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Operational Aspects of Space Radiation Analysis October 18, 2005 Mark Weyland

2. BACKGROUND. The SRAG was established at the NASA

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Operational Aspects of Space Radiation Analysis October 18, 2005 Mark Weyland

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    2. 2 BACKGROUND The SRAG was established at the NASA – Johnson Space Center in 1962 SRAG provided 24-hour support for all manned missions until 1994 Pre-flight, in-flight, and post-flight support Legal and moral reasons require NASA limit astronaut radiation exposures to minimize short and long-term health risks

    3. 3 ALARA Adherence to ALARA (As Low As Reasonably Achievable) is recognized throughout NASA’s manned spaceflight requirements documents Radiation protection philosophy-- All radiation exposure, no matter how small, increases the health risk to that individual (Linear Non-Threshold Theory) Astronaut exposures are much higher than the typical ground-based radiation worker Space radiation more damaging than radiation typically encountered by ground-based workers

    4. 4 BACKGROUND Acute affects Affects range from mild and recoverable to death Risk of acute affects during LEO missions is very small Long-term risks Cancer risk increase Cataracts Genetic affects Heart risks

    5. 5 Limits 30 Day: NASA BFO (NCRP 98) Eye (NCRP 98) Skin (NCRP 98) Annual NASA BFO (NCRP 98) Eye (NCRP 98) Skin (NCRP 98)

    6. 6 REAL TIME SUPPORT NOAA SEC in Boulder, CO (EASY Mike) L-30, and L-3 day briefings And daily briefings when on console during real time support (discuss in a minute)NOAA SEC in Boulder, CO (EASY Mike) L-30, and L-3 day briefings And daily briefings when on console during real time support (discuss in a minute)

    7. 7 REAL TIME Nominal support on console from Mission Control Houston (MCC-H) is 4 hours per day In MCC-H continuously during significant space weather activity and all EVA's Examine available space weather data, reports, and forecasts for trends or conditions which may produce enhancements in near-Earth space radiation environment Tag-up with NOAA SWO Solar Forecaster for “big picture” of space weather conditions Check vehicle status and crew timeline for the potential for unscheduled EVAs Report crew exposure status and space weather conditions to flight management Examine available space weather data, reports, and forecasts for trends or conditions which may produce enhancements in near-Earth space radiationenvironment Tag-up with NOAA SWO Solar Forecaster for “big picture” of space weather conditions Check vehicle status and crew timeline for the potential for unscheduled EVAs Report crew exposure status and space weather conditions to flight management

    8. 8 SPACE WEATHER

    9. 9 SPACE WEATHER

    10. 10 SPACE WEATHER

    11. 11 REAL TIME

    12. 12 REAL TIME

    13. 13 REAL TIME

    14. 14 REAL TIME

    15. 15 REAL TIME What do we do during contingency situation (usually middle of night)What do we do during contingency situation (usually middle of night)

    16. 16 SRAG Space Weather Alarm System Log 20 Jan 2005 17:18z SPE (>10MeV) Decreased Below 1000 Level: 17:05:00 645.6; pager called 20 Jan 2005 08:35z X-ray Flare Event Ended at 08:34:00 - M4.85/ Peak at: 07:01:00 - X7.12/ 1.805278 hours; pager called 20 Jan 2005 08:34z Flare Decreased Below M5 Level: 08:33:00 - M4.95; pager called 20 Jan 2005 07:28z Energetic SPE (>100MeV) Has Peaked at: 07:10:00 652.359985; pager called 20 Jan 2005 07:28z SPE (>10MeV) Exceeded 1000 Level: 07:15:00 1113.5; pager called 20 Jan 2005 07:28z X-ray Flare Half Peak Event Ended at 07:27:00 - X3.43/ Peak at: 07:01:00 - X7.12/ 0.690000 hours; pager called 20 Jan 2005 07:18z X-ray Flare Has Peaked at: 07:01:00 - X7.12; pager called 20 Jan 2005 07:17z Flare Decreased Below X5 Level: 07:16:00 - X4.93; pager called 20 Jan 2005 07:15z Energetic SPE (>100MeV) Exceeded 600 Level: 07:10:00 652.359985; pager called 20 Jan 2005 07:05z Energetic SPE (>100MeV) Exceeded 400 Level: 07:00:00 426.760010; pager called 20 Jan 2005 07:01z Energetic SPE (>100MeV) Exceeded 200 Level: 06:55:00 217.960007; pager called 20 Jan 2005 06:57z Energetic SPE (>100MeV) Start (Crossed 1.0 Threshold) 06:50:00 21.980000; pager called 20 Jan 2005 06:53z Flare Exceeded X5 Level: 06:52:00 - X5.34; pager called 20 Jan 2005 06:47z Flare Exceeded X1 Level: 06:46:00 - X1.50; pager called 20 Jan 2005 06:46z M Flare Start (Crossed 5.000000e-05 Threshold): 06:45:00 - M9.04; pager called

    17. 17 ISS Crew Dose Summary From January 2005 Event Due to fortunate orbital phasing, crew only received around 2 days worth of additional dose (~0.035 cGy). If ISS had begun the high magnetic latitude passes during the start of the event, the doses would have been a factor of 10 higher for this event. If the Shuttle were on the way to the moon, the doses would have been around 6 cGy in the first 2 days. This is more than a ground based worker is allowed in a year.

    18. 18 CONTACT INFORMATION P339 – Treadmill (more shielded area) P327 – Next to R-16 P307 – Workstation (and at other end of module) Window 14 – Thinly shielded area on front end Doses rates change with attitude and altitude lately, and will approximately double at solar min Vary more than 35% in SMP339 – Treadmill (more shielded area) P327 – Next to R-16 P307 – Workstation (and at other end of module) Window 14 – Thinly shielded area on front end Doses rates change with attitude and altitude lately, and will approximately double at solar min Vary more than 35% in SM

    19. 19 CONTACT INFORMATION

    20. 20 Constellation Vehicle Shielding Radiation specific shielding on Exploration vehicles is unknown Already push-back on adding mass for radiation protection Best case scenario’s still leave short duration vehicles and EVAs (low shielding) vulnerable to SEPs

    21. 21 New Challenges for SRAG Train Space Wx Officers for each mission Implementation of design ideas (shielding, materials) Education (design engineers, management, crew) New models and tools Concept of Operations

    22. 22 SRAG Wish List Recommendations of the NASA Sun-Solar System Connection Radiation Working Group Report – July 2005 Real time data from spacecraft for operational purposes, (NDAs) Additional real time measurements in proton flux (50's &100's, but also 300's to 500's) Integration/transition from research models to configuration controlled V&V operational tools (CCMC?) Satellite data sent directly to future Constellation vehicles as well as the ground Quiet time forecasts Active/electronic personal dosimeters with well characterized charged particle/neutron sensitivities

    23. 23 FINAL THOUGHT Of all the risks encountered by astronauts during space flight, the increased risk of cancer induction from radiation exposure is one of the few that persists after landing

    24. 24 To design a flying machine is nothing; building it is not much; flight testing it is everything. Otto Lilienthal

    25. 25 To design a model is nothing; building it is not much; testing (V&V) is everything.

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