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 pAO 2 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 pAO 2 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 pAO 2 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 pAO 2 between Sea Level and 10,000 feet –And protect them from the effects of very low barometric pressures

12. Cabin Atmosphere Carbon dioxide (CO 2 ) 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 CO 2 in the cabin throughout the mission/flight

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

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

15. Acceleration Loads Long 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 Direction of impact acceleration Impact limit Rate of impact ±Gx20 G1,000 G/sec. ±Gy20 G1,000 G/sec. ±Gz15 G500 G/sec. 45° off-axis (any axis) 20 G1,000 G/sec.

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