NASA's Advanced Range Instrumentation Aircraft (ARIA) were used to track and relay telemetry from a spacecraft to the ground when it
was out of range of any fixed ground stations.
NASA used an extensive array of ground stations to track and communicate with orbiting spacecraft, supported by tracking ships which could
be moved into some ocean areas. However, the coverage provided by these ground-based tracking stations left considerable gaps.
For the Apollo project a fleet of 8 C-135 aircraft were modified to provide a flexible airborne answer to this problem. The resulting EC-135N Advanced
Range Instrumentation Aircraft (ARIA) provided spacecraft tracking, and telemetry/voice relay and recording capability for the Apollo lunar missions.
One of the ARIA officers during the Apollo era, Captain David J. Dunn, created an unofficial patch for the project in late 1970. He based
the patch design on the existing Apollo project patch and had around 400 examples produced, possibly by AB Emblem.
According to Dunn these patches were very popular with the ARIA Electronics Technicians and he believes
most of the patches were probably sewn to flight suits at the time. Most of these flight suits
were replaced by NOMEX versions in around 1971, at which point most of the original patches would have been lost.
Dunn only retains one unused example today along with
one example sewn to an
original flight suit which he managed to save from destruction.
Looking at the Apollo ARIA patches that have surfaced at auction over the last few years, most have appeared in pairs with one grey
example and one blue. Capt. Dunn has confirmed that he never produced (or saw) any blue versions of this patch during his time at ARIA
and close examination of these grey examples shows distinct differences with his 1970 originals.
Although my initial thought was that these later versions were likely reproductions
the source of my example stated that it was acquired at a surplus store in around 1980 and examining this example in detail
showed that it was indeed consistent with a vintage patch from the 1970s.
Since Capt. Dunn left the ARIA program in 1972 it seems possible that a member of one of the later ARIA crews covering the Skylab and ASTP missions of 1973 to 1975
may have had a batch of these grey and blue ARIA patches produced during this period.
You can read more about Capt. Dunn's ARIA involvement here with
more coverage of ARIA 4's role in the Apollo 13 reentry here.
Finally, there's an extensive site on ARIA in general called FlyAria.