**The most comprehensive collection of Shuttle, Ares, Orion and ISS related presentations and mission documentation, plus expansive daily processing documentation and updates are <\/em>available to download on L2<\/em><\/font> **<\/em><\/font><\/p>\n **ARES I LIVE UPDATE PAGES**<\/font><\/em><\/p>\n **ORION\/Exploration Vehicles LIVE UPDATE PAGES**<\/em><\/p>\n **ARES V \/ Mars LIVE UPDATE PAGES**<\/font><\/em><\/p>\n **EXPLORATION ALTERNATIVES (DIRECT, EELV) PAGES**<\/u><\/em><\/p>\n Space Shuttle models (adsbygoogle = window.adsbygoogle || []).push({});<\/p>\n **ALL NASASpaceflight.com CxP Articles**<\/font><\/p>\n Thrust Oscillation Update:<\/u><\/em><\/p>\n Thrust Oscillation is not a unique condition in relation to Ares I \u2013 but a recognized characteristic of solid rocket motors \u2013 in Ares I\u2019s case, the five segment first stage. <\/p>\n Also known as \u2018Resonant Burning\u2019 \u2013 described as vortices that shed within the solid rocket motors during combustion due to the shearing of internal flow at propellant discontinuities \u2013 the issue relates to when the frequency of thrust oscillations is coincident with the acoustic modes of the motor cavity. <\/p>\n <\/font><\/u><\/p>\n The problem relates to the crew riding Ares I inside their Orion vehicle <\/font><\/u>\u2013 when pressure oscillations drive resonant modes in the vehicle structure. These oscillations are capable of rendering the astronauts incapacitated, or worse.<\/p>\n Currently, astronauts riding in Ares I would be subjected to G forces in the range of 5-6 G at around 115 seconds into first stage flight. Engineers have been tasked with reducing Thrust Oscillation to the point at which astronauts would not suffer degraded operational capability.<\/p>\n The reduction target is based on historical data that dates back to the Gemini program, which had a crew specification \u2013 that allowed for coarse visual, manual tasks and speech to be unaffected \u2013 of 0.25 Gs. Between 0.3 and 0.5 G, the crew are restricted to simple visual and manual tasks only \u2013 deemed as performance degradation.<\/p>\n Above 3.7 G, and the jack-hammer properties of Thrust Oscillation enters the realm of health risks to the crew. Riding on the space shuttle currently sees the crew endure only 0.1 G. <\/p>\n Many options \u2013 some simple, some exotic \u2013 have been evaluated over the previous year, with favored options changing throughout the effort. The effort itself is based around the potential to eliminate or reduce Forcing Function, cancel or isolate Forcing Function, or detune stack from Forcing Function.<\/p>\n Ruled out from the mitigation process were concepts that called for a change to the Ares I configuration, including the shortening of the stage to a four segment first stage booster, and changes to the internal ballistics of the solid.<\/p>\n Plan A: The SoftRide Isolator decouples vehicle structural response from the Forcing Function, thus mitigating Thrust Oscillation on the first stage travelling through the vehicle stack to Orion. <\/p>\n However, there are concerns over the structural integrity of the interstage even prior to the spring dampers being installed. Failure of a few isolators could lead to rapid failure at the interface, sources note, with the system introducing vehicle bending. <\/p>\n Some mitigation of this threat has come via a small design change to the ends of the springs that will be attached in the interstage.<\/p>\n Notes also mention that this concept has a performance impact deemed to be red \u2013 though no explanation is given.<\/p>\n The main mitigation approach to Thrust Oscillation on Plan A is called the Aft Skirt TOA (Tuned Oscillating Arrays) Concept, which consists of 16 actuators around the circumference of the bottom end of the vehicle. <\/p>\n This system is replacing the Parasorber TMA concept, which was designed to damp Forcing Function in the area of the first stage parachutes.