Category: silbo (Page 3 of 22)

After months of sitting in pieces being worked on in labs ranging from the University of Sao Paulo to Teledyne Webb Research and Rutgers University, RU29 is back in the game.  David Aragon and Chip Haldeman spent roughly a week down in the USP facilities after gathering up all of her parts, where they then assembled Challenger and prepared her for her next mission- a feat that wouldn’t have been possible without the help of our friends at both the university in Brazil and at TWR.

Early Monday morning (Nov 17, 2014), the boat departed Ubatuba around 5:30am (2:30am EST) and within a few hours the glider was deployed amongst the rolling swell of the sea, off of the Southern Brazil Bight.

Now following the line dubbed the Ilhabela Line (Native for Beautiful Island after the island near to the deployment team’s departure point), Challenger will fly across the shelf before we eventually hit deep water and aim our sights on Cape Town.

For video of the deployment and initial test, click here

There is also some great news from our friends at Teledyne Webb Research on the other Challenger Mission Glider, Silbo.  After drifting at the surface for roughly 72 days and being rescued by fisherman off the coast of Barbados in August of 2013, Silbo has undergone a lengthy refurbishment process during which amongst a number of other upgrades, he has received a new pump and thruster system.  Soon he will be deployed for an off shelf test out of Woods Hole, Massachusetts where the new rig will be tested thoroughly before we set forth on the next North Atlantic Mission: spanning from North America across the northern region of the ocean basin towards our partners in Ireland and the United Kingdom and eventually Svalbard, Norway.

Force Wind Sea & Honor

On May 18, 2014, scientists and engineers from the Center for Ocean Observing Leadership (COOL) recovered RU 29 off the coast of Ubatuba, Brazil. The Slocum Electric Glider, which is part of Rutgers’ fleet of oceanographic research instruments, spent 189 days at sea traveling from Ascension Island to Brazil. This recent leg of RU 29’s voyage began in November 2013. A previous leg lasted 290 days and took RU 29 on a journey from Cape Town, South Africa to Ascension Island throughout most of 2013. These two legs combined to help RU 29 complete the 10,387 km (6,454 mile) mission across the South Atlantic. Undergraduate students served as the main pilots of this mission, giving direction to RU 29 every few hours as its surfaces.

Building off of the success of RU 27’s crossing of the North Atlantic in 2009, members of COOL are now leading a global effort to complete the Challenger Glider Mission: an two-year initiative to simultaneously pilot 16 ocean-fairing robots around the world’s ocean basins while spreading ocean literacy and educating the general population about our changing planet. COOL is still seeking donors to help purchase additional gliders for this mission.

To date, a mission from Iceland to Barbados by way of the Canary Islands was completed in the North Atlantic by the Slocum Glider “Silbo,” while RU 29 completed its South Atlantic Crossing. Over the next month, RU 29 and “Silbo” will be deployed off of Cape Cod, Massachusetts and Santos, Brazil, to set forth on return journeys across the North and South Atlantic.

Hey All!

So just about a week ago, Challenger crossed the EEZ of the British Overseas Territory of St Helena

St Helena is a volcanic island along our path that is a territory maintained by the UK.  It stretches just 10 miles across and out of its population of roughly 4,000 people, we have been able to find a man willing to help us out!

In the northwest sector of the island, along the shores of the cities of Jamestown and Ruperts, there looks like there is significant boat activity.  One of these boats will be setting sail within the next month equipped with means of communication back to the COOL room where we will provide shore support as our volunteers sail out to Challenger inspect her and scrape off the suspected biological growth we suspect has been causing our technical issues.

Over the past few weeks, Dave has been hard at work with Scott adjusting the gains and settings on our flight parameters, tweaking and adjusting ever so slightly until they were able to trim our heading error down to a fraction of what it was.  However, due to what ever has grabbed hold of the glider we are no longer able to use the currents calculated by the glider for navigation.  As it turns out, the algorithm that is used to create these vectors is meant for use on a clean glider and does not account for drag.  So, as barnacles grow and create drag, the algorithm can mistake this as a head current.

With the latest numbers, Challenger has been flying between 10 and 11 km/day. Being just 250 km from the western shores, that leaves us just 25 days from the island.

Although we are almost there, there is an obstacle in the way; one last seamount.  Just 35 km to the south west, we are trying for some evasive maneuvers by moving the way point a bit to the east to allow us to fly to the south of the sea mount.

