HOUSTON - Ending a more than a two-and-a-half-year hiatus, Space Shuttle Discovery launched from NASA's Kennedy Space Center July 26, 2005. The flight, officially known as STS-114, carried a crew of seven on one of the most intricate and closely watched missions in history. The Discovery mission included on-orbit maneuvers, tests of new equipment and procedures, and a first-of-its-kind spacewalk repair. Throughout the entire mission, audio of shuttle and station communications, mission commentary, media feeds, and audio from the various NASA operations centers was coordinated at Houston’s Johnson Space Center (JSC) on a recently installed Euphonix System-5B broadcast console.
    The Johnson Space Center serves as the hub for all of NASA’s human space flight broadcasts—be it the space station or the space shuttle. In addition to its space missions, NASA also operates NASA TV, a digital service with four channels— producing content accessible by the public, a channel developed specifically for the media, and a fourth channel reserved for institutional internal broadcasting. In addition to the production of training materials, a considerable amount of mix minus product is produced for press conferences and similar NASA events, as well as all broadcast operations for NASA TV.
   The entire Discovery mission was mixed on the System 5. According to John Stoll, Senior Audio Technician with Tessada & Associates (the company contracted to handle audio related services at the Johnson Space Center), “Throughout the recent Discovery mission, the System 5 was used 24/7 from the time the shuttle launched, until it landed. When the public heard the astronauts speaking, it was via the System 5. All press conferences that occurred throughout the mission were also handled on the console. With the exception of the roar of the engines at takeoff (which is produced by the audio team at the Kennedy Space Center [KSC] in Florida), we mixed and built everything else the public heard, including the launch narrations.”
   To assemble the Discovery’s engine roar with other audio content during the live broadcast of the launch, an ISDN connection between the Kennedy and Johnson Space Centers was utilized. The KSC audio team then assembled the composite audio mix and delivered it to NASA TV.
    During Discovery’s mission, the JSC Audio Control Room (ACR) team was responsible for the patching in of network media affiliates located around the country to conduct interviews with the space shuttle crew while in orbit. Additionally, they mixed all the communications from space and NASA’s various operations centers—combining the signals with NASA commentary that was produced at JSC via the agency’s public affairs office. These materials were also broadcast to the public

   For internal use, the JSC ACR team produces a considerable amount of “support audio” as part of the broadcast mix. Stoll described the process, “We do a lot of telecons, where we’re manually building mix minuses for multiple telephone interfaces that we then insert into a high profile meeting or some similar function. As an example, upper level management may call a conference, and we’ll tie in multiple locations from around the country.”
   Coordinating the multiple audio signals from both space and NASA’s various ground operations is no small task. Producing multiple clean feeds from the more than 800 audio signals that converge in the audio room keeps the ACR team plenty busy. For the recent space flight, there were two audio loops that went to and from the space shuttle, with another two loops for the space station. Bringing those four loops into the System 5, the JSC ACR team then generated clean feeds that went to multiple media locations. Feeds were also delivered to the Kennedy Space Center in Florida as well as to the team responsible for feeding audio to the host of media trailers at the Johnson Space Center. Further, ACR team members also generated clean feeds for monitoring purposes for NASA TV’s technical director and producer.
    In addition to pulling all the various audio sources together—many of which are analog while others are AES digital— JSC’s ACR team must compensate for considerable delay between space and ground operations. The Discovery’s audio delay is roughly .75 second while the space station’s delay is about 1.5 seconds. When one considers the fact that these vehicles orbit the earth at almost 18,000 mph, it’s pretty amazing to realize these delays are being compensated for live. At any given point in time, there are roughly 250 audio sources feeding the System 5’s PatchNet audio routing system.

   Stoll described the process involved in mixing sources from space as well as NASA’s multiple operations centers and then sending the mixes to a variety of destinations. “We only have two mix sections that we generate,” said Stoll, “and they’re both mono mixes—but we have twenty-eight groups that we actively mix to during a space shuttle mission. We have nine auxiliaries, three or four of which are actively mixed. The bulk of our mixing occurs over our group feeds. It’s these mix sections that were used to generate the NASA TV feed.”
   Coordinating a live audio program from multiple locations around the country and sometimes even around the world —not to mention space—and then distributing the appropriate combination of signals to the required destinations requires exacting attention to detail and the ability to function under tremendous pressure. The installation of the new System 5 has made a significant difference in the way audio is mixed for NASA’s varied requirements, as well as the manner in which the JSC ACR team operates.
   “The System 5 has opened up a world of operational ease for us”, notes Stoll. “Previously, we required a fairly lengthy amount of time between special events we were scheduled to mix in order to properly prepare. With the System 5, this preparation time has been reduced to roughly five minutes. The console’s snapshot capability makes it very easy to recall configurations we use, the PatchNet routing system makes signal management much easier, and as a digital console, its layout provides a channel strip familiarity that we find really appealing. I’m already looking forward to the next mission.”