Another “seven minutes of terror” - this time for China’s Mars rover Zhurong

The entry, descent, and landing phase of a Mars mission takes seven minutes, which is quicker than radio signals can reach Earth from Mars for communication. The process needs to be autonomous and much can go wrong. About half of humanity’s previous missions to Mars have failed.

Those at mission control in China could do nothing but wait during the nail-biting descent. The radio signals finally arrived, and China’s state media confirmed Zhurong - meaning “fire god” - had safely made it to the surface intact at eighteen minutes past midnight (British Summer Time/UTC+1) .

China’s first Mars rover is named Zhurong (“fire god”) Credit: CNSA

Zhurong is packed with a suite of six scientific instruments to study the topography, geology, and atmosphere in the area. There’s nothing groundbreaking, but the China National Space Administration (CNSA) is rapidly catching up with NASA when it comes to space exploration. They’ve got a challenging program for the Moon, having already successfully landed two lunar rovers. Competition is usually a healthy motivator to do better, quicker. NASA - albeit successful - have dragged their heels for far too long since the Apollo missions, taking safe mini-steps forward. They’re an institution excessively concerned with preserving their reputation and funding.

Curiosity rover approaching Mars (artist’s concept) Credit: NASA/JPL-Caltech

NASA’s first rover, Sojourner, rolled off the Mars Pathfinder lander in 1997. It was small, not much bigger than a wheel of the later Curiosity and Perseverance rovers. Sojourner never ventured more than 40ft or 12m away from its lander. The twin rovers Spirit and Opportunity touched down three weeks apart on opposite sides of Mars in 2004. They confirmed liquid water once flowed across the Martian surface. Opportunity drove 28 miles or 45km - the furthest of any rover to date.

Two of Curiosity’s wheels, showing wear and tear Credit: NASA/JPL-Caltech/MSSS

Curiosity descended into the Gale Crater on 6th August 2012. It’s the size of an SUV car. Curiosity’s wheels are amazing, well engineered, but have suffered wear and tear whilst moving over the rough Martian surface. To date, the rover has explored along a route of 15.5 miles or 25 km.

Data collected from Curiosity has shown that ancient Mars likely had the right chemistry to support living microbes. Drilling into Martian rocks, the rover has discovered what are believed to be the key ingredients for life - carbon, hydrogen, oxygen, phosphorus, and sulfur. Curiosity has also found a tiny background level of methane in the atmosphere, detecting (so far) puzzling spikes of ten to twenty times higher on a few occasions.

Perseverance rover, with Ingenuity below (artist’s concept) Credit: NASA/JPL-Caltech

Perseverance - nicknamed “Percy” - landed in the Jezero Crater on 18th February this year. This is another six-wheeled, car-sized rover. One of NASA’s mission aims - at long last - is to search for past life on Mars. Public interest has so far focused on Ingenuity (or “Ginny”), a small robotic helicopter. Ginny has made five very short flights, mere technical demonstrations, in keeping with NASA’s one tiny step at a time mentality.

As we’re a British organisation, this is a good opportunity to remember the planetary scientist Colin Pillinger (1943-2014). He was a courageous maverick, best known as the force behind Beagle 2. Pillinger gave new meaning to the phrase “book launch” when he literally launched several copies of My Life on Mars: (The Beagle 2 Diaries) high up into the sky inside a small rocket, before then signing the books after touchdown in situ. Great British eccentricity, which typified the fresh thinking approach of this unusual and inspiring scientist - who was fond of saying "The only thing that increases in value, if you share it, is knowledge".

Colin Pillinger’s first job was with NASA, surprisingly. By the time he spearheaded the Beagle 2 project - which was a Mars lander, not a rover, but what the hell! - he was critical of NASA’s seemingly reluctant approach to hunt for possible life on Mars, past or present. “Unlike their robots, Beagle 2 won’t be going sightseeing. It is intent on discovering where there is or was life on Mars.” Throughout the project, Pillinger was everywhere, doing anything required to fight bureaucracy and lethargy to get Beagle 2 into space.

Beagle 2 landed on Christmas Day 2003, with much eager anticipation in the UK, but was presumed a failure after no communications were received. Months afterwards, Pillinger was pushing for a Beagle 3, later saying: "If we'd turned around immediately and said we'll give it another shot, we could have men on their way to Mars by now. It's not that the money isn't there. It's the will that seems to be absent." It was only in 2015 - shortly after his death, following a fight against multiple sclerosis - that pictures from the Mars Reconnaissance Orbiter seemed to show Beagle 2 safe on the ground, but with two of its four solar panels still folded up – unable to communicate with Earth.

Colin Pillinger - the courageous maverick Credit: Mike Peel/Jodrell Bank Centre for Astrophysics

Colin Pillinger would have been amongst the first to encourage the next generation of scientists to be daring and outspoken. Contrary to what some may think, this challenging mentality is not at odds with the rigour of the scientific method. The two, together, form a stronger bond and driving force for quicker progress. Pillinger’s attitude is summed up by this quote: “A little set back like a lost lander should not discourage visionaries.”

Written by Cal Stewart, 15th May 2021