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