How does SpaceX’s Dragon get back to Earth from Orbit? How exactly it re-enters and lands!

hi it's me tim dodd the everyday astronaut for the first time in history two humans will return from space riding a spacex vehicle it's time that astronauts bob benkin and doug hurley return home after about two months on the international space station so how exactly do you re-enter from space do you just pump the space breaks and then just fall out of the sky and and re-enter back to earth well not quite there's actually a lot of really fun physics involved in deorbiting and today we're going to do a summary of how you deorbit go over all the hardware that allows the crew dragon capsule well and frankly almost any spacecraft to re-enter safely splash down we'll go over the sequences of events and even the exact conditions that need to be met in order to allow for a safe re-entry okay let's get started i'm assuming you all remember when history was made on may 30th 2020 when dm2 or demonstration mission 2 took off from nasa's kennedy space center it was the first time that humans have launched into orbit from u.s soil since the retirement of the space shuttle in 2011. they rode on spacex's awesome falcon 9 rocket and sat inside the brand new crew dragon capsule that bob and doug ended up naming endeavour now this was a nod to the space shuttle endeavour which was the name of the orbiter that just so happened to take each of them to space for their very first flights but on separate missions now this video is intended to be a general overview of deorbiting re-entry and landing and it's kind of for pretty much all vehicles but it is a little bit more tailor-made specifically for spacex's crew dragon capsule since this will be the first time humans will return from space in this particular vehicle and it's the first time a crude mission has done a splashdown or a water landing since 1976. you might think now hold on a second the last spacecraft that did a splashdown instead of landing on land was the apollo capsule and the last mission with an apollo capsule was the apollo soyuz mission in july 1975. so why was there a splashdown with humans in 1976 well long story short soyuz 23 accidentally landed in one of the only large bodies of water in kazakhstan and although the soyuz spacecraft is designed to handle water landings the crew barely escaped because of some absolutely wild circumstances you guys know i love going to tangent towns but since this story is way off topic already and we're just at the beginning of the video may i suggest watching scott manley's video on soyuz 23 because it's a really really good story alright let's get the timestamps up on screen for this video like always we have timestamps in the description below we also have the play bar on youtube divided up into the sections and there's also an article version of this video as well which has some sources [Music] okay let's talk about the dragon timeline from undocking to splashdown now again this video is going to have some generic reentry things that are kind of applicable to basically every spacecraft but we're using the crew dragon timeline now to highlight and focus on since it's brand new and exciting now again other vehicles will have their own specific timelines and considerations but if they're departing from the international space station they'll probably be very very similar to this but as we get into this timeline of events you're going to hear me mention weather and recovery criteria quite a bit so here's what i'm actually talking about you can't have wind any greater than 16.5 kilometers an hour at the splashdown zone wave period and height must not be the same or greater than 7 degree wave slope there has to be less than a 25 probability of rain well specifically a 25 decibel relative to z on the weather radar within the landing area whatever that means lightning can't be within 16 kilometers or greater than a 25 probability of lightning within the landing area the recovery helicopter must pass a start and hover test to confirm operational capability the helicopter is there for a quicker crew transit to shore and or on standby in case there would be a medical emergency which would require the crew to be flown out immediately to shore or in case it needs to be in aid of like additional potential rescue operations as well but even the helicopter has its own criteria so here's the conditions to operate the helicopter there could not be more than four degrees of pitch or roll on the spacex recovery vessel which the helicopter takes off and lands on there are two virtually identical sibling ships named go searcher and go navigator which one services the gulf while the other services the atlantic there must be more than 150 meters of a cloud ceiling and there must be more than 0.8 kilometers of visibility at day and 1.6 kilometers of visibility at night so here's the sequence of events that nasa and spacex will do in order to bring the crew dragon home unfortunately because of huge variables that can change up to just two hours before splashdown we can't really provide exact timing of most of these things but we can at least provide the order and the sequence of events between 24 and 48 hours before departing from the space station spacex and nasa will make a decision to depart based on the status of the primary and alternate splashdown sites there are seven potential sites four in the gulf of mexico and three in the atlantic all surprisingly close to shore with sites ranging between 35 kilometers and about 280 kilometers from shore now these sites are chosen based on weather conditions amount of time between undocking and splashdown based on the orbital mechanics and whether or not the splashdown opportunity would be in daylight or not at six hours before undocking with the international space station nasa and spacex choose a primary splashdown target at 2.5 hours before undocking the teams at spacex and nasa monitor changes to conditions to confirm whether or not to continue with the undocking process if things are looking good the astronauts will suit up strap in and get ready to depart now assuming it's all still go and it's time to undock the crew dragon capsule undocks from the international space station by releasing the hard docking