Exploring Venus: A NASA Robotic Target

100730-VenusMission-hmed-203p.grid-6x2 After more than 20 years of benign neglect, the Venus is once more drawing NASA's eye for ambitious new missions, including  exploration flotilla a ground robot, planetary airplane and orbiting manned spacecraft. The potential mission to Venus could investigate its surface from up-close for the first time in several decades, a NASA scientist said.

"Recently there has been a renaissance in looking at proposals to study Venus," researcher Geoffrey A. Landis at NASA's John Glenn Research Center in Ohio told Space.com. "One very good reason is that there has been a renewed interest in study of the atmospheres and climates of planets, and being the planet that is most like the Earth in size learning more about the atmosphere of Venus may help us learn more about the atmosphere (and climate) of the Earth."

There hasn't been a dedicated U.S. mission sent to Venus since the Magellan probe in 1989, but that doesn't mean the planet has not seen its share of visitors. The European Space Agency currently has an orbiter called Venus Express circling Venus, and Japan launched its spacecraft Akatsuki (Japanese for "Dawn") toward the planet in May. Several NASA probes have flown by Venus in the last 20 years, but only as a pit stop on the way to other planets in the solar system.

Venus also saw visiting probe from the United States and Russia the 1960s, '70s and '80s, even some landings on the Venusian surface. But those probes were extremely short-lived because of the crushing pressure and extreme heat of Venus' atmosphere.

And after two decades of technological advancements, an extended robotic landing on Venus is now possible, Landis said. Today's high-temperature electronics, power and cooling systems could allow a ground probe to explore for longer than two hours.

Scientists suspect that Venus's atmosphere might hide extraterrestrial lifeforms, and in the most extraordinary safari ever, they want to go there and capture them with a flying balloon.  Interplanetary travel, extraterrestrial life, and Venusian airships – anyone doing anything other than science is missing out.

Venus doesn't score very highly when we think of life-capable planets – with surface pressures twenty times those of Earth and temperatures which can melt tin and vaporise mercury, it's not a a good place for organics.  In fact, it's not a good place for Terminators.  But go up far enough and you find clouds with Earth-like temperatures, pressures, even chemistry (at least as far as original ingredients go).  The fact that Venus boiled off all its oceans and turned them into sulfuric acid doesn't cancel out the fact there's water and heat aplenty.

In fact, the sulphur might help.  High above the Venusian surface the atmosphere is bathed in ultraviolet radiation, aka "That stuff that burns big things and kills small ones", but Professor Ingersoll (of the Californian Institute of Technology) and colleagues believe that extraplanetary microbes could learn to use these chemicals as a sunscreen – if they haven't adapted to UV altogether.

We've already seen Earth-borne bacteria surviving high in the clouds or in acidic environments, and the fact we haven't seen both at the same time is only because Earth doesn't have places like that.  Some suggest that Venus's conversion from an early Earth-a-like to a fair approximation of hell might have been slow – slow enough to allow life to occur, then evolve to adapt to a narrowing habitable zone.

Venus' lower cloud deck at an altitude of 50 kilometers has water vapor, potential nutrients, and a temperature of 30 to 70 degrees centigrade and pressure similar to Earth's surface. The theory is that microbes that might have evolved in the ancient oceans of the second planet billions of years ago when the Sun was much cooler, adapted to a purely airborne state as the oceans boiled away. The atmosphere of Venus has a chemical disequilibrium similar, although not as pronounced as Earth's demands an explanation, and a clear possibility is that biology is at work.

There's even a NASA option to fly there, deploy a floating collector, and rocket the samples back to Earth for analysis.  Not only might there be other life in the universe – they might live right next door.

The last spacecraft to land on Venus was Russia's Venera 14, which touched down on Venus in March 1982 and survived for 57 minutes nearly twice its expected design lifetime, according to NASA records.

But humans from Earth will still likely not step foot on the hellish Venus surface, where the temperature is hotter than most ovens about 870 degrees Fahrenheit and the atmospheric pressure is about 90 times that of the Earth.

"Venus is so hostile that we're not likely to land humans on it anytime in the foreseeable future," Landis said.

But scientists still have a technique up their sleeves that could allow humans to explore Venus virtually via "teleoperation" of a remote-controlled probe from inside an orbiting spaceship. By connecting astronauts to real-time visual and tactile data streamed by the robot, the system can allow astronauts to interact with the Venusian environment without the time-lag of controlling a robot from Earth, Landis said.

Venus explorers orbiting the planet would still need radiation and heat protection from the effects of orbiting a little closer to the sun. In addition, a source of artificial gravity may be necessary to counteract the loss of bone mass expected for astronauts living for long periods in weightlessness.

"Fortunately, we are learning a lot about long-duration habitation in space from the International Space Station, and by the time we're ready to send this mission, most of the difficult questions will be better understood, and many of the technologies chosen," Landis said

Another possible component of the mission may involve resurrecting a solar-powered airplane concept to traverse the planet's thick and "tremendously exciting" atmosphere, Landis said. Venus resembles the surface of Earth when it first formed; the thick carbon dioxide covering Venus could tell us a lot about our own planet's evolution, he added. A compact plane that could unfold during entry could be a vital probe to record conditions from inside Venus' atmosphere.

"Venus rotates so slowly that we could essentially fly forever because the airplane can fly faster than the speed it rotates and then stay in sunlight all the time. It never runs out of fuel, or energy," Landis said. Venus' long days do come with a price: high winds that would challenge the plane's flight limits.

In theory, the plane's speed would be a mere 10 mph. But once immersed in the atmosphere of Venus, the aircraft would have to battle wind speeds of around 200 mph in order to keep in the sun. So the speed required to compensate would be pretty high for solar airplanes but slower than a typical airliner, Landis said.

Casey Kazan via NASA and space.com


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