<\/p>\n However, Plan A lists this as the passive system, whereas CxP manager Jeff Hanley noted an electrically driven system \u2013 via 600V Li-Poly batteries \u2013 although the concept could still work passively, should a failure occur during ascent.<\/p>\n The Active Aft Skirt RMA (Reaction Mass Actuator) Concept is the specific name for the battery-driven TMA version. With the appearance of a car shock absorber, multiple RMAs are combined in a single control loop known as \u2018virtual actuator\u2019 controlling. The RMA concept is shown as the second option on \u2018Plan B\u2019 (B2).<\/p>\n Interestingly, a third mitigation technique is called for on Plan A, noted as Crew Seat Isolators \u2013 the final approach to finally bring down the Thrust Oscillation X-axis acceleration from 1 G to 0.25G.<\/p>\n While it is possible this concept is only required in tandem with the passive version of the Aft Skirt TOA, the concept may still be required as fallback mode during a potential failure of the electronic RMA system.<\/p>\n Crew seat isolators \u2013 which is a 500lb system that calls for a seat\/pallet interface into the Orion vehicle \u2013 is still on the table, but is currently classed as an immature design, with further work required. <\/p>\n This work would not be completed in time for the Thrust Oscillation status report to the PDR (Preliminary Design Review), which is due to be completed in around a month\u2019s time.<\/p>\n It was noted on the teleconference that there is a desire to remove such a concept from the vehicle \u2013 given it will only be used for a few seconds of the flight, and an unnecessary mass impact for missions in total.<\/p>\n Plan B:<\/u><\/em><\/p>\n Known as the Active Pulsing RCS Concept, this closed loop, active control propulsion system, is designed to provide an order of magnitude oscillation amplitude reduction. This is still active as a potential system \u2013 as noted on \u2018Plan B\u2019 as the first option (B1).<\/p>\n However, serious problems with implementation and design removed this option from being an option on Plan A, notably with over four years of development time estimated, and a concern with the aft end of the first stage being enveloped by plume induced flow separation during the time the thrusters need to be active.<\/p>\n Work had been carried out to reduce the drag factor by around half, via the installation of fairings around the pods. This also solved the potential issue of the thrusters being torn away from the vehicle during the aerodynamic environment during first stage flight.<\/p>\n Interestingly, the second option on \u2018Plan B\u2019 (B2) is the option that was referenced by the CxP managers, which works on two systems of TO mitigation \u2013 namely the Active Aft Skirt RMA and SoftRide Isolators. <\/p>\n Due to the immaturity of Plan A\u2019s crew seat isolator option, Plan B2 allows for a smoother transition through the PDR process.<\/p>\n \u2018Plan B3\u2019 is listed as an extension of B2, with a second set of SoftRide Isolators installed into the area between the second stage of Ares I and the service module of Orion.<\/p>\n A large amount of work remains, notably due to the lack of flight data. This will begin to collate during November\u2019s STS-126 flight with Endeavour, with also some data to be gained from next year\u2019s Ares I-X test flight.<\/p>\n Currently, CxP have to rely on ground test data from four segment firings of the Solid Rocket Motor, and computational models. New data will also be gained via NASA Ames later this year.<\/p>\n Notably, this phase of mitigation appears to be aimed mainly at the Orion that will fly to the International Space Station (ISS).<\/p>\n A target block upgrade for the Lunar Orion has been referenced on information as an effort to initiate cold flow\/subscale testing of internal motor physics.<\/p>\n However, the over-riding priority is to fine-tune a workable solution to TO, without causing any further pressure on the 2015 manned flight for Orion 2.