Posted on by Nancy Atkinson

Colonizing Venus With Floating Cities

Cloud city of Bespin, from Stars Wars. Credit and copyright: Ralph McQuarrie

Seemingly, people in the space community have a tendency to push the boundaries of thought about all the possibilities that await us in the universe. Case in point: Geoffrey Landis. Landis is a scientist at NASA’s Glenn Research Center who writes science fiction in his spare time. Last week Landis shared with us his ideas for using a solar powered airplane to study Venus.

This week, Landis goes a step farther (actually, several steps farther) with his ideas about colonizing Venus. Yes, Venus, our hot, greenhouse-effect-gone-mad neighboring planet with a crushing surface pressure that has doomed the few spacecraft that have attempted to reach the planet’s mysterious landscape. Landis knows Venus’ surface itself is pretty much out of the question for human habitation.

But up about 50 kilometers above the surface, Landis says the atmosphere of Venus is the most Earth-like environment, other than Earth itself, in the solar system. What Landis proposes is creating floating cities on Venus where people could live and work, as well as study the planet below.

“There’s been a lot of people who have been proposing space colonies, such as colonies that are in free space, separate from any planet,” said Landis. “And I said, well, if you’re thinking that far into the future why don’t we think of some more groundbreaking, or perhaps we should say atmosphere-breaking possibilities.”

50 km above the surface, Venus has air pressure of approximately 1 bar and temperatures in the 0°C to 50°C range, a quite comfortable environment for humans. Humans wouldn’t require pressurized suits when outside, but it wouldn’t quite be a shirtsleeves environment. We’d need air to breathe and protection from the sulfuric acid in the atmosphere.

In looking at Venus, the fact that struck Landis the most is that Earth’s atmosphere of nitrogen and oxygen would actually float in Venus’ atmosphere of carbon dioxide. “Because the atmosphere of Venus is CO2, the gases that we live in all the time, nitrogen and oxygen, would be a lifting gas,” he said. “On Earth, we know to get something to lift, you need something lighter than air. Well, on Venus, guess what? Our air is lighter than air, or at least lighter than the Venus atmosphere.”

So, create a bubble, fill it with Earth-like atmosphere, and it would float on Venus. “If you could just take the room you’re sitting in and replace the walls with something thinner, the room would float on Venus,” said Landis.

The biggest challenge would be using a substance resistant to sulfuric acid to form the outer layer of the bubble; ceramics or metal sulfates could possibly serve in this role, but of course, you’d want to be able to see outside, as well. “Just think of the great pictures you could get,” said Landis.

Asked if he has ever thought about terraforming Venus, Landis said, “Oh, yes, of course! That’s one of the reasons I started thinking about the floating cities on Venus. The more you look at Venus, the more you say, ‘oh my goodness, terraforming would be a really hard project.'”

Back in about 1962 when Carl Sagan first talked about the concept of terraforming Venus, it wasn’t known what a challenge Venus would be.

“They didn’t quite know how difficult Venus is, they didn’t know how thick the atmosphere was on Venus and how hot it was,” said Landis. “They knew it had a greenhouse effect, but they didn’t know how bad. But the more we look at the problems, the more we say, goodness, terraforming is a very difficult proposition.”

But Landis thinks Venus already has a very nice environment.

“What I like to say, the problem with Venus is if you define sea level as the place in the atmosphere where it’s the same as Earth, the place of “sea level” on Venus is just too far above the ground.”

While Landis’ plans for a solar powered airplane are a true possibility for an upcoming mission to Venus, his ideas about colonizing that planet are a little more speculative. “This is really just a thought exercise,” said Landis, “an exercise in imagination rather than something we’re likely to do in the near term. I don’t expect people will be building cities on Venus, at least probably not in this century.”

Anyone having visions of Bespin and Lando Calrissian from “The Empire Strikes Back”?

Maybe that should be “Landis” Calrissian.

More information about Geoffrey Landis.

Posted on by Nancy Atkinson

New Evidence for a Wetter, Warmer Ancient Mars

A 3-D image of a trough in the Nili Fossae region of Mars shows phyllosilcates (in magenta and blue hues) on slopes of mesas and canyon walls, showing water played a role in Mars’ past.

