After hurtling hundreds of millions of kilometres through space since the middle of last year, three robotic explorers are ready to hit the brakes at Mars.

After hurtling hundreds of millions of kilometres through space since the middle of last year, three robotic explorers are ready to hit the brakes at Mars.
The stakes and anxiety are sky high.
This illustration provided by NASA depicts the Mars 2020 spacecraft carrying the Perseverance rover as it approaches Mars.
The United Arab Emirates orbiter reaches Mars on Wednesday, followed less than 24 hours later by Chinas orbiter-rover combo.
Nasas rover, the cosmic caboose, will arrive on the scene a week later, on February 18, to collect rocks for return to Earth a key step in determining whether life ever existed at Mars.
Both the UAE and China are newcomers at Mars, where more than half of Earths emissaries have failed. Chinas first Mars mission, a joint effort with Russia in 2011, never made it past Earths orbit.
We are quite excited as engineers and scientists, at the same time quite stressed and happy, worried, scared, said Omran Sharaf, project manager for the UAE.
The launch of the “Amal” or “Hope” space probe at the Mohammed bin Rashid Space Centre in Dubai, United Arab Emirates. The orbiter is scheduled to reach Mars on Wednesday.
All three spacecraft rocketed away within days of one another last July, during an Earth-to-Mars launch window that occurs only every two years. Thats why their arrivals are also close together.
Called Amal, or Hope in Arabic, the Gulf nation’s spacecraft is seeking an especially high orbit 22,000 kilometres to 44,000km all the better to monitor the Martian weather.
China’s duo called Tianwen-1, or Quest for Heavenly Truth will remain paired in orbit until May, when the rover separates to descend to the dusty surface. If all goes well, it will be only the second country to land successfully on the red planet.
The US rover Perseverance, by contrast, will dive in straight away for a harrowing sky-crane touchdown similar to the Curiosity rovers grand Martian entrance in 2012.
An illustration of the Perseverance rover firing up its descent stage engines as it nears the Martian surface.
The odds are in Nasas favour: Its nailed eight of its nine attempted Mars landings.
Despite their differences the 1-ton Perseverance is larger and more elaborate than the Tianwen-1 rover both will prowl for signs of ancient microscopic life.
Perseverances NZ$4 billion mission is the first leg in a US-European effort to bring Mars samples to Earth in the next decade.
To say were pumped about it, well that would be a huge understatement, said Lori Glaze, Nasas planetary science director.
Perseverance is aiming for an ancient river delta that seems a logical spot for once harbouring life. This landing zone in Jezero Crater is so treacherous that Nasa nixed it for Curiosity, but so tantalising that scientists are keen to get hold of its rocks.
This image made available by the China National Space Administration shows the Tianwen-1 probe en route to Mars.
When the scientists take a look at a site like Jezero Crater, they see the promise, right? said Al Chen, whos in charge of the entry, descent and landing team at Nasas Jet Propulsion Laboratory in Pasadena, California. When I look at Jezero, I see danger. Theres danger everywhere.
Steep cliffs, deep pits and fields of rocks could cripple or doom Perseverance, following its seven-minute atmospheric plunge.
With an 11½-minute communication lag each way, the rover will be on its own, unable to rely on flight controllers. Amal and Tianwen-1 will also need to operate autonomously while manoeuvring into orbit.
Until Perseverance, Nasa sought out flat, boring terrain on which to land one giant parking lot, Chen said. That’s what China’s Tianwen-1 rover will be shooting for in Mars’ Utopia Planitia.
Nasa engineers watch the first driving test for the Mars 2020 rover, later named “Perseverance,” in a clean room at the Jet Propulsion Laboratory in Pasadena.
Nasa is upping its game thanks to new navigation technology designed to guide the rover to a safe spot. The spacecraft also has a slew of cameras and microphones to capture the sights and sounds of descent and landing, a Martian first.
Faster than previous Mars vehicles but still moving at a glacial pace, the six-wheeled Perseverance will drive across Jezero, collecting core samples of the most enticing rocks and gravel. The rover will set the samples aside for retrieval by a fetch rover launching in 2026.
Under an elaborate plan still being worked out by Nasa and the European Space Agency, the geologic treasure would arrive on Earth in the early 2030s. Scientists contend its the only way to ascertain whether life flourished on a wet, watery Mars 3 billion to 4 billion years ago.
Nasas science mission chief, Thomas Zurbuchen, considers it one of the hardest things ever done by humanity and certainly in space science.
The United Arab Emirates’ Hope Mars probe. (Alexander McNabb/MBRSC via AP)
The US is still the only country to successfully land on Mars, beginning with the 1976 Vikings. Two spacecraft are still active on the surface: Curiosity and InSight.
Smashed Russian and European spacecraft litter the Martian landscape, meanwhile, along with Nasas failed Mars Polar Lander from 1999.
Getting into orbit around Mars is less complicated, but still no easy matter, with about a dozen spacecraft falling short. Mars fly-bys were the rage in the 1960s and most failed; Nasas Mariner 4 was the first to succeed in 1965.
Six spacecraft currently are operating around Mars: three from the US, two from Europe and one from India. The UAE hopes to make it seven with its NZ$278-plus million mission.
The UAE is especially proud that Amal was designed and built by its own citizens, who partnered with the University of Colorado at Boulder and other US institutions, not simply purchased from abroad. Its arrival at Mars coincides with this years 50th anniversary of the countrys founding.
A lander is lifted during a test of hovering, obstacle avoidance and deceleration capabilities of a Mars lander at a facility in Huailai in China’s Hebei province.
Starting off the year with this milestone is something very important for the people of the UAE, said Sharaf.
China hasn’t divulged much in advance. Even the spacecraft’s exact arrival time on Thursday has yet to be announced.
The China Academy of Space Technology’s Ye Peijian noted that Tianwen-1 has three objectives: orbiting the planet, landing and releasing the rover. If successful, he said in a statement it will become the world’s first Mars expedition accomplishing all three goals with one probe.
The coronavirus pandemic has complicated each step of each spacecrafts 480 million kilometre journey to Mars. It even kept the European and Russian space agencies’ joint Mars mission grounded until the next launch window in 2022.
An image from Nasa depicts a possible area through which the Mars 2020 Perseverance rover could traverse across Jezero Crater.
The flight control rooms will contain fewer people on the big day, with staff spread over a wider area and working from home. Desks have dividers and partitions. Masks and social distancing are mandatory.
Perseverance’s deputy project manager Matt Wallace, whos working his fifth Mars rover mission, said the pandemic wont dampen the mood come landing day.
I dont think Covids going to be able to stop us from jumping up and down, and fist-bumping, he said. Youre going to see a lot of happy people no matter what, once we get this thing on the surface safely.