mechanism inside the international docking adapter then there's two very small thruster firings to help separate the spacecraft from the station although the thrusters that are directly facing the station are disabled during this time the crude dragon capsule is now in free flight and eventually gets far enough away from the space station to perform departure burns which get the spacecraft safely away from the space station and into a slightly different orbit they do this regardless of whether or not conditions are currently supported at the landing sites in normal operations the splashdown can occur anywhere from 6 hours to 30 hours from this exact point assuming they aren't in a no-go for landing conditions then several hours later the crude dragon does a phasing burn lasting about six minutes that lines up the orbital path with its targeted splashdown zone these small little thruster firings make a huge difference in the final trajectory when you're traveling at around 28 000 kilometers an hour but if conditions are currently no go at that point the spacecraft will stay in orbit for the next landing attempt which basically delays the entire process 24 to 48 hours but if conditions are above the accepted criteria at five hours before deorbit spacex and nasa will make a decision whether or not to deorbit at 110 minutes before splashdown there is one last final decision whether or not to proceed with the deorbit burn based on the weather conditions so yes there's lots of go no-go poles during this entire process they have to be constantly monitoring the sea and weather states at their target landing zone assuming conditions are still go at the landing site at 56 minutes before splashdown the dragon capsule separates from the dragon trunk because it's in a relatively low orbit the trunk will slowly deorbit from small amounts of atmospheric drag and eventually burn up on re-entry it honestly really really surprises me they jettison the trunk before they do the deorbit burn which leaves the trunk up in orbit substantially longer but it's probably safe to assume that this ensures that the trunk doesn't have any risk of coming in contact with the vehicle after trunk separation the dragon faces nose first or nose prograde for the deorbit burn at around 52 minutes before splashdown the d orbit burn begins which lasts around a whopping 15 minutes it takes that long for those low powered draco thrusters to slow the vehicle down enough to lower its orbit to intersect with a thick enough portion of earth's atmosphere to fully deorbit we'll get more into this process in a minute and i'll show you the physics and mechanics behind all this at around 36 and a half minutes before splashdown the deorbit burn is complete and the spacecraft is now committed to re-entry immediately after the de-orbit burn is complete the dragon capsule closes its nose cone that houses the guidance navigation and control units as well as the docking port and turns around so the heat shield is facing forward from this point on the vehicle slowly experiences more and more atmospheric pressure and the heat shield begins experiencing higher and higher temperatures during the period of reentry due to the plasma buildup around the spacecraft there's six minutes of communication blackout between the ground and the spacecraft during this time the heat shield experiences a maximum temperature of about 1900 degrees celsius and the crew will experience peak g forces of around three or four g's right around four minutes before splashdown after the atmosphere has slowed the vehicle down to about 560 kilometers an hour and at an altitude of around 5500 meters the dragon spacecraft will deploy two drogue parachutes that help orient the vehicle and continue slowing it down to prepare it for main parachute deployment just prior to three minutes before splashdown at an altitude of around 1800 meters and at a speed of roughly 191 kilometers an hour the drogue shoots are cut and the pilot shoots pull the four main parachutes into the windstream around two minutes and 40 seconds before splashdown after roughly 25 seconds of being partially deployed the main chutes will have fully opened up and slow the vehicle down to its touchdown velocity of around six and a half to seven and a half meters per second for the last kilometer of its descent and splashdown at this point the recovery crew rushes out on fast boats and begins crew recovery operations which includes doing a hypergolic gas check checking the integrity of the vehicle and potentially removing the parachutes from the top of the spacecraft like we happen to see on the dm1 splashdown the second fastboat is actually the one in charge of recovering the parachutes from the water within an hour the recovery vessel is to have pulled the dragon capsule out of the water with a large hoist on the back it places crew dragon on a nest and prepares to help the astronauts egress the astronauts will be weak and their bodies won't be used to 1g so they'll be assisted out of the capsule and immediately taken to a medical facility for checkouts right on the deck of the recovery vessel just underneath the helipad now perhaps you're wondering why is it the crew of space shuttle missions could just walk right off the space shuttle and trot down those stairs like it's no big deal well space shuttle missions never lasted more than about two weeks due to limitations in the fuel cell so they really just never got weak enough to be you know totally acclimated to space so it really just wasn't nearly as big of a deal to come back down and experience gravity again at this point the journey home is just a simple boat ride or depending on how far away they are a helicopter ride back to shore welcome home dragon riders this timeline probably brought up a lot of questions like why does it take anywhere from 6 hours to 30 hours to get home how can there be that big of differences when it comes to re-entering and landing on a target when you're traveling at 28 000 kilometers an hour we'll get into that in a second but i think we should do an overview of some of the interesting hardware that makes this journey home possible first and then i'll show you the orbital mechanics and how it all comes together there's really about three main things that