{"id":16131,"date":"2015-08-13T19:07:31","date_gmt":"2015-08-13T11:07:31","guid":{"rendered":"https:\/\/wp-productionenv-bjg9h2g2bgg5b8aa.southeastasia-01.azurewebsites.net\/news\/rocket-engine-fires-up-in-latest-test-for-behemoth-booster\/"},"modified":"2015-08-13T19:07:31","modified_gmt":"2015-08-13T11:07:31","slug":"rocket-engine-fires-up-in-latest-test-for-behemoth-booster","status":"publish","type":"post","link":"https:\/\/starpath.global\/news\/rocket-engine-fires-up-in-latest-test-for-behemoth-booster\/","title":{"rendered":"Rocket engine fires up in latest test for behemoth booster"},"content":{"rendered":"<figure id=\"attachment_8255\" aria-describedby=\"caption-attachment-8255\" style=\"width: 620px\" class=\"wp-caption alignnone\"><img fetchpriority=\"high\" decoding=\"async\" class=\" wp-image-8255\" src=\"http:\/\/spaceflightnow.com\/wp-content\/uploads\/2015\/08\/EyeTVSnapshot1082.jpg\" alt=\"NASA test-fired an RS-25 development engine Thursday at the Stennis Space Center in Mississippi. Credit: NASA TV\/Spaceflight Now\" width=\"620\" height=\"349\" srcset=\"https:\/\/spaceflightnow.com\/wp-content\/uploads\/2015\/08\/EyeTVSnapshot1082.jpg 1248w, https:\/\/spaceflightnow.com\/wp-content\/uploads\/2015\/08\/EyeTVSnapshot1082-300x169.jpg 300w, https:\/\/spaceflightnow.com\/wp-content\/uploads\/2015\/08\/EyeTVSnapshot1082-768x432.jpg 768w, https:\/\/spaceflightnow.com\/wp-content\/uploads\/2015\/08\/EyeTVSnapshot1082-1024x576.jpg 1024w, https:\/\/spaceflightnow.com\/wp-content\/uploads\/2015\/08\/EyeTVSnapshot1082-678x381.jpg 678w\" sizes=\"(max-width: 620px) 100vw, 620px\"><figcaption id=\"caption-attachment-8255\" class=\"wp-caption-text\">NASA test-fired an RS-25 development engine Thursday at the Stennis Space Center in Mississippi. Credit: NASA TV\/Spaceflight Now<\/figcaption><\/figure>\n<p>A hydrogen-fueled rocket engine ignited with a bone-rattling sonic wave Thursday at NASA\u2019s test facility in Southern Mississippi, throttling up to more than a half-million pounds of thrust to verify upgrades to the space shuttle\u2019s main engines can power a humongous new launcher off the planet.<\/p>\n<p>Engineers recorded data from hundreds of telemetry channels routing information about the engine\u2019s pressures, loads, temperatures and performance while the powerplant stayed bolted inside a test stand at the Stennis Space Center in Mississippi.<\/p>\n<p>The engine fired at 5:01 p.m. EDT (2101 GMT; 4:01 p.m. CDT) and promptly powered up to 512,000 pounds of thrust within six seconds. In NASA-speak, the power level is known as a 109 percent throttle setting.<\/p>\n<p>Pre-test plans called for the engine to power down to about 80 percent thrust later in the firing, then ramp back up to more than 90 percent performance, according to Steve Wofford, manager of the engine project for the Space Launch System, a huge rocket NASA is developing to eventually send astronauts farther from Earth than any mission before.<\/p>\n<p>Burning more than 300 gallons of cryogenic liquid propellant every second, the rocket engine let out a thunderous blast for 535 seconds \u2014 nearly nine minutes \u2014 and launched a billowing cloud of water vapor exhaust thousands of feet into a sun-splashed sky.<\/p>\n<p>Hundreds of VIPS, reporters and social media representatives invited to the test by NASA viewed the engine firing from 1,250 feet away, snapping photos while wearing earplugs to protect against the 120-decibel roar from the engine.<\/p>\n<p>Thursday\u2019s test firing is the latest in a series of runs to qualify modifications to the shuttle-era RS-25 engine to fly on the new rocket in a configuration never envisioned by its designers.<\/p>\n<p>NASA managers selected the space shuttle engines for the Space Launch System as a cost-saving measure. The engines are also well-suited for the new launcher, but four of them will fly per mission instead of the triplet configuration used on the shuttle.<\/p>\n<p>\u201cIt\u2019s the best technical solution, by far, for SLS propulsion,\u201d Wofford said. \u201cIt\u2019s also the most affordable solution for this vehicle.