Led by Dr. João Borges de Sousa of the Laboratório de Sistemas e Tecnologia Subaquática (LSTS) of Portugal, a multinational, multidisciplinary team of scientists have designed, built, and deployed seven autonomous underwater vehicles (AUVs) in the North Pacific Subtropical Ocean Front using the Schmidt Ocean Institute’s research vessel Falkor.

Ocean fronts are areas where drastic changes occur in the properties of waters. These changes are of interest to scientists studying Earth’s climate and marine ecosystems. The particular ocean front examined by the teams is situated about 1,000 nautical miles SW of Southern California. It’s here that less dense and cold waters coming from the Arctic meet the otherwise saline waters of the Pacific.

Three scout ASVs (autonomous surface vehicles) were sent to detect the ocean front ahead of the Schmidt Ocean Institute expedition. The area was then mapped for three weeks by a fleet of AUVs, UAVs (unmanned aerial vehicles) and the R/V Falkor.

In order to map the 3D structure of this dynamic front, the AUVs cycled in a ‘saw-tooth’ pattern between the water’s surface at a depth of 100 meters. The AUVs were controlled from either the R/V Falkor or across the world from an ocean space center in Portugal, with commands sent via RockBLOCKs and the Iridium network.

Operating 24/7, the AUVs would also periodically upload preliminary sensor data, like temperature, salinity, chlorophyll, and turbidity profiles (water properties at different measured depths).

When interesting features would appear, UAVs were deployed to measure the same features from the air using thermal and multispectral cameras. This feat wouldn’t have been possible using only traditional marine/aerial vehicles, due to the logistical and financial restrictions involved with these larger assets.

In less than three weeks, the AUVs traversed over 1,000 nautical miles, operating approximately for 500 hours and sending over 12,000 transmissions – or 2.5 megabytes of Iridium data – to researchers via Rock Seven (now trading as Ground Control)’s servers.

The mission’s success proves that lower-cost, autonomous, and connected vehicles can play a key role in collecting abundant data sets from remote locations. This allows research vessels like the R/V Falkor to shift their role from being a primary sampling unit to a command center, reducing operational costs while increasing scientific knowledge.

Iridium connectivity also allowed the replica command center based in Portugal to take over the second shift, giving scientists round the clock control of their research assets.

More information about this research can be found in the Schmidt Ocean Institute’s expedition page.

Thanks to advancements in IT and DIY fabrication, missions reserved for national space agencies just a decade ago are becoming increasingly accessible to hobbyists. Cue the High Altitude Photography Platform (HAPP), created by Christopher Couch and James Mayes.

The two engineers designed and built the HAPP, which is comprised of a jet-stabilized aircraft resembling the iconic three-man Apollo re-entry vehicle: a balloon system designed to take the aircraft to its 30km apogee and all the peripheral equipment and electronics that made that project successful. Though not the first high-altitude photography project, the HAPP is the first to capture stabilized 360-degree video.

Even more amazing was the project’s focus on DIY: over 80% of the 22 months for development were dedicated to creating tools and methods rather than actually producing flight hardware. The result is a project that can be replicated by hobbyists using locally sourced parts.

The HAPP can drift as much as 100km during each mission, so it was important to keep track of the lander and provide flight data to air traffic control. The RockBLOCK 9603 was vital in sending telemetry and system sensor data from the Arduino-based flight control computer at an altitude of up to 22km on the maiden flight, mission HAPP-M1.

While the power supply was in a temperature-controlled enclosure, the U-Blox board and PCBs were exposed to the atmosphere for the duration of the mission, experiencing temperatures ranging from +42°C down to -45°C, and pressures from 1atm down to 0.05atm.

The project’s creators have done a great job in documenting the project build and sharing the valuable knowledge they’ve gained. Their videos, including the glorious 4K mission HAPP-M1, can be found here.

In the spring of 2017, an international team of students from Luleå University of Technology in Sweden gathered together to brainstorm a REXUS/BEXUS program idea. The European program supports scientific and technological experiments on research rockets and balloons, sending two of each into space every year.

After some deliberation by the team, it was a scientific article on the potential of a manned mission to the upper Venusian atmosphere that gave the impetus for the Balloon Ejection Student Prototype INvestigation (BESPIN) Project. Though Venus’s runaway greenhouse effect makes the planet’s surface hot enough to melt lead, at a height of 50km temperature and pressure conditions are very similar to those found on Earth. This makes a balloon-assisted manned mission to Venus highly plausible.

That’s why the BESPIN experiment is made up of two parts – a flotation probe and a descent probe. At apogee (around 80km), both probes are ejected as a single free-falling unit (FFU) from the rocket’s nose-cone. The FFU freefalls until it reaches an altitude of about 5km, when a parachute is deployed on the descent probe.

When the FFU’s velocity has dropped below 7 m/s, a balloon on the flotation probe will inflate. Once it’s fully inflated, the descent and flotation probes will separate. The descent probe will continue parachuting down towards the ground, while the flotation probe uses its fully inflated balloon to attempt a controlled descent.

Following the deployment of the descent probe parachute, the team will be using a RockBLOCK 9603 to communicate housekeeping and positional data to a ground station. Like the rest of the equipment, the RockBLOCK will be undergoing rigorous testing to ascertain its suitability for vibration, shock, and pressure changes associated with the mission.

More on this story from the European Space Agency.

The SuperBIT can collect several gigabytes of data per night, and relaying it back to Earth is not just complex but expensive. One idea put on the table was to periodically offload the data via radio or microwave from an under-flying plane. The balloon’s remote position over the ocean though would make this logistically difficult.
 

Paul Clark, head of engineering at Durham CfAI, said: “Our slightly crazy idea is to carry out data drops whenever the balloon passes over land. Imagine a TB flash drive being dropped from the telescope gondola and coming down to the ground on a parachute. The challenge then is to track the data payload as it descends and find it once on the ground. That’s where the Iridium 9603N comes in.”

 
The SuperBIT beacon that tracks the payload uses a GPS receiver and an altitude/pressure sensor integrated with the Iridium 9603N modem. The beacon design has proved reliable, even at high altitudes where the temperature falls below -50C and the air pressure is very low. Battery chemistry has also been carefully chosen to withstand the extreme conditions. The beacon is robust enough to have been recovered from a tree and a lake.

The team is now getting ready for a third engineering flight from Palestine, Texas, while the main ultra-long-duration balloon flight (ULDB) is scheduled for 2020 in New Zealand. It’s this final mission that will demonstrate the SuperBIT’s capability as a facility-class instrument.

When fully operational, the SuperBIT will study strong and weak gravitational lensing and map out the distribution of dark matter around hundreds of galaxy clusters.

Photos (c) Department of Physics, University of Toronto.