SLS and Orion endure rigorous wind tunnel testing

by Chris Bergin

Both the Space Launch System (SLS) and the Orion crew capsule have continued their wind tunnel testing this month, with the Block 1 Heavy Lift Launch Vehicle (HLV) – otherwise known as the SLS-1000x – set to facilitate a complete aerodynamic force and moment database delivery by the end of this year.

SLS Wind Tunnel Runs:

The SLS configurations are all pressing towards the Preliminary Design Review (PDR) phase of their development, with a concentrated effort on the initial HLV configuration of the 70mt Block 1 – currently tasked with the first two launches of NASA’s new rocket.

“Testing has been initiated for the Space Launch System (SLS) Block I vehicle configuration (SLS-1000x) at the Boeing Polysonic Wind Tunnel (PSWT) in St. Louis, Missouri,” noted information on L2’s SLS rolling update section.

“This is a continuation of the testing of the 0.8 percent scale, medium-fidelity force and moment model that was tested in the Langley Research Center’s Unitary Plan Wind Tunnel (UPWT) in May 2012.”

The wind tunnel runs at LaRC’s UPWT completed the Structures and Environments (STE) Aerodynamic Force and Moment Testing on SLS and marked its final role ahead of its closure. It would appear that Boeing’s PSWT has now taken the role continuing these testing activities.

“This test will cover cases in the range of Mach 0.5 – 1.6 and will be combined with the data from UPWT testing at Mach 1.5 – 4.5 to facilitate a complete aerodynamic force and moment database delivery planned for December, 2012,” the notes continued.

“The test has been proceeding well in two-shift operations, with about 30 percent of the planned test matrix completed.”

LaRC’s role with SLS testing has since moved on to the “Rigid Buffet Wind Tunnel” work, which saw the vehicle model installed in the Transonic Dynamics Tunnel (TDT), ahead of runs that began at the start of October.

“Overall, the installation on the model has checked out with 99.7 percent successful instrumentation operation, with only one bad Kulite pressure transducer. The model (carried out) an Air-flow checkout run to ring out any remaining issues. Full up testing (was) initiated immediately following that.”

Other testing has taken place, including on the Block 1B cargo only (SLS-27000) and crewed (SLS-28000) configurations, via the Force and Moment Test Program in the Trisonic Wind Tunnel at the Marshall Space Flight Center (MSFC). Even the Block 2 SLS – not set to launch until the 2030s – has undergone wind tunnel runs.

Orion Progress:

Wind tunnel testing is also continuing with the Orion crew capsule, as the Aerosciences team completed its planned wind tunnel tests at Calspan-University of Buffalo Research Center.

The testing was based around how Orion’s Reaction Control System (RCS) jet firings interact with air flowing around the crew module during re-entry and the effect of shock layer chemistry on heating to the Avcoat heatshield.

“These data will improve aerothermodynamic heating predictions on the crew module backshell and reduce heating uncertainties,” noted an Orion status update.

“The Aerosciences team is chartered to deliver environment databases covering all Orion flight phases as a government furnished equipment (GFE) product, and since program inception, the team has completed over 40 aerodynamic and 25 aerothermodynamic wind tunnel tests in facilities across the country.”

A major milestone for Orion is expected to take place in 2014, when a Delta IV-Heavy lofts the spacecraft on its first trip into space on the Exploration Flight Test-1 (EFT-1) mission.

Work is continuing inside Kennedy Space Center’s Operations & Checkout (O&C) building on the EFT-1 Orion that arrived from the Michoud Assembly Facility (MAF), with the placement of a birdcage tooling structure now seen around the vehicle, in order to assist the team with assembly operations.

“The team began installation of the ground test instrumentation and structures, including the forward gussets,” noted Orion Status. “The side hatch and docking hatch structures were delivered to KSC in preparation for the crew module proof test in October.”

Installation of the EFT-1 Service Module forward outboard ring is in progress and backshell panels were also installed on the Orion Ground Test Article – which is being prepared for loading in the crew module transportation fixture in support of an upcoming pyrotechnic shock test – around the same time as final assembly of one of the EFT-1 Service Module inboard panels was complete at MAF.

This panel is now ready to ship to KSC for final processing, while the other five service module composite inboard panels, all four diamond panels and one shear panel have all completed testing and will be ready for final assembly. In total, 49 panels that make up the service module composite panel structure.

MAF engineers have also completed the final curing of the EFT-1 Launch Abort System (LAS) conical adapter, final inspection of the EFT-1 Motor Adapter Truss Assembly flight cone following its final cure, and arrival of the LAS fillet panels 1 and 2, which were installed on the fixture for further assembly.

(Images: L2’s STS Sections, with additional via NASA)

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