› 2016 › 04 › 05_nakamura_akatsuki... · akatsuki returns to venus05-04-2016 · akatsuki...
Post on 27-Feb-2020
5 Views
Preview:
TRANSCRIPT
AKATSUKI RETURNS TO VENUS
MASATO NAKAMURA
VENUS AS THE MORNING STARJANUARY 1, 2016
Akatsuki is now orbiting this planet …
PLANET-C the Venus Climate Orbiter
Near IR camera 1 λ=0.9, 0.97, 1.01µm
Near IR camera 2 λ=1.65, 1.73, 2.02, 2.26, 2.32µm
Longwave IR camera λ=8-12µm
UV camera λ=283, 365nm
Lightning and Airglow cameraλ=777, 551, 558nm
Science goal : Atmospheric dynamicsLightning, Cloud physics, Active Volcano, Geological SurveyLaunch : Summer 2010Arrival : December, 2010 -> 2015
3-D meteorological observation by multi-wavelength cameras
Near-IR UV
LaunchMay 21st 2010 6:58:22JST
7:25Spacecraft separation
Start of Occultation 08:50:43JST
End of Occultation09:12:03JSTNo telemetry
2010/12/7Nominal case: 9:01:00JST OME stop Actually 8:51:38JST
OME start2010/12/7. 08:49JST
Orbit Plan
10:26JST Spacecraft was discovered
5
Failure of VOI on December 7th, 2010
Venus
Broken OME(500N)
RCS (23N x8)thrust
Reaction Control System should be used for orbital maneuver instead of broken OME
7
ORBITAL MANEUVER(2011-2015)
-2
-1.5
-1
-0.5
0
0.5
1
1.5
2
-2 -1.5 -1 -0.5 0 0.5 1 1.5 2
Venus
Earth
Akatsuki
AkatsukiEvents
EarthEvents
VenusEvents
AkatsukidV
EarthdV
VenusdV
J2000Eclipticcoordinate
x108km
太陽
あかつき
金星
地球
2015/12月2015/1/1
2015/2月
2015/5月 2015/7月
2015/8月2015/1/1DV4(2015/7月)
近日点(2015/2月,8月)
遠日点(2015/5月,12月)VOI-R(2015/12月)
2015/1/1
2015/2月
2015/5月
2015/8月
2015/7月
DV42015/07 ΔV 89m/s
Last perihelion 2015/8/30
• Orbital maneuver (DV1-3)was done in 2011 to meet VENUS on 22 November, 2015• Orbit analysis revealed that the spacecraft would crash with Venus very shortly• July 2015 additional maneuvers (DV4-1,2,3) was done to correct the orbit to meet
Venus on 7 December, 2015
3
VOI-R1Geometry(Suncenter)
0.55�����
Venus
Akatsuki
EarthdV
AkatsukidV
VenusdV
Venus1daystep
Akatsuki1daystep
J2000Eclipticcoordinate
x108km
-2
-1
0
1
2
�� �� � � �
Earth
Akatsuki
Venus
EarthdV
AkatsukidV
VenusdV
J2000Eclipticcoordinate
x108km
Sun
EarthNov9,2015
Planet-C
Venus
Dec7,2015
Nov9,2015
Dec7,2015VOI-R1
Dec7,2015VOI-R1
Dec1,2015
[Suncentered]
Dec6,2015
AttitudechangeforVOI-R1
Red:Venus,Green:Planet-CTicks:everyoneday
VOI-R1 ON 7 DECEMBER, 2015
Doppler monitor
10
First light
SUMMARY
11AKATSUKI returns to Venus,Nakamura et al., submitted to Earth, Planets and Space, 2016
• Akatsuki becomes the 1st Japanese probe orbiting other planet 15 years after the proposal to ISAS.
• All the sub systems are working almost perfectly.
• Akatsuki will send data over two years to us, and it means that Japan’s exploration enters the new era when Japan deliver the continuously changing planet’s data to the world.
top related