![]() When an unusually high level of hydrogen was detected in Challenger's engine compartment during its FRF on Dec. The data collected during the engine firing before Challenger's first flight is a case in point.Ĭhallenger's main engines were the first qualified to perform at 104 percent of their rated power level. That analysis is invaluable to prevent costly delays and even the loss of the vehicle, Rivera said. "I'm sure that is going to be the case for SpaceX, as well." "I'm glad that our commercial partners are following the same customary engine firing test before committing a new vehicle to launch," Rivera said. The data collected will be analyzed before the demonstration flight later this month. ![]() The problem was addressed, and the test was successfully completed a little more than an hour later. On the first attempt, the exercise was aborted 47 seconds before engine burn because an unspecified technical parameter was set improperly. On April 30 of this week, Space Exploration Technologies, or SpaceX, one of NASA's commercial partners, conducted a two-second static fire test of the Falcon 9 rocket's nine Merlin engines in preparation for the upcoming COTS launch. Thanks to the FRF, Endeavour's maiden launch took place when all of its systems were "go," at 7:40 p.m. The precautionary measure caused no impact to the launch date. When an FRF was completed, any problems with the ground support equipment were identified, as well, and the launch team had experienced a full-scale dress rehearsal.ĭuring Endeavour's FRF on April 6, 1992, before its first flight, irregularities were detected in two of the three new engines' high-pressure oxidizer turbopumps during the 22-second firing.Ī buildup of pressure in one of the engine's pump preburner was detected just after it was shut down, and a slightly elevated frequency in vibration in the ball-bearing cage was recorded in another.Īlthough the irregularities would not have been a safety concern if the FRF had been an actual launch, all three of Endeavour's main engines were replaced with ones that had previously flown. The primary differences between the test and a launch-day countdown were that the two solid rocket boosters were not ignited and no flight crew was on board. The FRF countdown was terminated after 22 seconds. The FRF was the first opportunity for the engines to perform in a clustered flight configuration although each had been test fired individually before they were delivered to Kennedy. The fueled test involved igniting the shuttle's main engines during a launch countdown to verify their performance while operating under the extremes of cryogenic conditions. "It’s definitely a good practice in reducing the risk of the actual flight." "On every FRF that we conducted, we learned something new about the vehicle which made our process and flight hardware better,” said Rivera, who was deputy shuttle processing chief engineer at the close of the Space Shuttle Program. In the case of the shuttle, the test was known as a Flight Readiness Firing, or FRF. One of the most important milestones leading up to the first launch of any new spacecraft is a test to validate the overall performance of its main propulsion system. Construction began in 1987, and it rolled out of the assembly plant in Palmdale, Calif., in April 1991. "Subsystems that tested fine in isolation may interface with each other in a different way, which could create a bigger problem."Įndeavour was commissioned to replace shuttle Challenger, destroyed in an accident in 1986. Test is the best control or mitigation for hazardous conditions that could impact the mission," said Jorge Rivera, Vehicle Integration and Operation chief engineer. " 'Test as you fly, fly as you test' mentally has always been good to us. Twenty years ago, a similar launch campaign was under way in Launch Complex 39 at Kennedy Space Center for space shuttle Endeavour's first launch. ![]() It's déjà vu for NASA this spring as the much-anticipated SpaceX launch for NASA's second Commercial Orbital Transportation Services, or COTS, demonstration flight approaches from Space Launch Complex-40 on Cape Canaveral Air Force Station. Image above: A 22-second Flight Readiness Firing of space shuttle Endeavour tested its propulsion system during a "dress rehearsal" for its first launch 20 years ago. Image above: Exhaust collects under space shuttle Endeavour's three main engines at Kennedy Space Center's Launch Pad 39B as a 22-second Flight Readiness Firing gets under way on April 6, 1992.
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