The Sixth Orbiting Solar Observatory (OSO 6) operated from August 1969 until January 1972. The orbital period was ∼95 minutes, with the orbital day lasting ~ 60 minutes of each orbit. The spin rate was 30 rpm.
Mission Characteristics
Lifetime
Aug 1969–Jan 1972
Lifetime
Aug 1969–Jan 1972
Payload
Instrument
Characteristic
Details
Hard X-ray Detector
Energy Range
27–189 keV
Effective Area
5.1 cm2
Field of View
17° × 23° collimator (FWHM)
Energy Resolution
four channels
The hard X-ray detector NaI(Tl) scintillator with 4 energy channels (separated 27–49–75–118–189 keV). The detector spun with the spacecraft on a plane containing the Sun direction within ±3.5°. Data were read with alternate 70 ms and 30 ms integrations for 5 intervals every 320 ms.
NRL experiment
Energy Range
23–500 keV
Effective Area
1.3 cm2
Time Resolution
2.56 s
The NRL experiment meant primarily to monitor solar flares. This X-ray detector operated from August 1969 until January 1972. The NaI(Tl) scintillator was 2.54 cm thick, and operated during daylight periods only (∼70% of each 99.8 minute orbit). It had 6 energy channels covering 23–82 keV, and an integral channel for <82 keV out to about 500 keV. Spectra were accumulated for 2.56 s.
Hard X-ray Detector
Energy Range
27–189 keV
Effective Area
5.1 cm2
Field of View
17° × 23° collimator (FWHM)
Energy Resolution
four channels
The hard X-ray detector NaI(Tl) scintillator with 4 energy channels (separated 27–49–75–118–189 keV). The detector spun with the spacecraft on a plane containing the Sun direction within ±3.5°. Data were read with alternate 70 ms and 30 ms integrations for 5 intervals every 320 ms.
NRL experiment
Energy Range
23–500 keV
Effective Area
1.3 cm2
Time Resolution
2.56 s
The NRL experiment meant primarily to monitor solar flares. This X-ray detector operated from August 1969 until January 1972. The NaI(Tl) scintillator was 2.54 cm thick, and operated during daylight periods only (∼70% of each 99.8 minute orbit). It had 6 energy channels covering 23–82 keV, and an integral channel for <82 keV out to about 500 keV. Spectra were accumulated for 2.56 s.
Science Highlights
Intended primarily to study bursts and flares from the Sun, the instrument was also used to search for hard X-ray coincidences with known gamma-ray bursts (primarily those seen by the Vela satellites). Three such coincidences were observed. The NRL instrument, when combined with data from the OGO-5 satellite, confirmed 5 hard X-ray bursts (they detected 12 altogether).
