Appendix Q Launch Debris and Staging Impact Locations

Transcription

1 Appendix Q Launch Debris and Staging Impact Locations K.R. Bohman, Vehicle Systems Division, The Aerospace Corporation, Aerospace Report No. TOR-99 (1103)-2, September, Jettisoned Body Analysis Using ascent trajectory data provided by the contractor, nominal drag impact locations for the launch vehicle jettisoned bodies were determined by trajectory simulation. The solid motor casings, spent core stage, and payload fairing for each Evolved Expendable Launch Vehicle (EELV) configuration were assumed to have similar aerodynamic characteristics as current launch vehicle jettisoned bodies that have similar length to diameter ratios. Thus, tumbling drag coefficients that are used for current launch vehicle range safety analyses (References [1]&[2]) were applied to EELV jettisoned bodies with the appropriate scaling of the aerodynamic reference area and using appropriate jettisoned weights. Separate 3- degree-of-freedom simulations from jettison to surface impact were executed for the Atlas V solid rocket motors (SRMs), the Delta IV solid rocket motors (graphite epoxy motors or GEM 60s), the payload fairings (PLF), and the expended first stages (Stage 1). Note that separation velocities were not modeled. For solid strap-ons and the fairing, the separation velocity is generally of small magnitude and in a lateral direction. Therefore, it would have a very small effect on the calculated impact location. The velocity imparted to the spent core stage could be significant and in the aft direction. If so, the expected impact location would shift uprange by about 10 to 20 nautical miles. The Eastern Range refers to launches from Cape Canaveral Air Force Station and the Western Range refers to launches from Vandenberg Air Force Base. Nominal (No-Wind) Impact Locations for the Atlas V with SRMs and the Delta IV with the larger GEMs: Eastern Range Vehicle Configuration & Mission Jettisoned Body Latitude Longitude Atlas V 511 GTO SRM PLF Stage Atlas V 551 GTO SRMs PLF Stage Atlas V deg Inclined SRMs PLF Stage Delta IV-M+(4,2) GTO GEMs PLF Stage Delta IV-M+(5,4) GTO GEMs PLF Stage SAC/PKG2002.DOC/ DOC Q-1

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3 SAC/PKG2002.DOC/ DOC Q-3

4 Nominal (No-Wind) Impact Locations for the Atlas V with SRMs and the Delta IV with the larger GEMs: Western Range Vehicle Configuration & Mission Jettisoned Body Latitude Longitude Atlas V 512 Inclined SRM PLF Stage Atlas V 512 Polar SRM PLF Stage Atlas V 552 Inclined SRMs PLF Stage Atlas V 552 Polar SRMs PLF Stage Delta IV-M+(4,2) Inclined GEMs PLF Stage Delta IV-M+(4,2) Polar GEMs PLF Stage Delta IV-M+(5,4) Inclined GEMs PLF Stage Delta IV-M+(5,4) Polar GEMs PLF Stage Q-4 SAC/PKG2002.DOC/ DOC

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7 Obviously, the actual jettisoned body impact locations are dependent on the day-of-launch conditions and trajectory. Therefore, jettisoned body impact ellipses are constructed via downrange and crossrange dispersion distances from the nominal impact point. The dispersion distances may be determined by simulating the vehicle performance and wind effects separately and then root sum squaring (RSS) the results together. For this study, notional performance dispersion distances were applied based on experience from other launch vehicles (References [2]&[3]). Wind effects were determined by simulating the jettisoned body s fall through a 99 percent outer profile wind. In each case (headwind, tailwind, left and right crosswinds) the wind was adjusted for azimuth using the appropriate wind rose factor. For this analysis the primary concern was the potential impact region just off the coast, thus, only solid motor jettison ellipses were estimated. The following tables show the estimated dimensions for the SRM/GEM impact ellipses for various EELV configurations involving the use of solid motors. SRM Drag Impact Dispersion Distances from Nominal SRM Impact Locations Atlas V 511 ER GTO Performance dispersions* Wind effects RSSed total Atlas V 551 ER GTO Performance dispersions* Wind effects RSSed total Atlas V 552 ER LEO Inclined Performance dispersions* Wind effects RSSed total *Performance dispersions are estimated based on related studies for other launch vehicles SAC/PKG2002.DOC/ DOC Q-7

8 Estimated Solid Motor Impact Ellipses Atlas V 511 and 551 GTO Launches Estimated Solid Motor Impact Ellipses Atlas V 552 LEO 55 deg Inclined Launch Q-8 SAC/PKG2002.DOC/ DOC

9 SRM Drag Impact Dispersion Distances from Nominal SRM Impact Locations Atlas V 512 WR Inclined Performance dispersions* Wind effects RSSed total Atlas V 512 WR Polar Performance dispersions* Wind effects RSSed total Atlas V 552 WR Inclined Performance dispersions* wind effects RSSed total Atlas V 552 WR Polar Performance dispersions* Wind effects RSSed total *Performance dispersions are estimated based on related studies for other launch vehicles SAC/PKG2002.DOC/ DOC Q-9

