While testing out the updated version of the NTRS I found another missed opportunity for NASA (See also: http://www.unmannedspaceflight.com/index.p...=4472&st=0)
TRW in 1968 proposed that Pioneer E be modified so that it could be launched and become the first ever spacecraft to orbit Venus (On or about the 16th of December 1970, with the orbital mission running to at least May of 1971). While the instrumentation would have been unchanged, battery power would have been increased, the attitude system modified to allow mid-course corrections and most importantly a solid rocket would have allowed the spacecraft to enter Venusian orbit.
While not equipped to take photographs or directly study the planet itself, it would have allowed the long term study of the Venusian near space environment to begin much earlier than it did.
For the 11mb Volume 1 Technical report (The remaining volumes do not seem to be available online)