London:
Researchers in Sweden have launched a giant balloon taller than a football field that is now flying at the edge of space to collect data on cosmic rays -- the most super-charged particles in the universe.
A team at University of Delaware has set afloat the balloon, which is 396 feet tall and 459 feet in diameter when fully inflated, last week from Esrange Space Center near Kiruna in Sweden in the Arctic Circle.
According to the researchers, it is flying at a speed of more than 40 knots and an altitude of nearly 27 miles.
Its payload of cosmic ray detectors housed in a pressurised shell, will be cut free in northwestern Canada and float back down to Earth on a parachute and then recovered likely by helicopter.
Cosmic rays are extraterrestrial high-energy electrons and protons, and heavier nuclei that enter our atmosphere.
"The bulk of cosmic rays are likely produced by strong shock waves from Supernova explosions within our galaxy.
It is well documented that these high-energy particles can threaten the health of astronauts in space and expose airline workers to radiation," said John Clem, who led the team.
In fact, the effort entails launching two helium- filled high-altitude balloons -- one to carry the 'Low Energy Electrons' instrument payload, which is now afloat, and one to carry the 'Anti-Electron Sub-Orbital Payload', put in flight today to travel to the upper limits of the atmosphere.
According to the researchers, about a thousand cosmic rays strike every square meter of Earth's atmosphere a second, depending somewhat on the location.
"The data from the balloon flights will be used to study solar modulation, the variation in cosmic ray intensity that's correlated with solar activity.
"The level of solar activity rises and falls over a period of approximately 11 years and influences cosmic ray intensity.
As solar activity rises, cosmic ray activity decreases.
Currently, solar activity is low, and we are in a period of high cosmic ray intensity.
"We're working to better understand how the sun's changing magnetic field affects cosmic ray propagation through the solar system," Clem said.