A baffle system for an airglow photometer, which will be on board the Korea Sounding Rocket-III(KSR-III), has been designed to suppress strong solar scattered lights from the atmosphere below the earth limb. Basic principles for designing a baffle system, such as determination of baffle dimensions, arrangement of vanes inside a baffle tube, and coating of surfaces, have been reviewed from the literature. By considering the constraints of the payload size of the KSR-III and the incident angle of solar light scattered from the earth limb, we first determined dimensions of a two-stage baffle tube for the airglow photometer. We then calculated positions and heights of vanes to prohibit diffusely reflected lights inside the baffle tube from entering into the photometer. In order to evaluate performance of the designed baffle system, we have developed a ray tracing program using a Monte Carlo method. The program computed attenuation factors of the baffle system on the order of 10 -6 for angles larger than 10°, which satisfies the requirements of the KSR-III airglow experiment. We have also measured the attenuation factors for an engineering model of the baffle system with a simple collimating beam apparatus, and confirmed the attenuation factors up to about 10 -4. Limitation of the apparatus does not allow to make more accurate measurements of the attenuation factors.

It is realized that the extraterrestrial matter is in ionized state, plasma, so the matter of this kind behaves as not expected because of its sensitiveness to electric and magnetic fields and its ability to carry electric currents. This kind of subtle change can be observed by an instrument for the magnetic field measurement, the magnetometer usually mounted on the rocket and the satellite, and based on the ground observatory. The magnetometer is a useful instrument for the spacecraft attitude control and the Earth's magnetic field measurements for the scientific purpose. In this paper, we present the preliminary design and the test results of the two onboard magnetometers of KARl's (Korea Aerospace Research Institute) sounding rocket, KSR­III, which will be launched during the period of 2001-02. The KSR-III magnetometers consist of the fluxgate magnetometer, MAG/AIM (Attitude Information Magnetometer) for acquiring the rocket flight attitude information, and of the search-coil magnetometer, MAG/SIM (Scientific Investigation Magnetometer) for the observation of the Earth's magnetic field fluctuations. With the MAG/AIM, the 3-axis attitude information can be acquired by the comparison of the resulting dc magnetic vector fields with the IGRF (International Geomagnetic Reference Field). The Earth's magnetic field fluctuations ranging from 10 to 1,000 Hz can also be observed with the MAG/SIM measurement.