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Following the tremendous success of the previous NASA rover missions on Mars,
like Sojourner, Spirit, Opportunity and Curiosity, there is still one tantalising question to answer.
Was there life on Mars? According to these Mars missions, there is plenty of evidence that Mars
was once a world with a thick atmosphere and large bodies of liquid water on its surface.
It was a place conducive to life as we know it, however none of NASA’s prior missions came
equipped to actually detect microbial life. But NASA has big ambitions for Perseverance.
I’m Alex McColgan, and you’re watching Astrum, and in this first episode of the Perseverance
rover series, we will look into the goals of the mission, what exactly it’s equipped with,
and have a detailed look into one of the most impressive landings on Mars yet.
By the end of this episode, I really hope I can earn your like and subscription.
Perseverance launched on the 30th July 2020 on an Atlas V rocket. There was a great launch
window around this time, where Earth and Mars were aligned just right for a quick rendezvous.
In fact, China and the UAE also launched a rover and a probe respectively during the same launch
window. The cruise took seven months, and checks on the systems showed that Perseverance was in
good shape for the atmospheric entry. Landing is the most nerve-racking part of the whole journey,
the extremes in temperatures and speed involved make it very dangerous.
NASA have had a lot of practice at it though and seem to be getting better and better every time.
NASA have this cool visualisation on their website that I want to show you, because I
want you to appreciate that landing a car sized rover on another planet is no mean feat. First,
about 4000km from the landing site and travelling over 16,000km/h, the cruise stage is detached,
and thrusters are used to stop the craft from spinning. At an altitude of 120km, the craft
has sped up to over 19,000km/h, but it’s here that the Martian atmosphere begins slowing Perseverance
down. Due to turbulence in the atmosphere, thrusters are being used to keep the spacecraft
steady and to keep this heatshield facing forward, as friction from the atmosphere is heating the
shield up to over 1,300°C. Computers onboard are autonomously monitoring its position, keeping it
aimed at its final landing goal. At 60km up, and 16km from the target, the atmosphere has slowed
Perseverance down to 3000km/h. Now this is where things start to get interesting, as the spacecraft
was fitted with a number of video cameras, giving us an unprecedented view of the landing sequence.
First, the huge 21 metre parachute was deployed. You may notice the odd pattern in red and white.
This is useful for scientists to be able to see the orientation of the parachute,
but there’s also a code hidden in there, “Dare Mighty Things”, the NASA Jet Propulsion
Laboratory motto, written in binary code, with the GPS location of JPL on the outside.
At 10km up, and having slowed down to 600km/h, the heat shield is released,
reducing the weight, and exposing Perseverance to the Martian atmosphere for the first time.
At around 4km up, the spacecraft begins imaging the surface to search for a safe place to land.
At 2 km up, once it’s happy with a landing spot, the upper casing of the spacecraft separates,
leaving just Perseverance and the rocket propelled descent stage. Rockets are
necessary as the parachute can’t slow the fall anymore, Mars’ atmosphere is simply too thin.
The rocket stage slows the fall from 300km/h to zero, and it hovers 20m above the surface.
The rover itself is then lowered using cabling, suspended by what is known as the sky crane. Once
it’s safely on the ground, the rocket stage sky crane cuts loose to crash a safe distance away.
How amazing is that? And actually being able to really see it is incredible.
So, Perseverance has landed safely. What will it be doing on Mars?
Perseverance is NASA’s most ambitious rover yet. To give you a sense of scale, the thing is
massive, NASA have basically sent a car to Mars. You may notice though that its looks are heavily
based on its famous predecessor, Curiosity. While it may appear almost identical, there have been
some major improvements of the design based on what didn’t work so well on Curiosity. One
noticeable difference is the wheels. Curiosity’s wheels have shown some serious wear so far,
so Perseverance’s wheels are thicker and more durable. They are also less wide but
have a larger diameter. Another improvement is its robotic arm, which is longer and stronger
than the one on Curiosity. But the most notable differences are unsurprisingly
the scientific instruments onboard. Because while Curiosity was designed to investigate whether Mars
was once a place conducive to life, Perseverance is looking for actual evidence of fossilised life.
The first step for it will be to find compelling rocks,
and it has an advanced suite of instruments to help it do just that. On the mast is a powerful
camera, called the SuperCam, which uses a laser to identify the composition of rocks.
The camera itself takes a photo to visually identify what the laser is pointing at,
so it’s not actually this camera that takes the impressive panoramas you’ll see later.
