NASA goes old school with SLS aerodynamic testing
NASA is turning to a 56-year-old wind tunnel to put its next generation Space Launch System (SLS) rocket through its aerodynamic paces. The model used in the test represents a cargo variant of the SLS that will stand slightly taller than the eventual first crewed version of the rocket, which will be tested during an unmanned mission in late 2018.
The SLS is being designed as a multi use launch vehicle, which will extend the capabilities of manned spaceflight beyond the limits of low-Earth orbit. Among other goals, the powerful launch system will make possible the first manned exploration of a near-Earth asteroid, and, alongside the agency's Orion spacecraft, will represent a vital element of NASA's grand ambition of placing mankind on Mars.
The SLS rocket family will eventually be available in four distinct configurations, allowing the launch system to cater for a wide range of crew and cargo transportation needs. The first and smallest configuration of the rocket, known as SLS Block 1, will launch in late 2018, catapulting an unmanned Orion spacecraft on the first step of its test mission to orbit the Moon.
For the recent aerodynamic tests, NASA looked beyond the rocket's maiden flight to test the qualities of the SLS 1B Cargo configuration. This 327 ft (99.6 m) tall manifestation of the SLS will boast an impressive lift capacity of 105-metric-tons (115-tons).
The ability to transport heavy payloads into space will allow NASA to operate in the area surrounding, and beyond, Earth's moon. This isolated yet accessible environment represents the perfect region in which to test technologies that will later be used in the journey to Mars.
However, prior to plunging a payload into the inhospitable environment of outer space, the SLS 1B will first have to survive a journey through Earth's dense lower atmosphere. To test the structural strength and aerodynamic qualities of the future SLS 1B, NASA placed a 10 ft (3.4 m) model of the rocket inside its venerated Transonic Dynamics Tunnel, located at the agency's Langley Research Center in Virginia.
The model was fitted with 446 miniature microphones, and subjected to transonic wind speeds in an attempt to simulate a high-velocity journey through Earth's lower atmosphere.
"Just below supersonic is where shock waves begin to form on the vehicle and can dance and oscillate on the rocket," explained Langley rocket scientist Dave Piatak. "The first step of these missions is safely getting above Earth's atmosphere and into orbit."
As the faux rocket was put through its paces, the onboard microphones harvested data detailing how the launcher behaved when confronted with uneven winds and pressures. Moving forward, this data will be used to inform a computer model of the SLS, which will allow NASA to undertake detailed simulations regarding the rocket's structural strength during flight.