The second Van Allen Probe of NASA was shut down by ground controllers on Friday, three months after the first one was switched off. The closure of the second satellite was conducted for putting an end to a seven-year-old mission, which carried out experiments on earth’s radiation belts.
Of late, the Van Allen probes were running out of their fuels following maneuvers conducted earlier this year, for lowering their orbits, so much so that the satellites could naturally fall back into the earth’s atmosphere before burning up in the next 15 years or so.
The two satellites originally called Radiation Belt Storm Probes were launched on August 30. 2012 abroad a United Launch Alliance Atlas 5 rocket from Cape Canaveral. On several occasions, they flew through the clouds of various charged particles and electrons surrounding the earth. The cloud changes constantly in terms of density and charges, which takes a heavy toll on the avionics of electronic circuitry of the satellites upon being exposed for a prolonged period. That is the reason this radiation belt is at best avoided by satellites. However, for the Van Allen Probes, this was the area of operation.
The twin spacecraft were named after the American space scientist James Van Allen, who discovered the radiation belts. Van Allen was the lead scientist in charge of Explorer 1, which was the first American satellite to get to the orbit.
In 1958, Explorer 1 confirmed that the Earth is surrounded by a layer of radiation clouds. However, the Van Allen belt was not deciphered adequately until the early years of the Space Age. In 1990, the physicists for the first time confirmed that these radiation belts are not stale that was once perceived. Rather, the belts expand upon being heated and contracts, mainly when the charged particles emanating out of massive solar irruptions finally reach Earth.