The Japanese space agency has deduced that a faulty engine valve was the reason the Akatsuki spacecraft did not go into orbit around Venus as planned on December 6, 2010. According to the Daily Yomiuri, a malfunctioning valve in the probe’s fuel pressure system caused the engine to function abnormally. The valve is a standard component in many previous space missions, JAXA said, and it was not modified at all for Akatsuki.
Earlier, JAXA reported that Akatsuki’s engine did perform a burn to slow it down, but 152 seconds into the burn the fuel pressure dropped and the probe became unbalanced. Because the retrofiring of the rockets failed to slow down the probe enough for Venus to capture it, it was unable to enter into orbit around the planet, and then went into safe mode.
The JAXA investigation identified five possible causes of the mishap and all stemmed from the valve’s failure to open. JAXA also said they intend “to further investigate why the valve did not open, and how much damage was caused to Akatsuki’s thruster nozzle, by conducting tests that also will indicate whether the probe will be able to go into orbit around Venus when it comes near the planet six years from now.”
After Akatsuki’s launch in May, the functions of its main engine were tested in June. However, the engine was fired for too short a time to detect the problem with the valve, JAXA said.
The findings were presented to the Education, Culture, Sports, Science and Technology Ministry’s Space Activities Commission.
Source: Daily Yomiuri