divers measure coral near Aquarius.|
The NEEMO experience
parallels space flight in several ways. Like a spacewalk, a dive
is planned in advance with a series of objectives in mind and a
timeline for reaching each goal. Also like a spacewalk, the duration
of each dive is limited by the consumables available to the participants
outside their safe havens. Participants
often mention the analog of deep-sea diving to spacewalking.
3, Astronaut Danny Olivas wrote:
"Regardless of how tired and hungry I get, I regret having
to come back to the Hab. It's one of those things that you just
know you're gonna miss the next amazing thing, waiting right around
the corner, if you go in now. If only you had just a few more minutes
... just a few more seconds. My appreciation for safety (and air)
always overrides, however, and in I go. I imagine that spacewalking
will be similar. To be outside the space station ... looking back
at earth ... not wanting the moment to end, but knowing that consumables
drive everyone back."
of Conch Reef, where Aquarius is located. |
Numbered areas: 1) Shallow S4 Current Meter; 2) Pinnacle
Wall; 3) Deep S4 Current Meter; 4) Northeast Waystation;
5) Ridge Site.
Here is a list
of common NEEMO dives and objectives:
Aquanaut team visits the south site, beginning at the Pinnacle and
transiting toward the habitat. They pay attention to all surroundings
and become familiar with topography and excursions lines.
Site Orientation Dive
Aquanaut team visits the north site, beginning at the Deep transect
and transit toward the habitat.
and 5 Leg Site Orientation Dive
Aquanaut team visits the deep site beginning at the end of the S4
line by performing a very large circle sweep.
Aquanaut team will deploy NASA tags along the excursion lines that
will systematically identify the location. These tags will eventually
become the basis for an entire grid network of the Aquarius site
and are used in conjunction with the Communication Task.
Aquanauts test the power and clarity of the underwater communications
system by venturing away from the habitat, measuring their distance
traveled and provide comm voice tests at given intervals. The aquanaut
buddy pairs transit to many areas on a certain site and provide
voice checks, which are documented and used to characterize the
useful range of the communications system.
This exercise is completed during five separate dives. During the
first exercise, the aquanauts work as a team to locate and transport
pieces of the Waterlab and the required tools, which are located
in another area. They construct the base unit of the structure,
which is in the form of a stack built of PVC. For the second dive,
the buddy pair constructs the truss part. During the third dive,
the buddy team constructs the antenna and connects cables. The fourth
dive includes construction of the solar array and cable connections.
During the final dive, the crew takes down the Waterlab.
NEEMO 4 Aquanaut
Rex Walheim wrote in his journal:
"The task on our first dive was to build a structure called
water lab. It was similar to a spacewalk task, but the local conditions
add a few challenges that I didn't have to deal with in space. First
of all, the current kept trying to separate us from the structure.
Then we had a bit of sand get in our bag of bolts. It makes you
appreciate the cleanliness of space. We managed to get the structure
put together nicely, and then a large barracuda swam into it as
if to inspect it. Apparently he approved of our construction job,
because he moved on his way."
Aquanauts perform tasks associated with data collection on the coral
reef. This involves setting up of transect lines perpendicular to
the excursion lines and measuring the size and health of the coral.
Each coral is photo-documented and the results compiled and given
wrote in his journal that he enjoyed exploring the reef and gathering
data: "Diving today was awesome! We mainly explored the full extent
of the major excursion lines. We recorded the depth and surrounding
flora and fauna at certain intervals along the excursion lines.
We filled tanks at the distant way-stations, and we performed exploratory
excursions off of the main lines using our own line reels."
aquanauts dive at night to experience different techniques, departing
the habitat during sunset and diving during nighttime conditions,
using specialized techniques and equipment.
The aquanauts dive during sunrise to experience changing environmental
conditions, departing the habitat 30 minutes before sunrise and
witnessing changing conditions.
Gernhardt wrote about terminator diving in his journal:
"This morning we made a terminator dive. Something I used to
do when I worked in the Islands years ago. We entered the water
at nighttime and watched the earth move from night through the terminator
into daylight, from the underwater perspective. It takes about 90
minutes to 2 hrs to see the full transformation."