Alternative forms of communication include AUXCOM and sign language or writing over the video feeds.
The Habitat and Mission Control CAPCOMs communicate over a closed-circuit telephone system, which is the main audio link between the Habitat and MC, and which is supplemented by radio headsets as available. Buzzers were formerly used to call a CAPCOM to the phone when their counterpart needs to contact them, but there is currently no buzzer system and consequentially CAPCOM never hangs up.
Radio transmissions complete the communication system between EVA astronauts and the habitat. There is currently no way for Mission Control to communicate directly with the EVA astronauts. Many members feel strongly that Mission Control should not be able to contact astronauts on EVAs, since this could very easily lead to conflicting instructions in an area where, especially during Space Walks, there is absolutely no room for error.
During Mission Daedalus 2010 the telephone system was under repair and redevelopment, so two networked computers using Windows NetMeeting were used in place of the telphones for all but one night of the mission. This setup also allowed the habitat and mission control to contact one another while mission control was in the Spacesim Office, far out of range of a direct telephone line.
Prior to 2004-05 radios were used exclusively for CAPCOM with no telephone system. Until 2008-09, speakers Betty and Veronica, hooked up to a radio receiver, allowed everyone in Mission Control to listen to all radio transmissions.
In the new CAPCOM system developed in 2009-10 by Chris Hawthorne, Matt Farkas-Dyck, and Stefan De Young with help in construction from Nevin Hotson, each of the Airlock, Hotlab, Interlock, Longhouse, and Command and Control have a CAPCOM telephone located on a wall in that module. There is also a handset located in the Simulator Loft, and the system can communicate over the VPN to Mission Control at Lisgar in the Sim Office. This system has yet to be successfully implemented, but the Buzzers Task Force is well into the construction process.
- Main article: CAPCOM Procedures
CAPCOM operators are expected to conform to the highest standards of professionalism, while pretending that their telephone is a radio (or, alternatively, that it is a radio reciever built to look like a telephone for the comfort of the crew).
Closed-Circuit Telephone Systems
- Main article: Closed Circuit Telephone Systems
A Closed circuit telephone system acronymed to CCTS is a group of telephones that are wired to each other instead of using an external telephony service provider. Spacesim uses a CCTS for its primary CAPCOM.
- Main article: Buzzers
When using a closed circuit telephone system, the voltage is often too low to drive the ringer in any phone. In this case, we can substitute Buzzers, which are electromechanical noise makers running on direct current.
Events during Daedalus
The buzzer system was not ready for Mission Daedalus 2010. Prior to liftoff, all of the buzz boxes were installed in the Habitat. The card in the simulator loft was completed after takeoff, and during the first test, it was discovered that the buzzers sounded whether or not the transistors were activated by the software. This may be due to a short in the wiring. The ability of the Habitat to buzz MC was not verified.
It was suggested that the Buzzers be used as a Master Alarm in order to not waste the pre-Daedalus time that went into them. They were used as a wake-up call for the astronauts, but only on one occasion.
Chris Hawthorne put out a remarkably successful last-ditch effort to get the telephones working to re-establish communications, while Stefan De Young attempted to sound the buzzers to get the attention of the astronauts towards the telephones. The ploy worked, but it was observed that every time the buzzers were sounded, there was a visible arc across the contacts of each transistor. In addition, Mr. De Young was electrocuted many many times.
After the disaster was successfully resolved, the buzzers were not sounded again for the rest of the Mission for fear of harming the buzzer system.