o-4-4 Solar Sail �gIKAROS�h 4
Session Date : June 10 (Fri) 16:50-18:20 Room : Theater

2011-o-4-12v A Study on Improvement of Orbit Determination Accuracy for IKAROS.
Shiro Ishibashi (Fujitsu Limited, Japan)
IKAROS was launched together with AKATSUKI(PLANET-C)by the H-IIA rocket from Tanegashima in May 21, 2010. IKAROS is a spacecraft of the world's first solar sail launched into deep space. It succeeded in deployment of the large sail about two weeks after launch, and many experimental missions have been carried out. IKAROS receives large solar radiation pressure, so it is necessary to develop a precise radiation pressure model for accurate orbit determination. In construction of this precise model, a several uncertainties should be considered elaborately. The form of the solar sail is maintained by the centrifugal force caused by spin motion of the spacecraft, so the cross section of the sail is indefinite. The direction of the spin axis has some uncertainties, because it is determined from the sun sensor and Doppler modulation caused by antenna offset. Moreover, the spin rate is gradually lowered by solar radiation pressure. This paper presents the results of model construction and improvement of the orbit determination accuracy for IKAROS.

2011-o-4-12v
A Study on Improvement of Orbit Determination Accuracy for IKAROS.

Shiro Ishibashi
(Fujitsu Limited, Japan)

IKAROS was launched together with AKATSUKI(PLANET-C)by the H-IIA rocket from Tanegashima in May 21, 2010. IKAROS is a spacecraft of the world's first solar sail launched into deep space. It succeeded in deployment of the large sail about two weeks after launch, and many experimental missions have been carried out. IKAROS receives large solar radiation pressure, so it is necessary to develop a precise radiation pressure model for accurate orbit determination. In construction of this precise model, a several uncertainties should be considered elaborately. The form of the solar sail is maintained by the centrifugal force caused by spin motion of the spacecraft, so the cross section of the sail is indefinite. The direction of the spin axis has some uncertainties, because it is determined from the sun sensor and Doppler modulation caused by antenna offset. Moreover, the spin rate is gradually lowered by solar radiation pressure. This paper presents the results of model construction and improvement of the orbit determination accuracy for IKAROS.

2011-o-4-13v Verification of the Solar Sail Propulsion for the Small Solar Power Sail Demonstrator IKAROS
Hitoshi Ikeda (JAXA, Japan)
No abstract

2011-o-4-14v Delta-DOR Observations for the IKAROS Spacecraft
Hiroshi Takeuchi (JAXA, Japan)
Delta-DOR (Delta Differential One-way Range) is an application of VLBI where delay measurements of a spacecraft radio signal are compared against similar delay measurements of angularly nearby quasar radio signals. Using Delta-DOR techniques, sky plane position of the spacecraft can be directly determined very precisely. IKAROS is the first Japanese deep spacecraft that has a capability of wideband multi tone generation for Delta-DOR based orbit determination. In order to demonstrate the effectiveness of this function, a total number of 24 international VLBI experiments were performed by using totally 15 antennas among 8 agencies. The outline of the experiments, detailed specification of the newly-developed VLBI data recording and processing system, and the results of the orbit determination with Delta-DOR observables are described in this presentation.

2011-o-4-14v
Delta-DOR Observations for the IKAROS Spacecraft

Hiroshi Takeuchi
(JAXA, Japan)

Delta-DOR (Delta Differential One-way Range) is an application of VLBI where delay measurements of a spacecraft radio signal are compared against similar delay measurements of angularly nearby quasar radio signals. Using Delta-DOR techniques, sky plane position of the spacecraft can be directly determined very precisely. IKAROS is the first Japanese deep spacecraft that has a capability of wideband multi tone generation for Delta-DOR based orbit determination. In order to demonstrate the effectiveness of this function, a total number of 24 international VLBI experiments were performed by using totally 15 antennas among 8 agencies. The outline of the experiments, detailed specification of the newly-developed VLBI data recording and processing system, and the results of the orbit determination with Delta-DOR observables are described in this presentation.