"Launch process complete: The Hope Probe has successfully separated from the launch vehicle," the mission said on its official Twitter account, where the launch was broadcast live.
Hope was launched from the space center on the Japanese island of Tanegashima on Sunday at 21:58 GMT using a Mitsubishi H-IIA booster.
"Two-way communication established. The ground segment has received and communicated the first signals with the Hope Probe," the mission said on Twitter shortly after the launch.
The launch was initially scheduled for 14 July but was postponed twice amid bad weather conditions.
"On behalf of NASA, I congratulate our friends in the United Arab Emirates (UAE) on the launch of the Emirates Mars Mission, Hope. Today marks the culmination of tremendous hard work, focus, and dedication, as well as the beginning of the UAE’s journey to Mars with the ultimate goal of human habitation of the Red Planet," NASA Administrator Jim Bridenstine said in a statement.
The Hope Probe is expected to reach Mars in February, 2021. It will study Mars’ atmosphere, collecting data for two years, with a possible extension of the mission until 2025.