[ad_1]
The United Launch Alliance has called for a planned launch of the Atlas 5 rocket at Cape Canaveral on Wednesday to fix the valves problem on the launch pad, while a SpaceX team to the south prepared Day Mail for an elevator on Thursday evening. With GPS navigation satellite.
On Wednesday the ULA launch team canceled an attempt to launch the Atlas 5 at 18:00 EST (2300 GMT), before failed attempts to fix the valve problem, first remotely and then with a team of technicians who launched the Atlas 5 out to sea. Party for the launch pad.
The Atlas 5 rocket will line up a classified payload for the US government spy agency, the National Reconnaissance Office. The launch was named NRL-1 101ated and the NRO did not provide any clarification on the payroll mission, other than assisting the agency in gathering and disseminating information to government intelligence agencies.
The ULA did not launch the Atlas 5 countdown on Wednesday morning, launched the rocket, and proceeded with tests of the guidance system and other controls before loading cryogenic propellants into the launcher before the scheduled lift at 5:54 am EST (2254 GMT). Done.
However, the initial team stopped the countdown “after a sudden response from a remotely operated ground system liquid oxygen valve,” the ULA said in a statement.
“The team continues to analyze the system and will defend our next launch commitment before November 6,” the ULA said.
The next opportunity to launch the Atlas 5 rocket will be Friday, the ULA said. The exact time of Friday’s initial effort was not announced immediately, but the mission start time was increased to four minutes per day. It will set the start time on Friday around 5:46 PM EST (2246 GMT).
The launch of the Atlas 5 was originally scheduled for Tuesday, but the ULA launched a rocket to replace the top-secret NRO payload atop the 206-foot (63) tall rocket to replace the environmental control system that powers the conduits . Returned to their upright hanger nearby. -M) vehicle.
Ground crews returned the Atlas 5 to its launch pad late Tuesday in preparation for Wednesday’s initial effort.
Before the launch of the next Atlas 5, SpaceX plans to launch a Falcon 9 rocket from nearby Pad 40 during the opening of a 15-minute window at 6:24 PM EST (2324 GMT) on Thursday.
The 229-foot (70-meter) long Falcon 9 rocket landed on Platform 40 on Wednesday in preparation for launch Thursday night. Pad 40 is located approximately 2.5km south of the Atlas 5 launch pad in Cape Canaveral.
The Falcon 9 rocket is designed to lift the SV04 GPS 3 navigation satellite for US space forces, filling the fleet of space and time stations used by billions of military and civilian users around the world.
SpaceX attempted to launch the GPS satellite on October 2, but an engine problem forced an automatic abortion just two seconds before lifting.
Engineers investigating the October 2 abortion found that the rocket had a tendency to ignite the split second before the first of nine planned nine-stage engines. Investigations showed that an outage in the gas generators of both engines was due to the pressure rising faster than the pressure created at the starter valve, and the engines and sensors detected the problem and stopped the countdown.
SpaceX engineer identified a masking treatment Last month, two of Merlin’s engines were unknowingly overlooked.
“When we look at the statistics, we see that two engines tried to start early and the automatic abortion stopped it,” said Hans Konigsman, vice president of spaceX at Build and Flight Reliability. “And in doing so, it prevented a potentially difficult start that could damage the engine hardware.”
Merlin is strengthened with the help of an inert fluid called TEA-TEB – or triethylluminium-triethylboraine – which helps in early PF. Ignition provides a bright green flash in order.
“And then we have liquid oxygen, and we have kerosene, or RP-1,” Koenigsman told reporters last week. “And you have to present these fluids in the right order. If you do it in the wrong order, if you want to drop liquid oxygen and RP-1 and igniter fluids, then what’s going to happen, we call it hard start. “
Konigsman said a strong start would “haywire” the engine in most cases, but could cause damage. “So you usually don’t want to. You want a good start. “
SpaceX sent Merlin’s engines back to a test site in central Texas, where inspections revealed a substance that interfered with one line, causing a pressure relief valve in the gas generator on the two engines. IS.
Konigsman said the vent door, which means only one sixth of an inch wide, was blocked by cut masking wood. He said liquid lacquer – similar to red polish – is used by a third-party vendor who anodizes aluminum engine parts for SpaceX.
The cabinet protects some parts during the anodizing treatment process, but the seller – who has not been identified by the authorities – should remove the material before sending the parts to SpaceX for construction of the engine.
The gas generator on each Merlin engine delivers a turbopump that feeds kerosene and liquid oxygen propellants to the main combustion chamber.
SpaceX’s McGregor test site engineers demonstrated that the engines operated normally after removing the obstruction from the vent valve. Koenigsman said the problem was “very subtle, but obviously there could be some negative effects on engine operation”.
“The GPS mission-mission will still use the same booster as the first launch attempt,” said the mission director GPS 3-4 at the Space Force and Missile Systems Center. “The two engines that boosted launch abortions have been replaced by inspections and verification reviews, with no surviving masking lacquer replacements.”
SpaceX and Space Force officials confirmed that all nine Marlin engines of the Falcon 9 rocket were ready to take off after a test launch on a pad 40 on Saturday.
In addition to rockets for GPS missions, engine problems have also affected vehicles for a couple of upcoming NASA openings. So far, the problem has only affected missions using the new Falcon 9 boosters.
The first operational flight of SpaceX’s Crew Dragon spacecraft will begin on November 14 for a six-month journey to the International Space Station with three NASA astronauts and a Japanese mission expert for a lift from the Kennedy Space Center.
SpaceX is replacing the two Merlin engines on the Falcon 9 rocket for the Curl Dragon mission, which engineers found disturbed by the same initial trend shown by the rocket’s engines for the GPS mission. The issue delayed the launch of Crew Dragon from October 31st to November 14th.
NASA commercial crew program manager Steve Stitch said last week that the agency’s engineers wanted to analyze engine data from the GPS launch before releasing the crew dragon for a lift at the end of the month.
The engine problem also delayed the launch of the US-European Sentinel-6 Michael Freilich oceanographic satellite from Vandenberg Air Force Base in California. That mission was originally scheduled to explode on November 10, but is now scheduled to launch on November 21.
Email the author.
Follow Stephen Clark on Twitter: Stephen Clark 1.
[ad_2]
Source link
