Do note that Scott Kelly was in zero-G for 340 days = >11 months in there (while Mars crew will be 6 months) in 2016, and then he reentered using Soyuz at around 4.5 gs on reentry (the explanation is like implying that the crew in LEO would move from 0 to 1 g which is not, they have to reenter into atmosphere with more g-load too, like Mars crew would!) Obviously he can't walk when just arrived at the Earth's surface, but once in a few days he return back to normal www.nbcnews.com/mach/science/astronauts-emergency-descent-was-harrowing-high-g-ordeal-ncna919246 Ofc they would reduce the amount of g load possible to the acceptable level for crew during Mars reentry, that's presumably why Elon mentioned around ~70° Angle of Attack during entry, but once landed there the crew can have an adaptation mode where they could just sit there for a few days until they're more suitable. Base construction, Mars exploration, etc can start later, they have a lottt of time anyway :D And oh, the Mars gravity is only ~38% of Earth right, thus the Mars crew should actually feel better after touchdown even than LEO one would! That being said, as always your explanations of the physics is fantastic, and I know even more about this upcoming flight!
This is a nicely made video which explains things well to layman. Few nits though :P : 1. You could use lift at Mars during capture phase. Just use it the other way! i.e. produce negative lift instead of positive one. That way you could keep your vehicle longer without escaping back to hyperbolic orbit. In fact this is what Elon has shown during 2017 presentation (flying about 60-70° AoA, but inverted). This in turn allows one to tune down g-loads 2. You only need to slow down to 18000km/h at Mars. Mars escape velocity is slightly above 18000km/h. If you're moving at 18000km/h you're in orbit, just not a circular one (such orbit would be called HEMO - Highly Eccentric Mars Orbit). 3. Tethers certainly are not free. They are hard to set-up, they mess up thermal design, comms design, etc. Moreover you'd have to dismantle it few days before landing. Few days is enough to mess up your vestibular system anyway. 4. Hoverslam/suicide burn is a thing -- F9 can't hover, it has TWR > 1 during landing, yet it lands. It's extremely hard to do manually, so hand flight simulator must dispense with that (but computer controlled rocket doesn't)
Oh yes the sim is set up to let you explore inverted flight during hyperbolic, entry, etc. The sim is there to let you experiment. As for the cable, you get 6 months of 1-G for basically zero fuel cost, and you worry about dis-assembling it a day or two before landing? No way: Not a concern compared to the benefit!
@@austinmeyer WRT cost & benefit - the major issue for humans after flight is actually vestibular system readjustment to gravity -- few days of microgravity messes it enough. But the cost of artificial gravity system is much more than just a cable and hooks: radiation shielding design is messed up, thermal design is messed up, your comms system is now more complex and fragile, your navigation system is more complex and fragile (to manual backup anymore), solar panel design is changed, setup is risky and hard (previous in-space attempts of various wire systems had roughly 50:50 failure rate). It essentially means major redesign of the vehicle. Anyway, Elon explicitly said they are not going to do that. NB. ISS missions are half a year with some nearly full year and some of them ended up with 7.5g reentry (if Soyuz guidance systems fail and they sometimes to, they use backup procedure which ends up in fully ballistic reentry) - so we have a strategy to deal with return to gravity after 6 months of microgravity. The drug + exercise regime works reasonably well to keep astronauts healthy. And artificial gravity doesn't solve other problems like radiation. Spinning actually makes radiation shielding less effective (significant fraction of charged particle radiation comes from the Sun, so so called shadow shielding works reasonably against it; spining messes up shadow shielding)
@@SebastianKaliszewski " spinning messes up shadow shielding" ...You can spin with shadow shielding... the normal vector to the plane of rotation simply points at the sun.... shadow shielding un-affected... imagine rotation with heat-shield bellies always turned to the sun... shadow effect not compromised... system is neutrally stable with no energy input of any sort to maintain it... unless gyroscopic precession starts altering the plane of rotation... not sure if that even HAPPENS with 2 masses on a cable.. feel free to do a youtube video laying it all out...
@@austinmeyer You then need a new shield along the side of the spacecraft, then (or expose the crew to increased radiation). A side of Starship crew cabin is bigger than its base so any added shielding is less efficient per area. And you get no benefit from shielding provided by thrust structure, methane header tank, main tank bulkheads, floors, etc. Those provide 30-40g/cm^2 of shielding (and methane header tank provides >100g/cm^2 but it's pretty small and far away from the cabin). 30-40g//cm^2 is probably good to go without adding much more. While, on the side you have about 8g/cm^2 -- the rest you must provide separately.
