When the exhaust nozzle on one of the Vulcan rocket's strap-on boosters failed shortly after launch earlier this month, debris scattered across the beachscape just east of the launch pad on Florida's Space Coast.
United Launch Alliance, the company that builds and launches the Vulcan rocket, is investigating the cause of the booster drift before Vulcan flights resume. Despite the nozzle failure, the rocket continued its climb and eventually reached its planned trajectory toward deep space.
The nozzle fell from one of Vulcan's two solid rocket boosters about 37 seconds after liftoff from the Cape Canaveral Space Force Station on Oct. 4. There were some indications of a problem with the booster a few seconds earlier, when tracking cameras observed hot exhaust gases just escaping. above the bell-shaped nozzle, which is screwed to the bottom of the booster housing.
A shower of sparks and debris fell from the Vulcan rocket as the nozzle failed. Julie Arnold, a spokesperson for ULA, confirmed to Ars that the company has recovered some of the debris.
“We recovered some small pieces of the GEM 63XL SRB nozzle that had been released near the launch pad,” Arnold said. “The team is inspecting the hardware to assist in the investigation.”
Under review
The solid rocket booster, or Graphite Epoxy Motor (GEM), was built by Northrop Grumman. It is a larger version of the booster used on ULA's Atlas V rocket, which will replace Vulcan. After the nozzle failure, the damaged booster continued to burn while the Vulcan rocket continued its descent over the Atlantic Ocean, albeit at a lower thrust level and with less efficiency.
Northrop Grumman graphite epoxy engines have a reliable track record. The GEM 63XL variant used on the Vulcan rocket is derived from smaller boosters that flew on the Atlas V, Delta IV, Delta III and Delta II rockets. The last failure of such a booster, a GEM 40 engine, was in January 1997, when a booster housing ruptured and led to the explosion of a Delta II rocket just 13 seconds after takeoff.
The Oct. 4 launch was the second test flight of the Vulcan rocket, following a nearly flawless debut launch in January. ULA launched the second Vulcan test flight without a payload after determining that Sierra Space's Dream Chaser spaceplane, originally assigned to fly on the second Vulcan rocket, would not be ready for launch this year.
