Arnold A. Angelici Jr., M.D. May 19, 2004

1. Minimum Environmental Control & Life Support Guidelines for Manned Commercial Suborbital Reusable Launch Vehicles Arnold A. Angelici Jr., M.D.May 19, 2004

2. NRC Grant Proposal • Develop draft guidelines for minimum requirements for environmental control and life support systems (ECLSS) on manned commercial reusable launch vehicles

3. R&D Project • The Civil Aerospace Medical Institute (CAMI), which is the medical certification, research, and education wing of FAA’s Office of Aerospace Medicine is tasked under an R&D project to support FAA/AST: • NRC of National Academy of Sciences approved CAMI to establish a post-doctoral research associateship program in support of FAA research activities

4. Approach to the Completion of the Guidelines • A list of 19 aeromedical & environmental safety issues was developed. They were combined into modules based on similar or overlapping criteria. Some of these modules include: - Cabin atmosphere and air quality* - Temperature and humidity - Short and long duration G* - Restraint systems - Vibration and noise - Fire detection and suppression - Radiation *Note: Presentation focuses on these.

5. Various sources • NASA • Manned space flight experience • FAA/CAMI • Research experience • Current literature • Non-classified military research involving humans in aerospace environments • OSHA (Part 1910), NIOSH databases • Rule making based on research to make the workplace safer

6. Cabin Altitude Spacecraft designers will select a capsule design altitude: Sea Level to 10,000 feet 10,000 to 27,000 feet 27,000 to 40,000 feet and will have to deal with depressurizations

7. Cabin Pressurization vs. % Oxygen

8. Cabin Altitude Option: If it is from Sea level to 10,000 feet • May have partial pressure of oxygen at the altitude equivalent or • Enrich the cabin atmosphere so that the alveolar pAO2 is between Sea Level and 10,000 feet by enriching the cabin oxygen concentration from 21% to a maximum of 24%

9. Cabin Altitude Option: If it is between 10,000 feet and 27,000 feet then: • Oxygen should be provided to the crew by a diluter demand system for the entire time that the cabin altitude is at these levels at an oxygen concentration that will maintain alveolar pAO2 between Sea Level and 10,000 feet

10. Cabin Altitude Option: If it is between 27,000 feet and 40,000 feet then: • Oxygen should be provided to the crew by a pressure demand system for the entire time that the cabin this altitude and provide an oxygen concentration that will maintain alveolar pAO2 between Sea Level and 10,000 feet

11. Critical Cabin Altitude: If it is 40,000 feet for any amount of time, then: • Oxygen should be provided to the crew by a means that would result in an oxygen concentration that will maintain alveolar pAO2 between Sea Level and 10,000 feet • And protect them from the effects of very low barometric pressures

12. Cabin Atmosphere • Carbon dioxide (CO2) should not exceed 0.05 psi (0.4 kPa) or 0.5% sea level equivalent pressure • There should be a means of monitoring the concentration of CO2 in the cabin throughout the mission/flight

13. Table 1 — Effects of various COconcentrations at sea level.(At altitude, the effects of COpoisoning and altitude hypoxiaare cumulative.) Table 2 — Effects of various COHb saturations. COHbSaturation (%) Symptoms CO Concentration(parts per million) Symptoms 0 - 10 None. (Smoking yields 3% to 10% COHb.) 35 No obvious symptoms after 8 hours of exposure. 10 - 20 Tension in forehead, dilation of blood vessels. 200 Mild headache after 2 to 3 hours. 20 - 30 Headache and pulsating temples. 400 Headache and nausea after 1 to 2 hours. 30 - 40 Severe headache, weariness, dizziness, vision problems, nausea, vomiting, prostration. 800 Headache, nausea and dizziness after 45 minutes; collapse after 2 hours. 40 - 50 Same as above, plus increased breathing and pulse rates, asphyxiation. 1000 Unconsciousness after 1 hour. 50 - 60 Same as above, plus coma, convulsions, Cheyne-Stokes respiration. 1600 Unconsciousness after 30 minutes. 60 - 70 Coma, convulsions, weak respiration and pulse. Death is possible. 70 - 80 Slowing and stopping of breathing. Death within hours. 80 - 90 Death in less than 1 hour. 90 - 100 Death within minutes. Carbon Monoxide

14. Acceleration Loads • Long Duration G loads (sustained) • Short Duration G loads (sudden)

15. Acceleration LoadsLong Duration: > 0.1 sec. • (gradual onset < 0.1G/sec.): +4 Gz -2 Gz 4 Gx 1 Gy By J. Burns & Wm. Albery, AFRL/HE

16. G-LOC • Hazards to the safety of manned commercial space flight due to G-LOC • Pilot might be unaware that G-LOC had occurred • Lack of physical control post G-LOC • Poor insight to what had happened • Embarrassment over loss of consciousness • Return to consciousness but not to control

17. Incapacitation due to G-LOC • Absolute incapacitation +Gz: 16.6 ± 5.9 sec. • Relative incapacitation +Gz: 14.4 sec. • Total incapacitation +Gz: 31.0 ±11.7 sec. • G-LOC occurred between 3.1 and 4.0 G • The period of Relative incapacitation is accompanied by confusion and disorientation. • Training reduced the duration of Relative incapacitation by 8.5 sec.

18. Mitigation • Training of air crews by exposure to G-loads has demonstrated: • Improved tolerance to G-loading • Reduction in the duration of relative incapacitation time • Monitoring • Incorporate an “Auto-recovery” mode into the vehicle if the flight profile would place the crew at risk of G-LOC • Use of an anti-G suit

19. Short Duration Acceleration Loads (<0.1sec.) • Aircraft ejection seat firings - up to 17 +Gz • Crash landings - from 10 to greater than 100 G's (omni directional) • Orbiter crew compartment design loads for crash landings are 20 Gx and 10 +Gz • Violent maneuvers - approx. 2-6 G's (omni directional) • Parachute opening shock - approx. 10 +Gz • Reference:5.3.2.1.3, p.5-31; NASA-STD-3000 Rev. B

20. Duration of Force <0.1 Sec. Reference: Fig. 5.3.3.3-1, p. 5-40, NASA-STD-3000

21. Restraint Systems • Utilize the knowledge from CAMI’s Biodynamics research to develop appropriate guidelines for restraint systems for Manned CRLV’s • Proper use of the restraint system will prevent serious injury in normal operation and have reasonable expectations of survival in the event of a crash

22. Restraint Systems • The restraint systems must protect the crew and passengers from: • Sudden, short duration G-loads (Transient Acceleration) • Sustained duration G-loads (Sustained Acceleration) • Acceleration (launch) • Deceleration (re-entry) • “Zero G”

23. Schedule • Complete R&D project in August 2004