For all the Mars romanticists out there, we (yes, that means me, too) hope and maybe even dream that Mars once harbored water. And not just a little spurt of groundwater every once in awhile; we want the water to have been there in abundance and for enough time to make an impact on the planet and its environment. Now, proof of copious amounts of water in Mars’ past may have been found. Two new papers based on data from the Mars Reconnaissance Orbiter (MRO) found that vast regions of the ancient southern highlands of Mars hosted a water-rich environment, and that water played a sizable role in changing the minerals of a variety of terrains in the Noachian period – about 4.6 billion to 3.8 billion years ago.

John Mustard, a professor of planetary geology at Brown University and deputy principal investigator for the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) on MRO investigated the pervasive presence of phyllosilicates, clay-like minerals that preserve a record of water’s interaction with rocks.

Specifically, Mustard and his team from 13 other institutions focused on phyllosilicate deposits in areas like craters, valleys and dunes all over the planet. Among the highlights, he detected the clay-like minerals in fans and deltas within three regions, most notably the Jezero crater. That discovery marks the first time hydrated silicates have been found in sediments “clearly lain by water,” Mustard said.

The team also found phyllosilicate deposits in thousands of places in and around craters, including the pointed peaks located at the center of some of the depressions. This suggests that water was present 4-5 kilometers below the ancient Martian surface, the team wrote, due to the generally accepted principle that crater-causing collisions excavate underground minerals that are then exposed on the crater peaks.

“Water must have been creating minerals at depth to get the signatures we see,” Mustard said.

The clay minerals were formed at low temperatures (100-200°C) – an important clue to understanding the Red Planet’s potential for habitability during the Noachian period.

“What does this mean for habitability? It’s very strong,” Mustard said. “It wasn’t this hot, boiling cauldron. It was a benign, water-rich environment for a long period of time.”

In another paper, graduate student Bethany Ehlmann and colleagues from Brown and other institutions analyzed sediment deposits in two exquisitely preserved deltas in the Jezero crater, which held an ancient lake slightly larger than Lake Tahoe. The deltas suggest a flow from rivers carrying the clay-like minerals from an approximate 15,000-square kilometer watershed during the Noachian period.
Ehlmann said scientists cannot determine whether the river flow was sporadic or sustained, but they do know it was intense and involved a lot of water.

The deltas appear to be excellent candidates for finding stored organic matter, Ehlmann said, because the clays brought in from the watershed and deposited in the lake would have trapped any organisms, leaving in essence a cemetery of microbes.

“If any microorganisms existed on ancient Mars, the watershed would have been a great place to live,” Ehlmann said. “So not only was water active in this region to weather the rocks, but there was enough of it to run through the beds, transport the clays and run into the lake and form the delta,” she said.

Original News Source: Brown University Press Release

Posted on by Nancy Atkinson

Eta Vs. Peony: Which Star Will Go Supernova First?

The reigning champion for brightest star in the Milky Way is Eta Carinae, a highly unstable star prone to violent outbursts. Astronomers say Eta Car’s life will probably end in 100,000 years or so with a supernova explosion. That’s relatively soon in cosmic terms. But the Spitzer Space Telescope has unearthed a contender, both in brightness and in the supernova competition, found in the dusty depths of our galaxy’s center. Astronomers say the Peony nebular star might be as bright as Eta. But the biggest question may be, which star will be the first to go supernova?

Eta Carinae has the luminosity of 4.7 million times the brightness of our sun. And the new challenger, Peony, burns with the brightness of an estimated 3.2 million suns. But astronomers say it’s hard to pin down the exact brightness for these blazing stars, so they might shine with a similar amount of light.

Scientists already knew the Peony nebula star was out there, but they couldn’t get a good look at it to estimate its luminosity because of its sheltered location in the dusty central hub of our galaxy. Spitzer’s dust-piercing infrared eyes can penetrate the dust, and look into areas not visible with optical telescopes. Spitzer data was teamed up with infrared data from the European Southern Observatory’s New Technology Telescope in Chile to calculate the Peony nebula star’s luminosity.

