{"id":12139,"date":"2020-10-31T23:15:54","date_gmt":"2020-10-31T15:15:54","guid":{"rendered":"https:\/\/wp-productionenv-bjg9h2g2bgg5b8aa.southeastasia-01.azurewebsites.net\/news\/spacex-test-fires-falcon-9-rocket-before-gps-launch\/"},"modified":"2020-10-31T23:15:54","modified_gmt":"2020-10-31T15:15:54","slug":"spacex-test-fires-falcon-9-rocket-before-gps-launch","status":"publish","type":"post","link":"https:\/\/starpath.global\/news\/spacex-test-fires-falcon-9-rocket-before-gps-launch\/","title":{"rendered":"SpaceX test-fires Falcon 9 rocket before GPS launch"},"content":{"rendered":"
\"\"
A Falcon 9 rocket test-fires its nine Merlin 1D engines Saturday at 7 p.m. EDT (2300 GMT). Credit: Spaceflight Now<\/figcaption><\/figure>\n

SpaceX test-fired a Falcon 9 rocket at Cape Canaveral on Saturday in a pre-flight checkout designed to verify the launcher\u2019s engines are ready to loft a U.S. military GPS navigation satellite into orbit Nov. 5.<\/p>\n

An engine problem forced SpaceX to abort a launch attempt in early October.<\/p>\n

After identifying the issue, SpaceX test-fired the Falcon 9 rocket for the GPS mission again Saturday at 7 p.m. EDT (2300 GMT) on pad 40 at Cape Canaveral Air Force Station. The test was intended to verify corrective actions have resolved the issue.<\/p>\n

SpaceX rolled the two-stage rocket \u2014 without its GPS navigation satellite payload \u2014 to pad 40 and raised the Falcon 9 vertical Saturday. The launch team stationed in a nearby control center oversaw loading of kerosene and liquid-oxygen propellants into the rocket Saturday evening ahead of the 7 p.m. test-firing.<\/p>\n

The rocket\u2019s nine Merlin 1D engines ignited with a flash and a rumble across the Cape Canaveral spaceport. The engines fired for several seconds, ramping up to 1.7 million pounds of thrust as hold-down clamps kept the Falcon 9 firmly on the ground.<\/p>\n

SpaceX later confirmed in a tweet that the test-firing was completed, setting the stage for final launch preparations. The mission is scheduled to lift off Thursday, Nov. 5, SpaceX wrote in a tweet.<\/p>\n

The mission had previously been scheduled to launch as soon as Wednesday, according to multiple sources.<\/p>\n

The Falcon 9 rocket will be rolled back to its hangar, where SpaceX will mount the U.S. Space Force\u2019s GPS 3 SV04 navigation satellite onto the vehicle. The spacecraft is already encapsulated inside the Falcon 9\u2019s payload shroud.<\/p>\n

The GPS 3 SV04 mission was ready to take off Oct. 2, but SpaceX halted the countdown at the start of the engine ignition sequence just two seconds prior to liftoff.<\/p>\n

Engineers investigating the Oct. 2 abort found that two of the engines on the rocket had a tendency to ignite a split-second earlier than expected. Inspections showed a blocked relief valve in the gas generators of the two engines caused pressures to rise sooner than designed at startup, and sensors on the engines detected the problem and halted the countdown.<\/p>\n

SpaceX presumably has replaced the two suspect engines on the Falcon 9 rocket. A Space Force spokesperson referred inquiries to SpaceX, and a SpaceX spokesperson did not respond to questions on the matter.<\/p>\n

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The GPS 3 SV04 navigation satellite is encapsulated inside the payload fairing of its Falcon 9 launcher near Cape Canaveral. Credit: U.S. Space Force<\/figcaption><\/figure>\n

The Lockheed Martin-built GPS 3 SV04 navigation satellite is the fourth in a new generation of GPS satellites with longer lifetimes, higher power, and more accurate navigation signals. The GPS 3 SV04 spacecraft is set to join 31 operational GPS satellites in orbit 12,550 miles (20,200 kilometers) above Earth.<\/p>\n

SpaceX engineers identified a masking treatment inadvertently left behind in two Merlin engines as the cause of the Oct. 2 abort.<\/p>\n

\u201cWhen we looked at the data, we saw that two of the engines attempted to start early, and the auto abort prevented that,\u201d said Hans Koenigsmann, SpaceX\u2019s vice president of build and flight reliability. \u201cAnd by doing that, it prevented a possible hard start that could have been damaging to the engine hardware.\u201d<\/p>\n

The Merlin engines power up with help from an igniter fluid known as TEA-TEB \u2014 or triethylaluminium-triethylborane \u2014 that gives off a bright green flash at the start pf the ignition sequence.<\/p>\n

\u201cAnd then we have liquid oxygen, and we have kerosene, or RP-1 as its called,\u201d Koenigsmann said last week in a conference call with reporters. \u201cAnd you need to introduce these liquids in the right order. If you do this in the wrong order, if you happen to throw in the liquid oxygen and the RP-1 and the igniter fluid, then what would happen is we call it a hard start.\u201d<\/p>\n

A hard start would \u201crattle\u201d the engine in most cases, but could cause damage, Koenigsmann said. \u201cSo in general, you do not want that. You want a good startup.\u201d<\/p>\n

