Monday witnessed the genesis of a perilous manoeuvre by the UAE's "Hope" probe to enter Mars' orbit, a half-hour process that will determine the fate of the Arab world's first space mission.

If it succeeds, the probe which is designed to reveal the secrets of Martian weather, will become the first of three spacecraft to arrive at the Red Planet this month.

The United Arab Emirates, China and the United States all launched missions last July, taking advantage of a period when the Earth and Mars are nearest.

The venture marks the 50th anniversary of the unification of the UAE's seven emirates. Landmarks across the Gulf state have been lit up in red at night and government accounts and police patrol cars emblazoned with the #ArabstoMars hashtag.

Mission officials said Hope had begun a 27-minute "burn" to slow itself enough to be pulled in by Martian gravity, in what they warn is the most challenging part of the journey.

The probe will rotate and fire all six of its powerful thrusters to dramatically slow its average cruising speed of 121,000 kilometres (75,000 miles) per hour to about 18,000 kph.

With an 11-minute communications lag, the time it takes for a signal to travel back to Earth, the spacecraft must be highly autonomous.

"Fifty percent of missions that tried before us were not able to enter orbit," said Sheikh Mohammed bin Rashid Al-Maktoum, UAE prime minister and Dubai's ruler.

However, he said, even if the probe does not enter orbit, "we have entered history. This is the farthest point in the universe that Arabs have reached in our history."

The "burn" is scheduled to end at 1557 GMT, and at 1608 GMT the UAE will have its moment of truth.

In the mission control room, officials in traditional dress, together with face masks, stood behind curved white monitoring stations.

And as the clock ticked down, Dubai's needle-shaped Burj Khalifa, the world's tallest tower, lit up in red with blue laser lights, to the backdrop of dramatic music.