are fun to talk about when it comes to re-entry the thrusters that maneuver the vehicle and bring it back home the heat shield that allows the vehicle to survive the punishing reentry conditions and the parachutes that slow descent down to a survivable rate now again i'm going to be specifically talking about spacex's crew dragon capsule because it's topical and fun but there's really very very similar hardware on just about every vehicle that's ever re-entered besides orbiters like the space shuttle and the soviet union's baron those things were just kind of different beasts altogether so starting with the maneuvering thrusters known as the draco thrusters the draco thrusters are the 16 tiny little rocket engines that are visible all around the dragon capsule they run on hypergolic propellants specifically in this case monomethylhydrazine and nitrogen tetroxide or nto mmh this fuel mixture is highly storable and very stable because they can operate at a wide variety of temperatures and won't end up boiling off in the environment of space and they also ignite when they come in contact with each other making them extremely reliable and a simple solution for rocket engines this makes hypergolics the ideal choice for maneuvering thrusters since you really need something reliable and responsive they're highly pressurized stored in relatively small high pressure tanks that allow the thrusters to operate as a simple pressure fed engine so there's no need for elaborate turbo pumps or anything like that draco thrusters and again most thrusters don't throttle so they're either on or they're off so they have to be controlled via extremely precise short little bursts small fractions of a second in duration with some high end thrusters having pulses as short as three hundredths of a second and through these tiny little bursts they can have extremely precise control of a spacecraft because they don't throttle and are controlled via little bursts they're not very powerful in fact the draco thrusters only produce 400 newtons of force so even if four of them are pushing around a nearly empty dragon capsule which weighs about three tons their maximum thrust-to-weight ratio is only about 0.05 to 1. maximum thrust to weight ratio which is about 300 times less thrust of weight than a fully fueled falcon 9 taking off from the launch pad so obviously you don't want to use these little tiny thrusters to try and get off the ground on earth because you're certainly not going to go anywhere but a fun side note the sibling of the draco thrusters the super draco has an extremely high amount of thrust the crew dragon also has eight super draco engines in four pods around the vehicle that function as the abort motors if a problem were to arise either during fuel up on the pad or during ascent the super draco thrusters run on the exact same fuel as the draco thrusters and what's awesome about that is in the need of an abort they obviously have all the fuel necessary but assuming the vehicle doesn't abort there's a very healthy extra margin of fuel on board the spacecraft that can be used for additional maneuvers if for some reason that's necessary now i already have a video that goes really deep into why they have these super draco abort motors how they're used why they went with liquid fuel instead of solid fuel why they're pushers instead of pullers there's a lot of cool info in there so definitely check that video out if you want to know more so here's where you might have two questions about the super draco thrusters why don't they use them to deorbit and can they use them for landing for the deorbit burns they're much less efficient than the draco thrusters since they're optimized for ground operations as opposed to dracos which are more optimized for the vacuum of space but perhaps more importantly is the high thrust makes for a very short and narrow deorbit burn that's not a good thing that long 15 minute burn of the draco thrusters would only be a 5 second burn if he used the super dracos at their maximum thrust so a slow long burn time allows for an extremely high precision maneuver since everything is essentially happening in slow motion compared to the 5 seconds firing of the super dracos which allows for plenty of time to make precise adjustments but you might also be tempted to ask the old could they use the super dracos to land or as a backup if the parachutes wouldn't open physically yes yes they could be used for that purpose and of course that was spacex's original plan for landing was to use the super dracos to land and have the parachutes as a backup now again if you need to know more about why they're not landing with those super draco thrusters i've already made a video about why exactly they canceled that in case you need more homework but as far as using the super draco thrusters as a backup to the parachutes it would be a nightmare to certify them for a very very fringe use case to have to arm the system during the parachutes and then write the software for when they might need to be used if the shoots would happen to fail is just asking for more problems than solutions engineering time would probably be much better spent just making sure the parachutes work and are more reliable than trying to add a loop that enables the super dracos to be used as a backup to the shoots next cool piece or should i say hot piece of technology is the heat shield the heat shield is a relatively simple solution to an extreme problem the problem is when a spacecraft re-enters the atmosphere 10 times faster than a bullet the air can't get out of the way fast enough this causes the air to get compressed and due to the laws of thermal dynamics when a gas is compressed it heats up and as you might know the gas gets heated up so much it actually turns into another state of matter a plasma you may hear its air friction that causes the heat on reentry but it's actually not it's literally just extremely compressed gas and plasma that's stuck between the oncoming airstream and the blunt bottom of the spacecraft and there's actually a boundary layer between that extreme compressed heat and the heat shield itself so very very little heat actually transfers from the bow shock to the heat shield you'll notice most capsules have that same blunt bottom