Hey All,

It’s been a little while since our last post so I just want to update everyone on Challenger’s progress.

Basically, she has been FLYING.  After 32 days at sea, she has flown 800km, with most recent days clocking in at 28-30 km/day! At this rate we could be seeing the shores of Brazil by late April of 2014.

And her flight has been smooth as well. So far we are seeing no signs of biological interaction with this mission.  She is completing 5 yos between 150 to 980 m every 14 hours like clock work.  It seems, all of Dave’s hard work of changing the duration of a segment between each surfacing to minimize surface time at night when the flying fish lay their eggs and the overall effort to avoid contact with barnacles is proving to pay off.

This week, we gave Challenger a new wp to the south west.  After reaching the edge of the submarine ridge, we made the decision to now add a more southern component to our progress as we are now free of the potentially harmful bathymetry and magnetic presence. Another interesting fact that we have noticed as we progressed passed the ridge, is that the currents have ceased the oscillation we had encountered and have now returned to the steady north east flow from earlier in the mission.

Looking to Antonio’s visualization of the myocean model via PINZON, the currents to the surface continue to flow in our favor to the south west towards South America, confirmed by the direction of our surface drift (blue vector in the second image below).  However if we dive below that past 300m, the subsurface currents persist to the East/NorthEast.  This subsurface resistance we believe will continue for some time, and so it is very important that we continue to avoid any biological hinderance as this will cause drag and slow us further.

As for now, Challenger is handling things like a champ and we will do our best to keep it that way.

Back at home, the semester is coming to a close and the students are preparing for their finals.  On Tuesday, the students of the Ocean Observatories Class presented their semesters work to Dean Rich Luedescher.

This semester, over 45 students participated in 9 team projects each lead by an undergraduate mentor. Topics covered this fall ranged from future tracks of the Challenger Gliders, analysis of Hurricane impact on the Mid-Atlantic Bight to future collaborative efforts with the Korean research group KIOST.

To view the students presentations, view the classes website here

Force Wind Sea & Honor

Hey All!

Just last night, 29 leapt over another hurtle crossing the EEZ into International Waters and leaving Ascension behind.

Looking onwards to the journey ahead, for roughly another 10 days (~300km) we will continue to do our best to fly to the west. Then we will turn our nose to the south and make the long journey down towards Sao Paulo.

The reason for the delay in when we switch from making western progress to heading south west, is the string of sea mounts that line up to the south west of 29’s current position. This line of volcanic mountains includes Ascension Island and the Steward Sea Mount that we just flew past.

Now although the remaining sea mounts do not appear to reach up high enough in the water column to pose a problem, these sea mounts potentially could cause a disturbance in the magnetic field that could pose a problem to the glider.

Looking to the ocean models, although the RTOFS and Myocean do not quite match up, they both agree in a sense that in the upper regions of the water column there are favorable components for the direction we are hoping to fly (RTOFS @ 300m due west; Myocean @ 318m due south.)

RTOFS Temperature and Currents at 300m

Comparison of Currents: Black Vectors are RTOFS at 300m and White are Myocean at 318m

However if we peel back the layers of the ocean and analyze it at depth, the deep flux continues to be weak to the North East.

PINZON 4D Visualization of Myocean currents

As we continue to make progress to the west the currents at depth should begin to swing in our favor and help us along our way as 29 flies towards Brazil.

Force Wind Sea & Honor

Hey All

Challenger is continuing to make good progress as she flies west towards the sunny shores of Brazil.

Now more than half way to the edge of the exclusive economic zone, she continues to fly at incredible speeds of just under 30 km/day!

This is an immense increase compared to on the previous mission where we were flying much closer to low 20 km/day into the high teens and at some points even below 10km/day!

While on the island, Scott came in contact with a group of researchers that have studied the migration pattern of Sea Turtles that frequent a path from Ascension to Brazil. The team was generous enough to share a number of files with us that included gps tracks of the turtles movements.

Based off of this new map I was able to create with the google earth tool box in matlab, we plan to continue our flight due west for the time being. We will then move the way point south west where we see that gap in the green line.  In this region, there is a gap in the sea mounts that are scattered through this area that we will utilize in order to make southern progress towards Sau Paulo.

Although many of these sea mounts do not appear to reach high enough up to pose a physical barrier to Challenger’s progress, we want to avoid these areas just in case the magnetic properties of the rock  are to blame for the issues we had in our previous mission.

Force Wind Sea & Honor

Hey All,

Well Challenger is back in the game flying to the west of Ascension with her eyes set on Brazil.

Now that we are flying to full depth and with the current at our back, we are making great progress reaching speeds of up to 27 km/day!  Dave has set the gliders parameters so the pump thow is -200/+175 with dives and climbs at an angle of 26˚.

Looking to the PINZON visualization of the myocean forecast, the currents at surface will be pushing us right along on our way while at depth, although not in a completely favorable direction, are weak enough where they won’t slow us down too far.

