Aerospace Environment ASEN-5335 Instructor: Prof. Xinlin Li (pronounce: Shinlyn Lee) Contact info: phone: , or , fax: , website: Office hours: 9:00-11:00 pm Wed at ECOT 534, Tue & Thu, after class. Read Chapter 1 & 2.

Energetic electrons and protons are not able to penetrate down to the Earth’s surface directly. Particles gain entry through the cusps that are shaped like funnels over the polar regions or they enter far downstream from the Earth. Particles that enter downstream can be transported toward the Earth and accelerated to high energies, producing auroras and radiation belts. The Earth’s Magnetosphere

The flare was an ‘X-class’ and accompanied by one of the largest solar energetic proton events ever recorded c3714

These protons reach Earth in less than 30 minutes Less than 1 hour after the initial proton arrival the POLAR/VIS imager is saturated and remains so for almost a day Vis-proton-bastille

A Schematic View of the Locations of Radiation Belts Blue: inner belt, >100MeV protons, rather stable Purple: outer belt, 100s keV and MeV electrons and ions, not stable at all Slot region in between Yellow: ACRs, stable White line: Earth’s magnetic field, approx. by a dipole field

Charged Particle Motions in Earth’s Magnetic Field Gyromotion motion:  =p 2  /2mB (1st), T_g~10 -3 sec Bounce Motion: J=  p || ds (2nd), T_b~10 0 sec Drift motion:  =  BdA (3th), T_d~10 3 sec

PARTICLE ENERGIES OF CONCERN

EVA EVAs - additional radiation exposure concern –Lower shielding –Eye dose –Skin dose 51.6 degrees, new concern for electron events –One area where we don’t currently have a good model. Have limited measurements outside at our orbits during events from Shuttle and MIR, so we don’t have enough data for any kind of empirical model. 145 more EVAs are planned for ISS completion

The flare was an ‘X-class’ and accompanied by one of the largest solar energetic proton events ever recorded c3714

ISS ALTITUDE PROFILE

LEOGEO Earth’s Debris Environment Ground based radar and optical map > 1 cm below 2000 km and > 10 cm above 2000 km Shuttle surface and window damage for LEO Need for smaller debris (<10 cm) map in most of space

National Space Weather Program To Advance observing capabilities fundamental understanding of processes data processing and analysis numerical modeling transition of research into operational techniques and algorithms forecasting accuracy and reliability space weather products and services education on space weather

National Space Weather Program To prevent or mitigate under- or over-design of technical systems regional blackouts of power utilities early demise of multi-million dollar satellites disruption of communications via satellite, HF, and VHF radio disruption of long-line telecommunications errors in navigation systems excessive radiation doses dangerous to human health