However, this instrument is really important, it can analyse a rock from several metres away,
which means the rover itself doesn’t need to move within arm’s reach of a rock it wants to identify,
allowing it to move on to a new region quicker. The 3D panorama cameras are also located in the
mast, and they can zoom, focus and take video. Once intriguing rocks have been identified with
the cameras, Perseverance can move in closer and examine them with the spectrometers in its arm.
There are also two cameras in the arm. A normal colour camera, called Watson, and another laser
camera which can also take microscopic images called Sherloc. Interestingly, I found these
images in the raw files of the cameras, and upon investigation it turns out they brought
this along to test the cameras are focusing well, and that the laser reads the material correctly.
There are various materials on the rover including spacesuit fabric, and some with Sherlock Holmes
easter eggs. For example, this has a maze on it with a tiny Sherlock Holmes image in the middle.
And this rock sample has 221B Baker written on it, the famous address in the books. Apparently,
one of these rock cross-sections is actually from a suspected Mars meteorite. If true, it
would be the first known instance of a rock from Mars doing a full round trip to Earth and back.
Another of the instruments is basically a weather station,
an instrument that will keep track of the wind, temperature, humidity, pressure, and dust levels.
Towards the back of the rover, there is a ground penetrating radar instrument,
which will be used to see the geologic features under the surface. And there is also a rather
special experiment module that will be used to see if oxygen can be extracted from the
Martian atmosphere, a crucial necessity for the survival of future human colonies.
The last experiment on board relates to Perseverance’s primary objective,
finding compelling rocks that may host microbial fossils. Once the cameras and spectrometers have
identified promising candidates, the arm is equipped with a drill that can either
abrade the top layers of a rock, to expose the un-weathered surface beneath, or if the
mission team wants to extract a sample from the rock, the drill can also core out a chunk.
The arm will feed the sample through to the body of the rover, where a second arm will move the
core to a place where it is sealed and then a place where it gets stored in one of 20 caches
that will be onboard. Interestingly, although Perseverance was cleaned as much as was possible
before launch to avoid contaminating Mars and also these samples, even tiny traces of gasses
from the rover itself could skew readings. To combat this, there are also some witness tubes
that are preloaded with witness materials that can capture molecular and particulate contaminants.
Each witness tube will be opened on Mars to capture the ambient environment.
They will then be sealed like the normal sample tubes. Comparing the witness tubes with the
cached samples will allow scientists to know what the contaminants are and eliminate them.
But sadly, Perseverance will not be able to confirm the existence of microbial life by itself,
it is actually designed as a forerunner mission. Once Perseverance has filled all the caches,
it will place them on the ground for another mission to pick up. NASA wants this to be a sample
return mission, however the means of collecting these samples has not been finalised yet.
A launch is currently slated for 2026, using a little Opportunity sized rover to pick up the
samples and deliver them to a rocket, where this rocket will rendezvous with an orbiter, which will
make the journey back to Earth, with the samples in our hands come 2028. It’s a very complicated
system, so let’s hope the mission teams will really get everything right in the coming years.
So how can we make such bold claims about the habitability of Mars?
Well, it is thanks to the forerunner missions of the previous rovers, including Curiosity. If you
want to see how Curiosity’s instruments differ from Perseverance’s, there is an informative
documentary you can watch called the “Voyage of Curiosity”, which is available on MagellanTV.
It goes into detail about how these instruments determined that water was once present on Mars,
and talks about what Curiosity did and saw on the planet’s surface.
MagellanTV is a subscription service that has the richest and most varied Science content available
anywhere with over 3000 documentaries to choose from, including a lot more about
space. If you want to check out the Curiosity rover documentary, you can use my link in the
description to give yourself a one-month free trial, so I highly recommend checking it out!
So, there we have it, almost everything you could want to know about Perseverance’s landing and
mission objective. I was going to talk about its first month on Mars in this episode too,
but I just couldn’t skip over the landing and what makes this rover so unique and special,
so I will have to save the first month for next episode. If you want to follow
the journey of Perseverance with me, be sure to subscribe so you don’t miss out.
Thanks for watching! If this kind of video was your cup of tea,
then you’ll probably enjoy this video about what the Opportunity rover did during its mission too.
Thanks as always to my patrons and members for supporting the channel,
it really goes a long way, with a special thanks this month to Townys 85 for donating $50,
I really appreciate it, thank you. If you too want to have a shoutout or have your
name added to this list, check the links in the description. All the best, and see you next time.