JPL’s Venus aerial robotic balloon prototype aces test flights

A scaled-down model of the aerobot that would one day take to the Venusian skies efficiently accomplished two Nevada check flights, marking a milestone for the venture.

The extraordinary strain, warmth, and corrosive gases of Venus’ floor are sufficient to disable even probably the most sturdy spacecraft in a matter of hours. However a number of dozen miles overhead, the thick atmosphere is much extra hospitable to robotic exploration.

One idea envisions pairing a balloon with a Venus orbiter, the 2 working in tandem to review Earth’s sister planet. Whereas the orbiter would stay far above the atmosphere, taking science measurements and serving as a communication relay, an aerial robotic balloon, or aerobot, about 40 ft (12 meters) in diameter would journey into it.

To check this idea, a crew of scientists and engineers from NASA’s Jet Propulsion Laboratory in Southern California and the Close to Area Company in Tillamook, Oregon, lately carried out two profitable flights of a prototype balloon that is a few third of that dimension.

The shimmering silver balloon ascended greater than 4,000 ft (1 kilometer) over Nevada’s Black Rock Desert to a area of Earth’s ambiance that approximates the temperature and density the aerobot would expertise about 180,000 ft (55 kilometers) above Venus. Coordinated by Close to Area, these assessments symbolize a milestone in proving the idea’s suitability for accessing a area of Venus’ ambiance too low for orbiters to succeed in, however the place a balloon mission may function for weeks and even months.

“We’re extraordinarily proud of the efficiency of the prototype. It was launched, demonstrated controlled-altitude maneuvers, and was recovered in good situation after each flights,” mentioned robotics technologist Jacob Izraelevitz, who leads the balloon growth because the JPL principal investigator of the flight assessments. “We have recorded a mountain of information from these flights and are trying ahead to utilizing it to enhance our simulation fashions earlier than exploring our sister planet.”

The one balloon-borne exploration of Venus’ ambiance thus far was part of the dual Soviet Vega 1 and a pair of missions that arrived on the planet in 1985. The 2 balloons (which had been about 11.5 ft, or 3.6 meters, in diameter when crammed with helium) lasted slightly over 46 hours earlier than their devices’ batteries ran out. Their brief time within the Venusian ambiance offered a tantalizing trace of the science that might be achieved by a bigger, longer-duration balloon platform floating inside the planet’s ambiance.

‘Roving’ the skies

The last word aim of the aerobot can be to journey on the Venusian winds, floating from east to west, circumnavigating the planet for no less than 100 days. The aerobot would function a platform for a spread of science investigations, from monitoring the ambiance for acoustic waves generated by venusquakes to analyzing the chemical composition of the clouds. The accompanying orbiter would obtain knowledge from the aerobot and relay it to Earth whereas offering a worldwide view of the planet.

Very similar to a Mars rover is commanded to drive to an attention-grabbing rock or different function, the aerobot might be directed to lift and decrease its altitude—one thing the Vega balloons could not do—to conduct science between about 171,000 and 203,000 ft (52 and 62 kilometers) inside Venus’ ambiance.

The prototype balloon was fabricated utilizing Close to Area’s methods for efficiency aerospace inflatables. Designed as a “balloon inside a balloon,” it has a inflexible interior reservoir crammed with helium below high pressure and an encapsulating outer helium balloon that may increase and contract. To extend altitude, helium vents from the interior reservoir into the outer balloon, which expands to present the aerobot further buoyancy. When it is time to cut back altitude, helium is pumped again into the reservoir, inflicting the outer balloon to shrink and reduce the aerobot’s buoyancy.

“The success of those check flights is a large deal for us: We have efficiently demonstrated the know-how we’ll want for investigating the clouds of Venus,” mentioned Paul Byrne, an affiliate professor at Washington College in St. Louis and aerobot science collaborator. “These assessments kind the inspiration for a way we will obtain long-term robotic exploration excessive above Venus’ hellish floor.”

No picnic within the clouds

Whereas this area of Venus’ ambiance is extra forgiving than its decrease reaches, long-duration flights within the rocky planet’s clouds, which comprise sulfuric acid and different corrosive chemical substances, can be no picnic. So the multilayered materials developed for the aerobot’s outer balloon consists of an acid-proof coating, a metallization layer to cut back solar heating, and a structural interior layer that retains it robust sufficient to hold the science devices under. New methods have additionally been developed to make sure a long-duration acid-proof seal with minimal helium leakage from the seams.

“The supplies getting used for Venus survivability are difficult to manufacture with, and the robustness of dealing with we have demonstrated within the Nevada launch and restoration provides us confidence for balloon‘s reliability on Venus,” mentioned co-investigator Tim Lachenmeier, chief government officer of Close to Area.

Whereas the current Nevada assessments had been a milestone for a future idea designed with Venus in thoughts, the researchers say the know-how is also utilized by high-altitude science balloons that want to regulate their altitude in Earth’s skies.