Page 114 - Intro to Space Sciences Spacecraft Applications

Spacecraft Environment
101
stations is affected by the atmosphere and ionosphere which also fluctu-
ate constantly.

Man in Space

All of the above situations must be considered when man is placed into
the space environment. In most cases, a suitable environment can be pro-
vided within a spacecraft or with the use of a space suit. However, humans
are particularly susceptible to high-energy particle radiations in the form
of cosmic rays (from distant stars and galaxies), the particles trapped in
the geomagnetic field, and those produced by solar flares. These particles
have the ability to pass through shielding and can produce cell damage to
astronauts, so exposure must be measured and limited. Fortunately, the
areas associated with commonly used nonpolar low-earth orbits have low
enough radiation levels to be relatively safe with simply a small amount
of protection.

REFERENCEWADDITIONAL READING

National Aeronautics and Space Administration, Space Physics Strate-
gy- Implementation Study, 2nd ed. Washington: NASA, 199 1.
Interagency Group (Space), National Security Council, Report on Orbital
Debris. Washington: National Security Council, 1989.
T. Wilkerson, M. Lauriente, and G. Sharp (Eds.), Space Shuttle Environ-
ment. New York: Engineering Foundation, 1985.
C. Cochran, D. Gorman, and J. Dumoulin (Eds.), Space Handbook.
Alabama: Air University Press, 1985.
Tascione, T., Introduction to the Space Environment. Colorado Springs:
U.S. Air Force Academy, 1984.

1. Draw a graph showing the estimated temperature (T) and density (p)
variations of the sun from 0 to 2 solar radii (R,) based on the informa-
tion given in the chapter. Use logarithmic scales for T and p and a lin-
ear scale for R,.

2. Starting with a value for the solar constant in the vicinity of the earth of
1,390 W/m2: