Last week, the latest NASA mission to Mars, the Mars 2020 Perseverance Rover, launched successfully from the Kennedy Space Center, Florida. Over the next 7 months, the rover will make its way to the Red Planet. It will land in Jezero crater on 18th February 2021. The mission is known as Mars 2020, due to the fact the mission would make use of the 2020 launch window to Mars. Every 26 months, there is a launch window that allows for the shortest possible travel time to Mars. This year, there are 3 missions making use of this window, Mars 2020 (USA), Tianwen-1 (China) and Hope Orbiter (UAE). ESA and Roscomos had also hoped to send the Rosalind Frankin rover but it has been delayed due to issues with parachutes and COVID-19. The rover was named Perseverance by Alexander Mather, after a competition where the public could submit suggestions.
The objectives of the mission are look for signs of past and present life on Mars. It will look to find bio-signature of past life in the rock on Mars. The mission will also aim to collect soil and rock cores, storing them in tubes which will eventually be picked up by a sample return mission and returned to Earth. These will be analysed in labs here on Earth, which have much better equipment than we can send on a rover. As well as collecting samples and looking for signs of past life the rover has a number of technology demonstrations which will aid future missions, both robotic and manned.
One of the technology demonstrations is called Ingenuity and is a small helicopter. This will be the first time that an aircraft will fly on another planet. The plan is that a helicopter such as Ingenuity could allow Perseverance and future missions to scout potential driving routes from the air. Another technology demonstration is called the Mars Oxygen ISRU Experiment (MOXIE). This experiment will attempt to convert a small amount of CO2 from the Martian atmosphere to Oxygen. This is something that will be vital to future human exploration of Mars. We won’t be able to carry all of the resources needed for a long duration stay on Mars so utilizing resources that are already available will be very important.
The instruments onboard Perseverance are;
- Mastcam-Z – Panoramic cameras for navigation, imaging and studying geological features.
- MEDA – Weather station that will track martian weather including dust and clouds.
- PIXL – X-ray spectrometer which will be used to find the chemical composition of rocks on the surface.
- RIMFAX – Ground penetrating radar that will allow the rover see the layers beneath the surface.
- SHERLOC – Ultraviolet spectrometer and microscopic camera. It will help identify rocks with organics so they can be collected for the sample return misson.
- SuperCam – Laser micro camera which zaps the rock with a laser so it can determine it’s chemistry from the resulting plasma.
In addition to the instruments, Perseverance carries 23 cameras to record the mission, aid in navigation and collect science data. This will be the first time we will have HD footage of a landing on Mars by way of cameras aboard the descent stage. The rover also has a microphone and will be the first spacecraft to record audio from the surface of Mars.
Mars 2020 launched on an Atlas V rocket from the Kennedy Space Center in Florida on 30th July 2020. It is currently in the cruise stage of its journey to the Red Planet. During this stage, the rover is housed inside a protective cover called the aeroshell. This is attached to the cruise stage which will power and guide the spacecraft on its journey. In the image below, you can see the cruise stage at the top, suspended by cables and the white aeroshell below.
The journey to Mars 2020 takes 7 months and the landing is scheduled to take place on 21st February 2021. The landing on Mars is one of the most risky parts of the mission. The landing sequence is as follows;
- 10 mins before the spacecraft reaches the atmosphere, the cruise stage will separate.
- The spacecraft, with the heat shield to the front, enters the atmosphere. The friction from the atmosphere will cause the heat shield to heat to 2100 degrees C, while slowing the spacecraft down.
- 11 km above the ground the parachute will deploy, slowing the spacecraft further.
- 8 km above the ground, the heat shield drops off as it is no longer needed. This exposes the radar equipment so that the spacecraft can calculate its speed and altitude.
- 80 seconds later the the rover and decent stage releases from the aeroshell and parachute. The rover will then free fall for a few seconds.
- 8 retro rockets then fire to show the fall of the rover. These rockets slow the descent of the rocket to 2.7 km per hour.
- About 7.5 metres above the ground, the rover will be lowered by cables from the descent stage.
- Once the wheels of the rover touch the surface, the rover will send a signal through the umbilical cable back to the descent stage. Once this is received the cables are cut and the descent stage will fly off to a crash landing site some distance away.
You can see an animation of the decent stage here. https://mars.nasa.gov/mars2020/timeline/landing/
Mars 2020 also carried on board 3 silicone chips that were etched with nearly 11 million names of people from around the world who submitted their name to be sent to Mars. Mars 2020 launched during the COVID-19 pandemic and the mission team attached a small plaque to honor the healthcare staff working during the pandemic.
Paul Smith 