While acknowledging the Dec. 7 maneuver is risky, Imamura said “we do not think of this operation as very dangerous.”The smaller thrusters aboard Akatsuki generate just 5 pounds of thrust, a fraction of the power provided by the probe’s main engine. Even with four of the rocket jets operating — there are two sets of four pointing forward and aft from Akatwuki’s main body — the secondary thrusters do not have the energy to put the spacecraft into its originally planned orbit.Instead, Akatsuki will go into a higher orbit than intended, and the change has some impact to the craft’s science mission, Imamura said.Rather than taking about 30 hours to complete a lap around Venus — as was planned after the botched 2010 arrival — Akatsuki will complete one orbit every 15 days. Another maneuver in March will nudge Akatsuki closer to Venus, placing the probe in a nine-day orbit.Imamura said three of Akatsuki’s five cameras were recently switched on for the first time in more than four years, and they appeared to be in good health. The other two cameras will be activated once the probe is in orbit at Venus.Engineers plan to instruct Akatsuki to turn its cameras toward Venus immediately after the insertion burn in a bid to collect “contingency” imagery of the planet in case the maneuver fails.
Tiny thrusters to do heavy lifting as Japanese probe approaches Venus<snip>
VOI burn will be start at December 6, 23:51 (UTC).
10 minutes to the critical 20 minutes long VOI burn; spacecraft conditions are nominal as it slipped into Venus' shadow some minutes ago.