\u201d<\/p>\n<p>Kathryn Crowe, an RS-25 engineer, calls it the \u201cFerrari of rocket engines.\u201d<\/p>\n<p>\u201cIt is designed to be highly efficient,\u201d Crowe said. \u201cWhen you\u2019re looking at designing a rocket engine, there are several different ways you can optimize it. You can optimize it through increasing its thrust, through increasing the weight to thrust ratio or increasing it\u2019s overall efficiency and how it consumes your propellants. With this engine, they maximized all three of those.\u201d<\/p>\n<p><iframe loading=\"lazy\" width=\"678\" height=\"381\" src=\"https:\/\/www.youtube.com\/embed\/fKCI7K2-NEE?start=1869&amp;feature=oembed\" frameborder=\"0\" allowfullscreen=\"\"><\/iframe><\/p>\n<p>The shuttle main engines are a product of the 1970s, and were designed in an era lacking the high-fidelity modeling and computational analysis available to rocket engineers today.<\/p>\n<p>But the engines are still at the leading edge of rocket science, said a chorus of engineers visiting with reporters at Stennis on Thursday.<\/p>\n<p>Temperatures inside the engine reach 6,000 degrees Fahrenheit, and super-cold liquid hydrogen chilled to minus 423 degrees channels through the engine to keep it from overheating. Exhaust coming out of the nozzle exits at 13 times the speed of sound, according to NASA.<\/p>\n<p>\u201cThe amazing thing about the RS-25 is the amount of energy that\u2019s packed into such a small machine,\u201d said Tom Martin, project manager for advanced space and launch at Aerojet Rocketdyne, the engine\u2019s manufacturer. \u201cIt\u2019s literally at the edge of engineering.\u201d<\/p>\n<p>But engineers say the powerplants on SLS will encounter more extreme conditions than they saw on shuttle launches.<\/p>\n<p>\u201cWhy do we test the engines? It\u2019s a stable design, it\u2019s a mature design, we have the engines in hand, and most of them have flown before, (but) there are some new things we had to develop and certify,\u201d Wofford said.<\/p>\n<p>Honeywell and Aerojet Rocketdyne developed a new computer to signal commands to the engine\u2019s valves, actuators and other systems. The upgraded controllers replaces an obsolete computer flown on the shuttle.<\/p>\n<p>The mammoth Space Launch System core stage stands 212 feet tall \u2014 much higher than the shuttle\u2019s rust-colored, foam-covered fuel tank \u2014 so propellant will rush into the engine at higher pressures.<\/p>\n<p>\u201cThat tall a tank gives you a greater pressure down at the bottom of the tank,\u201d Wofford said. \u201cIt\u2019s like being deep in a swimming pool. The pressure is pretty high at the bottom. It\u2019s higher than the engines are used to seeing. They can handle it, but we test to prove that they can handle it.\u201d<\/p>\n<p>Engineers were interested in several other key data points from Thursday\u2019s test, the sixth in a series of seven firings of a ground version of the RS-25.<\/p>\n<figure id=\"attachment_8256\" aria-describedby=\"caption-attachment-8256\" style=\"width: 622px\" class=\"wp-caption alignnone\"><img loading=\"lazy\" decoding=\"async\" class=\" wp-image-8256\" src=\"http:\/\/spaceflightnow.com\/wp-content\/uploads\/2015\/08\/9970558766_2b36565a1e_z.jpg\" alt=\"Artist's concept of the Space Launch System, showing its two solid rocket boosters jettisoned from the core stage, which is powered by four RS-25 main engines. Credit: NASA\" width=\"622\" height=\"350\" srcset=\"https:\/\/spaceflightnow.com\/wp-content\/uploads\/2015\/08\/9970558766_2b36565a1e_z.jpg 640w, https:\/\/spaceflightnow.com\/wp-content\/uploads\/2015\/08\/9970558766_2b36565a1e_z-300x169.jpg 300w\" sizes=\"(max-width: 622px) 100vw, 622px\"><figcaption id=\"caption-attachment-8256\" class=\"wp-caption-text\">Artist\u2019s concept of the Space Launch System, showing its two solid rocket boosters jettisoned from the core stage, which is powered by four RS-25 main engines. Credit: NASA<\/figcaption><\/figure>\n<p>Besides the new computer and higher pressures, the engines will get much hotter on the Space Launch System because the design puts them closer to the molten exhaust plume from the launcher\u2019s twin solid rocket boosters.