design this is of course very intentional and was a groundbreaking discovery for nasa when designing their first crewed vehicle the mercury capsule and the soviet union came to a similar conclusion by the time they designed their soyuz capsule after moving away from a mostly spherical shape like their previous vehicles the vostok and vosgod this design is not only extremely stable during reentry but by creating a large bow shock it also prevents that hot plasma from attaching to the side walls of the spacecraft and it can help create a survivable deceleration but considering that the giant surface is now experiencing temperatures about half as hot as the surface of the sun how can you possibly make it survive well the solution is so simple you could literally use wood as the heat shield most heat shields including spacex's dragon capsule use an ablative material or material that intentionally flakes away as it heats up and thereby takes some of the heat away with it when it falls off the material spacex uses on the dragon capsule is called pikax pikax is spacex's variant of the nasa designed phenolic impregnated carbon ablator which was designed in the 90s and has been used on mars missions and the orion spacecraft spacex's special formula allows for the same heat shield to be reused up to 10 times before replacement the heat shield along with the thrusters also do one pretty nifty thing together they can precisely steer the spacecraft through re-entry engineers intentionally have the center of mass offset from the middle of the heat shield so the heat shield can actually produce lift and help guide the spacecraft to the splashdown zone by just simply rotating the spacecraft the lifting vector changes so they can turn in one way and have the spacecraft pull up a little bit more out of the atmosphere or they can turn 180 degrees and have the spacecraft dive a little bit deeper down into the atmosphere by controlling this small amount of lift they can be extremely accurate when it comes to hitting the splashdown zone it's also pretty wild to think that a blunt bottom circular heat shield can provide lift so there's one last piece of the puzzle that's perhaps one of the most important pieces after all without the parachutes an otherwise perfectly successful mission would certainly lead to the loss of the spacecraft and the lives on board so the parachutes although they seem like a simple technology have easily been one of the most challenging things to be designed on the crew dragon capsule you'd think something that's been around for so long would be completely solved by now well come to find out nasa and its commercial partners boeing and spacex through testing and certifying the parachute systems for the commercial crew program found new errors and failures that had never been seen before nasa administrator jim bridenstine mentions this in an interview i had with him in 2019 at spacex's headquarters because we have been doing testing we have learned things about safety that we didn't know before we were taking risks with other parachutes that we did not know okay so now because we have done testing we now know what we didn't know before right and so we have to make iterative changes so you're avoiding what could have been catastrophic failures that we just got lucky enough during the apollo era and all that stuff that we're now because of increased testing and increased safety margins we're seeing some of these things making our astronauts safer it took spacex about 100 tests of the parachutes to certify them completely and it took three generations of parachutes to get a safe design the parachutes that finally managed to pass the stringent safety requirements was the mark iii design but the mark iii design itself went through 27 drop tests before is considered safe and ready for human use but because of its huge test campaign spacex now has one of the safest and most reliable parachutes ever made the biggest challenge with parachutes is they have a very narrow window of operation if you're going too fast and try to deploy a shoot the airstream can destroy the canopy or rip the lines or the attachment points of the lines to the canopy and of course if you deploy them too late they deploy too slowly and because you're going so fast you could end up smacking into the ground at an unsurvivable rate spacex started using xylon a unique polymer developed by researchers at stanford university in place of the nylon that was previously used in the parachute lines after all as the shoots initially deploy and as they reef open there can be big shocks and really high loads so the trick to developing a shoe is just one that deploys nice and slowly and smoothly one that doesn't tangle and most importantly one that doesn't fall apart the crew dragon capsule after it deploys its two drug shoots will deploy four main parachutes and has tested parachute out capabilities as the dragon capsule can splash down safely under only three shoots as well this is quite a big change from the dragon one capsule that only had three shoots to begin with but all of these systems have to work in unison if the shape of the capsule were designed wrong it wouldn't slow down enough in the upper atmosphere and its terminal velocity could be much higher making for harsher deployment conditions for the parachutes or less time for them to deploy fully it's the entire system that makes re-entry safe not just any one particular item and it's amazing the thought that has to go into each and every little bit of the vehicle in order to safely come back down from orbit it's time we put all the puzzle pieces together now that you know how the entire system works so let's show you what it actually looks like to get back down from orbit and try and precisely hit a target so let's pull up kerbal space program and show you how to deorbit what phasing is and why there can be such huge discrepancies between splashdown times of targets that are so close to each other a friendly reminder here kerbal space program is of course a wonderful game slash space simulator slash explosion factory but it's not a perfect representation of the real world especially the stock game which has a different planet that's much smaller than earth so although our numbers and stuff won't