CST-100 testing delayed until 2018
Space News has reported that testing for Boeing’s CST-100 spacecraft will be delayed from December 2017 to June 2018. This delay shifts CST-100’s first operational flight to the International Space Station, as part of NASA Commercial Crew Program, to late 2018.
Multiple issues in the background
Citing development and production concerns, Boeing spokesman William Barksdale told Space News on Oct. 11 that the company is delaying its test flights. According to the article:
Under the revised schedule, a pad abort test of the CST-100, previously scheduled for October 2017, is now planned for January 2018. An uncrewed CST-100 flight, called the Orbital Flight Test, has shifted from December 2017 to June 2018.
The specific issues Barksdale mentioned included production delays and minor component qualification test issues, as well as delays stemming from a spacecraft dome element, which was damaged during the manufacturing process. Aviation Week reported that a production flaw forced the scrapping of the lower dome of the crew module pressure shell for spacecraft number two. That vehicle is slated to be used in the first crewed flight test.
John Mulholland, Boeing’s vice president and program manager for commercial programs in space exploration, told Aviation Week:
[The dome] was over-machined due to an issue with the hold-down tooling. Each is cut out from one piece of aluminum that we form into shape and mill out pockets. But the hold-down fixture was not rigid enough and they got some movement, which was not detected and milled through […]. Luckily we formed a spare dome, but this only happened 2.5 weeks ago, and we realized there was an error in it when cooling flow in the pockets drained through.
The Aviation Week article noted that a joint Boeing / United Launch Alliance (ULA) tiger team is addressing issues with the spacecraft’s outer mold line. Higher-than-expected aerodynamic loads on the capsule in transonic wind tunnel tests require a change to the shape of the spacecraft’s adapter to the ULA Atlas V launch vehicle.
Despite the aforementioned challenges, Boeing’s production process continues. The company will ship the crew module structural test article from the Commercial Crew and Cargo Processing Facility at Kennedy Space Center in Florida to the company’s test site in Huntington Beach, California, to undergo structural loads and pressure testing. The testing is scheduled to last 11 months.
Mulholland told Aviation Week that Boeing will perform a series of separation tests for the vehicle’s various pyrotechnic separation systems. Additionally, Boeing is setting up for hot-fire tests of the service module, which will be conducted at White Sands, New Mexico.
Spacecraft 1, Boeing’s first CST-100, will fly on a pad abort test. It is being assembled at Kennedy Space Center. The company is also progressing through component qualification tests. Mulholland told Aviation Week: “Of the 200 components we have to get through qualification, 80 are already through or in the middle of qualification testing. We are coming up that ramp on component qualification and have had no issues to date, which gives us a lot of confidence.”
The future is waiting…
Boeing’s schedule challenges arise in the wake of the Sept. 1, 2016, explosion of a SpaceX Falcon 9 rocket. NASA’s Inspector General’s Office released a report on the same day as the Falcon 9 incident. The IG found that commercial missions to the ISS would likely be delayed until 2018, three years past the original target date. Both contractors’ challenges will create additional delays for the Commercial Crew Program.
Given these challenges, NASA will likely face additional criticism from Congress about the program. However, agency administrator Charles Bolden told Space News: “We are not presently looking at any additional seats beyond those that we have already purchased.”
Bart Leahy is a freelance technical writer living in Orlando, Florida. Leahy's diverse career has included work for The Walt Disney Company, NASA, the Department of Defense, Nissan, a number of commercial space companies, small businesses, nonprofits, as well as the Science Cheerleaders.