The U.S. Navy conducted a failed ballistic missile intercept in June using the Aegis combat system on the destroyer John Paul Jones. However, the ship successfully conducted a flight test earlier, in February, resulting in the first intercept of a ballistic missile target using the Standard Missile-3 Block IIA off the west coast of Hawaii. Details here: http://bit.ly/2krW2QP (Leah Garton/U.S. Missile Defense Agency) 
After questions from Defense News, the U.S. Air Force confirmed that an engine dropped out of a B-52 bomber during a training flight on Jan. 4. What happened? http://bit.ly/2BXpSEf (Senior Airman Justin Armstrong/U.S. Air Force) 
In February, Defense News reported that nearly two-thirds of the U.S. Navy’s strike fighters were grounded because the aircraft were either undergoing maintenance or simply waiting for parts or their turn in line on the aviation depot backlog. And that wasn’t the only issue: http://bit.ly/2z4OSe5 (MC3 Anthony J. Rivera/U.S. Navy) 
Retired U.S. Navy Chief Petty Officer Wendy Calderon leads a prayer and moment of silence dedicated to honor sailors who died onboard the destroyers John S. McCain and Fitzgerald in separate collisions this year. While Defense News and sister publication Navy Times reported extensively on these events and their aftermath (as seen below), this story led that coverage in readership: http://bit.ly/2yigNmZ (Chief Boatswain’s Mate Nelson Doromal/U.S. Navy) 
U.S. and Israeli officers broke ground in Israel in September for a permanent U.S. Army base that will house dozens of U.S. soldiers. Here’s the mission they’re charge with: http://bit.ly/2yX4hyN (Israel Defense Forces) 
In January, just days after U.S. President Donald Trump took office, the Pentagon confirmed that its civilian spots would be impacted by the president’s hiring freeze, but that Defense Secretary Jim Mattis could exempt any position “that he deems necessary to meet national security or public safety responsibilities,” a Pentagon official told Defense News. Here’s how it all began: http://bit.ly/2BFeP6h (Jim Watson/AFP via Getty Images) 
North Korea tested an intercontinental ballistic missile in July, which analysts said displayed for the first time the capability to exceed 10,000 kilometers in range, a distance potentially capable of threatening New York or San Diego. Here’s how the U.S. and South Korea responded: http://bit.ly/2Bh7rNU (AFP/KCNA via KNS via Getty Images) 
For more than a week, media reports routinely mentioned the approach of the U.S. Navy aircraft carrier Carl Vinson’s carrier strike group, seemingly implying an attack on North Korea could be imminent. But direction to mass off the Korean Peninsula was nowhere to be seen: http://bit.ly/2nSCjz3 (MC3 Matt Brown/U.S. Navy) 
The U.S. Air Force’s F-35A deployed internationally for the first time in April. The aircraft headed to Europe to conduct training exercises with NATO allies, the Pentagon explained. The story here: http://bit.ly/2nSA3b3 (Tech. Sgt. Ryan Crane/U.S. Air Force) 
A number of sources, including one inside the Trump administration, told Defense News that Defense Secretary Jim Mattis, left, and Mira Ricardel, a top defense voice on the Trump campaign who also served as a part of the defense transition team, were directly clashing over Pentagon nominees. The battle over appointments: http://bit.ly/2yiwYkb (Alex Brandon/AP; Jockel Finck/AP)
From internal clashes at the Pentagon to an engine falling from the sky, here are the most popular stories from this year:
Here is how the U.S. Navy collisions have unfolded:
• 7 US sailors missing after catastrophic collision
• Seven missing Fitzgerald sailors discovered dead
• Fitzgerald crew’s ‘heroic efforts’ saved their ship from sinking, admiral says
• Stricken destroyer John S. McCain arrives in Singapore, 10 crew still missing
• 7th Fleet commander sacked days after second deadly collision
• How the US Navy’s fleet has been on a collision course for years
• US Navy worked around its own standards to keep ships underway: sources
• Navy finds deep-rooted failures led to fatal collisions
• Navy crews at fault in fatal collisions, investigations find