<\/p>\n<p>\u201cWe\u2019re going after several specific test objectives,\u201d Wofford said. \u201cOne of those is to check the performance of the ablative material on the nozzle. The engines are co-planar with the boosters on SLS, so they see much higher temperature conditions. We\u2019re adding ablative (material) to the outside of the nozzle to protect against that.\u201d<\/p>\n<p>Thursday\u2019s hold-down firing also verified new engine chilldown procedures for SLS countdowns, in which controllers pre-condition the engines for ignition by routing cryogenic propellant through plumbing leading to the powerplants.<\/p>\n<p>NASA has 16 RS-25 engines in inventory, including new units assembled out of spare parts. The other 14 engines flew in space on shuttle missions.<\/p>\n<p>\u201cThat\u2019s a tremendous head start,\u201d Wofford said. \u201cThat\u2019s four full flight sets of RS-25s for SLS.\u201d<\/p>\n<p>The engines will collectively generate 2 million pounds of thrust at launch, about one-quarter of the 8.4 million pounds of total thrust when coupled with the Space Launch System\u2019s solid rocket boosters, also derived from shuttle technology.<\/p>\n<p>NASA plans to install a single-engine upper stage borrowed from United Launch Alliance\u2019s Delta 4 rocket on top of the huge main stage, giving the rocket enough energy to loft up to 70 metric tons \u2014 about 154,000 pounds \u2014 into low Earth orbit. Later missions will fly with a larger four-engine upper stage to carry up more cargo.<\/p>\n<p>The first SLS test flight is scheduled for 2018. Launching from the Kennedy Space Center in Florida, the rocket will send an uncrewed Orion spacecraft into orbit around the moon for a shakedown cruise lasting more than three weeks.<\/p>\n<p>A mission with four astronauts following a similar flight profile will take off in 2021.<\/p>\n<p>Engineers plan to fire the engines at 109 percent thrust on initial test flights, a level qualified for shuttle flights but never used. Later launches could fly with RS-25 engines at an even higher throttle setting.<\/p>\n<figure id=\"attachment_8257\" aria-describedby=\"caption-attachment-8257\" style=\"width: 620px\" class=\"wp-caption alignnone\"><img loading=\"lazy\" decoding=\"async\" class=\" wp-image-8257\" src=\"http:\/\/spaceflightnow.com\/wp-content\/uploads\/2015\/08\/rs25test_1.jpg\" alt=\"NASA distributed earplugs to protect against the 120-decibel roar of the RS-25 main engine. Credit: Stephen Clark\/Spaceflight Now\" width=\"620\" height=\"350\" srcset=\"https:\/\/spaceflightnow.com\/wp-content\/uploads\/2015\/08\/rs25test_1.jpg 940w, https:\/\/spaceflightnow.com\/wp-content\/uploads\/2015\/08\/rs25test_1-300x169.jpg 300w, https:\/\/spaceflightnow.com\/wp-content\/uploads\/2015\/08\/rs25test_1-768x434.jpg 768w\" sizes=\"auto, (max-width: 620px) 100vw, 620px\"><figcaption id=\"caption-attachment-8257\" class=\"wp-caption-text\">NASA distributed earplugs to protect against the 120-decibel roar of the RS-25 main engine. Credit: Stephen Clark\/Spaceflight Now<\/figcaption><\/figure>\n<p>\u201cWe want to be able to run these engines at 111 percent thrust,\u201d said Todd May, NASA\u2019s SLS program manager at the Marshall Space Flight Center in Huntsville, Alabama. \u201cFor us engineers, and if you\u2019re a little bit OCD, it\u2019s kind of interesting that we take engines that were designed for 100 percent and we do like Spinal Tap and turn it up to 11. But that\u2019s what we do, we run them at 111 percent.\u201d<\/p>\n<p>\u201c109 percent is the baseline plan,\u201d Wofford said. \u201cWe will later ramp up to 111 percent later in the program. 109 percent is low-hanging fruit, we could do that tomorrow and we have been doing that in this test series several times at quite a significant duration.