# Presentation: 670184

## Introduction toSimulation Analysis of Space Shuttle Manifest OptionsInput AnalysisNow includes unique OMDP analysis

- April 9, 2004
-  Grant Cates
- PH-M3

- Grant Cates PH-M3

- 03/24/2004

## OPF Run Chart for Added Work Days

- Sources of added work days include new program requirements (chits and modifications) and PRACA.

- STS-85 (Impacted by reflight of STS-83)
- STS-88 (ISS late hardware)
- STS-96 (Delay to STS-93 created additional time in OPF, low flight rate)
- STS-93 (AXAF Payload Delays created opportunity to add work)
- STS-103 (Wiring Inspections)
- STS-99 (Wiring Inspections)
- STS-92 (Launch Date Rebaselining created opportunity to add work)
- STS-97 (Same as 92)
- STS-111 (SSRMS Integration)
- STS-112 (MPS Flow Liner)

- Grant Cates PH-M3

- 03/24/2004

## OPF Run Chart for Added Work Days(After Removal of Selected Low Flight Rate Related Flows)

- STS-85 (Impacted by reflight of STS-83) was removed.
- STS-88 (ISS late hardware) was removed.
- STS-96 (Delay to STS-93 created additional time in OPF, low flight rate) was removed.
- STS-93 (AXAF Payload Delays created opportunity to add work) was removed.
- STS-103 (Wiring Inspections)
- STS-99 (Wiring Inspections)
- STS-92 (Launch Date Rebaselining created opportunity to add work) was removed.
- STS-97 (Same as 92) was removed.
- STS-111 (SSRMS Integration)
- STS-112 (MPS Flow Liner)

- Grant Cates PH-M3

- 03/24/2004

## OPF Histogram and Cumulative Frequency Distribution for Added Work Days Post Delta LSFR Data from Selected Low Flight Rate Related Flows Removed

- Having the ability to absorb 4 added work days will preserve the the ability to rollout of the OPF on time with a **.5** probability.
- To increase that probability to **.9** would require the ability to absorb approximately 21 added work days.

- Grant Cates PH-M3

- 03/24/2004

## Modeling OPF Added Work

- Arena Representation:  DISC(0.2319,0, 0.3043,1, 0.3623,2, 0.4783,3, 0.5217,4, 0.5362,5, 0.5942,6, 0.6087,7, 0.6522,8, 0.6667,9, 0.7246,10, 0.7536,11, 0.7681,12, 0.7826,13, 0.8261,14, 0.8696,15, 0.8986,17, 0.9130,19, 0.9275,20, 0.9420,22, 0.9565,25, 0.9710,45, 0.9855,50, 1.0,81)

- Grant Cates PH-M3

- 03/24/2004

## OMDP Flow Run Chart for Added Days

- Grant Cates PH-M3

- 03/24/2004

## OMDP Type FlowsHistogram and Cumulative Frequency Distribution for Added DaysArena Representation

- Grant Cates PH-M3

- 03/24/2004

## VAB 

- Sources of added work days are typically PRACA related.

- STS-33 (SSME HPOTP installation in VAB)
- STS-57 (Engine Installation in VAB)
- STS-58 (Pad Unavailability)
- STS-98 (ET/SRB Pyro Cable Inspections)

- Grant Cates PH-M3

- 03/24/2004

## VAB 

- Approximately 50 percent of the time, no work days are added to the VAB flow.
- Having the ability to absorb **2 **added work days will preserve the the ability to rollout of the VAB on time with a **.7** probability.
- To increase that probability to **.9** would require the ability to absorb approximately **4** added work days.

- Grant Cates PH-M3

- 03/24/2004

## Modeling VAB Added Work

- Arena Representation:
- DISC(0.4598,0, 0.6322,1, 0.7126,2, 0.8276,3, 0.8966,4, 0.9425,5, 0.9540,6, 0.9655,11, 0.9770,12, 0.9885,14, 1.0000,18)

- Grant Cates PH-M3

- 03/24/2004

## Launch Pad (Prior to Beginning Countdown) 

- Sources of added work days are typically PRACA or Environment related.

- STS-38 (Added Mini-Tanking Test, & P/L Problem)
- STS-46 (Flight Crew and MOD Training)
- STS-57 (Replace HPOTP, & Investigate “Big Bang”)
- STS-70 (Woodpeckers)
- STS-79 (Two Hurricane Rollbacks & Booster Replacement)

- Grant Cates PH-M3

- 03/24/2004

## Launch PadPrior to Beginning Launch Countdown 

- Approximately 25 percent of the time, no work days are added to the Pad flow (not including launch countdown).
- Having the ability to absorb **3 **added work days will preserve the ability to begin countdown on time with a **.5** probability.
- To increase that probability to **.9** would require the ability to absorb approximately **14** added work days.

