If you would like to see more articles like this please support our coverage of the space program by becoming a Spaceflight Now Member . If everyone who enjoys our website helps fund it, we can expand and improve our coverage further.

CAPE CANAVERAL — NASA’s OSIRIS-REx spacecraft today moved a step closer to starting a voyage to explore an uncharted world in our solar system — the mountain-sized Asteroid Bennu — by joining the booster rocket that will propel it from Earth next week.

Liftoff from Cape Canaveral atop a United Launch Alliance Atlas 5 rocket remains on schedule for Thursday, Sept. 8 at 7:05 p.m. EDT (2305 GMT). Launch will be possible at every five-minute interval for two hours till the window closes at 9:05 p.m. EDT (0105 GMT).

The $800 million OSIRIS-REx project is the first U.S.-led asteroid sample return mission, a 7-year trek to grab a piece of Bennu and bring it back to Earth for study.

“We’re interested in material from the earliest stages of solar system formation,” said Dante Lauretta, the OSIRIS-REx principal investigator.

“We started out as a giant molecular cloud that collapsed down, conservation of angular momentum caused that material that didn’t fall down into the proto-sun at the center to spin out into a disk. Inside that disk is where the planets formed, but before that could happen, material condensed into very tiny grains, dust, ice and organic molecules. We think those organic molecules were critical for the origin of life on our planet, and tantalizing clues are provided as to the possibility of the origin of life on other planets.”

Like a time capsule, the primitive Bennu holds an unspoiled record of the conditions that existed during the solar system’s formation 4.5 billion years ago. OSIRIS-REx will collect up to four mounds of that material and return it in a pristine canister, landing in Utah on Sept. 24, 2023.

“I’ve been interested in phosphorus compounds, and trace phosphates, which may be critical for DNA, RNA, ATP, critical molecules for our genetic information and for our energy in our cells. It’s only by getting these samples into laboratories on Earth that we can address the fundamental science questions that we’re interested in,” Lauretta said.

In preparation for the mission, the spacecraft was driven from Kennedy Space Center’s Payload Hazardous Servicing Facility to Cape Canaveral’s Complex 41 before dawn today, pulling up to the doorway of the Vertical Integration Facility where the Atlas 5 rocket was assembled aboard a mobile launch platform.

Already hidden from view inside the rocket’s aluminium nose cone, the satellite was hoisted from its transporter by an overhead crane and maneuvered atop the Centaur upper stage for mating.

The payload connection tops off the rocket at 189 feet tall.

The Integrated Systems Test — a tip-to-tail electrical checkout of the combined satellite and launch vehicle — will be performed later this week, followed by holding the Flight Readiness Review.

After a quiet three-day holiday weekend, the Launch Readiness Review will be conducted next Tuesday and the rocket rolls out to the pad next Wednesday, the day before liftoff.

Here’s a look at some stats about the AV-067 launch. This will be:

The 647th launch for Atlas program since 1957

The 352nd Atlas launch from Cape Canaveral

The 236th mission of a Centaur upper stage

The 213th use of Centaur by an Atlas rocket

The 472nd production RL10 engine to be launched

The 71st flight of an RD-180 main engine

The 65th launch of an Atlas 5 since 2002

The 13th NASA use of Atlas 5

The 54th launch of an Atlas 5 from Cape Canaveral

The 5th Atlas 5 launch of 2016

The 98th Evolved Expendable Launch Vehicle flight

The 111th United Launch Alliance flight overall

The 57th Atlas 5 under United Launch Alliance

The 26th NASA launch by United Launch Alliance

The 80th United Launch Alliance flight from Cape Canaveral

The 44th 400-series flight of the Atlas 5

The 4th Atlas 5 to fly in the 411 configuration

The 81st launch from Complex 41

The 54th Atlas 5 to use Complex 41

See earlier OSIRIS-REx coverage.

Our Atlas archive.