Yohkoh

Yohkoh (Japaneseようこう, Yoko, " sunbeam " ) was a space telescope to observe the Sun.

The satellite was first developed by the Japanese Institute of Space and Astronautical Science ( ISAS ) with American and British participation under the name SOLAR -A and started on 30 August 1991 with a Mu rocket from the Kagoshima Space Center. The instruments were:

• A telescope for soft X- radiation ( 0.5 to 2 keV).
• A telescope for hard X-rays ( 14-93 keV).
• A broadband X-ray and gamma spectrometer.
• A high-resolution Bragg - crystal spectrometer.

Yohkoh observed the sun for almost an entire sunspot cycle and took in this period, several million radiographs. The mission ended by a position control problem on 14 December 2001, in consequence of the batteries in the power supply have been exhausted. The re-entry into Earth's atmosphere took place on 12 September 2005.