伊藤 琢博

© 2018 Univelt Inc. All rights reserved. On February 3, 2018 at the JAXA Uchinoura Space Center, JAXA experimented SS-520 No. 5 launch with a 3U sized cube sat called TRICOM-1R aboard. After liftoff, flight of SS-520 No. 5 proceeded normally. Around 7 minutes 30 seconds into flight, TRICOM-1R separated and was inserted into its target orbit. And the launcher became the world’s smallest class satellite launcher. SS-520 launch vehicle is one of sounding rockets operated in JAXA/ISAS, and originally two-stage rocket. In this experiment, to make this vehicle put a satellite into orbit, the third stage motor is added. And this sounding rocket has four tail fins for spin stabilization, but usually don’t have an attitude control system during the flight. But in this mission, it is needed to control its attitude to ignite second and third motor toward horizontal after first stage burn-out. The gas jet system is installed into between the first stage and the second stage of the vehicle as a unique active attitude control system. The gas jet system can control the spin axis direction and the spin rate of the vehicle during the coasting fight. Because of this constraint, the apogee altitude after the burn out of the first stage motor almost correspond with the perigee altitude of the elliptical orbit. In this mission, the sounding rocket-based Nano launcher is planned to put TRICOM-1R into the elliptical orbit. Its targeted apogee altitude is about 1,800 km and its perigee altitude is about 180 km. Because the perigee altitude is relatively low, the orbit life is very short. One of the mission requirements is to make the vehicle an orbit insertion with more than 30 days orbital lifetime. The vehicle error or the environment error deeply affect the achieved trajectory. These errors must be small enough to put TRICOM-1R into orbit. This paper discusses about the trajectory design on how to manage the sounding rocket into a satellite launching vehicle, the effect of the orbital distribution depending on the various errors, the flight safety analysis, and finally flight performance evaluation.

© 2016 Institute of Electrical and Electronics Engineers Inc.. All rights reserved. JAXA has successfully launched the SS-520 No.5 with micro-satellite 'TASUKI' on February 3rd 2018 at Kagoshima Space Center at Uchinoura in Japan. The base-line of the SS-520 sounding rocket is a two-stage rocket which has a capability for launching an 80kg payload to a maximum altitude of about 1000 km. and spun by 4 tails for attitude stability. Enhanced SS-520 No.5 is a three-stage rocket for the smallest-class launch system in the world, which has the orbit injection capability of a micro-satellite of a few kilograms by adding a high-performance third solid motor and advanced rhumb-line control system. Total length of the rocket is about 9.6 meters, the gross weight is 2.6 metric tons, and the reference diameter is 0.52 meters. The `TASUKI` has some experimental purposes for 'store & forward' communication on orbit and earth observation by some commercial cameras and others. The key points of this launch was to newly develop the rhumb-line control system, compact and high performance avionics, some lightweight structures, and the third motor made of CFRP. The rhumb-line control system established an attitude maneuver of about 70 degrees to inject the 'TASUKI' into the orbit of perigee altitude 180km and apogee altitude 2000km. This rhumb-line control system has some high performance functions. It has an angular momentum control function with high attitude maneuver rate, and the suppression function of nutation angle generated by the disturbance of RCS thruster injection during high spin rate of about 1.6Hz. We performed a Motion Table (M/T) Test 'Real-time Simulation Test' with flight models of the avionics for verification of the rhumb-line control design and the soft-wear in the loop test for verification of the flight soft-wear. An active nutation control (ANC) function is also equipped for the reduction of the residual nutation angle after the rhumb-line control. We show the outline of the rocket system and developments, especially the rhumb-line control system with the compact avionics system. Finally flight results are showed and we show one of the future enhanced ideas of SS-520 No.5 type launcher for 10 kilograms class satellite.

© 2017 International Astronautical Federation IAF. All rights reserved. This paper proposes a guidance law that is suitable for the terminal phase of a precise lunar landing. During this phase, as a spacecraft continues its vertical descent for a few minutes until touchdown, such preparatory actions for landing as vertical braking, terrain relative navigation, position correction maneuver, and obstacle detection and avoidance must be taken continuously or simultaneously. The developed guidance law can produce a vertical descent trajectory with low calculation resources, where the fuel consumption and maneuver time for horizontal position correction are minimized. Moreover, the developed law is designed to output two indexes ( and ) that indicate the feasibility of vertical braking and horizontal position correction prior to trajectory computation, in order to prevent any divergence. The simulation results verify that the proposed law performs effectively in evaluating the feasibility of a trajectory based on the discriminants and , in addition to computing trajectories for minimizing fuel consumption and maneuver time when both discriminants are greater than or equal to zero.

Copyright © 2017 by the International Astronautical Federation (IAF). All rights reserved. On January 2017, JAXA/ISAS launched the Nano launcher based on the sounding rocket. Unfortunately, the rocket was not able to put a satellite into orbit. This paper discusses the trajectory design regarding how to manage the sounding rocket as a satellite-launching vehicle. At JAXA/ISAS, there are three types of sounding rockets. Two are single-stage rockets called S-310 and S-520, and one is a two-stage rocket called SS-520. These sounding rockets have tail fins for spin stabilization, but usually lack an attitude control system during flight. When attitude control is required to achieve the mission requirements, a gas jet system is available as an optional device. The gas jet system can control the vehicle's spin axis direction and spin rate during coasting fight. To enable the sounding rocket to put a satellite into orbit, a third-stage motor is added to the SS-520 two-stage sounding rocket. The gas jet system is a unique and active attitude control system installed between the first and second stages of the vehicle. Given this constraint, the apogee altitude after burnout of the first-stage motor almost corresponds with the perigee altitude of the elliptical orbit. In this mission, the sounding rocket based Nano launcher is planned to put a 3U-size CubeSat into elliptical orbit. Its targeted apogee altitude is about 1,800 km and its perigee altitude is about 180 km. As the perigee altitude is a relatively low altitude, the orbit life is very short. Thus, any vehicle or environment errors significantly affect the achieved trajectory. Such errors must be small enough to put a CubeSat into orbit. This paper also discusses the effect of orbital distribution depending on various errors.

大気球シンポジウム 平成27年度（2015年11月5-6日. 宇宙航空研究開発機構宇宙科学研究所 (JAXA)(ISAS)）, 相模原市, 神奈川県資料番号: SA6000044007レポート番号: isas15-sbs-007

大気球シンポジウム 平成26年度（2014年11月6-7日. 宇宙航空研究開発機構宇宙科学研究所 (JAXA)(ISAS)）, 相模原市, 神奈川県著者人数: 18名資料番号: SA6000021014レポート番号: isas14-sbs-014