- Grant Cates PH-M3

- 03/24/2004

## Modeling Launch Pad Added Work

- Arena Representation:
- DISC(0.2558,0, 0.3605,1, 0.4419,2, 0.4884,3, 0.5814,4, 0.6395,5, 0.7093,6, 0.7558,7, 0.7674,8, 0.7907,9, 0.8140,10, 0.8256,11, 0.8488,12, 0.8953,14, 0.9186,20, 0.9419,21, 0.9651,22, 0.9767,25, 0.9884,26, 1.0000,31)

- Grant Cates PH-M3

- 03/24/2004

## Launch Countdown Delays General Information

- How often is a planned launch attempt delayed one or more days _once the countdown has started_?
- Approximately 45 percent.
- What are the general categories of the causes for the delay?
- Flight Hardware
- Weather
- Infrastructure
- Operational Prerogative
- When do delays occur?
- Prior to Tanking (L-2 Day, L-1 Day, or at Pre-Tanking MMT)
- During Tanking
- After Tanking
- T-3 Hour Hold, Counting to T-20 minutes, At T-20 Minute Hold, At T-9 Minute Hold, During Terminal Count

- Grant Cates PH-M3

- 03/24/2004

## Post-S0007-Start Delay History

- STS-41-D (SSME Abort, VAB return for SSME replacement)
- STS-35 (Total of 166 days for Hydrogen Leaks)
- STS-51 (Three scrubs/delays... MLP Ordnance, SRB HPU, & SSME abort)

- Grant Cates PH-M3

- 03/24/2004

## Post S0007-Start Delay Durations (Cumulative Frequency Distribution)Based on historical data since STS-1.

- Approximately 54% percent of the time, launch occurs on time once the count has started.
- Having the ability to absorb **2 **delay days in the down stream OPF flow will preserve the the ability to achieve an on time OPF rollout with **.7** probability.
- To increase that probability to **.9** would require the ability to absorb approximately **14** delay days.

- Grant Cates PH-M3

- 03/24/2004

## Modeling Post S0007-Start Delay Days(Excludes STS-35)

- Arena Representation:
- DISC(0.5405,0, 0.6847,1, 0.7117,2, 0.7387,3, 0.7838,4, 0.8108,5, 0.8649,6, 0.8739,7, 0.8829,8, 0.8919,9, 0.9009,11, 0.9099,12, 0.9189,14, 0.9279,15, 0.9369,17, 0.9459,22, 0.9550,24, 0.9640,25, 0.9730,35, 0.9820,43, 0.9910,57, 1.0000,66)

- Grant Cates PH-M3

- 03/24/2004

## Launch Success Rate Moving Average (20-launch-attempt moving average)Since Return-to-Flight

- Grant Cates PH-M3

- 03/24/2004

## Cumulative Delay/Scrub Percentages (Since STS-1)

-    Reliability of Flight Hardware Improving
-    Delays/Scrubs attributable to Weather Increasing

- Grant Cates PH-M3

- 03/24/2004

## Mission Duration

- Sources of _**added**_ on-orbit mission days include added planned days from the program post Delta LSFR, on-orbit problems, and delays for landing weather.
- Reasons for _**shortened**_ missions are typically flight hardware problems.

- STS-2 (Number 1 Fuel Cell Failure)
- STS-35 (Orbiter landed one day early in advance of bad weather)
- STS-44 (Failure of one of three IMUs)
- STS-83 (Fuel Cell #2 Suspect Problem)

- Grant Cates PH-M3

- 03/24/2004

## Mission Duration

- Approximately 70 percent of the time, the planned mission duration is not increased.
- Having the ability to absorb the effect 1 added mission day in the down stream OPF flow with be adequate 90 percent of the time.
- There is a correlation between missions that have added days and missions that land at DFRC.  The last 10 missions diverted to DFRC have averaged one additional day on orbit for weather.

- Grant Cates PH-M3

- 03/24/2004

## Non-WX Mission Day Additions

- Arena model representation
- DISC (.88, 0, .98, 1, 1.0, 2)

- Grant Cates PH-M3

- 03/24/2004

## KSC Landing Success

- Grant Cates PH-M3

- 03/24/2004

## Mission Extension Days for Landing Weather

- Above table reflects Arena model representation.

- Grant Cates PH-M3

- 03/24/2004

## DFRC Contingency

- Current manifest ground rules show 6 days of Dryden Reserve.
- This actually protects for a vehicle returning from Dryden and beginning the OPF flow on day 8 (relative to where it would be given a KSC landing).
- Less 1 day for OPF flow work accomplished at DFRC (PRSD offload)
- Less 1 day landing at DFRC vs KSC (counting procedure)
- Threats correlated with DFRC landings
- Landing Delay in hope that KSC weather will improve.
- Dryden Turnaround delays.
- Delays during Ferry.
- Frequency of missions diverted to DFRC is approximately 21 percent.

- Grant Cates PH-M3

- 03/24/2004

## DFRC Ferry Prep Duration

- Ferry Prep Duration has been increasing.
- From 4 days at time of Challenger to 5 days in the early Return-To-Flight Era. This was the result of the addition of safety enhancements (e.g. Ball Valve Cavity Drain).
- Grew to 6 days due to scheduling of SCAPE activities and reduction of turnaround team.
- Grew to 7 days due to reduction of turnaround team on station at landing.
- Note that PRACA and weather conditions can result in 1-2 added work days.

- Grant Cates PH-M3

- 03/24/2004

## Ferry Flight Duration

- Ferry Flight Duration has been increasing.
- The solid line shows a 6-flight moving average.  Over the past several years the average time to ferry from DFRC to KSC has been 4 days. Planned ferry duration is typically 2 days.
- During the late spring and early summer one day ferry flights are theoretically possible. However, none have been achieved in the Return-To-Flight era.

- Grant Cates PH-M3

- 03/24/2004

## Ferry Flight Duration

- Arena Representation:
- DISC(.39, 2, .71, 3, .84, 4, .87, 5, .90, 6, .97, 7, 1.0,10)

- Grant Cates PH-M3

- 03/24/2004