«ABSTRACT On August 9, 2012 the Morpheus 1.5A vehicle crashed shortly after lift off from the Kennedy Space Center. The loss was limited to the ...»
6. FREE FLIGHTS A. Risk Posture Heading into free flights at KSC, it was important for the project to maintain a consistent risk posture. The vehicle was built from the beginning as a single-string prototype vertical take-off and landing vehicle. That approach enabled the project to pursue lean development and make advances in design, testing and operations in a more rapid fashion. However, there are inherent risks to the vehicle using this approach. The project put forth significant effort in identifying and mitigating single-point failures that could cause loss of vehicle prior to heading to KSC. That included substantial subsystem-level testing, all of the tether testing previously described, and system-level protoqual testing, such as the ground hotfire test.
The primary exception to the single-string philosophy included safety systems in subsystems such as pressure systems and range safety. Pressure systems have redundant pressure relief components built in. There is also a dualredundant thrust termination system (TTS) on board the vehicle that that includes 2 independent valves in the propulsion system, either of which can cut engine thrust on command. This exemplifies the project emphasis on safety, even in light of accepting additional risk to the test vehicle itself.
The purpose of the ground hot-fire test was specifically to envelope the environments expected during liftoff of a free flight. HotFire 6 did exactly that. The vehicle was outfitted with a variety of instrumentation, including accelerometers, microphones and thermocouples, and was chained to the ground launch pad. Upon ignition, the engine was throttled up to 100% and remained for 5 seconds to conservatively characterize the environment. Beyond this type of testing, there were no standard qualification tests of components due to the prototype nature of the vehicle.
In addition to the actual testing accomplished, it was important to ensure all stakeholders were fully aware of the risk posture for free flights. The loss of the Morpheus 1.5A vehicle was pre-declared a test failure and not a mishap as long as no personnel were injured or infrastructure was damaged. In this light, the loss of vehicle was considered an acceptable risk for the purpose of advancing our understanding of all of the components of integrated vehicle performance.
Figure 9 – Shuttle Landing Facility at KSC: Morpheus Free Flight 1at ignition; and Free Flight 2 after it crash landed.
American Institute of Aeronautics and Astronautics: SPACE 2013 Free Flight 2 was attempted two days later, on August 9. In this test, the data from the only active IMU was lost 0.6 seconds into flight, causing the vehicle to lose control and crash. The combined JSC/KSC team immediately executed the pre-rehearsed emergency action plan to protect personnel and property, so damage was limited to vehicle hardware.
The timeline of events during takeoff is shown in Table 1.
7. FINDINGS AND CORRECTIVE ACTIONSThe engineering investigation described herein was accomplished over three months and incorporated inputs from the entire Morpheus team as well as independent expert reviewers. The findings and corrective actions that resulted from the investigation are summarized in Table 2.
American Institute of Aeronautics and Astronautics: SPACE 2013 One final new test is planned before the team moves to KSC to begin free flight campaigns. A Ground Takeoff and Landing (GTAL) test, while still constrained via tether, will be conducted at JSC in September 2013. The concept is to buy down risk by demonstrating liftoff over a flame trench followed by a nominal translation, descent and landing back on the ground. The tether only provides range safety and will minimize any damage if there is a problem during the test. This will be the last test planned at JSC before the vehicle is moved back to KSC for testing at the SLF.
5 Accepted single-string IMU Dissimilar, non-colocated backup IMU(s) a. Test backup IMU down-mode and soft abort logic risk b. LCC requirement for operational backup IMU(s) 6 Accepted risk of brief (1) Reduce vibro-acoustic environment for IMUs with flame trench, vibe Americanisolation and relocation and Astronautics: SPACE 2013 Institute of Aeronautics exceedance of IMU qual limits due to HF6 and FF1 (2a) Use PA1 SIGI flight unit test experience
9. CONCLUSIONSNASA’s Morpheus Project has developed and tested a prototype planetary lander capable of vertical takeoff and landing, designed to serve as a testbed for advanced spacecraft technologies. The ‘Alpha’ version of the Morpheus vehicle successfully performed a set of integrated vehicle test flights including hot-fire and tether tests, but was lost during the second free flight test at KSC. The test failure investigation identified a proximate cause as the loss of navigation data most likely due to excessive vibro-acoustic environments. A number of contributory factors were also identified and discussed, with appropriate corrective actions.
In early FY13, Morpheus rebuilt a ‘Bravo’ vehicle after loss of the ‘Alpha’ vehicle, and made a number of upgrades and improvements to the vehicle and ground subsystems, including integration of the Autonomous Landing and Hazard Avoidance Technology (ALHAT) Project’s hardware and software components. These upgrades will provide improved performance, expanded capabilities, and better robustness for an extended test campaign that will culminate in high energy trajectories that simulate a landing approach on a lunar, asteroid or planetary surface. The initial test campaign at JSC will be followed by free flights and high energy trajectories at KSC.
Jon B. Olansen, PhD – Dr. Olansen serves as the Project Manager for the Morpheus Project. He began his career as a Space Shuttle flight controller, supporting 32 missions and logging 4200 hours in Mission Control. Jon earned his B.S. in Aerospace Engineering and M.S. in Mechanical Engineering from the University of Notre Dame. He obtained his Ph.D.
in Mechanical Engineering (Biomedical Focus) as a National Instruments Fellow at Rice University, where he specialized in biomedical experimentation in electrophysiology and cardiopulmonary hemodynamics. He has published several journal articles related to his research and authored a reference book on biomedical instrumentation. He returned to NASA to represent the Astronaut Office in the design, development, and operation of human life sciences experiments destined for the International Space Station. Dr. Olansen has since held a number of positions of increasing responsibility including tours in Safety & Mission Assurance, the Shuttle Program Office and the Exploration Systems Mission Directorate at NASA Headquarters, before undertaking his current role.
Stephen R. Munday – Mr. Munday serves as the Deputy Project Manager for the Morpheus Project. His NASA career spans 26 years as a lead engineer, technical board chairman, system manager, and international technical liaison for various NASA programs including the X-38 Crew Return Vehicle, Space Shuttle, Orion Crew Exploration Vehicle, and International Space Station (ISS). His engineering expertise is primarily in the fields of aerodynamics and GN&C. Prior to joining the Morpheus team, he spent 4 years helping to manage NASA’s Moscow Technical Liaison Office in Russia’s Mission Control Center and in the Baikonur Cosmodrome in Kazakhstan on behalf of the ISS Program. Mr. Munday holds an M.S. degree in Aerospace Engineering (G&C focus) from the University of Texas in Austin, an M.S. in Computer Engineering from the University of Houston at Clear Lake, and a B.S. in Aerospace Engineering (aerodynamics focus) from the University of Missouri – Rolla (now the Missouri Univ of Science & Technology).