# Presentation: 924786

## Space Weather Challenges Intrinsic to the Moon, Mars, and Beyond Vision

**Space Weather Challenges Intrinsic to ****the Moon, Mars, and Beyond Vision**

**Prepared by**
**Ron Turner**
**5 April 2004**

## Why Should We Care About Space Weather?

**Radiation exposure will be a significant and serious hazard during any human expedition transiting deep space**

## The Greatest Single Challenge to LWS is to Improve Our Ability to Forecast Solar Particle Events

**While significantly lower in energy that the GCR, the proton flux of SPEs is orders of magnitude greater for hours to days **
**Principle of ALARA requires that exposure to SPEs be minimized**
**Potential to be caught away from shelter on the Lunar or Martian surface will impose operational rules that will limit flexibility and reduce efficiency**

## Forecasting SPE is a Multidiscipline Challenge

**Predict the eruption of a CME**

## Significant Events in the Moon, Mars, and Beyond Vision

**2000**

**2010**

**2020**

**2030**

**Return to the Moon**
**2015-2018**

**On to Mars**
**Date TBD**

**SDO**

**STEREO**

**SOHO**

**ACE**

**Sentinels**

- Only One More Solar Cycle Left to Learn What We Must Learn

**Cycle 24**

## Solar Monitoring

**Routine solar monitoring is the necessary first step to forecast and characterize of SPEs **
**Near-real-time observations of solar active regions and emerging Coronal Mass Ejections (CMEs) may provide data useful to forecast the progress of an on-going SPE over a period of hours to days**
**Additional progress in understanding the physics of CMEs may lead to a multiday forecast of the probability of an SPE**
**LWS Solar Dynamics Observatory and the Sun-Earth Connections STEREO Mission can build on the current suite of research spacecraft and ground-based facilities to select the appropriate operational instruments for solar monitoring**

## Heliospheric Monitoring

**Heliospheric observations provide information necessary to model or monitor the propagation of solar energetic particles from the source to the astronauts**
**The data that may be necessary for SPE propagation models include **
**State of the ambient solar wind plasma**
**Interplanetary magnetic field**
**Local disturbances moving through the inner heliosphere**
**LWS Sentinel Missions will provide experience and proof of concept from which we will be able to learn more about the underlying physics and select the appropriate operational instruments for solar monitoring**

## Solar Wind Forecasting and Specification

## Heliospheric Monitoring (continued)

**Plasma Analyzers**

**Radio Burst Detectors**

**Scattered Light Imagers**

**Solar Surface Magnetic Field Maps**

**A Variety of Tools are Potentially Available to Help Characterize the Heliosphere**

## What We Must Know About Solar Particle Events to Reduce the Risk to Astronauts

** **
**For astronaut radiation safety, the important SPE energy range is ****from 30 MeV up to 100-200 MeV**
**Spectral slope is very important**
**SPE forecast goal according to findings of 1996 SPE risk mitigation workshop is**** **
**10 to 12 hour forecast prior to a likely event**
**6 to 8 hour forecast of magnitude and spectral slope after event on-set**
**3 to 4 hour rolling forecast as SPE progresses**
**Realistic near-term challenge:**
**8 hour rolling forecast as SPE progresses**
**Predict, at event on-set, the time of arrival and magnitude of shock-enhanced peak**
**Reliably forecast 3 to 7 day “all clear”**

## SPE Forecasting

- Cycle 22 SPEs

## SPE Forecasting (Continued)

**Can we use solar observations and observations of an event at one point in the solar system to reliably characterize the SPE at a nearby point in the solar system?**

## Improve SPE Forecast Rate

**If only ****5 percent**** of all CMEs are sufficiently fast to generate an SPE, then the prediction that a CME will ****not be**** one of these 5-percenters must be better than ****99%**** reliable to keep the SPE forecast success rate ****above 80 percent**

**SPE Forecast**

**96 No**

**4 Yes**

**99 % Accurate**

**99 % Accurate**

**95 No**

**  ****0 No**

**1 Yes**

**4 Yes**

**95 No**

**5 Yes**

**Observation**

**Leads to an SPE forecast success rate of 4 out of 5, or 80 percent**

**100 CMEs**

## Credibly Forecasting “All Clear” is a Challenge

**Histogram of days between SPEs**
**for 1989-1991**

** ****Between 1989 and 1991:**
**974**** days no SPE**
**117**** days of SPE***

***GOES Data; an SPE is underway when the 5-minute flux of protons with energy greater than 10 MeV exceeds 10 particles/cm****2****-sec-sr for 15 minutes**

**To be credible, a 3-day “All Clear” forecast must be right more than 95% of the time and must avoid more than 95% of the SPEs **

**0**

**2**

**4**

**6**

**8**

**10**

**Number of occurances**

**1-5**

**6-10**

**11-15**

**16-20**

**21-25**

**26-30**

**31-35**

**36-40**

**41-45**

**46-50**

**51-55**

**56-60**

**61-65**

**More than**
** ****65 days**

**Consecutive days with no SPE**

## Can We Forecast Shock-Enhanced Peaks?

**Challenge:**
**Which events will have a**
**significant shock enhanced peak, when will it arrive, and how large will it be?**

## How Can LWS Science Support the Moon, Mars, and Beyond Vision

**Better understanding of Solar Dynamics**
**Improved Forecasting of Coronal Mass Ejections**
**Improved forecasting of SPEs**
**Better understanding of Heliospheric Dynamics**
**Improved Forecasting of Solar Wind profiles**
**Improved forecasting of SPEs**
**Better understanding of SPEs**
**Improved design of habitats and shelters**
**Higher confidence in mission planning****	**
**Better forecasts of SPE evolution after on-set**
**Higher confidence in exposure forecast**
**Implementation of more flexible flight rules**
**Reduced period of uncertainty**
**Greater EVA scheduling flexibility**
**Less down-time of susceptible electronics**
**Prediction of SPEs before on-set**
**Higher confidence in exposure forecast**
**Greater mission schedule assurance**
**Less down-time of susceptible electronics**
**Prediction of “all clear” periods**
**Higher confidence in exposure forecast**
**Greater EVA scheduling flexibility**
**Greater mission schedule assurance**

**Improved Safety and Enhanced Mission Assurance**