be accurate when showing you this the physics are similar in kerbal and it's just a great tool to illustrate how all this stuff works so welcome to kerbal space program now i'm not going to bore you here with how exactly i built this ugly turd of a crew dragon capsule but do you know it basically has all the major features of the crew dragon including 16 thrusters a few more powerful thrusters acting like super draco's just for fun two drogue shoots four main shoots and of course a heat shield all right so i pretty much just threw this thing straight into a 100 by 100 kilometer orbit around the equator notice that we're actually looking down from the pole so we're looking straight down and all we're going to do is we're going to try to land at an equatorial landing site so the landing zone is on the equator too we're flying around the equator nice and easy this is about as easy as it gets and all we have to do is we have to start slowing down on the opposite side of the planet from our intended splashdown site the reason you do this is if you slow down somewhere in orbit the opposite side of you will lower if you speed up an orbit the opposite side of you will raise that's how orbits work just nice and easy but what we're going to do is we're going to lower our lowest point or our periapsis into some of the atmosphere so we're going to get it around 50 000 meters in altitude and then that will allow the atmosphere to start slowing the spacecraft down for us so fast forward here a little bit and the atmosphere will actually just start biting away at our speed and slowing us down lowering our orbit and eventually we just get slow enough that we can deploy our parachutes we get low enough that we can deploy our parachutes and if we did things right we'll actually get pretty darn close to our splashdown site now even though i got pretty close and that looked fairly easy in kerbal space program it was really easy when you are doing that on the equator so if your splash downside is on the equator and you're doing an orbit perfectly around the equator you actually get a landing attempt every single time you orbit so on earth it'd be about every single 90 minutes you'd have an attempt at splashing down because it's all lined up it's nice and easy unfortunately though that's not the way this works i actually can't think of a single time it's ever been like that let's use kennedy space center as an example for this since obviously that's kind of near where dm2 is going to be landing is really close to kennedy space center which is at 28.5 degrees north of the equator and the international space station is traveling at 51.6 degrees inclination so that means that orbit's tilted at 51.6 degrees and kennedy space center is 28.5 degrees north of the equator now what this means is the kennedy space center will basically pass underneath the path of the orbit twice a day it'll pass under the orbit once when the orbit's going up from southwest to northeast and then again basically 12 hours later it'll do it again when the orbits going from north west to southeast or going down so this is why there's such a big range of how long it takes to actually hit your target from orbit so the hard thing is you're you're aiming for a moving target and you're a moving target too so it's not as much that you deorbit when you're exactly opposite of the earth either you have to predict or take into account the rotation of the earth so that by the time you get to the opposite side of the earth your splashdown site is lined up with you it's uh it's just it just absolutely blows my mind that nasa and spacex has to do all these little phasing maneuvers to precisely line up their orbits to their landing site or where the landing sites going to be and it all just needs to be perfectly handled because even a tiny little air could put you hundreds of kilometers off target [Music] orbital mechanics are awesome aren't they i love all the stuff that goes into this there's an incredible amount of thought and engineering involved in quite literally every tiny millimeter of a vehicle as well as a lot of science that goes hand in hand with each and every second of reentry it's all the little stuff like this that makes me not only appreciate the work being done today to keep astronauts safe but it especially highlights the skills of the early engineers who figured most of this stuff out in the 1950s it's astonishing so what do you think do you also think all this stuff is astonishing did we answer all your questions about how you actually get back down from orbit or do you have a better understanding now of all the interesting little physics that are involved let me know if you have any other thoughts or questions in the comments below i owe a huge thank you to my patreon supporters for helping make all this stuff possible for helping me take this little hobby and turning it into a career and helping me make this cool new studio space that i think is just super awesome and it's evolving and still getting better and tweaking so you'll see it change a little bit here and there if you want to help me continue to do what i do please consider becoming a patreon supporter where you'll gain access to our scripts and research before videos come out so you can give me your thoughts and opinions and help make the videos better but you can also gain access to our exclusive subreddit our exclusive discord channel which is an incredible community and exclusive live streams as well head on over to patreon.com everydayastronaut and while you're online be sure and check out our awesome merchandise at everydayastronaut.com shop like this f1 t-shirt now of course all of our shirts are totally handmade here in the united states they're not print on demand so they're really premium high quality shirts with custom tags custom instructions and we have new stuff like the new full flow stage combustion cycle hoodie we have new key chains the shop is constantly evolving and changing so you better get in there before supplies run out because all this stuff is limited edition and we don't keep them in there forever so head on over to everydayastronaut.com shop thanks everybody that's gonna do it for me i'm tim dodd the everyday astronaut bringing space down to earth for everyday people

