Category: Challenger Mission (Page 25 of 37)

Hey All!

well it is hard to believe, but Silbo has been back at sea for a month already as he voyages south towards Cape Verde.

Granted we have had a bit of a sluggish start as we have had unfavorable currents basically since deployment, I have made an estimate of where Silbo will be on the first of each month as he crosses the Atlantic basin.

If we can keep Silbo in more favorable currents (which will easier in the coming weeks) we will undoubtedly fly faster than this projection shows, but Silbo should make landfall in Rio sometime in late spring 2013.

As for our current flight, the currents are pretty mundane and so we are nearly flying at our own will, allowing us to fly a nearly straight line towards the way point.  In the coming days as we move further south, we plan on swinging the way point out west to catch some south westerly currents that will carry us out further from the west african shelf.

Force Wind Sea & Honor

Nilsen & Antonio

Hey all

After our little bought with the strong north east currents, Silbo has gotten back on course towards the south west.  Looking onwards, Silbo has a long and winding road ahead, as he flies south past the Cape Verde Islands, across the Equator and on the Rio de Janeiro.

The distance between Silbo and our ideal recovery sight is roughly 7,400 km, with our only safety net being Cape Verde.  This leaves us with nearly 5,000 km of open ocean flight where if we run into any trouble, it will be tough to get ourselves back out.  But in the name of science and adventure, Silbo is backed with a team that are determined to safely navigate him through the Atlantic and assure his safe arrival.

One way in which we have prepared Silbo for this journey is we have crammed his hull to the brim with lithium batteries, which when coupled with the new low power mode setting released by TWR has given Silbo over a year of energy!

In the plot above, we can see that Silbo’s batteries are projected to last somewhere between 14 and 16 months from now giving us the potential to fly until January 2014.  How low power mode works is that instead of leaving the flight computer on 24/7, the computer is only turned on every 30 seconds during dives and climbs (after becoming situated during the process of inflection).  This conservation of energy has now given Silbo a very nice cushion, relieving us all of the stress of running out of power.

Force Wind Sea & Honor!

Nilsen & Antonio

Hey All,

I just wanted to update everyone on what happened last week when we flew backwards.

Last week, Chris DeCollibus (TWR) looked into the surface dialogs from Silbo around those surfacings and found the answer.  It seems that Silbo miscalculated the currents that it was encountering which resulted in the flying backwards.  When the mission was reset after we gave Silbo a new way point, the calculations of the current showed a significant difference, and so when Silbo was flying towards the way point, he flew using his dead reckoning and the incorrect currents.  This lead Silbo to believe that he would surpass the way point and needed to turn in order to arrive in the correct location.  If he were to continue flying without turning, the logic of  the glider believed that it would fly well beyond the way point.  This mishap combined with the strength of these currents resulted in Silbo then flying 14km “backwards”.

Now we have new questions to answer: how can we speed Silbo up?

In the image above, I have taken the average velocity of Silbo for each segment he flies: red indicates the trip from Azores to Canaries and blue is the current mission.  So far on this mission, Silbo has been flying significantly slower than on the previous mission.  This potentially could be from the increased weight from the batteries over the previous configuration, but we need to discuss means of speeding up a bit.  On another note, in figure above, the red line from the previous mission shows how towards the end of the mission the velocity decreasing by nearly 1/3.  This correlates with the presence of the two barnacle cohorts described and analyzed here: http://www.i-cool.org/?p=11984

Force Wind Sea and Honor All!

Yesterday, NASA’s rover Curiosity made history as it touched down on our dusty neighbor, Mars.

(http://www.space.com/13699-nasa-mars-rover-curiosity-11-facts.html)

After a 36 weeks in space and a well crafted 7 min fall through Mars’ atmosphere, this miraculous droid touched down and kicked off its mission to answer a number of questions about this alien landscape.  For more information on the mission check out nasa’s web page: http://www.nasa.gov/mission_pages/msl/index.html

While all of this excitement was unfolding, Silbo continued to struggle with his conditions back here on Earth.

As seen in the image above, Silbo got caught in a very strong northward current.  This current was recorded going over .3m/s, which poses quite a problem for our little droid.  The current proved to be so strong, that even with the way point to the south, Silbo flew west north-west.

Silbo lately has also been hurting.  If we look at the figure above where the average speed between surfacings was plotted, Silbo has been roughly moving only about .11cm/s, where .10cm/s is typically not considered good.

To try and help Silbo out a bit, we have proposed to try the at depth inflections that we successfully tested on Ru29 last month.  Seen below in the images from Antonio and ULPGC, the current is strong in a general northward direction for the first 30m while deeper than that point, the current weakens potentially allowing Silbo to better fight these currents.

As of this afternoon, we were flying two yo’s per surfacing between 25m-1000m.  However this afternoon, we switched to single yo dives and we will begin implementing the low power mode.  Instead of the glider computer running constantly, this setting will turn the computer off for roughly 30 seconds at a time to further conserve power.

Stay tuned for further updates throughout the week.

Force Wind Sea & Honor

Nilsen & Antonio

Hey All,

So Silbo puzzled us a number of times today, leaving us with a few questions we are still investigating and will update everyone on once we find the answers.