10 Current restrictions of over-flight of Channel Islands requires nominal trajectory of IIP west of Santa Rosa Island. All azimuths proposed will be evaluated by Flight Safety Officer to ensure acceptable risk levels for general public are not exceeded. Q-10 SAC/PKG2002.DOC/ DOC

11 GEM Drag Impact Dispersion Distances from Nominal GEM Impact Locations Delta IV-M+ (4,2) ER GTO Performance dispersions* Wind effects RSSed total Delta IV-M+ ( 5,4) ER GTO Performance dispersions* Wind effects RSSed total *Performance dispersions are estimated based on related studies for other launch vehicles Estimated Solid Motor Impact Ellipses Delta IV-M42 and M54 GTO and LEO Launches SAC/PKG2002.DOC/ DOC Q-11

12 GEM Drag Impact Dispersion Distances from Nominal GEM Impact Locations Delta IV-M+ (4,2) WR Inclined Performance dispersions* Wind effects RSSed total Delta IV-M+ (4,2) WR Polar Performance dispersions* Wind effects RSSed total Delta IV-M+ (5,4) WR Inclined Performance dispersions* Wind effects RSSed total Delta IV-M+ ( 5,4) WR Polar Performance dispersions* Wind effects RSSed total *Performance dispersions are estimated based on related studies for other launch vehicles Q-12 SAC/PKG2002.DOC/ DOC

13 Current restrictions of over-flight of Channel Islands requires nominal trajectory of IIP west of Santa Rosa Island. All azimuths proposed will be evaluated by Flight Safety Officer to ensure acceptable risk levels for general public are not exceeded. SAC/PKG2002.DOC/ DOC Q-13

14 Debris Footprint Analysis For any space launch vehicle, there is the possibility of a launch failure early in flight. Hence, there is a risk of vehicle debris impacting the region surrounding the launch site as well as areas downrange of the launch site. The vehicle location, speed, and direction at the time of the explosion as well as the current wind conditions would largely determine a debris footprint from an actual failure. To generate a typical debris footprint that may occur from a launch failure, simulations of fragment trajectories were run using parameters that are consistent with current launch vehicle debris models. The fragments (with ballistic coefficients ranging between 2 and 400 psf) were initialized at some nominal, on-trajectory state, with a randomly selected induced velocity (between 0 and 200 fps in any direction) and then propagated to ground impact in the presence of a mean, annual wind model. Under these assumptions, simulation results show that the debris patterns generally lie on the Air Force Base/Station or just offshore. On the Western Range there is some risk of debris impacting the Point Conception area. More extreme wind conditions could result in debris footprints lying significantly onshore. It should be noted that the Space Wing Safety Offices for both eastern and western ranges adhere to an flight plan approval process for each launch vehicle and mission to ensure that the risks associated with launch vehicle operations do not exceed acceptable limits (Reference [4]). References [1] Sica, D.W., Range Safety Data for Titan IVB-24, Volume III: Trajectory/Jettison Body Data, Lockheed Martin Astronautics, MCR , September [2] Salerno, C.L., Range Safety Data Package For Titan II 23G-7, Lockheed Martin Corporation, MCR , August [3] Delvaux, M.J., Titan IVB-12 TAG Range Safety Data Package, Lockheed Martin Corporation, MCR , December [4] Flight Safety Analyst Training and General Reference Handbook, 30 th Space Wing/ Safety Office, January Q-14 SAC/PKG2002.DOC/ DOC

15 Debris Footprint for On-Trajectory Failure at T + 10 seconds Atlas V 552 LEO 55 deg Inclined Debris Footprint for On-Trajectory Failure at T + 30 seconds Atlas V 552 LEO 55 deg Inclined SAC/PKG2002.DOC/ DOC Q-15

16 Debris Footprint for On-Trajectory Failure at T + 60 seconds Atlas V 552 LEO 55 deg Inclined Debris Footprint for On-Trajectory Failure at T + 20 seconds Delta IV-M+(4,2) GTO Q-16 SAC/PKG2002.DOC/ DOC

17 Debris Footprint for On-Trajectory Failure at T + 30 seconds Delta IV-M+(4,2) GTO Debris Footprint for On-Trajectory Failure at T + 50 seconds Atlas V 512 SAC/PKG2002.DOC/ DOC Q-17

18 Debris Footprint for On-Trajectory Failure at T + 90 seconds Atlas V 512 Debris Footprint for On-Trajectory Failure at T seconds Atlas V 512 Q-18 SAC/PKG2002.DOC/ DOC

19 Debris Footprint for On-Trajectory Failure at T + 30 seconds Delta IV-M+(5,4) Debris Footprint for On-Trajectory Failure at T + 50 seconds Delta IV-M+(5,4) SAC/PKG2002.DOC/ DOC Q-19

20 Debris Footprint for On-Trajectory Failure at T + 70 seconds Delta IV-M+(5,4) Debris Footprint for On-Trajectory Failure at T + 90 seconds Delta IV-M 54 Q-20 SAC/PKG2002.DOC/ DOC