"We have found that the orbiter was not injected into the planned orbit as a result of orbit estimation," Japan Aerospace Exploration Agency (JAXA) officials said in a statement released Wednesday.
But the craft is still in working order, and JAXA officials stress that they are in contact with the probe.
Although Akatsuki does not have enough fuel left to turn around, it has settled into orbit around the sun. That means JAXA can try again for orbital insertion around Venus when Akatsuki returns to the planet in six years.
JAXA officials said in a press conference today that the likelihood of a successful insertion then is "high."
Still a Chance for Venus Probes to Collaborate
Akatsuki ("dawn" in Japanese) was supposed to have been the first Japanese spacecraft to orbit another planet. A 1998 JAXA mission to place a probe around Mars also failed. (Related: "Japan's 'Falcon' Spacecraft Returns—Asteroid Dust on Board?")
The first signs of trouble with the Venus mission appeared Monday evening, eastern time, when Akatsuki arrived at Venus and a planned 22-minute communications blackout lasted for an hour and a half.
JAXA confirmed today that the spacecraft had not slowed down enough to settle into orbit around Venus and had instead sped past the planet. JAXA has set up a team to investigate the cause of the failure.
Launched in May, Akatsuki was designed to orbit Venus for two years and study the sweltering planet's weather using a suite of five cameras. (See Venus pictures.)
The craft was meant to complement instruments aboard Venus Express, a European Space Agency (ESA) probe that is currently in orbit around Venus. (Related: "Venus Craft Reveals Lightning, Supports Watery Past.")
A series of observations that required Akatsuki and Venus Express to work together had been in the works for more than a year, but those plans will now have to be rethought, said Venus Express project scientist Håkan Svedhem.
For example, scientists had hoped to track atmospheric features for extended periods of time—something that is not possible with a single satellite.
"We are of course very disappointed, because everybody looked forward to these joint operations," Svedhem said. "Of course, this won't be possible now ... and it's really unfortunate."
The two spacecraft might still be able to work together if Akatsuki's next attempt to enter orbit is successful. Venus Express's mission was recently extended to 2014, and it's possible it could be extended again.
"If everything works fine, we could even survive until [Akatsuki] comes back next time," Svedhem said.
"That's a long time in the future, but we're not ruling that out."