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each section of the mission ensures that vehicles were out? tted with a homing the AUV can react if it’s taking too long system that could help them ? nd their to complete segments or heading out of way home even from 100km away. They mission territory. were also out? tted with a variable bal- • Robust Hardware: having the right last system to give them the ability to hardware is another important way park under ice and wait for an ROV to to mitigate risks. For example, nupiri transport them the ? nal distance to the muka was out? tted with a multibeam ice hole. To minimise risks of launch obstacle avoidance sonar that allowed it and recovery, these AUVs were also to see not only what was in front of it out? tted with underwater connectors for but what was below and above it as well. charging and data download.

Its avoidance algorithm was designed to All of this hardware needs to be tried react appropriately depending on where and true - mature designs, used for years the obstacle was, as simply rising and to ensure their reliability. Even one turning starboard is not always a safe failed system can make or break a mis- option. To improve navigational accura- sion.

cy nupiri muka was also equipped with a

DVL for following the ice in addition to On to success one following the ocean ? oor. Without As we can see, there were many con- this it would very quickly lose position- tributors to successful under ice mis- al accuracy and may not be able to make sions. Most discussed were in the ve- its way home. The vehicle also had an hicles themselves but it is important to extra acoustic modem pointing down- remember the planning and experience wards to help improve communication needed too. Every time the vehicle is for situations where the AUV was close sent out, its mission plan it should be to the surface ice. The more the pilot can carefully reviewed by individuals with help the AUV the higher the chance of polar experience. With this in mind – success. plus some blood, sweat, tears and may-

For Project Cornerstone the AUVs be a little luck - there is no reason why were deployed through an ice hole that there won’t be many more successful moved multiple kilometers per day. The polar missions in the future.

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