Listen to NURC Aquanaut, James Talacek, describe what it’s like living in the world’s only underwater habitat.
Today is decompression day for us. Currently we are at 17 fsw and almost half way through our 16 ½ hour decompression from saturation. As with most all of our missions, whether you are topside or living in Aquarius, this mission has flown by. But unlike our normal missions, this one has explored the use of a different diving technology. During most missions we use SCUBA as the primary diving system for Aquanaut excursions, but other diving operations involve tethered “Hookah” and Superlite 17 dive helmets, connected to the wet porch via umbilicals.
The U.S. Navy Specialized Research Diving Detachment (SRDD) has introduced us another diving technology, closed circuit rebreathers, specifically the MK16. Although rebreathers have been around for quite a while, this is the first Aquarius mission where they have been used for Aquanaut excursions. One of this mission’s primary goals was for “us” (NURC) to learn the specific techniques of supporting rebreathers diving from a seafloor habitat, and from my perspective we have definitely accomplished that goal.
The potential use of rebreathers for making excursions from Aquarius has several advantages, which in turn could have a “ripple effect” on our mission operations. Since rebreathers scrub the carbon dioxide out of the diver’s exhaled gas and re-circulate it, as opposed to SCUBA, which just exhausts all the exhaled gas into the water, the volume of gas required to support diving operations is greatly reduced.
If future Aquarius missions used rebreathers instead of SCUBA for Aquanaut excursions, the size of the compressors on the LSB (Life Support Buoy) could be reduced. Reducing the compressor requirement would in turn reduce the amount of AC current needed to run them, thereby reducing the size of generators needed to supply power, allowing for a smaller LSB to be used for supporting Aquarius, and so on (i.e. the “ripple effect”). Although this mission is just a “first step” in that direction, the potential benefits of it and additional similar missions are easy to imagine.
The Navy divers on the first of these two SRDD missions bring a combined diving experience of over 64 years to this mission and it shows. All of these guys are “aces” in their field and have provided immense technical support and information about rebreathers to the Aquarius program.
I would like to thank Master Chief Master Diver Jim Knudson, Chief Gene Buijten, Chief Tim Ige and Chief Bill Dodd for the knowledge they have shared with me and fellow HabTech Craig Cooper during this mission.
It’s been an honor and a pleasure to saturate with you guys, thanks!
Today is the last diving day for Leg 1 of our Sat Mission. Over the past 3 days, the saturation divers have done well adapting to using the closed-circuit underwater breathing apparatus from the Aquarius. Each closed circuit diver has experienced a highly successful 3-hour excursion from the habitat without the need for re-charging or exchanging CO2 absorbent. Compared to an open-circuit breathing apparatus, the closed-circuit system is a very efficient use of gas supply resulting in longer excursion times without the need for re-charging the gas supply. A re-breather re-circulates the divers exhalation by removing CO2 and providing a make-up volume of lost gas by adding a small amount of air/oxygen into the breathing loop.
In order to minimize the amount of unnecessary equipment and supplies stored inside the Aquarius, topside divers have been exchanging CO2 canisters and high pressure air and oxygen flask. The daily visits to the aquanauts are a minor chore compared to the daily activities the aquanauts must accomplish. Even so, the next saturation crew remains eager to exchange places. Our first set of divers, Master Diver Knudson, Navy Divers, Chief Gene Buijten, Bill Dodd, and Tim Ige will return to the surface tomorrow morning. I look forward to capturing their observations and sharing them with you. Please look for new postings from their experiences over the next few days.
I am very pleased so far with the performance of the UBA. This is the first time that the U.S. Navy has had the opportunity to use a closed circuit UBA operationally from a saturation platform. The continuing success of this application (using a closed-circuit underwater breathing apparatus from a saturated environment) may prove to be an alternative means to deploy future aquanauts and scientist from the Aquarius. As in all new endeavors, there are often lessons learned. Thus far, our list is very small and minor. I fully expect Leg 2 of this saturation mission to be equally successful.
Shortly after our NEEMO 9 mission, we started noticing a large amount of radio interference to our 5.8 GHz wireless bridge to our offshore buoy. You run this risk using this band because it is basically a free-for-all and do not have the regulations one would have in a licensed band. We chose this configuration because it was the only setup that was able to handle our unique application with the movement of the LSB (Life support buoy) After some research we learned that the DOT (Department of Transportation) fired up the last of their radios that are installed in the median of US 1 throughout the Florida Keys south of us, that raised the interference levels enough to impact the performance of our wireless bridge. These large tower structures along with the 5.8 GHz radios, antenna’s and a camera system were installed to provide “traffic management” throughout Florida highways.
With the mission starting soon we were in a scramble to figure out a workable solution. We contacted the DOT and they were cooperative in lowering the power (or shutting down) a couple of the towers in question just south of us. With a slight notice in change our wireless link was still borderline.
Time was running out for us because of this important mission with the Navy’s Specialized Research Diving Detachment (SRDD) to start on Tuesday, June 6th, something needed to be done ASAP.
Rob Miller and Bob Shaw of Orthogon (recently purchased by Motorola) were contacted by NURC to help in the troubleshooting of their radios. With the interference levels we were facing and not much we could do in the amount of time we had, they offered to send us the new Motorola/Orthogon Spectra radio system for us to beta test. This radio system operates in the 5.4 GHz spectrum and would be the first to be installed in the United States. The 5.4 GHz band is under review at this time with the FCC to be the next “public” band for new wireless technology.
Rob Miller made some phone calls and was able to get the system out for shipping last Thursday, June 1st to be delivered to us immediately. This system was sent from the UK and arrived on our doorstep Monday morning. With some quick configurations to the radios we sent one radio offshore to be installed on the LSB and one installed on our base tower. As easy as the first time we fired up the original Gemini radio’s, the system linked right up. The first thing we did was look at the spectrum. It was clear as can be! Our problem was solved and we are now on day 2 of this mission and data is flowing perfectly.
We would like to send a special thanks to Rob Miller and Bob Shaw of Motorola for going out of their way to make sure we received these radios in time. You Rock!!
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