The UAE's orbiter took off from a Japanese launch centre on Monday morning.
The United Arab Emirates launched the Arab world's first-ever interplanetary mission, sending a spacecraft on a seven-month journey to Mars.
The orbiter, named Amal, or Hope, is carried by a Japanese H-IIA rocket which lifted off successfully from the Tanegashima Space Centre, on a small southern Japanese island on Monday morning.
People watching at a space centre in Dubai cheered and clapped after the liftoff.
The launch was initially scheduled for Wednesday but was delayed due to bad weather.
The rocket has been provided by Mitsubishi Heavy Industries.
The Hope probe is expected to reach Mars by February 2021, when the UAE will be celebrating 50 years since its formation.
This launch will be followed in the coming days by two other Mars missions by the US and China, while Japan has planned a Martian moon mission for 2024.
Hope will study the upper atmosphere of Mars as well as monitor climate change on the Red Planet over a period of two years.
The UAE hopes it will provide a complete view of the Martian atmosphere during different seasons.
The country has so far successfully launched three observation satellites, but has not gone beyond the Earth’s orbit.
Omran Sharaf, project director of Emirates Mars Mission, said on Sunday that this mission "is a message of hope to the Arab youth. If a young nation like UAE is able to reach Mars in less than 50 years, then we can do much more as a region.”
The event will be live-streamed on the Emirates Mars Mission website.
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