American space agency NASA halted the planned launch of a pair of radiation probes for the second day in a row early Saturday, due to weather conditions.
NASA's Radiation Belt Storm Probes (RBSP) were due to be sent into space from Cape Canaveral Air Force Station but managers postponed the launch of the Atlas V carrier rocket for 24 hours, according to a NASA announcement.
Forecasters said the chances for acceptable weather appeared to be worsening, to 40 percent on Sunday morning.
The twin probes were originally scheduled to launch Thursday morning, but that appointment to send RBSP outside Earth's atmosphere was delayed due to "an anomalous engine condition."
The mission was re-scheduled to launch Friday from Space Launch Complex-41, however this was at first delayed slightly before the weather issue forced it to be postponed a further day.
The probes are designed to fly and operate in the heart of the most hazardous regions of near-earth space.
The RBSP mission, launched in 2012, will last two years and help understand the Sun's influence on Earth and near-Earth space by studying the Earth's radiation belts on various scales of space and time.
