1. From Space, Down to Earth
Nigel J. Packham, Ph.D.
Associate Director, Safety and Mission Assurance
NASA, Johnson Space Center
Houston, Texas 1

2. The Final Flight
Mission STS-135 2

3. 3

4. 4

5. 5

7. The Debris Field from the Columbia Accident was 400 miles long and 10 miles wide

8. Is it Safe? Is it Safe? Space Shuttle Columbia break-up during entry
BP/Transocean Deepwater Horizon explosion on
April 20th, 2010, resulting in the loss of eleven crewmembers
Space Shuttle Columbia break-up during entry
on February 3rd, 2003, resulting in the loss of all
seven crewmembers

9. Is it Safe? Is it Safe? Space Shuttle Columbia break-up during entry
United Airlines Flight 232 Incident, Sioux City, Iowa (registration N1819U)
July 19th Survivors; 111 Fatalities
Space Shuttle Columbia break-up during entry
on February 3rd, 2003, resulting in the loss of all
seven crewmembers

10. Is it Safe? Is it Safe? Space Shuttle Columbia break-up during entry
on February 3rd, 2003, resulting in the loss of all
seven crewmembers
Union Carbide India Limited
Pesticide Plant, Bhopal, Madhya Pradesh, India,
December 2nd, tons of methyl isocyanate release,
resulting in (estimated) 25,000 fatalities

11. “Is it Safe?”

12. A Real Life Scenario
A critical circulation pump in a thermal control system is malfunctioning
Required to deliver mmHg
Delivering mmHg
Thermal Control Systems Engineer asks several questions
How long has this been going on – what’s the pumps history?
Gradual decline over several months
What does the real-time X-Ray show?
Shows potential leakage around inlet and outlet valve seals
What is the effect on downstream systems
Lower cooling capacity in the system; could reach critical point in 6 months at present rate of decay, leading to shutdown of life support systems

13. These are all Risk versus Risk Trades
A Path Forward
What are the options?
Remove and replace the pump
Pump no longer manufactured; will take 12 months and $5 Million to build a new one from scratch
Remove and replace the valve seals
Assumes seal integrity is the contributing factor
Can an astronaut be trained to perform the procedure in zero-G?
Do nothing to the pump; provide secondary cooling to the life support system until replacement pump can be manufactured
Secondary cooling system is available on-orbit
Relatively simple operation
Astronaut is on orbit that has experience with this pump
Refresher training available by “Just-in-Time” training
Do nothing
Space Station life has already exceeded expectations
Evacuate and terminate Program
These are all Risk versus Risk Trades

14. The Medical Equivalent
82 year-old male Patient presents with symptoms of circulatory problems
Hypotensive
Physician asks several questions
How long has this been going on – what’s the patient’s history?
What other symptoms are associated with the potential diagnosis?
What diagnostic tools are available?
ECG?, Angiography?

15. These are all Risk versus Risk Trades
A Path Forward
What are the options?
Option A
Option B
Option C
Do nothing
These are all Risk versus Risk Trades

16. “Is it Safe?” Is that really the right question?
“Prove to me that it’s unsafe” versus “Prove to me that it is safe”
Management of risk is the key
Know what the risk is
Identify the cause(s)
Determine the likelihood (probability) and the consequence(s) (loss of life, mission, $’s) if the event were to happen
Mitigate the risk wherever possible
Accept any residual risk
Who accepts that residual risk?

17. The Shuttle Risk
At the time of the first Shuttle flight (1981), estimated risk to loss of crew (LOC) was calculated at between 1:1,000 to 1:10,000
Based on tools available at the time

18. The “Real” Shuttle Risk
1:17
1:90
Flight Sequence #
Probability
1:10
0.02
0.04
0.06
0.08
0.1
0.12 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95
100
105
110
115
120
125
130 1
STS-1
STS-51L, STS-26 and STS-29
STS-49
STS-133
STS-41B
STS-77
1:38
1:21
STS-86
STS-89
1:47
STS-110 STS-114
1:36
1:37
1:73
STS-103
1:12
STS-5
Wiggins Analysis
(1:1000 to 1:10000)
(1:1000 to
1:10000)

19. The Shuttle Risk
At the time of the first Shuttle flight (1981), estimated risk to loss of crew was calculated at between 1:1,000 to 1:10,000
Based on tools available at the time
At the completion of the Shuttle Program (2011) after 135 flights, the modern tools estimated the risk for the first flight at 1:12
Demonstrates that your understanding of risk depends upon the tools and data that you have available at the time

20. Human Spaceflight Incidents
How many fatalities in human spaceflight history have there been? 3 17 21 18 10

21. 3

22. 7

23. 7

24. 1

25. 3

26. Soyuz 11, 1967
Soyuz TMA-12, 2008

27. Human Spaceflight Incidents
How many fatalities in human spaceflight history have there been? 3 17 21 18 10

28. Injury or Loss of Vehicle or Mission
Loss of Crew
Related or Recurring Events
Human Error
Systems
Acronyms
Injury or Loss of Vehicle or Mission
Vehicles
Country
Story
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