Expensing an exploratory real estate investment trip

Travel/research expenses as described would be added to the Basis of property(s) purchased as a result. You can't 'expense', as you don't regularly trade in buying and selling properties. Keep details (who/when/why etc) ...

the first thing that must be determined is are you a real estate professional under IRC section 469(c)(7)(B)

Qualifications. You qualified as a real estate professional for the year if you met both of the following requirements.
• More than half of the personal services you performed in all trades or businesses during the tax year were performed in real property trades or businesses in which you materially participated.
• You performed more than 750 hours of services during the tax year in real property trades or businesses in which you materially participated.

If you file a joint return, don’t count your spouse's personal services to determine whether you met the preceding requirements.

the hour requirements are per property unless an election is made with the taxpayer's return under 469(c)(7)(A) to aggregate the properties.   changes in the tax rules may allow filing a late election.  seek professional help if you go this route

if you are not a REP and did not acquire the property, then then the expenses you incurred would be investment expenses which are no longer deductible starting in 2018.  if you are a REP, but didn't acquire the properties , such expense would be considered those  related to fruitless searches for new ventures and would be deductible under IRC section 165 on schedule C.  if you did acquire the property, these would be start-up expenses under  IRC section 195 REP or not. 

 https://www.law.cornell.edu/uscode/text/26/195

note that record keeping for the hours spent in real estate activities is crucial.  the IRS has been challenging those that classify themselves as REP's.  The IRS and courts have disallowed the classification where the record keeping was poor.  

I have 2 real estate properties that are running at a loss.

That's no surprise. In fact, the real surprise would be if you actually had a taxable gain. It is extremely rare for rental property to actually show a taxable gain "on paper" when you file your taxes. Especially if you have a mortgage on the property.

When you add up the deductible items of property taxes, mortgage interest, insurance and the depreciation you are required to take by law, that alone is usually enough to exceed the total rental income for the year. Add to that any other rental expenses allowed and you're practically guaranteed to show a loss on paper. Those losses just continue to increase with each passing year as prior year losses get carried over with each successive year. So the amount of losses carried over continue to grow with each passing year.  The potential tax hit will come in the year you sell or otherwise dispose of one or more rental properties.

When you sell a property that's when all those losses will actually be realized.  It works like this.

First, all that depreciation you've been required to take by law gets recaptured and taxed in the year you sell. That recaptured depreciation gets taxed at anywhere from 15% to a maximum of 25%. Though if your overall AGI is low enough it's possible to be taxed at 0% (yes, zero percent).

Then your cost basis in the property is reduced by the amount of depreciation taken (or should have taken if you did not depreciate as required by law.)  From that adjusted cost basis your loss or gain on the sale is figured.

 - First, your losses are deducted from any gain realized on the sale of the property. If that gets your taxable gain on the sale to zero and there are still losses left over then;

 - Remaining losses are deducted from other ordinary income (such as W-2 or 1099-MISC income) up to a maximum amount allowed each year (generally, $3,000). If there are still any losses left over to be deducted then;

 - remaining losses are carried forward to the next year where they can be deducted up to the maximum allowed again. This continues year to year until all losses are realized.

So if rental income is your only source of income, it's perfectly possible that with the sale of a rental property, losses could never be used up and at some point in time (such as when you die) those losses would just basically "evaporate" into la-la land, never to be seen again.

But generally when a person sells a rental property, all losses are used up on the gain from the sale leaving some of that gain taxable.  But that doesn't happen often enough to call it "common" or not enough to call it "rare".

Now with only two rental properties, I don't see how it's possible for you to qualify as a real estate professional under the IRS guidelines unless you are also a realtor that deals in the sale/purchase of other properties, like a real estate agency does. That "750 hours a year/15 hours a week" requirement pretty much kills that possibility. 

I have three rental properties myself and there is no possible way on this green earth that I can even come anywhere close to 750 hours a year/15 hours a week managing my three properties. Even if I had all three properties go vacant in the same tax year and did the turn around work myself (which is what I actually do) I would be hard pressed to justify 100 hours on all three properties combined for the entire tax year.  So if I was to claim I qualified as an RE Pro and later got audited on it, there's no question I would lose.

Now with all that said, your exploratory trips are not a valid expense in any way for tax purposes if the trip did not result in the acquisition of a rental property. As far as the IRS would be concerned, you're trying to deduct the cost of a vacation; and they'll pounce all over you for that.