Japanโ€™s Akatsuki Climate Orbiter muffed a critical engine firing Sept. 14, dimming the hopes of scientists that the error-prone satellite will be able to achieve an orbit around Venus conducive to observing the planetโ€™s weather patterns.

โ€œThe results mean that we might have enough propulsion for Akatsuki to enter some kind of Venus orbit, but not the correct orbit, required. Itโ€™s possible that it might be able to do some science, but we donโ€™t know yet,โ€ Eijiro Namura, a spokesman for the Japan Aerospace Exploration Agency (JAXA), said Sept. 16.

The $300 million Akatsuki probe failed to enter Venus orbit in December 2010 due to the early shutoff of its orbit maneuver engine.

JAXA has been conducting a series of increasingly ambitious test fires in preparation for making a second attempt at orbital insertion in December 2015.

A critical firing of the engine Sept. 14 yielded disappointing results, with the engine developing only one-eighth of the required thrust, according to JAXA.