CLEVELAND — In a bare concrete room at NASA Glenn Research Center, pieces of a 12-ton toxic oven patiently wait to be assembled. When engineers finish bolting the compact car-sized device together in May, it will scorch anything put in it at 1,000 degrees Fahrenheit, crush it under pressures nearly 100 times that of Earth’s and choke it with carbon dioxide, sulfuric acid and a cocktail of other noxious fumes. The hellish conditions should emulate the surface of Venus (above), a planet baked of its water and suffocated by greenhouse gases. “Venus used to be like Earth. There’s a lot of lessons for us to learn from it,” said NASA Glenn engineer Rodger Dyson, leader of the Extreme Environment Test Chamber. The problem with Venusian spacecraft is that they melt in an hour — two if they’re lucky. To know if next-generation landers or rovers could survive, engineers need a test chamber large enough to swallow their hardy robots. NASA’s chamber (below) will be the first one of its kind. “There’s no data to predict how long materials will survive on the surface,” Dyson said. “We don’t even know what physics and chemistry and mineralogy are occurring there.” Only 10 spacecraft have reached Venus’ surface in at least partial working order. Nine were Soviet landers. The only American surface mission launched in 1978. The last, Venera 13, beamed its final signal to Earth in 1984. Since that mission, most engineers have considered Venus’ environment too hostile to warrant plopping a nearly $1 billion probe on the surface to listen for earthquakes, analyze soil samples or even watch the weather. Better cooling and electricity-producing technologies, however, are making planetary scientists reconsider Venus surface missions. In theory, they could enable spacecraft to survive for days, weeks or months instead of hours. (In Earth time, that is; one day on Venus lasts 243 days on Earth.) “Imagine landing on Earth and trying to learn about it in one hour,” Dyson said. “You’d want to spend at least a day. We’re trying to enable that.” NASA spoke with Wired about making new Venus surface missions possible, and delivered a sneak peek at its toxic pressure cooker. Images: NASA 1) A radar map of Venus’ surface taken by the Magellan spacecraft. 2) Engineering illustration of how the Venus chamber will look when complete.

Heavy Blanket Because temperatures in the Venus chamber will be hot enough to melt lead, the chamber needs to be covered by a huge, insulating blanket to protect nearby workers. The main chamber (below) is made of solid steel more than an inch thick. The largest Venus-like chamber currently operating is located in California, and it can fit something 4.5 feet long, but only 4 inches high — not the dimensions of a practical spacecraft. NASA’s new 4-foot-long, 3-foot-wide Venus chamber won’t just be limited to just the hot and corrosive conditions on Venus. Thanks to its thick walls, it can simulate all conditions experienced during a trip to Venus: launch, the cold vacuum of space and even atmospheric entry. In the future, operators could simulate conditions found in Jupiter’s outer atmosphere, the Martian equator and even vents near volcanoes on Jupiter’s moon Io. Seven- and 10-foot-wide additions to the first chamber (below) could also make room for prototypes designed for ultra-cold conditions on the moons Europa, Ganymede and Titan. Images: 1) Dave Mosher/Wired.com 2) NASA Glenn Research Center

Super Bolts for Super Pressures The pressure inside the Venus chamber will reach about 1,350 pounds per square inch, or more than 90 times Earth’s atmosphere at sea level. The resulting force is so intense that custom hardware is required to keep it from exploding. “These super bolts are what hold the lid on,” Dyson said. The super bolts thread into larger bolts, which then go through a 4-foot-wide lid. The final design also called for a 4-inch viewing window in the center of the lid (below). Because glass would melt quickly, it will be made entirely of artificial sapphire. (One Venus lander had a lens made of diamond to hold up to corrosive gas and scorching temperatures.) Images: 1) Dave Mosher/Wired.com 2) NASA Glenn Research Center

Toxic Gas Mixer All gas that goes into the Venus chamber starts with the mixer, and Dyson's team will fill ‘er up first with nearly pure carbon dioxide gas. (Venus’ lower atmosphere is about 96 percent carbon dioxide.) In high concentrations, the compound is acidic, corrosive and asphyxiating. Yet far nastier gases will eventually be pumped inside, including sulfur dioxide, hydrogen chloride and hydrogen fluoride. “One part per million could kill everyone in this building,” Dyson said of hydrogen fluoride gas, which can dissolve glass and corrode metal. “We’d like to ignore it, and most people do, but if you’re going to have a mission on Venus for even 6 months you have to include that.” The rig (above) will allow for parts-per-billion fine-tuning of the artificial Venusian atmosphere. Gas emerges from the mixer around 130 pounds per square inch (psi), then heads to a booster that increases the pressure to 500 psi in the chamber. As heating elements raise the temperature to about 1,000 degrees Fahrenheit, the pressure jumps to 1,350 psi. Image: Dave Mosher/Wired.com

Materials Testing While spacecraft bake away in the test chamber, NASA also plans to sneak in piles of test materials to see what holds up best over the days, weeks and months of a future mission. Dyson said geologists and other researchers have signed up to stick in rock samples and see how the Venusian atmosphere alters them. Once a spacecraft encounters the real thing, it could help us better understand Earth’s atmosphere. “One of the main arguments for going [to Venus] is climate modeling,” Dyson said. “On Venus, it uses all of the same equations, but different chemicals. It’s one of the ways to verify if your models are right or wrong.” Images: 1) NASA Glenn Research Center 2) Dave Mosher/Wired.com

Hot Bot Dreams Surface landers are useful, but engineers and scientists dream of roving on Venus. Rovers are more complex and expensive than landers, but such a mobile robot could do the work of dozens of lander missions in a fraction of the time. The video above is a summary of one mobile mission envisioned by NASA planetary scientist Geoffrey Landis in 2006. A rugged metallic rover powered by nuclear material would take photos, analyze rock samples and measure seismic disturbances. A sealed, refrigerated sphere would keep high-temperature electronics insulated from the harsh Venusian atmosphere. The rover’s heat-sensitive control computers wouldn’t be on the rover; instead, they’d fly high above in disposable solar-powered planes. The planes would relay Earth’s commands delivered to an orbiting mother ship as well as process the rover’s data and beam it to the mother ship. Corrosive gases would eventually doom the plane, however, so the mother ship would deploy more planes over the mission’s lifetime. Video: NASA