re: Thankful for those that succeed: A short history of Mars Missions
Nice list. A few corrections
Mars 1962B was a flyby, not lander
Zond 3 (18/6/65) was a deep space probe using a Mars probe bus. It provided engineering and space science data out past mars orbit and should be included.
Mariner 6 returned only 50 pictures and suffered other instrument problems.
Mariner 7 retruned 126 pictures
Mariner 8 (9/5/71) was launch failure.
The Mars 6 and 7 carrier buses were not intended to enter orbit and returned flyby data.
Phobos 2 a large volume a lot of Mars data prior to failure at Phobos encounter (particle collision has not been ruled out).
Cheers
Jon