“Infrared astronomy opens extraordinary views into the environment of the central region of our galaxy,” said Lidia Oskinova of Potsdam University in Germany. “The Peony nebula star is a fascinating creature. It appears to be the second-brightest star that we now know of in the galaxy. There are probably other stars just as bright if not brighter in our galaxy that remain hidden from view.”

Peony, with its rather delicate sounding name, is really a Big Bertha of a star. Astronomers estimate the Peony nebula star started its life with a hefty mass of roughly 150 to 200 times that of our sun. It is a type of giant blue star called a Wolf-Rayet star, with a diameter roughly 100 times that of our sun. That means this star, if placed where our sun is, would extend out to about the orbit of Mercury.

Stars this massive are rare and puzzle astronomers because they push the limits required for stars to form. Theory predicts that if a star starts out too massive, it can’t hold itself together and must break into a double or multiple stars instead.

Peony (maybe in an effort to control her weight) sheds an enormous amount of stellar matter in the form of strong winds. This matter is pushed so hard by strong radiation from the star that the winds speed up to about 1.6 million kilometers per hour (one million miles per hour) in only a few hours.

Ultimately, the Peony nebula star will live a short life of a few million years and will blow up in the most fantastic of cosmic explosions called a supernova. In fact, Oskinova and her colleagues say that the star is ripe for exploding soon, which in astronomical terms mean anytime from now to millions of years from now.

When this star blows up, it will evaporate any planets orbiting stars in the vicinity,” said Oskinova. “Farther out from the star, the explosion could actually trigger the birth of new stars.”

In addition to the star itself, the astronomers noted a cloud of dust and gas, called a nebula, surrounding the star. The team nicknamed this cloud the Peony nebula because it resembles the ornate flower.

Eta and Peony. Deceptively petite and delicate names for such big stars about to go boom.

Let the competition begin!

News Source: JPL

Posted on by Nancy Atkinson

The “Other” Moon Rocket Some NASA Engineers Believe is Better Than Ares

Jupiter 110 and 232. From Directlauncher.com

There’s a group of NASA engineers who believe NASA is making a mistake with its new Constellation program to replace the shuttle, which will use the new Ares rockets for launches starting in 2014. Constellation is an all new program which requires everything to be built from the ground up. The group of engineers asks, why not use the systems we already have that work reliably? The engineers, who are working clandestinely after hours on their plans have been joined by business people and space enthusiasts, and they call the plan Direct 2.0. They believe this approach could be flying sooner than Ares, reducing the gap in the US’s access to space, and providing a smoother transition for the workforce. Additionally it is more powerful than Ares, has lower risks for the astronauts, adds additional servicing missions to the Hubble Space Telescope, and reduces the cost to orbit by half.

Proponents say the Direct 2.0 approach is more capable than Orion, can lift more mass into Earth orbit and boost more mass out of Earth orbit on to other destinations. The concept is simple: use the same orange external tank and booster rockets as the shuttle, but don’t use the orbiter. Put additional engines on the bottom of the tank, and the cone-shaped Orion capsule on the nose. They call the rocket system Jupiter, and not only would Jupiter have less cost per launch, but it would cost less per kilogram to put things in orbit. They also say the crew abort limits are safer than Ares 1, and would require only minor modifications to the current mobile launch platform.

Instead of having the separate Ares-I Crew Launch Vehicle (CLV) and Ares-V Cargo Launch Vehicle (CaLV) they use just one single Jupiter launcher, capable of performing both roles.

On their website, Directlauncher.com, they say “This change to NASA’s architecture completely removes the costs & risks associated with developing and operating a second launcher system, saving NASA $19 Billion in development costs, and a further $16 Billion in operational costs over the next 20 years.”

But recent articles by the Associated Press and the Orlando Sentinel say that NASA is not interested in this concept, and that its nothing more than a concept on the back of a napkin. Additionally, Ares is so far along, with test flights scheduled for next year, that there’s no turning back now.

