You wouldn't pick up information on submarines. There are something like 80,000 ships today that have these transmitters on board, and the number will increase over time as the requirements change. For submarines, you take a different approach.
I did talk about a series of constellations. The second one is low data rate communications. Low data rate communications can do all sorts of things. We're busy talking to people around the world about sending signals that monitor water levels and water pollution, that monitor other attributes related to what's happening on the earth, and that might be ice thickness or climate change information from remote areas that are sent to a satellite. One of the things you can do that we've talked to our government about is the potential of throwing transducers into the water that detect the sound of submarines going by, and those transducers have little transmitters on board that talk to our satellite. So we can actually monitor submarines through a spacecraft, but in quite a different way.