it's the moment we've all been waiting for the final countdown for nasa's perseverance rover to
land on the red planet but it isn't alone the united arab emirates hope orbiter and china's
tien1 mission have already arrived at mars orbit and it's been seven months since they took off
but for mars 2020 and tien when one one of the hardest parts is still yet to come
actually sticking the landing on the red planet fondly known as the seven minutes of terror
it takes about seven minutes from the time that the spacecraft first comes in contact with mars
of atmosphere until we get down to the ground and the terror part comes in um because you know
all of that stuff is difficult there are so many things that can go wrong as you're landing on mars
this part of the mission is known as the entry descent and landing or edl and it all starts
with the spacecraft hurtling through the martian atmosphere at roughly 20 000 kilometers per hour
causing the external heat shield to heat up to around 1300 degrees celsius with some help from
its heat shield the vehicle slows down to about 1600 kilometers per hour and this is when its
supersonic parachute deploys the heat shield then pops off but the parachute doesn't slow the rover
down enough for a safe landing the main reason for this is because of mars thin atmosphere it's about
one percent as dense as earth's atmosphere but not enough to really help you a lot once we end
up deploying our parachute to help us land safely the atmosphere doesn't actually slow us down that
much and so we end up having to get rid of that parachute and come down the rest of the way
using rockets these eight retro rockets located on the descent stage help to slow down the craft the
vehicle then performs a divert maneuver to avoid coming into contact with the discarded parachute
and finally about 20 meters from the surface the descent stage lowers the rover using cables
where perseverance unlocks its legs and wheels for the final touchdown and so all of this just adds
to the complicated nature of the systems that we need to build to get us safely down to the ground
and one of the many crucial parts of this system is the terrain relative navigation or playfully
referred to by the team as the spacecraft's eyes this will be the first time that a nasa
rover will be able to actually see where it's landing its onboard camera will snap pictures
of the surface's features to match them to its onboard map and divert its course to pick the
best possible landing zone so now you know we can reach that spot with an accuracy of about 30 to
40 meters and it really opens up the door to the planetary scientists to pick really interesting
spots to land is it that the geologists tend to like interesting rough spots on mars
and those tend to be dangerous to land in if successful perseverance will be the fifth
nasa rover to safely reach the martian surface but it's up against some pretty
tough odds as only forty percent of all missions sent to mars have been successful
hoping to also beat those odds is china's tienwen1 spacecraft it recently just entered mars orbit on
february 10th and it's quite an ambitious first attempt to reach the planet since the mission is
composed of three parts an orbiter a lander and a rover the orbiter has already started imaging
the future landing locations for its lander and rover which will eventually descend to the surface
this anticipated landing won't happen until may and last but not least there's the uae's
first ever interplanetary probe called hope which arrived on february 9th this starts
a roughly two-year journey to capture the most complete picture of the red planet's atmosphere
it hopes to answer some crucial questions like how exactly gases escaped the atmosphere
a question that has long since puzzled scientists this is a thrilling time in mars exploration we
only have this opportunity every so often and so when we get a chance we like to take advantage of
it and this moment is historic in itself with the arrival of three separate missions to mars within
the span of just a couple weeks and for the mars 2020 team it'll be a bit of a nail-biter until
february 18th when perseverance begins its final descent to the surface so you can better believe
that i'm going to be gripping my desk on february 18th and crossing my fingers that everything goes
just as we planned it and as we tested it so i'm very excited for more countdown to launch check
out this playlist here if there's another launch that you want to see us cover let us know in the
comments make sure to subscribe and thank you so much for watching i'll see you next time you