As for now Challenger is flying like a champ and we will do our best to keep it this way!

Force Wind Sea & Honor

Hey All!

As of 2pm Ascension time, RU 29: Challenger is back on her feet sailing off towards the horizon!

Over the next day or so we will fly her to the north as to avoid any unfavorable bathymetry that lies to our west, but soon we will move our way point in the direction of Brazil as we set our sight on the shores of South America!

Force Wind Sea & Honor

Hey All,

It has been a long couple of days for the crew down in Ascension since their arrival.  After giving Challenger a thorough inspection of the kind of growth on the hulls and the corrosion that occurred over the course of the previous 288 day mission, they set to work on getting her ready to get back in the water and set sail towards Brazil.

Among a number of tasks to be done before re deploying Challenger and sending her on her way are:

1. Inspect for corrosion (on end caps), damage, plugged pressure sensors, document any damage with pictures so we have them for the future. Take note of fouled locations if you can, otherwise we can use Jame’s pictures from Helena.
2. Inspect internally for leak, salt, corrosion. Pitch threads. Take off and clean nose cone and buoyancy pump diaphragm.
3. Check compass!!!
4. Check digifin operation with different ranges specified.
5. Scrub glider down, perhaps lightly on the painted sections, remove old bio films.
6. Open glider, backup flash cards in 2 locations, Format cards, Upgrade to software 7.13
7. Re-battery, compare battery weights on labels, do best to account for that with bottles, etc. Glider was about 40 g lighter than average density, which I think was good, wouldn’t want to go too much outside of 50 g too light/heavy. I think goal is to maybe leave it a tad light with 2 wing rail weights. Tape and paint will add some weight and we can use wing rail weights to add the rest… We were ballasted pretty-much perfect so if were close to where we were before that is our best bet. Our best check may be a ballast dunk at the dock.
8. Replace digifin?
9. Re-seal for deployment, new o-rings
10. Apply new antifoul items, paint, tape…
11. Re-cal compass

At the base that was used for technical support, Drew Avery, an ex-navy diver from Greenland who now works at the local US base lent his steady hand to perform the “open heart surgery” that was required to set 29 up to get back in the water.

Once Challenger was put all back together, the team put her in the back of the pick up and drove her down to the beach where they then used a tidal pool that was separated from the open ocean by low tide as a ballast tank.

In this pool they were then able to trim the ballast on the glider until they were certain she was ready to continue her trek towards Sao Paulo.

Next up is the deployment- stay tuned!

Force Wind Sea & Honor

Hey All,

To add stress to our plans for repair and redeployment operations in such a remote place as Ascension Island, the plane that is to carry Chuck Chip and Scott to the island was delayed on its return from the Faulkland Islands.  The team now plans to arrive on the island between the 5-6 of November to work on Challenger

More details to come soon

Force Wind Sea & Honor

Hey All!

This afternoon, Collin took his ship out of George Town, Ascension Island and carried out a successful recovery of RU29: Challenger!

He sailed out about 25 nm to where he found Challenger drifting at the surface, covered in the eggs of Flying Fish

Now back on shore, Challenger will remain on station until Nov 4th when Chip Chuck and Scott will arrive on the island to replace the batteries, make the necessary repairs and redeploy.  From there she will continue on to Brazil to complete her crossing of the south Atlantic

Force Wind Sea & Honor

Hey All

So we seem to have run into some trouble over the past day.  Challenger has had a sudden drop in voltage which we have come to find is associated with the lithium batteries being dangerously low on juice.

Challenger is now up at the surface drifting as we do not want to test how much remaining battery we have left.  We have been in contact with Collin out on the island to see if he is available for an emergency recovery.

Looking to PINZON’s forecast of the currents, it is dire that we get this glider out of the water soon, as it looks like the overall flow will be away from the island over the forecasted period, pushing us out of the recovery zone

We will keep you updated on the details of the recvoery, but for now here is some of the data we collected during our sampling missions.  It will be a much more complete data set once we recover and get the full files, but for now we can continue to see the oscillation up and down of the thermocline that we were hoping to capture.

Force Wind Sea & Honor

Hey All

Once again Challenger is making great time on her approach towards the recovery location.

Unfortunately, she may even be coming in too fast; so much so that Antonio and I have devised another sampling scheme to attempt over the next 10 or so days until our recovery team will be in place.  The plan we came up with is actually a relic from Silbo’s second mission, flying from the Azores to the Canaries back in the spring of 2012.

The plan we have come up with is to take Challenger and run a sampling mission through the eddy present within the lea of the island. As seen in the first image of this post, we will fly a “wind mill pattern” within the 35 nm recovery range over the course of the next week that will land us within 20 nm of the port we are to be recovered from by the first of November. From there, we will make slow progress towards the port by Nov 4th when we plan to finally get 29 out of the water, fix her up, and send her way ward back towards Brazil

Force Wind Sea & Honor