Editing Dinitrogen tetroxide (section)

===The Apollo-Soyuz mishap===
On 24 July 1975, NTO poisoning affected three U.S. [[astronaut]]s on the final descent to Earth after the [[Apollo-Soyuz Test Project]] flight. This was due to a switch accidentally left in the wrong position, which allowed the [[Spacecraft attitude control|attitude control]] thrusters to fire after the cabin fresh air intake was opened, allowing NTO fumes to enter the cabin. One crew member lost consciousness during descent. Upon landing, the crew was hospitalized for five days for chemical-induced [[pneumonia]] and [[pulmonary edema]].<ref>[https://news.google.com/newspapers?id=RBgsAAAAIBAJ&sjid=kMgEAAAAIBAJ&dq=apollo%20gas&pg=993%2C1384026 "Brand Takes Blame For Apollo Gas Leak"], ''Florence, AL - Times Daily newspaper'', August 10, 1975</ref><ref>Sotos, John G., MD. [http://www.doctorzebra.com/drz/s_medhx.html#ASTP_incident "Astronaut and Cosmonaut Medical Histories"], May 12, 2008, accessed April 1, 2011.</ref>