Apollo Anniversary

The US space agency on Sunday marked the 40th anniversary of the historic Apollo 8 mission that brought three astronauts to orbit the moon for the first time.

On December 21, 1968, Apollo 8 blasted off from Cape Canaveral, Florida and three days later, Frank Borman, James Lovell and William Anders became the first humans to enter lunar orbit.

The mission ultimately led to the first footsteps on the moon when Neil Armstrong took his "one small step" in 1969.

Apollo 8 also marked a rare moment of unity in the United States in a tumultuous year marred by the assassinations of Martin Luther King, Jr and Robert Kennedy, violence peaking during the Vietnam War and riots across American cities.

Shortly after entering the moon's orbit, astronauts aboard the Apollo 8 witnessed Earth rising above the moon.

"Earthrise", a photograph of the event taken by Anders, became one of the most famous images of the 20th century.

In a Christmas Eve broadcast timed to coincide with a full view of Earth, the crew read the first 10 verses of the Book of Genesis that forms the basis for Judaism, Christianity and Islam.

Message from space

The International Space Station (ISS) crew paid homage to Apollo 8 in a video message broadcast from space this week.

"Forty years ago, a trio of astronauts ... set out on what was at that time humanity's boldest journey," said Commander Michael Fyncke, who heads Expedition 18, the current ISS mission.

"We remember those brave explorers and are honoured to stand on their shoulders as we continue their journey."

John Glenn, the first American to orbit the Earth, reflected on Apollo 8 in a Nasa video commemorating the mission.

"Launched just before the Christmas holidays, the mission balanced the tensions of the space race with a transcendent feeling that the accomplishment was truly for all of humanity," Glenn said.

Soviet competition

Apollo 8 was originally planned to orbit Earth for 10 days and test a lunar landing module but the mission changed to a more ambitious lunar orbital flight in the face of Soviet competition.

The Soviet Union had set the pace for space exploration for over a decade in the Cold War battle for supremacy that became known as the Space Race.

The Apollo 8 mission also reflected former president John F Kennedy's objective for the United States to land the first man on the moon.

"I believe that this nation should commit itself to achieving the goal, before this decade is out, of landing a man on the moon and returning him back safely to the earth," Kennedy declared in 1961.

"No single space project in this period will be more impressive to mankind, or more important for the long-range exploration of space; and none will be so difficult or expensive to accomplish."

By the end of the decade, the United States was pouring billions of dollars annually into its space programme and its lunar launch programmes.