PASADENA, Calif. — With Mars looming large, NASA's most high-tech rover ever built was on track to plunge into the red planet's atmosphere early today and attempt a series of difficult acrobatics to land safely on the surface.
The Curiosity rover was poised to hit the top of the Martian atmosphere at 13,000 mph. If all went according to script, it would be slowly lowered by cables inside a massive crater in the final few seconds.
Mission control at the NASA Jet Propulsion Laboratory expected to hear a signal at 1:31 a.m. EDT. The space agency warned that confirmation could take longer if an orbiting spacecraft that's supposed to listen for Curiosity during the descent is not in the right place.
Curiosity's trajectory was so accurate that engineers decided to wave off a last chance to tweak its position before atmosphere entry.
"We're ready to head in," said mission manager Brian Portock.
Hours before the planned touchdown, Jet Propulsion Laboratory director Charles Elachi said engineers have done their best to ensure a successful mission. But if they have a bad day, Elachi put his own spin on a Theodore Roosevelt quote: "It's far better to dare mighty things even though there is a risk of failure."
Curiosity was launched to study whether the Martian environment ever had conditions suitable for microbial life. The voyage took over eight months and spanned 352 million miles.
The nuclear-powered rover, the size of a small car, is packed with scientific tools, cameras and a weather station. It sports a robotic arm with a power drill, a laser that can zap distant rocks, a chemistry lab to sniff for the chemical building blocks of life, and a detector to measure dangerous radiation on the surface.
It also tracked radiation levels during the journey to help NASA better understand the risks astronauts could face on a future manned trip.
After several weeks of health checkups, the six-wheeled rover could take its first short drive and flex its robotic arm.