The UAE's Hope Probe is well on its way to enter the Red Planet’s orbit at about 7.42pm local time on February 9. And it will be a nail-biting moment for the engineers at the Mohammed Bin Rashid Space Centre (MBRSC), where all eyes will be riveted to the multitude of large displays spanning the ground station in Dubai.
The upcoming milestone will mark one of the most crucial phases of the mission since its launch from Japan's Tanegashima Island on July 20 last year. A complex manoeuvre, the Mars Orbit Insertion (MOI) will see the 1,350 kg mass spacecraft (think the size of an SUV!) rapidly decelerate to enter a stable orbit with the Red Planet.
With less than eight days to go, Khaleej Times got a sneak peek into the control rooms at the space centre — and how the team is gearing up for what is set to be another milestone in the Emirates Mars Mission project.
Why is MOI critical?
Elaborating on the difficulty of the upcoming manoeuvre, Mohsen Mohammed Al Awadi, System Engineer Lead, said, “During MOI, the six main thrusters will burn almost half of the fuel onboard the spacecraft. When the spacecraft was fully fuelled, it was 800kg. We have been using fuel for trajectory manoeuvre correction. Besides that, we did not use much. Of whatever fuel is left — assuming it is around 750kg now — half will be used just for braking during MOI.”
The capture orbit should be more than 300km from the planet, he explained. "It will take the Hope Probe as close as 1,000 km above Mars’ surface and as far as 49,380 km away from it. It will be changing the orbit in the first 30 days after the MOI phase and then the spacecraft will enter the Science Orbit.”
All live commands were stopped a month before the scheduled orbit insertion on January 9. The only commands being sent now are no-operation commands. “We don’t want to do anything that might cause issues to the spacecraft," Al Awadi explained. "We don’t want to risk anything because this is one of the most critical phases. We stopped sending any sequences that are unnecessary. So far, nothing has come up and the status seems good.”
He added, “Today, for example, we sent a command to the spacecraft — but it’s not to command the spacecraft to do anything; it’s actually commanding the spacecraft to do nothing. It was a way for us to confirm that we are still able to communicate with the spacecraft.”
Engineers explained that contact with the Hope probe was limited to an average of 8 hours, twice a week, in the run up to February 9.
Zakarayya Hussain Al Shamshi, Deputy Project Manager, Mission Operation, said, “So far, our calibrations show that the spacecraft is moving in the right direction. The spacecraft will slow down from the cruising speed of 121,000 km/h to something nearer to 18,000 km/h to achieve MOI. The problem with MOI is that the calculation that we have put is best to our own knowledge. If it's going too fast, the spacecraft will not be captured by the Martian orbit and if it’s too slow, it will crash into Mars. But there is a margin there as well. If there was live commanding, one could have gone ahead and fixed it, but there is no scope for that over here.”
The Emirates Mars Mission, known as the Hope Probe, will go into orbit around Mars on February 9. https://t.co/hGOLzrEnMK— CNN (@CNN) February 2, 2021
Tense moment for all
Contact with the Probe will be temporarily lost as the spacecraft gets eclipsed by Mars during occultation. There is a time lag of 11 minutes before the first telemetry is received from the satellite.
Scientists note there is always a 50 per cent chance of it not being successful because, despite thorough checks, there are so many unknown factors at play.
“It takes radio signals 11 to 22 minutes to travel from Hope around Mars to the ground network on Earth — hence, the need for autonomy. We rely completely on programmed manoeuvres set into the orbiter to accomplish this. Therefore, it will also be a tense blackout period for all of us,” added Al Shamshi.
All commands have been tested on a model satellite on ground — called a flatsat — to gauge reactions.
Inside the spacecraft, a sequence application will start executing commands according to the design, four hours before MOI.
Ibrahim Abdulla Al Midfa, Flight Software Lead, opined, “It’s the first time we will be firing for almost 30 minutes to de-accelerate. That’s why it is risky and time is a critical factor. We still don’t know if this amount of firing will be successful or not, but we are pretty confident about our designs and our systems. It’s a braking mechanism. We have all the contingencies built into the spacecraft and have prepared for different scenarios.”
What happens afterwards
Nasa’s Deep Space Network radio antenna in Madrid, Spain, which is MBRSC’s service provider, will get the nascent signals to know if the orbit insertion is successful.
After spending 40 hours in the capture orbit, Hope Probe will enter into the science orbit, where it will spend two years studying the planet’s upper and lower atmosphere.
The probe will gather and send back 1,000 GB of new Mars data to the Science Data Center in the UAE via different ground stations spread around the world.
Khalid Badri, instrument science engineer, explained, “The scientific instruments like the infrared spectrometer, exploration imager and ultraviolet spectrometer will be tested. Once it is in the science orbit, all the data that will be received by the instruments will be downlinked and the science team will analyse it.’
He added, “We have two to three downlink periods for 6-8 hours per week. During that time, the data will be downlinked, processed through the pipeline and then given for analysis."
There will be no embargo period when sharing the data with the general public, he said. "That's because one of the main missions is to help the science community around the world. Everyone is excited to see new and unique data from Mars. This is the first mission that will actually give a global, diurnal and seasonal data set for the Red Planet. We will also provide exciting visualisation tools that will help people see and understand things about the Red Planet simply by looking at different graphs.”
This article has been adapted from its original source.
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