But the Orlando Sentinel article says that NASA ended a study last fall which showed Direct 2.0 would outperform Ares. The initial results showed Direct 2.0 was superior in cost, overall performance and work-force retention, which is a big issue for Florida.

The engineers who work at NASA say they can’t speak out directly for fear of being fired, but an outside group who supports their efforts are trying to get the word out about the plan.

Check out their website includes a discussion forum, a presentation on their concept and much more. Here’s a video that explains the concept:

In short, they say the Direct 2.0 approach introduces many advantages over the current Ares Launch Vehicles, such as:

Shorter “gap” after the Shuttle retires (3 years vs. 5)
Earlier return to the Moon (2017 vs. 2019)
Deletes all risks and costs associated with a second new launch vehicle
Optimum use of the existing NASA & contractor experience

Original News Sources: AP, Orlando Sentinel, ABC’s Science and Society Blog, Directlauncher.com

Posted on by Nancy Atkinson

Echus Chasma From Mars Express

echus chasma. Credits: ESA/ DLR/ FU Berlin (G. Neukum)

 

Do these valleys on Mars come from gushes of water from past rainfall, or groundwater springs, or could they have possibly been formed from magma flows on Mars surface? That’s the debate surrounding the many valleys, chasms and dry gullies found on the Red Planet.

The majority of planetary geologists seem to favor the idea of water flowing on Mars surface in the past. The images shown here of Echus Chasma are from the European Space Agency’s Mar’s Express, and its High-Resolution Stereo Camera (HRSC). Echus Chasma is believed to be one of the largest water source regions on the Red Planet. The valleys, cut into the landscape look similar to drainage networks found on Earth.

The image here has a ground resolution of approximately 17 m/pixel, and is so clear and distinct it almost makes you feel like you’re there!

echus chasma. Credits: ESA/ DLR/ FU Berlin (G. Neukum)
Image of the Echus Chasma showing elevation. Credits: ESA/ DLR/ FU Berlin (G. Neukum)

Echus Chasma is approximately 100 km long and 10 km wide. Echus Chasma is believed to be the water source region that formed Kasei Valles, a large valley which extends thousands of kilometers to the north. It’s located in the Lunae Planum high plateau, north of Valles Marineris – the Grand Canyon of Mars. This image indicates elevation data, also obtained by the HRSC.

Echus Chasma mosaic. Credits: ESA/DLR/ FU Berlin (G. Neukum)
Echus Chasma mosaic. Credits: ESA/DLR/ FU Berlin (G. Neukum)

An impressive cliff, up to 4000 m high, is located in the eastern part of Echus Chasma. Possibly, gigantic water falls may once have plunged over these cliffs on to the valley floor. The remarkably smooth valley floor was later flooded by basaltic lava.

Echus Chasma. Credits: ESA/ DLR/ FU Berlin (G. Neukum)
Overhead view of the Echus Chasma. Credits: ESA/ DLR/ FU Berlin (G. Neukum)

The smaller valleys, also called sapping canyons, are believed to originate from the discharge of groundwater.

Original News Source: ESA

Posted on by Nancy Atkinson

Where Do Meteorites Come From?

If you’ve ever held a real meteorite in your hand, you probably wanted to know, “Where has this rock been in space and where did it come from?” Until now, no one has been able to definitively establish where the majority of meteorites found on Earth came from because of the changes that occur in meteorites after they are ejected from the asteroids they were originally part of. The most common type of meteorite found on Earth, about 75% of those identified, are chondrites, stony bits of space rocks that didn’t undergo any melting while out in space. Two astronomers say have determined that most of these meteorites come from the asteroid belt between Mars and Jupiter. Using the GEMINI telescope, they found that asteroids in that region are similar to chondrites found on Earth.

This discovery is the first observational match between the most common meteorites and asteroids in the main belt. It also confirms the role of space weathering in altering asteroid surfaces.

To find the parent asteroid of a meteorite, the astronomers compared the spectra of a meteorite specimen to those of asteroids. This is a difficult task because meteorites and their parent asteroids underwent different processes after the meteorite was ejected. In particular, surfaces of asteroids are known to be altered by a process called “space weathering”, which is probably caused by micrometeorite and solar wind action that changes the surface and spectra of asteroid surfaces.

