NASA’s Psyche Mission to a Metal Asteroid Is Ready to Launch

Is the asteroid Psyche really a hunk of mostly metal? Is the object, which is nearly as wide as Massachusetts, the core of a baby planet whose rocky outer layers were knocked off during a cataclysmic collision in the early days of the solar system?

Right now, all that astronomers can say is maybe, maybe not.

NASA is launching a spacecraft, also named Psyche, on a journey to the asteroid belt between Mars and Jupiter to find out.

When is the launch, and how can I watch it?

After an earlier delay this week because of poor weather, liftoff is currently scheduled for Friday at 10:19 a.m. Eastern time from Kennedy Space Center. The spacecraft is flying on Falcon Heavy, the largest of SpaceX’s orbital rockets, which is needed to provide the power to loft the massive Psyche spacecraft. The launch will be streamed live on NASA TV and on the agency’s YouTube channel, starting at 9:30 a.m.

There is an instantaneous launch opportunity each day — meaning that the rocket would have to lift off at one particular moment. For Friday’s weather forecast, prospects for an on-time liftoff are currently at 85 percent favorable, a significant improvement from a Thursday report that warned of thick clouds potentially grounding the mission.

There are also launch opportunities in the days to come. The $1 billion Psyche mission needs to launch by Oct. 25, before the celestial alignment of the solar system is too far out of line for the spacecraft to reach the asteroid.

What is Psyche?

The asteroid named Psyche was spotted in 1852 by Annibale de Gasparis, an Italian astronomer, and named for the Greek goddess of the soul. It was just the 16th asteroid to be discovered.

Observations starting in the 1960s with telescopes, and later radar, suggested that Psyche differed from other asteroids in the region between Jupiter and Mars.

Scientists also found that it was potentially much denser than rock.

“Some of those early estimates were like, wow, this is really quite unusual,” said Jim Bell, a professor of earth and space exploration at Arizona State University who will lead studies of the asteroid with a camera aboard the spacecraft.

Psyche appeared to be almost pure metal, giving rise to the thought that it could be the remnant of a core of a baby planet. Or that hypothesis could be completely wrong.

“Psyche could be something entirely different than that,” said Lindy Elkins-Tanton, a professor of earth and space exploration at Arizona State University who serves as the mission’s principal investigator. “I would love to be totally surprised.”

More recent measurements have led to lower estimates of the asteroid’s density, suggesting it is made of metal plus something else — perhaps rock, perhaps empty space.

“My best guess is that it’s more than half metal, based on the data that we’ve got,” Dr. Elkins-Tanton said.

What happens after the launch?

The Psyche spacecraft will swing by Mars in May 2026, using its gravity as a slingshot toward Psyche the asteroid, arriving in August 2029 after traveling 2.2 billion miles.

The spacecraft will spend at least 26 months in orbit around the asteroid studying the body with a variety of instruments.