Announcements

Space Shuttle Era Concludes (2011 July 21)

The 40-year Space Shuttle program came to an end today with the return of shuttle Atlantis from its final mission. After authorization by President Nixon in 1969, vehicle design began in the early 70s, and the first atmospheric test flights were performed at Edwards AFB in 1977 (Enterprise). The culmination of one of the most technically challenging projects in history came on 1981 Apr 12 with the successful launch of STS-1 (Columbia) from Cape Canaveral. Space shuttle crews ultimately built a space station, launched numerous satellites, performed the famous Hubble Space Telescope repair, collected magnificent IMAX footage, and oversaw thousands of critical space technology experiments.

The image to the right is a time exposure of the shuttle re-entry taken from the International Space Station. This awesome shot shows the parabolic trajectory of Atlantis as it begins to glow from frictional heating of the thermal tiles in the upper atmosphere. (Blurring of the clouds is caused by the Space Station's orbital velocity of 7.8 km/s.) The shuttle navigated low-Earth orbit (LEO), well above the massive shielding of the atmosphere, but within the protective sheath of Earth's magnetic field. The Space Shuttles were originally flown at an inclination of 28.5° to the equator and later at 51.6°. The radiation environments of these two orbits are quite different, but both are much less severe than polar orbits. Space Radiation provides tools for evaluating the relative strength of radiation environments at all orbit altitudes and inclinations.

Coronal Mass Ejections (2010 Aug 1)

A notable series of four coronal mass ejections was observed from NASA's Solar Dynamics Observatory on August 1, 2010. These events produce high-energy ions, primarily protons, that are predicted to arrive at Earth on August 4 and 5. CMEs can directly affect the function of geostationary, geosynchronous and polar orbiting satellites. Depending on the magnitude of the events, low-earth orbits may be affected. Extremely large events can increase neutron fluences in the atmosphere affecting aircraft crew and electronics. Space Radiation is designed to predict the effects of CMEs and other natural radiation sources in all orbits, as well as along aircraft and ballistic trajectories.

New Version: Space Radiation 6.0