Jay, a LOI is a letter of intent. A joint venture means both companies are going to spend resources to see if the product works.
Actually Cavanaugh said it right. This is a way of cementing relationships. If it works well, there'll most likely be an order and due to Raytheon's involvement with the process, they do take some ownership in it and will give an order less grudgingly.
An LOI means that an order is eminent.
So far neither company (IMO) is hearing the cash register ring.