While the test was in mid-April,this Friday United Launch Alliance announced the completion of a critical milestone on the road to resuming flights with its Vulcan rockets.
On April 15, the company said Northrop Grumman performed a successful static fire test of a Graphite Epoxy Motor (GEM) 63XL Solid Rocket Booster (SRB). A spokesperson told Spaceflight Now on Thursday that the test served to “demonstrate nozzle design enhancements which were already in work and an advanced propellant technology for future solid rocket motors across their portfolio.”
You will recall that, like the second Vulcan launch, on the third Vulcan launch an SRB failed during the first stage ascent - the earliest phase of the rockets trip to orbit. This affected the mission, but the control systems on the vehicle were able to compensate for the difference in thrust and its direction and still deliver the payload to the desired orbit.
“There was some asymmetric thrust when we had that solid motor fail, it reduced performance,” said Gary Wentz, vice president of Government and Commercial Programs at ULA. He spoke with Spaceflight Now in the days leading up to the Artemis 2 launch.
“The BE-4s and our avionics system gimbaled to control that. We did see some roll, and the BE-4s were able to compensate to arrest that roll. We were well within our environments and limits, so it was nothing overly concerning for the BE-4s.”
The ULA voices quoted in the article express confidence that the Vulcan will be cleared to fly before the end of this year, but they don't really provide information about the cause of the SRB problem and what's being done to address keeping it from happening again. They do mention that there are versions of the Vulcan that don't require the extra lift capacity the SRBs provide and those can be launched now.
“We’re available for other missions. [The Commercial Lunar Payload Services program] had a lot of smaller landers and things that we could fly to do some of those precursor efforts with the Moon and the mission that NASA’s laying out. So, we’re really excited about the opportunities.”
To accommodate the demand for launches, ULA has modified their launch complex on Cape Canaveral, Space Launch Complex 41, adding a newly finished Vertical Integration Facility – Amazon (VIF-A). This gives ULA two vertical integration options, either an Atlas 5 rocket or a Vulcan rocket in the original VIF, called VIF-G (Government), while a Vulcan rocket uses the new VIF-A.
Amazon Leo’s next flight is scheduled to be the Leo Atlas 07 (LA-07) mission, currently scheduled for no earlier than Friday May 29 at 12:27 PM EDT. The final batch of Leo satellites to fly on an Atlas V rocket will launch later this year on the LA-08 mission. The launch date of the LA-08 mission hasn't been announced yet.
ULA's Atlas V rocket lifts off from Space Launch Complex 41 at Cape Canaveral Space Force Station, Florida. Credit: United Launch Alliance
Wow, so good of them to test the SRBs after they have problems. Yeesh.
ReplyDeleteThey test them BEFORE as well. but those tests are static. This was a test of the FIXES for the problems they previously had in flight.
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