Naomi Murakami

SDS-4 Attitude Control System: In-Flight Results of Three Axis Attitude Control for Small Satellites

Abstract The Small Demonstration Satellite (SDS) program is a JAXA technology demonstration program, targeting the in-orbit demonstration of advanced technologies using small satellites. Following the success of SDS-1, the SDS-4 spacecraft was successfully launched on 18 May 2012 and continues the in-flight demonstration of a space-based Automatic Identification System (AIS) as well as numerous flight experiments. This paper describes the in-flight results of the Attitude Control System (ACS) for 50kg class small satellites using 3-axis zero-momentum stabilization.

Trajectory design for rendezvous in lunar Distant Retrograde Orbit

This paper describes solutions to the lunar Distant Retrograde Orbit (DRO) rendezvous in terms of trajectory and launch window design. Our study is motivated by the future potential to construct a new space station or fuel refilling ports in the Earth-Moon neighborhood. A DRO, which has a long-term stability, is a possible candidate for the orbit in which such habitable structures are located. Since these structures have to rendezvous with visiting vehicles from Low Earth Orbit (LEO), it is valuable to investigate rendezvous technology in DROs. Our current study is focused on designing rendezvous trajectories which require reasonable operational cost, such as delta-v and flight time. Launch window analysis derived from trajectory design is also within the scope of this paper. We applied a three-impulse transfer with retrograde powered lunar gravity assist, and examined the total delta-v and flight time required to transfer from LEO to various phase points in a certain DRO. The results showed how a certain region where the ΔV cost is low exists, and the flight time varies considerably according to the rendezvous point. We proposed an applicable launch window with these features in mind. We also conducted a case study to evaluate delta-v and the flight time required for rendezvous after the visiting vehicle is inserted into the DRO at a certain distance from the station. The result showed the potential to widen the option to rendezvous. In our study, trajectories are computed using Systems Tool Kit (STK) / Astrogator software module. Unlike a Circular Restricted Three-Body Problem (CRTBP) model, STK/Astrogator employs various force models and accurately integrates trajectories, which enables more realistic operation scenarios to be discussed.

Precision pointing control for SPICA: risk mitigation phase study

SPICA (Space Infrared Telescope for Cosmology and Astrophysics) is an astronomical mission optimized for mid- and far-infrared astronomy with a 3-m class telescope which is cryogenically cooled to be less than 6 K. The SPICA mechanical cooling system is indispensable for the mission but, generates micro-vibrations which could affect to the pointing stability performances. Activities to be undertaken during a risk mitigation phase (RMP) include consolidation of micro-vibration control design for the satellite, as well as a number of breadboarding activities centered on technologies that are critical to the success of the mission. This paper presents the RMP activity results on the microvibration control design.

Contactless Space Debris Detumbling: A Database Approach Based on Computational Fluid Dynamics

This paper aimed to investigate the feasibility of a contactless method to detumble space debris by using thruster plume impingement during proximity operation. To detumble the rotational debris, t...