\u201d<\/p>\n<p>Engineers have more margin to use because the RS-25s on the Space Launch System will be discarded in the ocean and not reused.<\/p>\n<p>\u201cOn shuttle, we would light the engines, they would take off, they\u2019d fly for eight-and-a-half minutes and they\u2019d come back with the orbiters (to be used again),\u201d said Timothy Duquette, an SLS propulsion engineer. \u201cFor SLS, it\u2019s not coming back. So these are now expendable engines. One of the things that allows us to do is we actually run them at slightly higher thrust than we used to, a higher power level. It\u2019s a little harder on the engine, we\u2019re running it a little closer to redline, but it\u2019s safe, especially for short durations on a mission like SLS.\u201d<\/p>\n<p>There is talk of seeing if the engines can safely perform at even higher thrust, May said, but such a power setting is not required for the SLS to meet its lift requirements.<\/p>\n<p>\u201c(With) money and time and testing and it can be done, you can expand your performance,\u201d May said. \u201cWe have discussed, for future blocks of the rocket once we get up and flying, seeing if we want to chase performance. One of our tenets, when we designed SLS, was that we have a very robust design and we actually have a lot of performance margin. We don\u2019t want to get into a situation where we\u2019re chasing performance, because that last little bit of performance is what really drives your cost.\u201d<\/p>\n<p>The test firing Thursday used a ground version of the RS-25 engine. It was the sixth of seven tests of the development unit scheduled for this year, after ground firings kicked off in January.<\/p>\n<p>\u201cWe learn every time we go,\u201d Wofford said. \u201cWe\u2019ll take the lessons learned and the data from this test and fold them into the test objectives for next time.\u201d<\/p>\n<p>Some time next year, engineers plan to run flight-rated engines through the test stand at Stennis. First will come an engine with flight heritage on the space shuttle to calibrate the test profile, then the two newly-assembled RS-25 engines will go on the test block, Wofford said.<\/p>\n<p>There are no plans to put every SLS rocket engine through its own regimen of acceptance testing before flight, Wofford said.<\/p>\n<p>But all four of the engines slated for the first Space Launch System test launch in 2018, known as Exploration Mission-1, will get run time together in an all-up hotfire test with the rocket\u2019s core stage at Stennis.<\/p>\n<p>The Earth-shaking test is a can\u2019t miss, NASA officials said. It is expected some time in late 2017.<\/p>\n<p><b><i>Email the author.<\/i><\/b><\/p>\n<p><em><strong>Follow Stephen Clark on Twitter: @StephenClark1.<\/strong><\/em><\/p>\n","protected":false},"excerpt":{"rendered":"<p>NASA test-fired an RS-25 development engine Thursday at the Stennis Space Center in Mississippi. Credit: NASA TV\/Spaceflight Now A hydrogen-fueled rocket engine ignited with a bone-rattling sonic wave Thursday at NASA\u2019s test facility in Southern Mississippi, throttling up to more than a half-million pounds of thrust to verify upgrades to the space shuttle\u2019s main engines [&hellip;]<\/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":[864,2363,624,787,3312],"class_list":["post-16131","post","type-post","status-publish","format-standard","hentry","category-news","tag-aerojet-rocketdyne","tag-rs-25","tag-sls","tag-space-launch-system","tag-stennis-space-center"],"acf":[],"_links":{"self":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts\/16131"}],"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=16131"}],"version-history":[{"count":0,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts\/16131\/revisions"}],"wp:attachment":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/media?parent=16131"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/categories?post=16131"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/tags?post=16131"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}