The composition of the solar wind is virtually identical to the element abundances in the Sun itself. Hydrogen and helium nucleii as well as atoms of carbon, nitrogen and oxygen predominate. near the earth, the wind travels at about 450 kilometers/sec, but strong storms and coronal holes on the sun can produce streams millions of miles wide traveling at 2 - 3 times this speed. The density of the wind is usually near 5-10 atoms per cubic centimeter so the pressure you would feel from this wind is about 1/2 density x velocity^2 or 2.6 x 10^-7 dynes/square centimeter. A solar sail about 10 kilometers in diameter would feel a pressure of 200,000 dynes, and for a payload weighing 10 kilograms you would have an acceleration of about 20 centimeters/sec/sec.
All answers are provided by Dr. Sten Odenwald (Raytheon STX)
NASA IMAGE/POETRY Education and Public Outreach program.