Mission Journal 9 — Marc Reagan: Mission Day 5: Friday, July 16th, 2004
Greetings!
One of the unique things about our NEEMO missions is the communication system we are using that allows the aquanauts in the water to converse with a ‘mission control’ team (called the Advanced Operations Cadre), located in the Experimental Planning and Operations Center (ExPOC) near the Mission Control Center in Houston. The aquanauts are wearing wireless underwater communication units attached to a special full face mask that allows them to talk to each other, the habitat, and the ExPOC all while performing complex tasks in the water. For all of the EVAs, the ExPOC is monitoring the crew’s location and other vital information by talking directly with the crew.
In order to characterize how these units perform in this environment, we have developed a communications task where the aquanauts swim out to a specific area on the reef and perform a prescribed test protocol. Back in Houston, the ExPOC rates the quality of the communications and records the results. This exercise is analogous to the types of activities a newly arrived crew on the Moon or Mars might perform.
Frankly, this is one area we’ve really struggled with this mission. Some days the quality of the voice is crystal clear between the aquanauts and ExPOC. Other times it resembles a bad Verizon commercial: “Can you hear me now?!” It can be very frustrating to all involved. The crew, ExPOC, and NURC staff are to be commended for their patience and diligence in working these issues day after day. Fortunately, today was one of those great days for comm!
A couple of interesting Engineering experiments were conducted today. The first is an experiment in conjunction with Rice University to measure bone strength. Loss of bone strength is of great interest to NASA because it is a problem seen by our astronauts in space. In the case of astronauts, the lack of gravity, and the fact that the bones are never seeing any weight or force on them, leads them to lose strength. Use it or lose it. Therefore we schedule a couple of hours per day for our astronauts to counteract this problem. The end effect is very similar to osteoporosis, a disease where bones lose their strength, and which afflicts millions. The bones throughout your body are constantly being torn down and rebuilt throughout your life time. This is a natural process that keeps them healthy.
When one has osteoporosis, the teardown keeps happening, but the buildup slows down. The net effect is bone loss. At the cellular level, bones are really a latticework of connections - picture how construction scaffolding looks. You have lengthwise members that provide strength, and cross members that keep them from buckling.
Current methods of looking at bone health (Dexa scans, etc.) do a good job of showing bone density, but it turns out that’s not really a good indicator of bone strength. Where the bone is lost on this scaffold is just as important to overall strength as how much is lost. On NEEMO 6 we will be operationally evaluating a small, portable acoustic vibration device which can give a measure of bone strength. In addition, it is designed to be usable for a normal person with minimal training. It’s likely that this device will be used at home by osteoporosis patients in years to come to monitor the progress of their disease, and also the treatment effects.
The other experiment the crew worked on today was the Wireless Physiological Monitoring system. Tara has been outfitted with sensors for this device for the last 4 days. The objective is to determine the usefulness of a commercial wireless medical monitoring device inside a metal-walled habitat (similar to the other kind NASA uses!) It’s even accompanied her on some of her dives. The system can measure heart rate and overall activity, skin temperature, and core body temperature. Evaluating it in the Aquarius environment will give us valuable data on how this system will perform in a space analog situation.