\u201cIf we see the pressure rise too early, then we know liquid is in there, and it shouldn\u2019t be there,\u201d he said. \u201cAnd software in the engine controller then stops the whole process.\u201d<\/p>\n

Inspections at the launch pad uncovered no sign of a hardware problem on the Merlin engines after the Oct. 2 abort. After returning the Falcon 9 rocket to its hangar, technicians removed the engines and shipped them to SpaceX\u2019s test facility in McGregor, Texas.<\/p>\n

SpaceX was able to analyze the engines\u2019 startup behavior in McGregor, and additional inspections found a blockage in a narrow line leading to a relief valve on the gas generator.<\/p>\n

Koenigsmann said the vent port, which means just one-sixteenth of an inch wide, was obstructed by a hardened masking lacquer. He said liquid lacquer \u2014 similar to red nail polish \u2014 is used by a third-party vendor that anodizes aluminum engine components for SpaceX.<\/p>\n

The lacquer protects certain parts during the anodizing treatment process, but the vendor \u2014 which officials did not identify \u2014 is supposed remove the material before shipping the components to SpaceX for engine manufacturing.<\/p>\n

The gas generator on each Merlin engine drives a turbopump feeding kerosene and liquid oxygen propellants into the main combustion chamber.<\/p>\n

\u201cIt\u2019s obviously a very important part,\u201d Koenigsmann said. \u201cThat little red substance was blocking a relief valve that caused it to (ramp up pressure) a little bit earlier than it was supposed to.\u201d<\/p>\n

\u201cProbably during the washing or the cleaning process some of that masking lacquer went into this vent hole and blocked it,\u201d Koenigsmann said.<\/p>\n

\u201cHow was this missed? The little borehole that goes to the vent valve is tiny. It\u2019s 60 thousandths of an inch \u2026 When something goes in there and is hung in there, it\u2019s possible you miss it,\u201d Koenigsmann said. \u201cYou shouldn\u2019t \u2026 but I can see how people overlook that and didn\u2019t quite see that, even if it is red.\u201d<\/p>\n

Engineers at SpaceX\u2019s McGregor test site also demonstrated that the engines performed normally after removing the blockage from the vent valve. Koenigsmann said the issue was \u201cvery subtle, but can have obviously some negative impact on the engine operation.\u201d<\/p>\n

\u201cNo question that rocketry is tough and requires a lot of attention to detail,\u201d Koenigsmann said. \u201cTo me, this almost tells me that rockets are humbling me every day I work with them. It\u2019s always a challenge, and it\u2019s always difficult, and you have to be super diligent and on your toes to get this right.\u201d<\/p>\n

SpaceX engineers had not detected the problem before. Older boosters in SpaceX\u2019s fleet of reusable Falcon 9 rockets seem to not exhibit early ignition data signature, but the rockets for the GPS and Crew-1 missions are brand new.<\/p>\n

\u201cWhat we\u2019ve noticed is this is something that must have happened within the last couple of months, so it affects primarily engine build dates that are on new boosters and not on old boosters,\u201d Koenigsmann said.<\/p>\n

Besides the rocket for the GPS mission, which will use a new Falcon 9 booster, the engine issue has also affected vehicles for a pair of upcoming NASA launches.<\/p>\n

The first operational flight of SpaceX\u2019s Crew Dragon spaceship is set for liftoff Nov. 14 from the Kennedy Space Center with three NASA astronauts and a Japanese mission specialist to kick off a half-year expedition on the International Space Station.<\/p>\n

SpaceX is replacing two Merlin engines on the Falcon 9 rocket for the Crew Dragon mission that engineers found suffered from the same early startup tendency exhibited by the engines on the rocket for the GPS mission. The problem delayed the Crew Dragon launch from Oct. 31 to Nov. 14.<\/p>\n

A U.S.-European oceanography satellite named Sentinel-6 Michael Freilich was supposed to launch on another brand new Falcon 9 booster Nov. 10 from Vandenberg Air Force Base, California. Kathy Lueders, head of NASA\u2019s human exploration and operations division, said Oct. 30 that the Sentinel-6 Michael Freilich launch would be delayed later into November, \u201cpending ongoing analysis of data from engines.\u201d<\/p>\n

Email the author.<\/i><\/b><\/p>\n

Follow Stephen Clark on Twitter: @StephenClark1.<\/strong><\/em><\/p>\n","protected":false},"excerpt":{"rendered":"

A Falcon 9 rocket test-fires its nine Merlin 1D engines Saturday at 7 p.m. EDT (2300 GMT). Credit: Spaceflight Now SpaceX test-fired a Falcon 9 rocket at Cape Canaveral on Saturday in a pre-flight checkout designed to verify the launcher\u2019s engines are ready to loft a U.S. military GPS navigation satellite into orbit Nov. 5. […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"inline_featured_image":false,"footnotes":"","_links_to":"","_links_to_target":""},"categories":[2],"tags":[1315,291,1736,1573,479,2015,2016,25],"class_list":["post-12139","post","type-post","status-publish","format-standard","hentry","category-news","tag-b1062","tag-commercial-space","tag-complex-40","tag-drone-ship","tag-falcon-9","tag-gps","tag-gps-3-4","tag-launch"],"acf":[],"_links":{"self":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts\/12139"}],"collection":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/comments?post=12139"}],"version-history":[{"count":0,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts\/12139\/revisions"}],"wp:attachment":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/media?parent=12139"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/categories?post=12139"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/tags?post=12139"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}