NASA's newest planet-hunting spacecraft will have to wait another couple of days before lifting off.
Two hours before Monday evening's scheduled launch, SpaceX announced it needed more time to check its rocket, which will carry the satellite to orbit. The next attempt will be Wednesday night.
The satellite known as Tess will survey almost the entire sky, staring at the brightest, closest stars in an effort to find any planets that might be encircling them. These mysterious worlds beyond our solar system, called exoplanets, could harbor life.
Scientists expect Tess — the Transiting Exoplanet Survey Satellite — to discover thousands of rocky and icy planets and gas giants, maybe even water worlds and places defying imagination. Bigger and more powerful observatories of the future will scrutinize these prime candidates for potential signs of life.
SpaceX said extra time is needed to examine the Falcon 9 rocket's guidance, navigation and control system. Additional information was not immediately available, according to a spokesman.
SpaceX sometimes uses recycled rocket boosters, but this one is brand new. The company hopes to land this first stage on a floating ocean platform following liftoff, and reuse it on a space station supply run for NASA this summer.
Here's a peek at little Tess and its creators' big ambitions.
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.