I hope it's the only one we have. One of the antennas at Goldstone, CA (DSS-15) is having some issues with their uplink system (an "uplink interlock" issue), so they have stowed the antenna. We still have DSS-25 tracking MRO, so we're good for downlink, but we're single-string there now. Not a big deal, but it is a glitch.
Update 4:04 pm: They have just reported that they will be back up and running and should be ready to receive MRO's signal in a few minutes.