Channel: undefined

Views: 480,003

Rating: 4.9316015 out of 5

Keywords: DM-2 Splashdown, DM-2 De-Orbit, Bob and Doug, SpaceX DM-2, SpaceX Demonstration Mission 2, SpaceX Landing, Crew Dragon Reenter, Crew Dragon landing timeline, Crew Dragon Splashdown Timeline, Bob Behnken, Doug Hurley, How to get back from orbit, how to deorbit, what is orbit, SpaceX crew dragon, Demonstration Mission 2, SpaceX DM2, NASA DM2, How to come back from space, deorbit manuever, heat shield, SpaceX Parachutes, Tim Dodd, Everyday Astronaut, DM-2 landing

Id: ZZ-4xuVeBIE

Length: 31min 58sec (1918 seconds)

Published: Sun Aug 02 2020

Reddit Comments

[u/everydayastronaut]

Hey /r/SpaceX! I’ve had LOTS of good questions about how exactly you get back down for orbit and specifically the new Crew Dragon! So here’s a full rundown for you! Let me know if you have any other questions or join me live at Splashdown - 90 minutes!!!

[u/OutBackCheeseHouse]

Big fan dude! Thanks for taking the time to do this.

[u/Raging-Bool]

Article version also available here: https://everydayastronaut.com/how-do-you-get-back-to-earth-from-orbit-how-nasa-astronauts-bob-and-doug-get-home/

[u/mvonthron]

Awesome video as usual, thanks /u/everydayastronaut!

[u/[deleted]]

Another great video! They have been amazing for my non-space family to help understand what is going on. I also appreciate YouTubers who are willing to plug other creators videos instead of acting superior, so thanks. Keep up the great work, looking forward to the next one.

[u/Everett_64]

Another great video Tim! I love your channel so much!

[u/extra2002]

Wanted to see more on phasing -- I assume that's to ensure that when the orbital plane crosses the landing site, the capsule is there too, rather than somewhere else in the plane. For this flight, Dragon flew lower than the ISS so moved ahead in its orbit. Does a departing vehicle ever stay higher than ISS for long enough to move significantly behind, before deorbiting?

When you showed Draco thrusters, you left off the 4 under the nose cone that actually do the deorbit burn ...

Another Dragon-specific detail would be what happens to the trunk, and why it's detached before the deorbit burn.

But thanks for doing this video!

[u/chud3]

At what time will this happen?

[u/WaitForItTheMongols]

If the superdracos aren't ready as a contingency, why was the "propulsion systems have safed" callout long after the main chutes had fully deployed?