The United Arab Emirates’ Hope probe has successfully entered the red planet’s orbit, marking an historic day for missions to Earth’s neighbour.
The achievement makes the UAE only the fifth country in history to reach Mars.
Seven months ago the Hope launched from Earth, with the mission to gather data on the planet’s climate.
But entering the planet’s orbit involved a critical and tricky manoeuvre, Mars orbital insertion (MOI).
Achieving MOI saw the spacecraft rotated to position for a deceleration burn of 27 minutes and slowed down from its cruising speed of 121,000km/h to something nearer to 18,000km/h.
During this process it will have burned around half of its fuel.
Going too slow would have meant the spacecraft crashing on Mars, and if it went too fast it risked skipping past the planet.
With an 11-minute one-way radio delay to Earth, the probe had to rely on autonomous self-correcting systems to achieve MOI, managing any exceptional circumstance and mitigating any system failures or performance issues during the operation without human intervention.
News of a signal from the spacecraft was met by applause and cheers, as those in the control room – wearing face masks – maintained social distancing.
Omran Sharaf, Emirates Mars Mission (Hope Probe) project director, Mohammed Bin Rashid Space Centre, said: “MOI was the most critical and dangerous part of our journey to Mars, exposing the Hope probe to stresses and pressures it has never before faced.
“While we have spent six years designing, testing and retesting the system, there is no way to fully simulate the impacts of the deceleration and navigation required to achieve MOI autonomously.
“With this enormous milestone achieved, we are now preparing to transition to our science orbit and commence science data gathering.”
After the gravity of Mars captures Hope it will enter a phase called the capture orbit.
The capture orbit takes the spacecraft from a distance of 1,000 to 49,380km from Mars’s planetary surface.
In this phase instrumentation will be tested and the spacecraft will, over the coming two months, transition to its science orbit.
The transition to Hope’s science orbit will be completed by April 2021.
The probe has a 20,000–43,000km elliptical science orbit and completes one orbit of the planet every 55 hours.
While it will be in daily contact with Earth during the capture orbit phase, in its science orbit contacts will take place two to three times a week.
It will take six to eight hours each time for data to be downloaded and updates and instructions to be uploaded.
The spacecraft will explore the atmosphere of the planet, something that has not been done by any previous probe to the planet.
Hope will aim to answer a number of questions, including how conditions throughout the Martian atmosphere affect rates of escape of hydrogen and oxygen – the building blocks of life.
And how the Martian exosphere (upper atmosphere) behaves at different times during the day and at different distances relative to Mars.
— Hope Mars Mission (@HopeMarsMission) February 9, 2021
The instruments on board will collect different data points on the atmosphere to also gauge seasonal and daily changes.
Sarah Yousef Al Amiri, minister of state for advanced technologies, chairwoman of the UAE Space Agency, said she hopes the mission will be in a position to share data by September.
She told the PA news agency: “One of our primary objectives is to ensure that we share the data as soon as we are comfortable, as a science team, that the data is usable by scientists and the data is correct.”
She added: “We hope to release the data at the latest in the beginning of September, and it will be data from the capture orbit that has been captured around Mars, and also from the beginning of our science phase.”
Hope is the first of three missions to arrive at Mars this month.
On Wednesday, China’s Tianwen-1 mission will also try to make it into orbit, and Nasa’s Perseverance rover will arrive on February 19.