Meteoroids are created, usually when there is a collision between asteroids. When an impact of a large asteroid occurs, the fragments broken off can follow the same orbit as the primary asteroid. These groups of fragments are called “asteroid families.” Until recently, most of the known asteroid families have been very old (they were formed 100 million to billions of years ago), and younger families are more difficult to detect because asteroid fragments are closer to each other.

In 2006, four new, extremely young asteroid families were identified, with an age ranging from 50,000 to 600,000 years. The astronomers, Thais Mothé-Diniz from Brazil and David Nesvorný from the US observed these asteroids, obtaining visible spectra. They compared the asteroids spectra to the spectra of an ordinary chondrite (the Fayetteville meteorite, shown in the top photo) and found they matched.

Identifying the parent asteroid of a meteorite is a unique tool when studying the history of our solar system because one can infer both the time of geological events (from the meteorite that can be analyzed through dating techniques) and their location in the solar system (from the location of the parent asteroid).

Meteorites are also a major tool for knowing the history of the solar system because their composition is a record of past geologic processes that occurred while they were still incorporated in the parent asteroid.

Original News Source: Astronomy and Astrophysics

Posted on by Nancy Atkinson

Spacewalk Retrieves Explosive Bolt

Two cosmonauts at the International Space Station conducted a spacewalk on Thursday and performed the delicate operation of removing an explosive bolt from the Soyuz capsule attached to the station. Ten explosive bolts in all on the Soyuz break the connections between the spacecraft’s crew capsule and its propulsion module during descent back to Earth. Engineers suspect one bad bolt delayed the compartment’s jettison during landings in October 2007 and April 2008, leading to steep, high-G descents, causing the capsule to land off-course and hit the ground harder than it should. Sergei Volkov and Oleg Kononenko removed the bolt located in the same spot as the ones diagnosed as being faulty on the other capsules. They placed it inside a blast-proof canister, which will be returned home aboard the Soyuz when the crew completes its mission in October.

The spacewalk took 6 hours and 18 minutes to complete. US astronaut Greg Chamitoff remained in the Soyuz during the spacewalk, part of the contingency plan for the unlikely event the Pirs airlock could not be repressurized. Otherwise he would not have had access to the station’s lifeboat through a depressurized Pirs. “We do not like to separate the crew from (the) escape vehicle,” flight director Bob Dempsey told reporters in a briefing last week. “Therefore Greg will be staying in there. He will have some laptops, books and computers to work on while he’s there.”

Although engineers assured the bolt would not denoted, Russian mission control repeatedly told the cosmonauts to go slow and take their time. About halfway into the spacewalk, the bolt had been removed and placed in the container. “Good! Thank God, it is in,” one cosmonaut exclaimed. Mission control then told the cosmonauts to take a five minute break “without any motions, without moving,” before moving on to complete their tasks.

Chamitoff will have another stay in the Soyuz next Tuesday, as Volkov and Kononenko will conduct another spacewalk on July 15 to outfit the Russian segment’s exterior, install one scientific experiment and retrieve another.

News Sources: NASA, NASA TV

Posted on by Nancy Atkinson

Phoenix Lander Tries Out Soil Probe and Atomic Microscope

It’s not that the Phoenix lander’s mission to Mars is over – not by a longshot. But Phoenix did stick a fork in it. The “fork” is a four-pronged thermal and electrical conductivity probe that Phoenix poked into the Martian soil for the first time. The probe tool can help the science team assess how easily heat and electricity move through the soil from one spike to another. These measurements can provide information about frozen or unfrozen water in the soil. The probe is mounted on the “knuckle” of Phoenix’s Robotic Arm. The probe has already been used for assessing water vapor in the atmosphere when it is held above the ground.

The image above is a series of six images, taken on July 8, 2008, during the Phoenix mission’s 43rd Martian day, or sol, since landing. The insertion visible from the shadows cast on the ground on that sol was a validation test of the procedure. The spikes on the probe are about 1.5 centimeters or half an inch long.

