The US Defense Advanced Research Projects Agency (DARPA) has attempted to attach X-61A Gremlins air vehicle (GAV) to the docking bullet that was extended from C-130 aircraft.
A total of nine attempts were made to mechanically engage the GAVs to the docking bullet.
It is part of DARPA’s latest flight test series that commenced in October. Testing was conducted at the Dugway Proving Ground in the US state of Utah.
The agency said that attempts aimed at airborne retrieval of three UAVs were just a few inches away from success.
DARPA Tactical Technology Office Gremlins programme manager Scott Wierzbanowski said: “All of our systems looked good during the ground tests, but the flight test is where you truly find how things work.
“We came within inches of connection on each attempt but, ultimately, it just wasn’t close enough to engage the recovery system.”
According to DARPA, hours of data has been collected over three flights as part of the testing.
This data included aerodynamic interactions between the docking bullet and the X-61A Gremlins air vehicle.
Currently, efforts are underway to study this data, update models and designs, as well as conduct additional flights and retrieval attempts in a fourth flight test deployment.
The fourth flight test deployment is expected to take place next year.
DARPA’s Gremlins programme is managed by the agency’s Tactical Technology Office.
The goal of Gremlins is to showcase the aerial launch and recovery of four GAVs in 30 minutes.
Wierzbanowski added: “We were so close this time that I am confident that multiple airborne recoveries will be made in the next deployment.
“However, as with all flight testing, there are always real-world uncertainties and challenges that have to be overcome.”
Leidos fully owned subsidiary Dynetics is the developer of the Gremlin vehicles.
The first flight test of X-61A GAV was conducted in January.
In August, Dynetics carried out the flight test of the second X-61A Gremlins Air Vehicle.