Wednesday, August 13, 2008

Akebono

1989-016A

The EXOS D auroral research satellite was launched on 1989 Feb 21 by Mu-3S-II from Kagoshima. It was named Akebono (`Dawn'). The satellite was placed in parking orbit at an inclination of 75 deg, and a small KM-D kick motor ignited to deliver the satellite to its final elliptical orbit with an apogee of 10500 km. The seven plasma experiments studied particle acceleration mechanisms in the aurora.

The satellite has 4 30-m wire antennae and two long magentometer booms. It is 1.0m high 1.4m dia octagonal box with 3.8m span across 4 solar panels, and 295kg in mass on orbit.

KM-D is 1.2m long 0.63d with a mass of 244 kg full 22 kg empty. It contains a spring used to expand the exit cone, about 2.4 kg 0.6?l 0.5d, which is ejected at 1.5m/s. The 0.5 kg, 0.1 x 0.05m igniter is also ejected on ignition.

Mass of EXOS-D and KM-D was 539 kg full 317 em, M-3B assumed to be 3595 f 305 em, dV = 2875 ln ( 4134 / 844 ) = 4568 m/s. I assume that the stage 1 and 2 orbits involved doglegs similar to those on EXOS-C.


Akebono 
 

DateTimeEventOrbit  

1989 Feb 21  2330  Launch by Mu-3S-II  KAG 
  T+0:40 SOB sep 
  T+1:24 Stage 1 cutoff, sep 
  T+1:26 Stage 2 start 
  T+2:36 Stage 2 cutoff, coast 
  T+2:35 Fairing sep
  T+5:09 M3B burn, 277 km  
 2336 T+6:36? M3B burnout 
 2336  T+6:40? M3B sep  267 x 527 x 74.6 
  KM-D nozzle extensor jettisoned 
 2336  T+6:50 KM-D burn 38s  
 2337  T+7:28 KM-D burnout   
  T+7:44 KM-D sep  276 x 10467 x 75.1 
 2337 T+7:56 yo-yo despin 
   211.15 275 x 10461 x 75.1 
1989 Feb 22  0030  Solar panels deployed 
1992   End of ATV data 
1994   End of LEP data 
1999   Still active 
2004 Jan   RDM still active 
2008 Apr 23  0659  End of operations (ST/SG/SER.E/766) 

Payload:

  • 30-m wire antennae (4)

  • RDM Radiation monitor

  • MGF Magnetic field detector with 5-m mast

  • EFD Electric Field detector

  • VLF VLF wave detectors with 3-m mast.

  • PWS Plasma wave detectors and sounder

  • LEP Low Energy Particle detectors

  • SMS Suprathermal ion mass spectrometer

  • TED Thermal electron detectors

  • ATV visible and UV Auroral television

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