Phoenix also tried out another instrument: atomic force microscope. This Swiss-made microscope builds an image of the surface of a particle by sensing it with a sharp tip at the end of a spring, all micro- fabricated from a sliver of silicon. The sensor rides up and down following the contour of the surface, providing information about the target’s shape.

“The same day we first touched a target with the thermal and electrical conductivity probe, we first touched another target with a needle about threeorders of magnitude smaller — one of the tips of our atomic force microscope,”said Michael Hecht of NASA’s Jet Propulsion Laboratory, Pasadena, Calif., lead
scientist for the suite of instruments on Phoenix that includes both the conductivity probe and the microscopy station.

The atomic force microscope can provide details of soil-particle shapes as small as about 100 nanometers, less than one-hundredth the width of a human hair. This is about 20 times smaller than what can be resolved with Phoenix’s opticalmicroscope, which has provided much higher-magnification imaging than anythingseen on Mars previously.

The team for the robotic arm is still working out the best way to get samples of ice from the trench dug earlier called “Snow White,” and be able to transfer the samples quickly into the Thermal and Evolved-Gas Analyzer (TEGA) which heats samples and identifies vapors from them.

Scientists have yet to release any information about the second test from the Wet Chemistry Lab. They are still analyzing the results.

Original News Source: NASA’s Phoenix site

Posted on by Nancy Atkinson

Nano-materials Could Protect Spacecraft and Satellites From Debris

Space junk in Earth orbit is becoming a big problem (here’s an previous UT article that illustrates the problem.) If the International Space Station or an operating communications or science satellite were struck by debris such as an old satellite, launch vehicle parts, or even something as small as a paint chip, it could mean disaster. Space debris also threatens the lives of astronauts and the launch of new satellites today, says Dr. Noam Eliaz, Head of the Biomaterials and Corrosion Laboratory at the School of Mechanical Engineering at Tel Aviv University. An expert in materials science and engineering, Dr. Eliaz is working to create and test new nano-materials and polymers to protect satellites and astronauts alike.

Eliaz is developing nano-based materials with special mechanical properties, such as high strength and wear resistance, and controllable electrical and thermal properties. “This could lead to a superior material for the external blankets of spacecraft,” says Eliaz. Some of the materials Eliaz has researched are being used by biomedical device companies and by aircraft industries worldwide.

One candidate Eliaz and his colleagues have investigated is a hybrid nano-material which incorporates small silicon-containing cages that can open and react with atomic oxygen to prevent further polymer degradation. Basically, a silicon skin would form to “patch” a puncture caused by a debris hit.

The team has also conducted space durability studies on polymers developed by the U.S. Air Force and Hybrid Plastics Inc, and the results are being reviewed by NASA and the European Space Agency (ESA). “Our simulation studies were done on Earth to determine how space debris will impact new polymers developed to protect space vehicles,” says Dr. Eliaz.

Original News Source: American Friends of Tel Aviv University

Posted on by Nancy Atkinson

Cruising the Cloud Tops of Venus With a Solar-Powered Airplane

With all the orbital missions at the various planets in our solar system, scientists have been able to glean an amazing amount of data to help us understand our neighboring worlds. But imagine a mission that could fly lower than orbital altitudes — actually flying in the atmosphere of another planet and closer to the surface — and imagine how much more detailed the data could be. This type of mission would be especially helpful on Venus, where the intense heat and crushing air pressure at the surface basically precludes the success of any type of lander mission. So, last year, when NASA formed a Science and Technology Definition Team (STDT) to study the concept of a flagship mission to Venus, waiting in the wings was Dr. Geoffrey Landis. For the past several years Landis and a group of scientists and engineers from NASA’s Glenn Research Center have been studying the concept of a solar-powered airplane at Venus. Landis says a small aircraft powered by solar energy could fly continuously in Venus’ atmosphere, and would be an ideal vehicle for gathering data on both the planet’s atmosphere and surface, with the ability to maneuver almost anywhere.

“There’s a lot of interest in Venus at the moment,” said Landis. “We’ve been looking at Mars quite a bit lately, and in some ways Mars is Earth’s twin, but in even more ways, Venus is Earth’s twin. So we learn a lot about Earth by studying Venus.”