<\/p>\n L2 Members: Refer to TAG keywords \u2018Ares I\u2019 and \u2018TO\u2019 for updates and expansive presentations.<\/em><\/p>\n Ares I TO Mitigation Plans and Notes. Ares V Frabrication Hardware Presentations and Photos. Ares V Point of Departure Presentation. Orion WEST in NBL Hi Res and Notes. 8th Floor News Updates. Ares V Alternative Engine Arrangement Presentation. Hi Res CxP Logos. Full (and very expansive) set of presentations on Ares\/Orion mass and status report. Ares I \u2018Parasorber\u2019 TO migitation hardware presentation and animation. Ares I TO Risk Slides. Ares I Risk Status. <\/p>\n Hi Res Images of Ares I FS Parachute Test Vehicle (JDTV). 20mb of new Lunar Images of Chariot, Athlete and Lunar Crane. Ares I KSC Processing Master Book \u2013 184 pages.<\/em> Changes for Ares I-X (Images). PRCB Transition Presentation (Shuttle to Ares). Ares V (5.5\/6xRS-68) Presentation (and more). Orion Parachute Vehicle Images. Latest Risk Matrix for Ares. SI Unit Directive Document. CxP PMR08 Manifest. PDR and associated notes from CPCB meeting. Orion Parachute Test Vehicle (PTV) Photographs. <\/em><\/p>\n 110mb worth of Ares I-X Weekly Test Presentations (Ares I-X, J2-X etc. up to end of April) The Orion LIDS (Low Impact Docking System) Section (Images, Videos, Engineering Notes). Hi Res Images of Ares I in the VAB. Ares I-X Integrated Milestone Charts. Ares I Thrust Oscillation Focus Team Status Presentations (over 50mb \u2013 includes DTO on Shuttle missions), Ares I-X Global Buckling Status Presentation, Ares I \u2013 Launch Pad Stabilization and Damping Presentation, Ares I: Purge\/Vent\/Drain and Vehicle Access Presentation. <\/em><\/p>\n Ares Tilt Up Umbilical Arm (TUUA) Test \u2013 Video, Ares\/Orion Comm and Tracking Presentation, Ares I Nozzle Extension Update Presentation, Ares\/Orion Integrated Stack TIM Summary (Major Issues) Presentation, Orion Land vs Water Landing Update + Crew Survival (post 36 hrs) Presentations.<\/p>\n Orion Rendezvous with the ISS CGI Video, plus AERCam Inspections. Ares I Thurst Oscillation Update Section. Images of completed PA-1 boilerplate Command Module at LaRC. CxP Planning for Architecture Closure \u2013 Feb 19. Ares V Overview Presentations. Other Major CxP Updates for Feb (List restricted to L2). Lunar Habitat Assembly. PRCB Presentations on hardware and infrastruction transition (from Palmdale to MLP Park) \u2018Follow live\u2019 Lightning Towers Construction images. Latest Mobile Launcher details. Orion\/Ares I\/Delta IV Heavy NEO Feasibility Study (Video). Constellation EVA Study Presentation. Superb Gene Kranz address to CxP workforce (Apollo to Orion feature) video. MOD \u2018LEO to Mars\u2019 presentations.<\/em><\/p>\n Superb Ares I Launch Ascent, Pad Abort Test CGI Videos (three). Integrated Stack (IS) Technical Interchange Meeting (TIM) notes \u2013 Nov 6 to Nov 15. The full \u20188th Floor News\u2019 \u2013 Constellation Update (performance issues) \u2013 Nov 5. Ares I Mobile Launcher PMR.<\/p>\n Presentation of Ares\/Orion impacts relating to Shuttle manifest acceleration. Ares I Interstage diagrams. Ares V Super Crawler. Ares I Launch Pad images (ML etc.) Hi Res images of Ares I-X Upper Stage. Orion 606-7 Data Updates. Updates Constellation launch schedule through to Orion 15. Orion Seat test photos. New ML Graphic and info. New Ares V graphic and baseline data. Large collection of hi res Orion paracute drop tests. SIX Part Series of Ares I Upper Stage Graphical Overviews. DAC-1C DDD Vast Slides on Vehicle Design. ATK First Stage Presentation. 