A rocket will take off from Cape Canaveral in Florida on Thursday night carrying Israel's Beresheet spacecraft, which aims to make history twice: as the first private-sector landing on the moon and the first from the Jewish state.
The 585-kilogram (1,290-pound) Beresheet, which means "Genesis" in Hebrew, is to lift off at 8:45 p.m. (0145 GMT Friday) atop a Falcon 9 rocket from the private U.S.-based SpaceX company of entrepreneur Elon Musk.
The Israeli craft will be placed in Earth orbit, then begin a seven-week trip under its own power to reach the moon and touch down on April 11 in a large plain.
The unmanned mission is part of renewed global interest in the moon and comes 50 years after American astronauts first walked on the lunar surface.
"For the future of our children, the state of Israel and for the belief that anything is possible, join us and wish Beresheet luck on its way to the moon!" said a collective message from SpaceIL, the nonprofit organization that designed the Israeli craft.
Entrepreneurs, not government space agencies, financed the mission, initially as a potential entry in the Google Lunar XPRIZE contest.
That competition planned to award $30 million to encourage scientists and entrepreneurs to offer relatively inexpensive lunar missions. The contest closed without a winner in March 2018 but the SpaceIL team continued its mission and purchased a spot on a SpaceX rocket.
Other partners are Israel Aerospace Industries (IAI), Israel's space agency, and the country's Ministry of Science and Technology.
So far, only Russia, the United States and China have made the 384,000-kilometer (239,000-mile) journey and landed spacecraft on the moon.
China's Chang'e-4 made the first soft landing on the far side of the moon on Jan. 3, after a probe sent by Beijing made a lunar landing elsewhere in 2013.
Americans are the only ones to have walked on the lunar surface, but have not been there since 1972.
For Israel, the landing itself is the main mission, but the spacecraft also carries a scientific instrument to measure the lunar magnetic field, which will help understanding of the moon's formation.
Technically, it is far from a trivial mission.
After its initial boost from the Falcon 9, the Beresheet's British engine will have to make several ignitions to place the spacecraft on the correct trajectory to the moon.
When it arrives, its landing gear must cushion the descent onto the lunar surface to prevent Beresheet from crashing.
Beresheet will carry a "time capsule" loaded with digital files containing a Bible, children's drawings, Israeli songs, memories of a Holocaust survivor and the blue-and-white Israeli flag.
At a cost of $100 million, "this is the lowest-budget spacecraft to ever undertake such a mission. The superpowers who managed to land a spacecraft on the moon have spent hundreds of millions of dollars in government funding," IAI said in an earlier statement.
"Beresheet is the first spacecraft to land on the moon as a result of a private initiative, rather than a government."
After China earlier this year, and now Israel, India hopes to become the fifth lunar country in the spring with its Chandrayaan-2 mission. It aims to put a craft with a rover onto the moon's surface to collect data.
Japan plans to send a small lunar lander, called SLIM, to study a volcanic area around 2020-21.
As for the Americans, a return to the moon is now the official policy of NASA, according to guidelines issued by President Donald Trump in 2017.
"This time, when we go to the moon, we're actually going to stay," NASA Administrator Jim Bridenstine said last week.
To achieve this, the U.S. space agency is changing its model and no longer wants to design the missions itself.
The National Aeronautics and Space Administration, which has installed equipment on Beresheet to upload its signals from the moon, said last week that it aims to land instruments later this year or next year and that it is inviting private-sector bids to build and launch the U.S. probes.
The U.S. space agency plans to build a small space station, dubbed Gateway, in the moon's orbit by 2026, and envisages a manned mission to Mars in the following decade.