A solar powered airplane has been a long-time interest for Landis. “I spent a lot of time in college building model airplanes, so the idea of flying an airplane on Venus sounded very interesting to me,” he said.

Since 2000, Landis and his team have been studying this concept, and Landis recently presented their findings to NASA’s STDT for Venus. “I’ve been trying to drum up enthusiasm for the things we’ve done,” he said. The main work the group has done so far has been focusing on the airplane itself, verifying that the concept is actually going to work.

“We’ve done a thorough design study to determine if there are any showstoppers,” said Landis. “We don’t think there are. We think it’s a very doable project.”

The airplane would have to fold up to fit inside a small aeroshell for a “Discovery” class scientific mission. After arriving at Venus the craft would deploy from the aeroshell, unfold and begin gliding through the atmosphere. With solar cells covering the entire surface, the airplane would fly strictly on solar power, not needing fuel. The team has come up with a foldable design that has a wingspan of 9 meters and a length of just under 7 meters.

Surprisingly, the density of Venus’ atmosphere shouldn’t be a problem for a solar airplane mission. “At the altitudes we’ll be flying, it would be like flying at moderate altitudes on Earth,” said Landis. “Venus is actually a very easy planet to fly on. Interestingly, the problem on Venus is the wind. It turns out it’s a very windy planet, and we would like to be able to keep our solar airplane flying underneath the sun, so we have to fly faster than the wind so we can stay in the sunlight. If we can do that we can basically fly forever.”

The craft would have to be capable of sustained flight at or above the wind speed, about 95 m/sec at the cloud-top level, 65 to 75 km above the surface. For exploration at lower altitudes, the aircraft could glide down for periods of several hours and then climb back to higher altitudes, allowing the cloud layers to be probed. But the airplane would have to be in sunlight for a majority of the time. The team’s analysis of a flight using battery storage shows that it wouldn’t work to keep the aircraft aloft on battery power during the passage across the night side of the planet.

As far as the science that can be gleaned from a solar-powered airplane at Venus, Landis’ team has primarily envisioned a mission to study Venus’ atmosphere. However, they’ve also looked at using it for a radar mission, and in particular if two airplanes could be used, one could be a transmitter and the other a receiver to do what’s called “bistatic radar” where you vary the angle between the transmission and the receiver to provide additional information about the planet. But mainly, an airplane flies much closer to the surface than an orbiting spacecraft, to gather greater detailed information about the planet.

The current focus of Landis’ team has been deciding what type of science could be done, and how it could best be achieved. “What we’ve been doing lately is just studying Venus and asking ourselves, what do we want to do,” said Landis. “Is an airplane the right thing? We’ve also been looking at airships. You can make a zeppelin fly at the planet Venus, which has both advantages and disadvantages over an airplane, so we’re asking ourselves, at what altitude in the clouds do we want to fly — above, below, or in the clouds — and what science we can do? The very hard part on Venus is flying low. It’s very easy to fly high, but the lower you could fly, the better the science you could accomplish. But flying low will be tricky.”

Interestingly enough, last year, students from Boston University also conducted a design study of a solar airplane at Venus, and they looked at the design that Landis’ team had come up with. The BU students also concluded such as mission was quite feasible. “They looked at the basic airplane design: Can you actually fly on Venus? We looked at things like, could you fold it up into the aeroshell, and how would it be deployed, etc.,” Landis said. “We found this second study to be a very useful sanity check for us, that an independent group of people looked at our ideas, and said that no, this isn’t out of the question.”

So, when could a solar-powered airplane mission be ready to fly over Venus? “It depends on how hard the mission you want to do is,” said Landis. “If you’re doing a simple solar airplane mission, we’ve shown that there aren’t any technology showstoppers in the airplane itself, so I think it’s something we could do in the near term, by the next decade. But the more difficult the mission you’re interested in, say if you’re interested in flying low or in the polar regions, places where it’s harder to fly, we’d have to back off and think about what the correct type of vehicle would be.”

This paper discusses more information about the Venus Solar Powered Airplane