Challenger has now been at sea for over 160 days and flown 4,100km and is continue to push onwards towards her goal of the shores of Cape Town South Africa.

Yesterday the team put their heads together on whether to turn to the north or south to navigate through the currents that lie ahead.

RU29_20151102_RTOFS

Despite the RTOFS (in green above) and Copernicus (in yellow below) disagreeing about the northern flux currently affecting 29, both models agree that if we continue pursuing the latest waypoint, we will enter a pretty persistent head current.

RU29_20151202_WaypointChange

As seen in the figures above, the Copernicus shows a pretty promising route to the south that RTOFS shows as being more of a mess.

To the north however, both models show what seems to be a number of more defined eddies that have meshed together.  This is the option that the team ultimately decided upon using the red path shown in both figures.  Beginning today and following through the weekend, Challenger will start pursuing the new way point at 35˚30S, 4˚W to swing her way to the north and through the eddy field.

As for the troublesome pump, we are continuing to take a few precautions to reduce the slipping we have seen over the past couple of months.  The slipping we have seen is caused by the oil that dictates the buoyancy of the deep glider leaking within the pump section of the glider, resulting in the pump having to move multiple times over the course of a dive/climb in order to maintain it’s flight path.  In order to reduce the number of times the pump has to move (which increases the wear and tear on the pump), Dave has reduced the depth 29 dives to to 500m and has adjusted the pitch angle on the dives and climbs.  By adjusting the angle, we are then able to change how quickly the glider moves through the water column with the aim of reaching the inflection depth before the pump has a chance to slip.  The issue has been variable over the past few months, but the team has been hard at work diagnosing and testing the issue along the way to find the best way to fly under the circumstances.

 

Force Wind Sea & Honor