NASA's planet-hunting spacecraft embarked Wednesday on a quest to find new worlds around neighboring stars that could support life.
Hawthorne-based SpaceX delayed the launch, initially scheduled for earlier this week, so the rocket's guidance, navigation and control system could be examined. NASA's Transiting Exoplanet Survey Satellite, or Tess, was set to be deployed about 50 minutes later.
The Tess mission, led by the Massachusetts Institute of Technology's Kavli Institute for Astrophysics and Space Research, is designed to find potential planets orbiting stars close to Earth. It will attempt to identify such planets by spotting decreased brightness of stars, a sign that a planet is passing in front of it.
The launch is the eighth of the year for SpaceX, which most recently launched a resupply mission to the International Space Station on April 2. Continuing its efforts to cut the cost of space missions by recovering rockets, SpaceX will attempt to land the first stage of its Falcon 9 rocket on a barge -- named "Of Course I Still Love You" -- in the Atlantic Ocean.
What to Know About the TESS Mission
The Spacecraft: At 5 feet (1.5 meters), Tess is shorter than most adults and downright puny compared with most other spacecraft. The observatory is 4 feet across (1.2 meters), not counting the solar wings, which are folded for launch, and weighs just 800 pounds (362 kilograms). NASA says it's somewhere between the size of a refrigerator and a stacked washer and dryer. Four wide-view cameras are surrounded by a sun shade, to keep stray light out as they monitor any dips in brightness from target stars. Repeated dips would indicate a planet passing in front of its star.
Orbit: Tess will aim for a unique elongated orbit that passes within 45,000 miles of Earth on one end and as far away as the orbit of the moon on the other end. NASA insists there's no chance of Tess hitting any other satellites or running into the moon, which should never be anywhere close. The lunar gravity will keep the spacecraft stabilized in this orbit for decades to come, with no fuel needed. It will take Tess two weeks to circle Earth.
Job: Tess will scan almost the entire sky during its $337 million mission, staring at hundreds of thousands, even millions of small, faint red dwarf stars. Scientists expect to discover thousands of planets that, over time, will undergo further scrutiny by powerful telescopes in space and on Earth. That's why NASA, Massachusetts Institute of Technology and and other collaborators are targeting stars within hundreds or, at most, thousands of light-years: It will make the detailed searches yet to come that much easier. NASA's planet-hunting pioneer, the Kepler Space Telescope, has spent the past nine years focusing on considerably fainter, more distant stars and discovered nearly three-quarters of the 3,700-plus exoplanets confirmed to date. With Tess, "our planetary census is going to move in" closer to us, MIT researcher Jenn Burt said Sunday. Satellite maker Orbital ATK's Robert Lockwood said he expects Tess to take exoplanet discovery to a whole new level.
Alien Life: Tess has no instruments capable of detecting life. Its job is to find and characterize planets that will become the main targets of future telescopes. "By looking at such a large section of the sky, this kind of stellar real estate, we open up the ability to cherry-pick the best stars for doing follow-up science," said Burt. NASA's James Webb Space Telescope, once launched in 2020 or so, will probe these planets' atmospheres for potential traces of life. Giant telescopes still in construction or on the draw zing board also will lend a hand.