When the spacecraft arrives, the Hope Probe will mark the UAE as only the fifth country in history to reach the red planet. The ambitions of the mission don’t stop there.
The probe, along with its three scientific instruments, is expected to create the first complete portrait of the Martian atmosphere. The instruments will collect different data points on the atmosphere to also gauge seasonal and daily changes.
This information will provide scientists with an idea of what climate dynamics and weather are like in different layers of the Martian atmosphere. Together, this will shed light on how energy and particles, like oxygen and hydrogen, move through the atmosphere and how they even escape Mars.
The mission was one of three that launched to Mars from Earth in July, including NASA’s Perseverance rover and China’s Tianwen-1 mission. Hope will orbit the planet, Tianwen-1 will orbit the planet and land on it, and Perseverance will land on Mars.
All three missions launched around the same time due to an alignment between Mars and the Earth on the same side of the sun, making for a more efficient journey to Mars. Hope is the first of those missions to arrive at Mars; Tianwen-1 is expected to arrive on February 10 and Perseverance on February 18.
Arrival at Mars
The Hope Probe is moving with such speed toward Mars that if it doesn’t slow down appropriately upon arrival, the spacecraft will literally use Mars’ gravity to slingshot it through deep space.
Almost half of the spacecraft’s fuel will be used to slow it down enough for the spacecraft to be captured by Mars’ gravity and go into orbit.
By firing its thrusters for 30 minutes before reaching Mars, it will slow down from a speed of more than 75,185 miles per hour to 11,184 miles per hour.
The Hope Probe’s team considers this phase of the spacecraft’s arrival at Mars, called the Mars Orbit Insertion phase, just as critical and risky as launching the spacecraft. And much like Perseverance will essentially land itself on Mars without any interference from NASA, Hope will be able to react to any issues and take care of itself, to some degree.
Once Hope has established an orbit around Mars, it will make contact with Earth through a ground station in Spain. One-way light time between Mars and the Earth takes between 10 and 11 minutes, so the signal will be slightly delayed.
“Less than half of the spacecraft that have been sent to Mars have actually made it successfully,” said Pete Withnell, program manager for the mission at the University of Colorado Boulder’s Laboratory for Atmospheric and Space Physics. “But this is a highly practiced, highly simulated and highly analyzed event. I cannot imagine being better prepared than we are right now.”
Capturing a new view
After the gravity of Mars captures Hope, it will enter an elliptical orbit around the planet, coming as close as 621 miles above the Martian surface and as distant as 30,683 miles from it. It will take Hope about 40 hours to complete one orbit.
The probe will send back its first image of Mars during this time.
During this transition, the ground teams will send some commands to the spacecraft to test the instruments and make observations of Mars to see if any of the instruments need tweaking.
Then, it will be time to maneuver Hope into the science orbit, which will allow the probe’s instruments to begin capturing scientific data of Mars.
Hope will complete one scientific orbit of the planet every 55 hours. This orbit will provide the first global picture of weather and atmospheric dynamics on Mars, which will be shared with the scientific community via the mission’s data center.
The mission is expected to last two years, with the possibility of being extended for a third year.
The probe will be in a different orbit from past spacecraft that have visited Mars.
“It’s a very high altitude orbit, much higher than any other Mars science missions,” Brain said. “In that high altitude orbit, where our instruments observe Mars from the global perspective, it will always be seeing roughly half of Mars no matter where we are in the orbit when we look at the planet.”
The orbit will take the probe fairly close to parallel with the Martian equator, which will enable the spacecraft to capture data at different times of day on the planet. And the fact that it’s an elliptical, or oval-shaped, orbit means that observations will be captured close to as well as distant from Mars.
“It can observe many geographic regions at a single time of day when the whole probe gets close to Mars and speeds up, and it can match the speed at which Mars is spinning on its axis,” Brain said. “It can hover above a single geographic region like the big volcano, Olympus Mons, and study the atmosphere there at many times of day.”
Every nine days of the mission, the probe will have completely captured a picture of the Martian atmosphere.
“We will have observed every geographic region at every time of day, every nine days,” Brain said.