The Glory satellite was a NASA Earth science mission designed to study the effects of aerosols and total solar irradiance on Earth's climate. Part of NASA's Earth Observing System (EOS), it was intended to provide crucial data to improve understanding of climate change mechanisms and maintain long-term climate data records.
Mission Objectives: The primary goals of the Glory mission were:
- Aerosol Characterization: To collect comprehensive data on the chemical, microphysical, and optical properties of aerosols—tiny particles suspended in the atmosphere. Aerosols can have complex warming or cooling effects on the planet, depending on their composition, size, and interaction with solar radiation and clouds.
- Total Solar Irradiance (TSI) Measurement: To accurately measure the total solar irradiance, which is the total amount of solar radiation received at the top of Earth's atmosphere. TSI is a fundamental driver of Earth's climate system and its variations can influence global temperatures.
Instruments: The Glory satellite was equipped with two primary scientific instruments:
- Aerosol Polarimetry Sensor (APS): This instrument was designed to measure the polarization of sunlight reflected by aerosols and the Earth's surface. By analyzing polarized light, the APS aimed to retrieve detailed information about aerosol properties such as size distribution, refractive index, and particle shape, which are essential for understanding their radiative forcing.
- Total Irradiance Monitor (TIM): As a successor to similar instruments on previous missions (e.g., SORCE), the TIM was intended to provide highly accurate and stable measurements of total solar irradiance, continuing a critical long-term climate data record.
Launch and Failure: The Glory satellite was launched on March 4, 2011, at 10:09 UTC from Space Launch Complex 576-E at Vandenberg Air Force Base, California. It was carried aboard an Orbital Sciences Corporation Taurus XL launch vehicle (tail number T6).
The launch was unsuccessful. Approximately three minutes after liftoff, during the second stage burn, the payload fairing—the protective nose cone that shields the satellite during the initial ascent through the atmosphere—failed to separate as commanded. The failure of the fairing to deploy meant that the additional weight prevented the rocket from achieving sufficient velocity and altitude to reach Earth orbit. The satellite and the upper stages of the launch vehicle re-entered the atmosphere over the southern Pacific Ocean.
Significance of Failure: The loss of the Glory satellite was a significant setback for climate science, as it represented a gap in the planned continuity of aerosol and solar irradiance data records. It was also the third consecutive failure of a Taurus XL rocket carrying a NASA payload attributed to a fairing separation anomaly (following the failed launch of OCO-1 in 2009, and TSX-5 in 1999, though TSX-5 had a different fairing issue). These repeated failures led NASA to discontinue using the Taurus XL for future missions. While the specific mission objectives of Glory were not fully replicated, aspects of its intended data collection were later pursued by other missions (e.g., OCO-2 for carbon dioxide monitoring, and TSIS-1 for solar irradiance measurements).