iphir interplanetary helioseismology by irradiance measurements scientific results t. toutain
Post on 20-Dec-2015
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IPHIR Instrument• Helioseismology instrument aboard the 2 probes of the USSR
Phobos mission to Mars. • Triple sunphotometer (335,500 and 862 nm) measuring solar
irradiance in the continuum. 2-axis solar sensor.
Institutes and persons involved :• PMOD/WRC (Davos, Switzerland) - C. Fröhlich(P.I.), Ch. Wehrli,
H.J. Roth• LPSP (Verrières-le-buisson ) – Boudine, J.C. Vial• Space Science Department of ESA - R.M. Bonnet, V. Domingo• Crimean Astrophysical Observatory - A. Bruns, V.A. Kotov, D.N.
Rachkovskii• Central Research Institute for Physics (Hungary) – Z. Kollath
Phobos mission• The last mission undertaken by the USSR was that of Phobos - a
mission involving two probes (Phobos 1 and 2) aiming at Mars.
• Phobos 1, launched 7 July 1988, never made it to Mars, losing contact with Earth on September 2, 1988. The problem was later found to be in a software upload problem on August 29/30 that caused the craft's attitude thrusters to power down, resulting in the craft no longer pointing to the sun and the solar arrays not charging the batteries.
• Phobos 2, launched 12 July 1988, reached Mars, and it gathered data on the Sun, interplanetary medium, Mars, and Phobos. However, a maneuver before the final phase of the mission to place the craft within 50 m of Phobos' surface to release two craft - a mobile "hopper' and a stationary platform - resulted in loss of communication. The mission ended when there was unsuccessful signal acquisition on March 27, 1989. The cause was traced to an on-board computer error.
Conclusions
• Uninterrupted long duration observations (160 days). Oscillation parameters determined accurately.
• Solar oscillations are excited by the solar convection
• Solar oscillations might be correlated(?)• Guideline for next-generation (VIRGO/SOHO)
and asteroseismology (COROT).• Thanks Boudine for your advices!
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