ULA Atlas 5 Launch Phase as SpaceX GPS Adjusts Rocket for Mission – Space Flight Now

The United Launch Alliance plans to launch an Atlas 5 rocket at Cape Canaveral on Wednesday to solve the problem of valves at the launch site, while a SpaceX team prepares a Falcon 9 rocket for liftof for the U.S. military on Thursday evening.

After failed attempts to fix the valve problem, ULA’s launch site cleared the Atlas 5 launch attempt just before 6pm EST (2300 GMT) on Wednesday, first remotely and then sent to the Atlas 5’s coastal launch pad with the technical team.

The Atlas 5 rocket will carry a classified load into orbit for the National Reassessment Office, the US government’s spy satellite agency. The launch pad is designated NROL-101, and the NRO has not released any details about the purpose of the payload, except to assist the company in its mission to gather and disseminate information to government intelligence agencies.

The ULA began the countdown of the Atlas 5 on Wednesday morning, launched the rocket, and continued with the guidance system test and other tests before loading the cryogenic propellants into the missile, at 5:54 pm EST (2254 GMT).

But the launch team stopped the countdown clock after an unexpected computer response from the remotely ordered ground system liquid oxygen valves, ”the ULA said in a statement.

“The team is constantly analyzing the system and will secure our next launch attempt before November 6th,” the ULA said.

The ULA said the next chance to launch the Atlas 5 rocket would be on Friday. The exact time for the Friday launch attempt was not immediately announced, but the launch time of the trip has been moved to four minutes earlier in the day. It will set Friday release time at 5:46 pm EST (2246 GMT).

The launch of the Atlas 5 was scheduled for Tuesday, but the ULA returned the rocket to its vertical hangar near the launch site, where the environmental control system pushes conditional air over a secret NRO ball above 206 feet (63) to replace the tube. -M) vehicle.

The crew returned the Atlas 5 to its launch pad late Tuesday in an attempt to launch it on Wednesday.

Ahead of the opportunity for the next Atlas 5 launch, SpaceX plans to launch a Falcon 9 rocket from nearby Bat 40 during a 15-minute window opening at 6:24 pm on Thursday.

The 229-foot-tall (70m) Falcon 9 rocket was standing on pad 40 Wednesday in preparation for Thursday evening launch. The Bat 40 is located a mile and a half (2.5 km) south of the Atlas 5 missile pad at Cape Canaveral.

The Falcon 9 rocket is set to launch the US space force’s GPS3 SV04 navigation satellite, filling the fleet of status and time stations used by billions of military and civilian users around the world.

SpaceX GPS Satellite Oct Tried to pay 2, but a mechanical problem forced an automatic stop two seconds before the lift.

Engineers investigating the October 2 shutdown said two of the rocket’s nine first-stage engines tended to ignite one split-second more than expected. Prohibited relief valve tests on the gas engines of both engines increased the pressure faster than initially designed, and the sensors in the engines detected the problem and stopped the countdown.

SpaceX engineers Has identified the occult treatment Two Merlin engines were inadvertently left to the countdown, which was abandoned last month.

“When we looked at the data, we saw that two engines initially tried to start, and the auto stop prevented it,” said Hans Kனniksmann, vice president of development and aircraft reliability at SpaceX. “In doing so, it prevented a difficult start that could cause damage to the machine hardware.”

Merlin engines operate with the help of an ignition fluid called TEA-TEB – or triethyllum aluminum-triethylporene, which initially gives a bright green flash-off ignition line.

“Then we have liquid oxygen, we have kerosene or RP-1,” Koenigsman said in a conference call with reporters last week. “You have to introduce these fluids in the right order. If you do this in the wrong order and you happen to be sprayed with liquid oxygen and RP-1 and ignition fluid, what happens is what we call a rough start. ”

A hard start can “noise” the machine in most cases, but can also cause damage, Koenigsman said. “So in general, you don’t like it. You need a good start. ”

SpaceX sent the Merlin engines back to a test site in central Texas, where experiments led to a pressure relief valve in the gas generator on two engines with an object blocking one object.

Koenigsman said the vent port, which represents one-sixteenth of an inch wide, is blocked by hardened mask lacquer. Liquid lacquer – similar to red nail polish – by a third-party vendor who anodizes aluminum engine components for SpaceX, he said.

The lacquer protects some parts during the anodizing treatment process, but the seller – who is not identified by the authorities – must remove the material before sending the components to SpaceX for machine production.

The gas generator in each Merlin engine delivers kerosene and liquid oxygen powered by a turbo pump into the main combustion chamber.

Engineers at SpaceX’s Macricore test site demonstrated that the engines worked normally after removing the block from the vent valve. Koenigsman said the issue was “very subtle, but could have some negative impact on mechanical operation.”

“The GPS 3-4 mission will use the same booster for the first launch,” said Walt Lauderdale, director of the GPS 3-4 mission at the Space Force’s Center for Space and Missile Systems. “The two engines that led to the launch site stop were replaced with what was confirmed by inspection and descent review that the remaining mask was not lacquered.”

SpaceX and Space Force officials checked that all nine Merlin engines in the Falcon 9 rocket were ready for flight after a test fire on Pad 40 on Saturday.

In addition to the rocket for the GPS mission, the engine issue has also affected a couple of upcoming NASA launch vehicles. So far, the issue has only affected the work planned to use the new Falcon 9 boosters.

The first operational aircraft of SpaceX’s Crew Dragon spacecraft is scheduled to launch its half-year journey from the Kennedy Space Center on November 14 with three NASA astronauts and a Japanese mission expert to the International Space Station.

SpaceX replaces two Merlin engines on the Falcon 9 rocket for the Crew Dragon mission, and the engineers have been affected by the same early launch trend that the engines on the rocket displayed for the GPS mission. This issue delayed the launch of the Crew Dragon from Oct. 31 to Nov. 14.

NASA Business Group Program Manager Steve Stitch said last week that the agency’s engineers wanted to analyze machine data from a GPS launch before clearing the Crew Dragon later this month.

The mechanical problem has also delayed the launch of the US-European Sentinel-6 Michael Freelich Maritime Satellite from the Vandenberg Air Force Base in California. That work was originally expected to explode on November 10, but is now scheduled to begin on November 21.

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