epsilon project manager, Takayuki Imoto, told an online press conference from Tanegashina that the explosion occurred 49 seconds into the planned two-minute test, causing fire and scattering broken parts of the engine and damaging the facility.

“We are very sorry to have failed to live up to expectations,” Imoto said. He said the cause of the explosion was still under investigation. Project staff are trying to recover broken pieces to analyze and determine the cause as soon as possible to minimize the delay of the program, Imoto said.