Chemtrails is a term originated by the Airforce DOD. So yet again, there is no question as to the existence of such terminology and/or technology. The associated patents to conduct this type of spraying have been provided in the Case Orange report as well as at numerous other locations. Chemtrails have been categorized and recognized as an exotic weapon in official legally admissible Congressional records. However wether you use the term "chemtrails" or "persistent contrails", the terminology is merely a matter of semantics, and makes no real difference. The real question is what are they spraying, and why, and how to get them to stop.
If opponents of chemtrails are still obsessed with proving the obvious reality of the situation to themselves despite the overwhelming wealth of knowledge that already exists, then by all means commission and conduct whatever additional experiments you see fit. However, be warned that meddling in the affairs of the military and department of defense is not a game.
Bob seems to think that the scientists that have researched this issue so far have not lived in fear of repercussions against them for releasing their findings, but that isn't true. All scientists for the Belfort Group that conducted an independent study of the phenomena of chemtrails/persistant contrails did so anonymously particularly because of fear and threats of persecution.
Concequently, for those who don't know the truth and haven't taken the time to credibly research it, but do nothing but sit idly by and criticize the scientific findings of others, you can incur the cost and risk of additional tests, experiments, etc., as you deem fit, and share any findings that aren't already in-line with the current state of existing scientific knowledge regarding the issue.