IKAROS

This article deals with the Japanese space probe IKAROS, for other similar terms, also in different spelling, see Ikarus (disambiguation) .

IKAROS
Model of the probe and the solar sail
NSSDC ID	2010-020E
Mission goal	Testing of a solar sail for propulsion and energy supply of a spaceship
Client	JAXA
Launcher	H-IIA
construction
Takeoff mass	approx. 310 kg
Instruments
72 liquid crystal elements 8 dust detectors 1 gamma ray detector / polarimeter (GAP) 1 radio interferometer for distance measurements (VLBI)
Course of the mission
Start date	May 20, 2010
launch pad	Tanegashima Space Center
End date	probably 2012
05/20/2010 begin 06/03/2010 Extending the awning 06/05/2010 Interruption of unwinding 06/09/2010 Continuation of the unwinding 06/09/2010 Development phase one completed 06/10/2010 Awning fully unfolded 06/10/2010 Electric power is produced for the first time. Start of the one-month test phase 06/16/2010 The DCAM 2 camera probe is deployed and transmits images of the unfolded sail 06/19/2010 Camera probe DCAM 1 also works successfully 07/07/2010 The first gamma ray burst is detected with GAP 07/13/2010 Sail control successfully activated via switchable LCD reflectors December 8, 2010 Fly by Venus December 8, 2010 Main mission completed successfully / start of the extended mission phase

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 space probe of the Japanese space agency (JAXA) for testing a solar sail as a drive and energy supply for a spaceship . The probe was launched on May 20, 2010 at 21:58:22 UTC together with the Venus Climate Orbiter with an H-II A-202 launcher from the Tanegashima Space Center .

Mission objectives

The mission has two goals: "Level 1" is considered successful if the plastic membrane , which is only 7.5 µm thick , is unfolded and information on the provision of electrical energy by the printed solar cells is achieved for a month . The mission is rated as “complete success” (also “Level 2”) if, over a period of six months, changes in orbit are possible due to the radiation pressure of the sun due to the square awning measuring 20 m in diagonal .

Mission history

Starting with 25 revolutions per minute, the solar sail was deployed from June 3, 2010 with the help of the centrifugal force of four pilot masses attached to the ends of the solar sail. After two days, the unfolding was interrupted because of a discrepancy between the mathematical models and the actual rolling process. The rotation rate at the interruption was 7.4 revolutions per minute, with the probe 6.3 million kilometers from the earth. The development continued on June 8th. On the same day, the sun sails, which were still folded into strips, were completely extended using the centrifugal forces of the four pilot masses, so that the first deployment phase was completed. On June 10th, the awning was rolled out and could produce electricity for the first time. A one-month test phase should then begin to check the behavior of the probe and the awning; only then should the awning serve as a drive. Five days later, images of the probe with the fully unfolded sail were taken using a micro-probe that was launched into space and contained a separate camera and battery. The rotation was then reduced to one revolution per minute in three days so that the weights that keep the sail under tension are relieved.

On December 8, 2010, the probe passed Venus as planned at a distance of 80,000 km to cause an orbit deflection of 20 °. However, no examinations on Venus were possible because no measuring instruments were installed for this. Nevertheless, the mission was successfully completed, so that the extended mission phase could begin from this point in time.

The primary mission was declared completed on January 26, 2011.

On October 18, 2011, the attitude control thrusters fired for 20 minutes to reverse the direction of rotation of the probe. This maneuver succeeded; the rotation speed was then 0.24 revolutions per minute. Because IKAROS moved away from the sun again and the awning was at an unfavorable angle to the sun, less electrical energy was generated and the on-board systems switched off before January 6, 2012. Twice a month they searched for the space probe until a radio signal was picked up again on September 6, 2012, which on September 8 could be assigned with certainty to the probe.

construction

The probe consists of a 173 m² large and 2 kg heavy awning, which was extended by centrifugal forces due to the probe's own rotation. It has an edge length of 14 m and is approx. 7.5 µm thick. 72 liquid crystal elements are used in the solar sail in order to adapt the flight attitude through their changeable reflection. There are also eight dust detectors that are used for scientific evaluations.

Compared to other engines, the drive has only a low drive force; even with optimal alignment (vertical incidence of sunlight) it is only 1.6  millinewtons , which gives the probe with its mass of 315 kg only an acceleration of 0.000.005 m / s² (corresponding to a speed increase of 2 cm / s in one hour or 12 m / s in a month).

Result

According to the JAXA, a driving force of 1.12  millinewtons was measured.

successor

If IKAROS should be successful, a successor with a sun sail with a diameter of 50 m is planned, which should fly to Jupiter in the next decade .

Web links

• JAXA: Small Solar Power Sail Demonstrator "IKAROS" (English)

swell

1. ↑ IKAROS: Solar Power Sail Demonstrator. Jaxa, accessed July 27, 2019 . 
2. ↑ Masato Nakamura, Takehiko Satoh: Status of the Venus Climate Orbiter . Ed .: ISAS / JAXA. 2007 ( PDF 692KB [accessed on June 4, 2010] English: Present Status of Planet-C .).
3. ^ H-2A Launch Report - Mission Status Center. Spaceflight Now, May 20, 2010, accessed June 4, 2010 . 
4. ↑ IKAROS before the start. In: Raumfahrer.net. May 1, 2010, accessed June 4, 2010 . 
5. ↑ IKAROS: A part is outside. In: Raumfahrer.net. June 3, 2010, accessed June 4, 2010 . 
6. ↑ IKAROS: pause for development. In: Raumfahrer.net. June 6, 2010, accessed June 8, 2010 . 
7. ↑ IKAROS: Development phase one completed. In: Raumfahrer.net. June 9, 2010, accessed June 10, 2010 . 
8. ↑ Icarus is sailing! In: Raumfahrer.net. June 11, 2010, accessed June 12, 2010 . 
9. ↑ JAXA: Small Solar Power Sail Demonstrator 'IKAROS' Successful Image Shooting by Separation Camera (engl.)
10. ↑ The Wings of Icarus. In: Raumfahrer.net. June 17, 2010. Retrieved June 17, 2010 . 
11. ↑ IKAROS passed Venus. In: Raumfahrer.net. December 17, 2010, accessed December 17, 2010 . 
12. ↑ ^{a b} Small Solar Power Sail Demonstrator "IKAROS". JAXA, September 11, 2012, accessed September 12, 2012 . 
13. ↑ IKAROS - All News Channel. (No longer available online.) Kavli Institute for the Physics and Mathematics of the Universe, July 9, 2019, archived from the original ; accessed on July 23, 2019 (English).