Looking forward, based of the latest calculations, Challenger has roughly 150 days of battery left based off a energy usage of 2.5 Ah/day which was what we maintained before and after the siesta back in May. If after the cleaning, we are able to maintain 20 km/day Challenger will be able to make easy work (relatively) of the transit from St Helena to Ascension Island.  There we can easily get a technician and fresh batteries out to prepare the glider for the next voyage.

To the North, Silbo has been doing a fascinating job as a drifter following the North Atlantic Gyre.

He has been drifting over 25 km a day over the past month and heading right for the Caribbean.  Now just ~80 km from the EEZ of Barbados and ~450 km from the eastern shore, Silbo seems dead set on hitting his finish line and taking a break even without the ability to control his movements.

The forecast even seems to be in our favor as tomorrow the surface currents seem to shift from North/NorthEast to more North West, further towards the Caribbean.  In the coming weeks a recovery mission may need to be planned as Silbo moves further towards shore.

Force Wind Sea & Honor

Hey All,

For two years now, Silbo has sailed the North Atlantic providing us with valuable, never before seen data while pushing the limits of what aquatic rotobics can achieve.   After being left to the will of the surface currents just over a month ago, he has continued to drift to the west now just 800 km from the northern shore of French Guiana and 950 from Barbados.

To the south, Challenger is continuing to fly towards St Helena, forcing her way through the eastward current.

In the myocean dataset, there is a strong surface current flowing to the North East in the <300m portion of the water column with the lower portion deviating a bit with less intensity.  However with this map the entire region is flowing away from St Helena with sparse option on an ideal path to get to our destination

The Hycom doesn’t look too promising either, as it has the currents flowing consistently due north with little variation throughout the water column.  These currents could only be a little more useful than myocean as the angle we are flying into would be less of a fight.

Finally, the glider team has been working together a budget over the past week continuing to weigh our options for a St Helena recovery.

Force Wind Sea & Honor

Hey All,

I just wanted to leave everyone with a quick recap of what has happened over the past few days:

Our team of pilots and technicians from RU and TWR have been working hard analyzing the steering data from Challenger trying to get her to fly better.  Last week, she started spinning occasionally on her dives and so we have been working to try and diagnose the problem and apply a fix.

We have also officially decided that we will recover in St Helena.  With Challenger just 480 km from the northern shore, Tina Chip and Dave have continued contact with the travel agencies that are familiar with the island.  Through here we have been able to confirm that we are able to get to the island by flying into Cape Town South Africa and taking a 5 day ride abord the RMS St Helena.  Today we also received confirmation that we will be able to get a new set of lithium batteries shipped to where we will need them in order to re launch Challenger after the recovery operation.  Chip was even able to secure us a ~40 ft sailboat as long as we are able to get to the island before the end of August.

To the north, Silbo continues to drift, now just 900 km from French Guiana as our friends up at TWR continue to try and find a way to rescue our brave little droid.  Sunday the 23 marks the 2 year anniversary since Silbo was deployed up in Iceland at the beginning of his journey.

Force Wind Sea & Honor

Hey All,

Today I finally made some progress, creating a map of the RTOFS data at depth, allowing us to see the sub surface currents that dictate the forces behind Challenger’s movements.

This now lands us with 3 road maps, all providing us with a various views into the depths of the oceans.

In the image above, HyCOM (the bulkier vectors), RTOFS (blue vectors) and myocean (red vectors) all show a strong flow to the north at depth (300m is shown) with various tendencies following depending on which model you refer to.  Seeing this consistency is  remarkable, however Challenger’s depth average currents are in disagreement, showing a current flowing strong to the south east, following the trend seen since we left the South African Shelf of an overall flow to the east.

It is possible that this is simply due to a lack of data fueling the models as there is a large gap in the locations of the drifters in the area.  Speaking with Antonio today, he provided us with a very interesting theory.  Pointing out that since we left the shelf and started flying deep, we have seen currents flowing in some way to the east, Antonio suggested that this may be a replenishment of the upwelling zone that covers most of the western coast of Africa.  The logic behind the theory is that the water coming up to the surface does flow from the west to the east sub surface before rising up along the shelf.  It could be possible that this is the eastward flow Challenger has been seeing.

