The right way to model multiple FACTs schema
So the first question is: Are you absolutely sure you need to use a star schema?  Having worked in a number of warehouses built to varying levels of quality, I have found star schema to be: 1. Inflexible 2. Difficult to use (tons of joins) 3. Really bad for time series.
The way you have described things (Product, Product State, Test) along with the need to track points in time would generate something like this (slight embellishment for party/test):

If you need to get the state as of a certain test this is attainable by a simple join, which can be encapsulated in a view so users don't have to worry about getting the logic correct:
SELECT
  ProductTest.ProductId
 ,ProductTest.TestDtm
 ,ProductTest.TestCd
 ,&lt;Other relevant columns&gt;
 ,ProductState.OwnerId
 ,ProductState.&lt;Location info&gt; --Don't know if this is address or lat/long, use whatever works best for you
FROM
  ProductTest ProductTest
LEFT JOIN
  ProductState ProductState
    ON ProductState.ProductId = ProductTest.ProductId
         AND ProductState.UpdateDtm =
               (
                 SELECT
                   MAX(UpdateDtm)
                 FROM
                   ProductState
                 WHERE
                   ProductId = ProductTest.ProductId
                     AND UpdateDtm &lt;= ProductTest.TestDtm
               )