atmospheric vortex at the south pole, and the detection of hydroxyl in the atmosphere. AkatsukiAkatsuki was launched on May 20, 2010, by JAXA, and was planned to enter Venusian orbit in December 2010. However, the orbital insertion maneuver failed and the spacecraft was left in heliocentric orbit. It was placed on an alternative elliptical Venerian orbit on 7 December 2015 by firing its attitude control thrusters for 1233-seconds. The probe will image the surface in ultraviolet, infrared, microwaves, and radio, and look for evidence of lightning and volcanism on the planet. Astronomers working on the mission reported detecting a possible gravity wave that occurred on the planet Venus in December 2015. Flybys Several space probes en route to other destinations have used flybys of Venus to increase their speed via the gravitational slingshot method. These include the Galileo mission to Jupiter, and the Cassini–Huygens mission to Saturn, which made two flybys. During Cassinis examination of the radio frequency emissions of Venus with its radio and plasma wave science instrument during both the 1998 and 1999 flybys, it reported no high-frequency radio waves (0.125 to 16 MHz), which are commonly associated with lightning. This was in direct opposition to the findings of the Soviet Venera missions 20 years earlier. It was postulated that perhaps if Venus did have lightning, it might be some type of low-frequency electrical activity, because radio signals cannot penetrate the ionosphere at frequencies below about 1 megahertz. An examination of Venus's radio emissions by the Galileo spacecraft during its flyby in 1990 was interpreted at the time to be indicative of lightning. However, the Galileo probe was over 60 times further from Venus than Cassini was during its flyby, making its observations substantially less significant. In 2007, the Venus Express mission confirmed the presence of lightning on Venus, finding that it is more common on Venus than it is on Earth.MESSENGER passed by Venus twice on its way to Mercury. The first time, it flew by on October 24, 2006, passing 3000 km from Venus. As Earth was on the other side of the Sun, no data was recorded. The second flyby was on July 6, 2007, where the spacecraft passed only 325 km from the cloudtops. BepiColombo flew by Venus on October 15th, 2020. During its second flyby of Venus, which occurred August 10th 2021, BepiColombo came 552 km near Venus' surface, and then afterwards left