Since 2006, NASA has conducted several tests each year of parachutes for the Orion space capsule at U.S. Army Yuma Proving Ground, Az., with the final air drop taking place in mid-September 2018. Nearly every parachute failure mode imaginable was replicated and studied during these years.A rousing success, the final test involved a mock-up of the Orion space capsule being dropped from a C-17 aircraft flying at an altitude of 35,000 feet. A carefully choreographed sequence of 11 individual parachutes slowed the spacecraft from a speed of over 300 mph to 20 mph by the time it came down for a landing at the proving ground's Phillips Drop Zone. The three "main" parachutes that deployed at 9000 feet were each equal in size to nearly a football field.Astronaut Randy Bresnick, a 14-year NASA veteran, was among those who witnessed the dramatic test. Earlier this year he returned from a 139 day stay on the orbiting International Space Station where he served as crew commander. He explained that NASA chose to conduct the parachute tests at YPG because of the drop zone's great expanse, as well as the high altitude restricted airspace above it."This is one of the few places in the United States NASA can do this," said Bresnick.He believes the past 12 years of testing was critically important."We can conduct a great future exploratory mission in space, but if the parachutes don't work on earth re-entry, it was all for naught," he said. An unmanned Orion mission will take place in June 2020 and the first manned mission two years later. The Orion will use the largest and most powerful rocket engines ever developed.It's interesting to note that over 100 drop tests took place during the development of the parachutes used in NASA's Apollo program that carried astronauts to the moon in the late 1960s and early 1970s. Sophisticated computer modeling and other advanced capabilities didn't exist at the time, so NASA engineers were able to whittle it down to a much smaller number for the Orion.One of the other interesting challenges faced by parachute developers involves the harsh, unforgiving conditions of outer space. Temperatures range from plus 270 degrees in the sun and minus 270 degrees in the shade. The parachutes themselves are tightly compressed to the density of oak wood during the flight to enable them to be packed in super-compact compartments.Ryan Tiaden, YPG Air Delivery Systems branch chief, has been working with NASA Orion parachute testing since it began 12 years ago and supported the space agency in other test projects in the years before that."It's somewhat bittersweet to see the Orion testing end, but this has been a great program with lots of good people," he said. "It was a great opportunity to see some excellent technology being developed."Tiaden says there will be future opportunities for YPG to support other spacecraft testing. Boeing is currently in the process of developing a space capsule for different missions using different rockets, which will require parachute testing.Lt. Col. Timothy Matthews, Yuma Test Center commander, was excited to be on the drop zone observing the exacting and complex proceedings taking place. He said the payload is huge and that he's proud to see YPG playing a critical role in NASA's Orion space program.Despite this, however, he says the complexity taking place is similar to that seen in other tests at the proving ground."We conduct a great amount of research and development testing of parachutes of virtually any kind," he said. "There's a ton of coordination that takes place conducted by YPG test officers, who do a great job. Without great technical support and test teams, we wouldn't be able to conduct the complex tests we perform throughout the year."What took place was the culmination of years of detailed and complex testing by a team fully dedicated to the safety of the Orion's crew, said Mark Kirasich, NASA Orion program manager. Though the day represented the conclusion of this round of testing, he feels NASA will return to the proving ground."The YPG range has a number of capabilities," said Kirasich. "We're currently setting up an exploration program that Orion will be part of, but has other elements. Parts of the architecture may require testing out here."Kirashich landed in Yuma the day before the early morning test and was thoroughly briefed on what would take place. He toured facilities and shook many hands."I met some incredibly dedicated and competent people at Yuma Proving Ground who intimately know how to do their jobs," he remarked. "People clearly know what they're doing out here."