First off, when Silbo surfaced on the 12:03am on August 1, he mysteriously popped up in a very unexpected location:

He had flown backwards nearly a day and a half worth of progress, surfacing directly where he crossed on the 30th.

To add to the mystery, the last two surfacings have taken longer than normal, up to ~12 hrs between surfacings (up from 10.5 for the previous days).  These two issues will be further investigated by our team over the next couple days.

Looking at my rough vertical velocity plot below, we can see that the previous two surfacings show that our average velocity seems to be a bit lower than previous segments.  We will look further in depth soon to see if we can find out what may have caused this.

Finally, we do have a bit of good news!  The battery estimates below are showing that we potentially have enough battery power to last us through September 2013!

Silbo is currently equipped with 3 lithium battery packs, which makes these numbers believable.  Although it shouldn’t take us that long to complete our mission, it is a nice security blanket seeing those numbers

Force Wind Sea & Honor

Antonio & Nilsen

Hey All,

Now 5 days into his new mission, Silbo is making some slow progress as he reluctantly leaves the sunny shores of Gran Canaria behind.

As we get back into the swing of things, we have been working on covering all of our bases: ocean models, bathymetry maps, battery plots and means of monitoring biofouling.

Silbo has covered roughly 100km in 5 days, however he is slowing down the further south we go.  This is due to an average northern flux that we are slowly entering, resulting in the gradual slowing we have seen.

ocean currents provided by Antonio Ramos and ULPGC

Real Time Ocean Forecasting System Sea Surface Height and Currents

As displayed in the two images above, I proposed to move the way point to the east to try and get us into more friendly currents.

It is crucial that we try and get back to the south east at first, as these northward currents persist for nearly the entire water column

Finally, Silbo has become the first glider to navigate both Arctic AND Antarctic Waters!

The image above is from Antonio Ramos, showing the temperature of the water at roughly 900m below the surface.  The purple and blue jets we are seeing are bands of Antarctic Intermediate Water that rises from the deep ocean in this region.

Force Wind Sea and Honor

Antonio & Nilsen

Hey all,

So after this mornings deployment, Silbo is now only a few kilometers south of Maspalomas, GC.  Due to the short distance traveled from shore, we are not quite yet in water deep enough to fly to a full 1000m, and so we are diving to about 300m until we hit the shelf.  Much like with Ru29’s shelf crossing, Silbo will see a very steep drop off in which the bathymetry drops off 1000m to a depth of 1400m in just 4 km.

We have also begun to think about path planning as Silbo distances himself from shore.  To the south west, there is a strong warm core eddy swirling in a clockwise manner.  I suggested to the group that we shift the way point to the south east corner of the eddy, as to ride the eddy instead of fighting it.

Once we round the eddy, there is a very nice current flying to the south-west which we should try and catch on our way towards Cape Verde.

Force, Wind Sea and Honor

Hey All

Roughly an hour ago, Silbo was deployed once again as he pushes the limits and continues his mission from one pole to the other!

Now that he is in the water, Silbo will fight the currents as he makes his way from Gran Canaria, south to Cape Verde, and then across the equator to the coast of Brazil.

We will update again as we get an update from the team on board the deployment vessel.

Force Wind Sea & Honor

Hey All,

So after another long weekend, we are at the eve of Silbo’s next deployment.  This time, the destination is Brazil.

After quite a few delays, Chris DeCollibus of TWR arrived in Gran Canaria and immediately met with Alvaro at PLOCAN to begin preparations for the deployment.

Among a number of issues to cover, they worked on ballasting, measuring the h-moment, replacing the membrane on the oil bladder, applying anti bio surfaces to the hulls, and upgrading the software.

One difficulty found while ballasting, is that there is not just one density Silbo will encounter on this journey.  He will by flying from 1025 to 1022 sigma units as he moves from the Canaries to Brazil.  To get the most accurate density readings, we drew data from the extensive argo buoy fleet along the proposed path we will take

As for the bio fouling, Silbo is now equipped with a single hull sheet sticker which causes the hull to be slick, preventing anything from latching on.  There is also a potential of a diaper cream of urethane based tape that will go over the seams in order to prevent growth on those surfaces.

Antonio also chimed in with his forecasts for the upcoming week, providing us with sea surface height, wind speed, and wave data for the area of deployment.

Wave Forecast for the next couple of days

Wind Forecast for the next few days

Sea Surface Height near the Canaries

From the forecasts that Antonio provided, the weather isn’t too bad and only gets better as the week goes on.  Also we can clearly see that upon deployment, Silbo will begin his journey by riding the strong warm eddy to the south around in a clockwise fashion as he makes his way south towards Cape Verde.

Early this afternoon, deployment details were finalized and the last of the preparations were made.  At noon tomorrow (Canary Time +5 hrs from EST) our team will set sail from the southern shores of Gran Canaria on The Blue Spirit (pictured below) out of Pasito Blanco yacht club.

Chris and Alvaro will lead the deployment and get back to us with further details.

Force, Wind, Sea & Honor!

Nilsen & Antonio