Space Cover 867: How many postmarks are needed?In past days of July, a massive forest fire devasted the Sierra of Madrid, place where is located Madrid DSCC (NASA-INTA Robledo tracking station).
This fire joined with another fire in Avila province, where was located older Cebreros tracking station, and in conjunction +120.000 people of many towns and villages were evacuated by smoke high risk. Hundreds of houses were burned and many damaged facilities.
Once fire is under control, now people is returning at home to see what has been the impact of fire in their lives.
Robledo tracking station personnel was also evacuated and only some fire brigades were fixed in the station to protect critical facilities like antennas. Meanwhile surrounding vegetation was scorched seems that antennas of Madrid complex were not affected. Technicians follow evaluating the situation.
It is necessary to praise the work of everyone who fought the fire.
And our astrophilatelic tribute to Madrid tracking station is served now with the above cover, postmarked at Robledo Aug 7, 1972 for last manned Apollo mission, Apollo 17. Printed cover bears a huge blue rubber stamp cachet and was signed by three unidentified people, most sure engineers and/or technicians that worked in Robledo in those years.
I wonder if the above cover is all a collector can get or if there are other chances to show the same space event with identical cover.
Below, the same cover, unsigned, but with two Robledo postmarks.
Why two postmarks? It could be answered because Robledo device is a bit poor and postal employee applied a second postmark to show better place and date.
This is not rare for most of collectors who usually require to postal employees two postmarks; one over stamp and another one in some place of the cover to read it clearly.

However, I am still wondering why three postmarks in the below cover.

The best postmark is applied over the stamp. For sure, it was the first one applied. Other two, applied later, are of worst quality because date is more difficult to read compared the first one. If the goal of additional postmarks were to get a clear postmark, it was not achieved at all. Second and third postmarks do not improve the first one. Then, should the collector request a fourth postmark? And a fifth? Is there a limit of postmarks?
In reverse side cover is blank, without any Robledo postmark.
Please, I would like to read your opinion about how many postmarks are needed to create a good space cover? How many postmarks do you require on your covers? Thanks.