We also hypothesize that this flow will be broken up by the line of sea mounts that lay ahead of us:

But getting to this line has become an issue.

As I have mentioned previously, Challenger has been performing sub par since we have regained contact after the no coms from May 15-25.  Since then the glider has been much more sporadic in her flying and much slower as well. Because of this, our testing continues as we try and diagnose the problem and see what we have to work with and from there extrapolating the data to see what our options are over the next few months.

From our daily glider meeting, we made a time line of tests to run on the next three surfacings.  For the surfacing that occurred just moments ago, we increased the data being pulled from the sbd files during file transfer to confirm that by flying in low power mode, the science computer is fully turning on and off as we think. This is an important question for us to determine how much battery power we have to work with. Chip also told Challenger to collect data on both the down and up casts on the CTD that way we can confirm it is working properly after our 10 days at the surface. Finally, we increased the pitch angle to 30˚ in an attempt to increase our velocity.

For tomorrow’s surfacing, we plan on turning the CTD completely off to get a better feel on how much power the increased pitch angle will actually draw over a 3 yo segment.  And then on the following segment,  we will increase the pitch further to an angle of 35˚ to see what effects that has on our speed and battery power. This issue has become more daunting as we get a better handle on the velocities Challenger has been hitting along with the remaining battery power.  With our decrease in speed and the projected further rate of decay, it is looking like it may take us upwards of 145 days to reach Ascension.  With only having roughly 180 days of battery left, there are some big decisions headed our way.

Finally the last alteration we made was that we added a new way point to Challengers repertoire.  Over the past day, the currents had rotated a bit to the south east, resulting in a flow that was contradicting our attempt at progress in nearly the opposite direction.  So after a discussion with Scott, we moved the way point a bit to the south, hoping to cause less of a struggle against the current, but also to keep our options open.

We are just about 600 km from St Helena.  So as we continue our tests to asses the state of our glider, we figured it would be wise to keep this island in mind as a last resort if it turns out that it is too risky to push onwards. From there, we may even do a short mission as we did with Silbo’s run from the Azores to the Canary Islands, taking Challenger with a pack of alkaline batteries (much more easily transported than lithiums) and continuing our flight to Ascension.

In other news, Silbo is continuing to drift at the surface as we weigh our options for a recovery mission for the poor guy

Since blowing his weight and becoming a drifter on May 19, Silbo has made roughly 100 km progress westward.  Now just 1280 km from Barbados, we can only hope he can continue to drift towards the islands where it will be much easier to conduct an emergency rescue.

Force Wind Sea & Honor

Hey All,

Over the past two days, Dave Tina and Chip have been running missions and pouring over data to determine the state that Challenger is in after what Antonio and the team has called her ‘siesta’.  These tests have included a process called ‘stepping down’ which included running dives to 60m, 400m, 750m, single dives to 1000m and now dual 1000m dives.  These have all been successful which has now led to focusing on the steering and energy budget.  The steering has proven to be a little out of whack, similar to what we saw off the coast of South Africa, but there is speculation this will be reduced after we reduce the throw on the pump and slow the glider down a bit- a project for early this week.

On top of the excellent news that Challenger is not only in contact with us again, but capable of flying, yesterday she became the first RU glider to Cross the Prime Meridian!

To the North, Silbo is continuing to drift at the will of the surface currents. Luckily, these currents are continuing to overall flow in the northwest direction, pushing Silbo slowly but surely towards the Caribbean.

Force Wind Sea & Honor

Hey All,

So just when we thought we have had enough bad news after last weeks issues with Challenger, we have now run into complications with Silbo.

Yesterday afternoon, Silbo ran into an issue with his pump, resulting in the ejection weight being triggered, turning Silbo into a drifter. No longer being able to fly, we are now at the will of the surface currents which has resulted in the c shape turn to the North.

One stroke of luck we have had, is the research ship Knorr is currently just 200 nautical miles north of Silbo’s location along the Mid-Atlantic Ridge. Although we don’t have any details on the research they are doing, they should be in this region for a couple weeks.

We are hoping this surface current persists pushing us northward while the ship is still in the area, that way as long as it is not too inconvenient for them the ship could possibly conduct an emergency recovery of Silbo.

As for Challenger, it has been over 130 hours now since last contact, and we are all still sitting on edge waiting for any word

Force Wind Sea & Honor