SDS (Solar Disk Sextant)

The Solar Disk Sextant (SDS) is a balloon-borne instrument whose objective is to measure the solar diameter, at different orientations, as a function of time. Results include the solar oblateness, the oscillation spectrum for use in helioseismology, and the rate of the secular variation of the solar diameter. The required instrumentation precision (a few milliarcsec) is attained by means of an objective beam splitting wedge which produces multiples solar images through consecutive reflections.

Balloon launched on: 10/13/2011 at  
Launch site: Scientific Flight Balloon Facility, Fort Sumner, (NM), US  
Balloon launched by: Columbia Scientific Balloon Facility (CSBF)
Balloon manufacturer/size/composition: Zero Pressure Balloon  
End of flight (L for landing time, W for last contact, otherwise termination time): 10/13/2011 at ??
Balloon flight duration (d:days / h:hours / m:minutes): ---
Landing site: Ground abort. Strong surface winds forced the launch vehicle to perform a run longer than anticipated, reaching the security limit.

• Variation of the Diameter of the Sun as Measured by the Solar Disk Sextant (SDS) Solar and Stellar Astrophysics (astro-ph.SR)