39B Lightning Towers Slides. DAC-1C Departure points to DAC-2 Upper Stage Graphcs (Many Changes). <\/i><\/em><\/p>\n Orion\/CEV Display Layout Presentation (40 pages). ATK figures on the 5-Seg Booster weight for CLV. Weather Shield (Rain Shield) for Orion on the pad. New Super hi-res images of Ares I. ATK Cutaway graphics of Ares I \u2013 perspective and axonometric. Ares I\/Orion CxP 72031 Requirements Validation Matrix Information. CEV Paracute Assembly System (CPAS) Presentation. <\/p>\n Orion Launch Abort System (LAS) overview presentation. Changes to Ares I Upper Stage \u2013 expansive details and data. Ares I\/Orion CxP 72031 Requirements Validation Matrix Information. CLV Umbilical Trade Matrix XLS. Vehicle interfaces for the DAC 1C version of Orion Ares. Ares I-X Test Flight Plan (full outline) Presentation. Ares I-X timeline and modification expanded info. Ares I Reference Trajectory. Boeing\u2019s STS to Ares \u2013 Lessons Learned Presentation. CLV DAC-1C (Changes to CLV Upper Stage). <\/p>\n 90 Minute Video of Constellation all hands meeting. Escape System Trade Study Presentation. CEV-CLV Design Analysis Cycle Review (DAC-2) Presentation. Flight Design and Dynamics Division CEV update. CLV Mono-propellant RCS system. CEV pressurisation system review. CLV\/CEV Configuration Images. The 2\u00d73 Seg SRB Crew Launch Vehicle Option Presentation\u2026<\/p>\n \u2026.plus much more (L2 Constellation over 200gb in size).<\/p>\n","protected":false},"excerpt":{"rendered":" Ares I engineers have created a \u201cPlan A\u201d option \u2013 which combines three mitigation techniques \u2013 to attempt to solve Thrust Oscillation issues during first stage flight. Plan A involves an active Tuned Mass Absorber (TMA) to the aft skirt, dampers on the interstage, and the crew seat isolators \u2013 though during a teleconference to […]<\/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":[],"class_list":["post-41328","post","type-post","status-publish","format-standard","hentry","category-news"],"acf":[],"_links":{"self":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts\/41328"}],"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=41328"}],"version-history":[{"count":0,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts\/41328\/revisions"}],"wp:attachment":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/media?parent=41328"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/categories?post=41328"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/tags?post=41328"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}<\/em><\/font>All of this article is based on documented L2 information. For an overview of how L2 works, <\/em>**click here for sample video**<\/em><\/font><\/p>\n
<\/u><\/em>As of this month, \u2018Plan A\u2019 involves the interstage receiving what is know as the \u2018Passive SoftRide Isolator Concept\u2019 \u2013 as seen before with ELV approaches to protecting the payload from the vibrations of launch and ascent, such as with GLAST.<\/p>\n
Plan B concepts work on several mixed approaches, including the very exotic system that called for multiple thrusters firing in the direction of flight. <\/p>\n
Selection of L2 Resources For Ares I, V and Constellation (some not listed): <\/em><\/p>\n
Altair Overview Presentation. Ares I Risks and Status. Ares I-X Booster Recovery Images and Video. Ares I-X Pad Images. Ares I-Y Mission Overview Video (50mb \u2013 Superb). Orion Lunar Transit CGI Video. (Several more videos, including first video of Orion splashdown). <\/p>\n
<\/em>
Orion 607 Overview Presentation (Jan 08), Constellation Program Status\/Budget and new Manifest to Orion 20 Presentation (Jan, 08). Michoud Transition to Ares I\/V (Jan 17, 08). Several MLAS (Max Launch Abort System) Presentations. Over 60 Hi Res Images of Orion Mock-up at JSC (Hatch, Seats, Flight Deck) \u2013 December. <\/em><\/p>\n\u2018Proposed\u2019 Ares I SRBSF (Mini VAB) and graphic. LSAM (LDAC-1) Video and Images. Several Constellation All Hands Videos and Presentations. Ares I Pad Rollercoaster (Old and New presentation and slides \u2013 the very cool \u2018CGI ride on the Ares pad coaster\u2019 video. Ares I VAB \u2018In-Line\u2019 Stacking presentation slides.<\/em><\/p>\n
Ares I-X: Four Seg+Dummy \u2018Tuna Can\u2019 stage. Ascent Developmental Flight Test Presentation. CLV Pad 39B Handover Info and Latest. New images of CLV on top of new MLP and LUT. Lockheed Martin CEV\/Orion Updates. ATK figures on the 5-Seg Booster weight for CLV. <\/p>\n