Atlas V and Starliner to conduct dry tests ahead of launch
Boeing and United Launch Alliance (ULA) are continuing preparations ahead of Atlas V launches with the Starliner spacecraft. Formerly known as the CST-100, the spacecraft is scheduled to begin test flights next year, with progress towards that milestone visible at the launch pad and in the processing facilities – but also on the paperwork, with launch processing requirements now revealing a “dry test” ahead of launch.
Atlas V and Starliner:
Early in 2015, NASA’s Flight Planning Integration Panel (FPIP) team revealed the projected launch dates (L2) for the historic test flights of the two NASA Commercial Crew Program (CCP) spacecraft – SpaceX’s Dragon 2 and Boeing’s CST-100 Starliner.
For Boeing, Starliner will first launch on an uncrewed test flight to the Station via the “Boe-OFT” mission in April or May, 2017 – on a 30 day mission, ending with a parachute-assisted return.
Should all go to plan, the second mission will involve a crew on a mission designated “Boe-CFT”, launching sometime between July and September, 2017, on a 14-day mission to the ISS.
The launch campaigns for the first Atlas V launches of the Starliner will be a little different than today’s typical campaign.
Current plans are for the spacecraft and launch vehicle to roll out to the pad from the Vehicle Integration Facility at SLC-41 for countdown demonstration tests, a reminder of the days of the Space Shuttle, the United States’ former crew vehicle.
In addition to the Wet Dress Rehearsal (WDR) that used to be more common for just the launch vehicle, there will be a “dry” test of the integrated vehicle on the pad that will allow the crew and the launch team to rehearse launch day without fuel on-board the Atlas and Centaur stages.
“We have what they call an idle test,” noted Howard Biegler, Launch Operations lead for ULA’s Human Launch Services group.”We are dedicating another day at the pad – which we typically don’t do – to run through those exercises.
“So it will be not just the crew, it’ll be the ground crew, it’ll be the launch crew – so we will do a full-up exercise with all the entities involved in a launch day event.”
The progress towards the day an Atlas V rolls out carrying a Starliner spacecraft is fast approaching, with the SLC-41 pad at the Cape Canaveral Air Force Station (CCAFS) now sporting the crew access tower.
Beginning after the MUOS-3 launch a year ago, pre-fabricated tiers of the tower began being stacked at the pad in April. With all the tiers now assembled, construction at the pad is currently focused on the outboard steel.
The final major piece of the tower is the crew access arm, tested at the Sauer Group, Inc.’s yard in Oak Hill, Florida, just north of the Cape Canaveral area.
Mr. Biegler said the arm was mounted in a test stand in the Sauer Group Yard just before Thanksgiving. The arm has already been rotated several times and is completely outfitted except for the environmental seal.
After a few months of testing, it is scheduled to be removed from the Oak Hill stand in the May-June timeframe for transport to Pad 41 for integration with the tower in the Summer. The integrated tower is estimated to be complete by mid-October.
Meanwhile, at the Kennedy Space Center (KSC), the assembly of the Starliner test articles is taking place at the Commercial Crew and Cargo Processing Facility (C3PF).
Inside the former Orbiter Processing Facility (OPF-3), the upper dome and the tunnel elements of the structural test article (STA) are being assembled in one stand.
Along with the lower dome in another stand, both are being outfitted with gauges to measure forces on the STA during upcoming testing.
The division of the command module into upper and lower halves should allow for more efficient vehicle processing.
“(In) the Apollo days and Orion, we had a welded structure and the limiting factor was the hatch that you see on the side here to get all your components in or out for integration,” said Danom Buck, Boeing Manufacturing and Engineering manager.
“(With Starliner) we have a bolted joint interface that leverages a lot of our technology from ISS days, so we can process all of our internal (avionics) boxes and external boxes offline separately and get more people in and around the vehicle itself.”
Mr. Buck added that once assembly of the upper and lower halves of the command module are complete, they will be outfitted with mass simulators.
“There are propulsion tanks, avionics boxes, things of that nature that don’t get populated on a structural test article – you use mass simulators to simulate that,” he noted. “Those get installed on the outside and the inside, then the upper half goes on the lower half and we ship that out to Huntington Beach.”
The STA is scheduled to go out to Boeing’s Huntington Beach site in California for testing next Spring.
“We have over a thousand gauges that are attached to the structure itself,” Mr. Buck said. “When we designed this we have a finite element model that tells us what our load cases are.
“That’s our predicted values; we go and we actually test this in the Huntington Beach lab, structurally testing it to all those worst cases to validate our model is telling us what we expect to see.”
Following behind the STA, elements of the qualification test vehicle (QTV) are also arriving in Florida for integration.
The QTV is a fully-outfitted Starliner spacecraft, including propulsion and avionics systems, that will be assembled next year. Plans are for the completed QTV to be shipped to Boeing’s El Segundo site, also in California, for acoustic and thermal/vacuum testing.
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