It is, after all, made of aluminum, and aluminum corrodes in space.The sphere is also losing its shine, which means it’s getting harder to see.But the data it collects is still reliable, and it’s still helping to keep our instruments pointed in the right direction.
The Lincoln Calibration Sphere 1 (LCS-1), an aluminum sphere just over one meter wide, was launched into orbit around the Earth on May 6, 1965. It was designed by MIT’s Lincoln Laboratory for the purpose of calibration, or to check the accuracy of scientific instruments before they are used to measure something new. This is done by bouncing radio waves off the sphere and seeing how the signal is affected by the atmosphere and the satellite dishes on Earth.
LCS-1 was more successful than its predecessors as it was bigger and its orbit was more circular, which made it easier to see and the calibration process less complicated. In 1966, it was used to calibrate radar measurements of the Moon, helping to prove that there were safe landing sites for astronauts.
Though it has experienced some wear and tear due to corrosion in space and has lost its shine, LCS-1 is still reliable and is helping to keep our instruments pointed in the right direction. A study published in 2012 found that the light reflected from the calibration sphere, known as LCS-1, is not as shiny as it used to be, and its brightness follows a predictable pattern. This suggests that the sphere is spinning and that a mark or ding has been made on its surface after spending more than half a century in space. Despite this minor damage, scientists have used LCS-1 and its twin, LCS-4, to measure how Earth’s atmosphere expands and contracts in response to the amount of light and matter the Sun emits. Additionally, LCS-1 has been used to track space debris and model how it spreads over time. Physicists, engineers, and Earth scientists have also used the calibration sphere to prepare satellites and astronauts for the worst case scenario of intense solar activity. Finally, the sphere has been suggested to be used to propel spacecraft into interplanetary and interstellar space by taking advantage of the fact that light can push on things. LCS-1 is an unsung hero of space history and its potential is still being explored.