15 research outputs found
Antimatter applied for Earth protection from asteroid collision
An Earth protection system against asteroids and meteorites in colliding orbit is proposed. The system consists of detection and deorbiting systems. Analyses are given for the resolution of microwave optics, the detectability of radar, the orbital plan of intercepting operation, and the antimatter mass require for totally or partially blasting the asteroid. Antimatter of 1 kg is required for deorbiting an asteroid 200 m in diameter. An experimental simulation of antimatter cooling and storage is planned. The facility under construction is discussed
Continuous Operation of Micro Plasma Thruster “Microwave Engine”
A low-power, microwave-discharge type electrostatic thruster named “microwave engine” has been developed for applications to 50 kg-class satellites at Advanced Technology Institute Ltd. (ATI) in Hokkaido, Japan. A prototype of the engine was manufactured, and its performance and random vibration tests have been reported in previous papers. An endurance test followed, and showed no failure in the engine after 400 hours of operation
Status of Nanosatellite Development for Mothership Daughtership Space Experiment by Japanese Universities
We have begun the feasibility study to build a small satellite in the 3kg mass range and in the power range less than 30W since October in 1998, sponsored by National Space Development Agency of Japan (NASDA). This satellite installs three reaction wheels for an attitude control and camera which will demonstrate optical navigation experiment by using image processing. The BBM design status is described in this paper. The components such as a small reaction wheel, electric flash and onboard computer were built. Mothership - daughtership technology and formation flying experiments are planned. New electric propulsion is being developed for small satellite
Microgravity experiments of nano-satellite docking mechanism for final rendezvous approach and docking phase
Advanced System of Micro Satellite for Hyperspectral Remote Sensing Mission
The Space-Science Industries Program has been performing investigations for the Micro-satellite and Hyperspectral remote sensing missions.The Earth Observation Micro-satellite “TAIKI” is a 50kg satellite which has low-cost and small bus-subsystems for advanced remote sensing missions.This bus-subsystem will be developed and manufactured products.The TAIKI is characterized by a small Hyperspectral sensor “HSC-III” which is targeted at the performances of 30m of ground sampling distance and 61 spectral bands in VINR (Visible and Near Infrared).The advanced remote sensing data such as Hyperspectral data are large volume so the downlink uses the laser communication of 100Mbps.The terrestrial laser communication has already been successfully experimented.In addition, HSC-III optics instrument which mainly consists of spectrometer, detector and on-board calibration systems has been developed in 2008.This paper reports the small bus-subsystem including the laser communication systems for the TAIKI and Hyperspectral sensor instrument
Hyperoxidized Peroxiredoxin 2 Is a Possible Biomarker for the Diagnosis of Obstructive Sleep Apnea
Peroxiredoxin (Prx) 2 in red blood cells (RBCs) reacts with various reactive oxygen species and changes to hyperoxidized Prx2 (Prx2-SO2/3). Therefore, Prx2 may serve as an indicator of oxidative stress in vivo. This study aimed to analyze Prx2-SO2/3 levels in clinical samples to examine whether the oxidation state of Prx2 in human RBCs reflects the pathological condition of oxidative stress diseases. We first focused on obstructive sleep apnea (OSA), a hypoxic stress-induced disease of the respiratory system, and investigated the levels of Prx2-SO2/3 accumulated in the RBCs of OSA patients. In measurements on a small number of OSA patients and healthy subjects, levels of Prx2-SO2/3 accumulation in patients with OSA were clearly increased compared to those in healthy subjects. Hence, we proceeded to validate these findings with more samples collected from patients with OSA. The results revealed significantly higher levels of erythrocytic Prx2-SO2/3 in patients with OSA than in healthy subjects, as well as a positive correlation between the severity of OSA and Prx2-SO2/3 levels in the RBCs. Moreover, we performed a chromatographic study to show the structural changes of Prx2 due to hyperoxidation. Our findings demonstrated that the Prx2-SO2/3 molecules in RBCs from patients with OSA were considerably more hydrophilic than the reduced form of Prx2. These results implicate Prx2-SO2/3 as a promising candidate biomarker for OSA