IKAROS

Ikaros ( Interplanetary Kite -craft Accelerated by Radiation Of the Sun, formally: Kogata solar Denryoku Sail Jisshōki (小型 ソーラー 電力 セイル 実証 機, dt " small-format solar electric sail detection device" ) ) is a Japanese space probe to test solar sails as drive and power supply for space ships. The spacecraft was launched on May 20, 2010 at 21:58:22 UTC clock along with the Venus Climate Orbiter aboard an H- IIA 202 rocket from Tanegashima Space Center.

Mission Objectives

The mission has two objectives: "Level 1 " is considered successful if the only 7.5 microns thick plastic membrane is deployed and it is possible for a month to gain information about the provision of electrical energy through the printed solar cells. As a " complete success," the mission is evaluated (or " Level 2"), if for half a year through the square, diagonally measured 20 m, awning track changes by the solar radiation pressure are possible.

Mission History

Starting at 25 revolutions per minute was deployed from the 3rd June 2010, using the centrifugal force of four attached to the ends of the solar wing pilot masses, the awning. After two days, the development was stopped due to a difference between the mathematical model and the actual Abrollverlauf. The rotation rate was at the beginning of the pause 7.4 revolutions per minute, and the probe was 6.3 million kilometers from Earth. The sequel has been carried out on June 8. On the same day the merged yet into strips awning with the help of the centrifugal forces of the four pilot masses were completely driven out, so that the development phase has been completed one. On June 10, the awning was rolled out and could produce electricity for the first time. A one-month test phase should now begin to check the behavior of the probe and solar sail, but only after the awning is to serve as a drive. With a suspended into space micro probe containing a separate camera and a battery, five days later be taken up images of the probe with the fully deployed sail. The rotation was then reduced in three days to one revolution per minute, thus the mass pieces that keep the sail taut, are relieved.

On 8 December 2010 the probe happened as planned Venus at a distance of 80,000 km, to cause a deflection path of 20 °. However, no studies of the Venus were possible, as no measuring instruments were installed for this purpose. But the mission has been completed successfully, so that from that moment began the extended mission phase.

The primary mission was declared on 26 January 2011 and ended.

On 18 October 2011, the attitude control thrusters fired for 20 minutes to reverse the direction of rotation of the probe. This maneuver succeeded, the rotation rate was then 0.24 revolutions per minute. The fact that IKAROS back away from the sun, and the solar sail was in an awkward angle to the sun, less electrical energy is generated, and at a time before January 6, 2012, the on-board systems switched off. Twice a month they were looking for the spacecraft to be on 6 September 2012 caught a radio signal that could be assigned with certainty the probe on September 8.

Construction

The probe consists of a 173 square meter and weighing 2 kg solar sail, which is extended by the centrifugal forces due to the self-rotation of the probe. It has an edge length of 14 m and is approximately 7.5 microns thick. 72 liquid crystal elements are used in the solar sail to adjust by their variable reflecting the attitude. Also are there eight dust detectors that are used for scientific analysis.

The drive has, compared to other engines, only a small driving force, since for optimal alignment, ie perpendicular sunlight, the force is only 1.6 milli- Newton. The probe with the mass of 315 kg would be accelerated only with 0,000.005 m / s ². This would be an increase in speed of 2 cm / sec in an hour or 12 m / s in a month.

Successor

If IKAROS should be successful, a successor with a 50 -meter diameter solar sail would be planned, the should over the next decade to fly to Jupiter.