Continuous path control of space manipulators mounted on OMV

Theoretical analysis on the formulation of kinematics for the manipulator mounted on a satellite is presented. Firstly, to solve the inverse kinematics, the authors define a new generalized Jacobian matrix, and utilizing this generalized matrix, the problem can be treated analytically. Secondly, the authors verify the method proposed here in the simulation study. Thirdly, they also discuss on the several points which are indispensable for further investigations.     

Cosmic ray H/H ratio measured from BESS in 2000 during solar maximum

The Balloon-borne Experiment with a Superconducting Spectrometer (BESS) was flown from Lynn Lake, Manitoba, Canada in August, 2000, during the maximum solar modulation period, with an average residual atmospheric overburden of 4.3 g/cm². Precise spectral measurements of cosmic ray hydrogen isotopes from 0.178 GeV/n to 1.334 GeV/n were made during the 28.7 h of flight. This paper presents the measured energy spectra and their ratio, ²H/¹H. The results are also compared with previous measurements and theoretical predictions.     

Lightning Detection by LAC Onboard the Japanese Venus Climate Orbiter, Planet-C

Lightning activity in Venus has been a mystery for a long period, although many studies based on observations both by spacecraft and by ground-based telescope have been carried out. This situation may be attributed to the ambiguity of these evidential measurements. In order to conclude this controversial subject, we are developing a new type of lightning detector, LAC (Lightning and Airglow Camera), which will be onboard Planet-C (Venus Climate Orbiter: VCO). Planet-C will be launched in 2010 by JAXA. To distinguish an optical lightning flash from other pulsing noises, high-speed sampling at 50 kHz for each pixel, that enables us to investigate the time variation of each lightning flash phenomenon, is adopted. On the other hand, spatial resolution is not the first priority. For this purpose we developed a new type of APD (avalanche photo diode) array with a format of 8×8. A narrow band interference filter at wavelength of 777.4 nm (OI), which is the expected lightning color based on laboratory discharge experiment, is chosen for lightning measurement. LAC detects lightning flash with an optical intensity of average of Earth’s lightning or less at a distance of 3 Rv. In this paper, firstly we describe the background of the Venus lightning study to locate our spacecraft project, and then introduce the mission details.     

Enhancement in low-energy region ofa proton flux associated with interplanetary shock waves

We study time evolution of an energy spectrum of a proton flux in the range of 47 – 4750 keV for the energeticparticle event occurred on 255 DOY in 1999, which we consider as one of typical diffusive acceleration events associated with interplanetary shocks and irrespective of large X-ray solar flares. Fast enhancement during evolution is found in the range of less than about 0.5 MeV. Our previous numerical simulations using Stochastic Differential Equation method could not show this behavior, although we obtained results showing a power law energy spectrum, which suggesting that energetic particles are accelerated diffusively by shock waves, the first-order Fermi acceleration. We consider that less than 0.5 MeV protons need to exist to explain behavior of the observational energy spectrum and perform numerical simulations in order to investigate proper injection models for this event.     

The pGAPS experiment: An engineering balloon flight of prototype GAPS

The General Anti-Particle Spectrometer (GAPS) project is being carried out to search for primary cosmic-ray antiparticles especially for antideuterons produced by cold dark matter. GAPS plans to realize the science observation by Antarctic long duration balloon flights in the late 2010s. In preparation for the Antarctic science flights, an engineering balloon flight using a prototype of the GAPS instrument, “pGAPS”, was successfully carried out in June 2012 in Japan to verify the basic performance of each GAPS subsystem. The outline of the pGAPS flight campaign is briefly reported.