@@zchris13 Nobody says it's preposterous. But the idea that it doesn't cost you anything as Austin says is not accurate either. It will cost you the weight of the steel cable and the mechanism to tether two Starships together. Because it has to be very strong, it will be a great deal of mass that has to get to orbit, which means less mass for your human cargo. Nobody knows what that trade off will be until the Starship is at least in the 3rd phase of testing. So the tether idea is a good one, but very unproven at the moment.
@LabPadre recommendation: That was exceptionally informative. The enthusiasm just radiates from the presenter. Would love to see a collaboration with LabPadre . Can't wait for StarShip belly-flop test. Subscribed.
23:32 Hooray! I've been saying for quite some time that they ought to tether two Starships together for the trip, and I haven't heard it batted around the media either. It's nice to finally hear someone else say it. I've been assuming that they would want less than a full g. A cable does have mass that could have been used for other payload items, and you want it to be rather long to minimize the Coriolis effect. Starships have the hardware to connect to a cable anyway, so that they can be lifted onto the booster (or the test stand, at this point) with a crane. So the cable itself is the only extra hardware.
Mars is meant to be the kickstarter for us to become a truly space fairing civilization. Mars is not meant to be the final destination, but its gonna push os toward having the need to improve spacetravel in orders of magnitude. Ever seen "The Expanse" ? That would be the next step with going interstellar after that. But you have to go to mars first and build a colony in order to start it.
Brilliant description. Ive been thinking about this a lot working on a KSP mod for Realism Overhaul which considers all these factors. So important to get vertical very late which is very scary of Mars
Thanks Austin, nice explanations. The artificial gravity had already been imagined by the von Braun team long ago. (We had von Braun, Korolev and now Musk).
Nope, it’s definitely three engines for the touchdown burn. It allows for engine-out capability and provides more control authority. It’s also more efficient because the engines can start later. The concept is demonstrated by the Falcon 9 landings; even at minimum thrust, the Merlin engine has a TWR well over 1.
Yes, suicide burn is also saving fuel. But for SN8 particular case, according to NSF they will use one engine for the flip, and then two for the rest of the burn
Thank you for uploading. I got the chance to see a rocket launch in 2018. Incredible experience. I uploaded a pretty cool montage of the journey to my channel.
Hi Austin, * What do you think would be a tolerable tethered-spin RPM? * Would you target earth or mars weight? * What cable length would be required? * What would be the required energy (fuel weight) for spin-up and de-spin? Sure hope our cable doesn’t snap on the way to mars.
The longer cable, the better. Why? Because the longer the cable, the less the motion-sickness possibility from rotation, because the rotation rate is lower.
I can answer the bit about energy; for a given radius and a target 'gravity', you end up needing to hit a certain RPM. This RPM has an associated tangential velocity, which is equal to the delta V necessary to spin up or spin down. For example, if we wanted to simulate 1 g with a 500 meter tether, we would need an RPM of about 1.3 and end up with a tangential velocity of 70 m/s. The total delta V necessary to spin up and then spin down later is therefore 140 m/s, which is totally doable. Also, this radius should be big enough to eliminate pretty much all of the nausea-inducing effects of living inside a centrifuge.
@@sycodeathman Exactly! The longer the cable, the less the 'living in a centrifuge' effect. Delta-V is negligible compared to space flight, and when you impart it once, you enjoy 1 g all the way to mars!
I think you would need to mount the human in a gimballed enclosure, such that you were not spinning relatively to each other. a bit like a Ferris wheel.
The artificial gravity scheme you proposed is similar to Zubrin's. And if you want to reduce the loading on the airframes, just pick a percentage of 1G that can be supported. Anything will be better then being in free-fall for 6 months.
This is a very cool app and the video was super informative. Amazing, that for the time you must put into this that you offer it for free. Thank you, and Happy New Year!
I have always thought that the tethering of two ships enroute to Mars is a good idea, but only do 0.38 g rotation. The ship already has hard attachment points on the nose that can support the entire front half of the ship in earth gravity so no major added structure required. The ship is already configured for occupancy in vertical orientation on mars. Once enroute there is almost no fuel onboard, so ship is not too heavy. Astronauts will arrive acclimated to Mars gravity.
Well, regarding the structural strenght of the ship required to be hung by a cable, I would point that's precisely how the current prototypes are lifted and mounted over the test structures (hung by a cable at 1G). At most you'll have to ensure the nose structure can distribute the load nicely onto the upper rings.
Great video! It definitely filled some gaps in my understanding of the ship's aerodynamics. One thing I haven't seen discussed too much is mission #6, leaving Mars and returning to Earth. Is there enough delta V lifting off from Mars with full tanks for Mars escape and transfer orbit to Earth? Do you slam into Earth's atmosphere at roughly 40,000 kph or use fuel to enter Earth orbit before committing to reentry at a slower 28,000 kph?
If you added the falcon heavy and falcon 9 and the super heavy and cleaned up the graphics a little bit it would be awesome also add a full flight mode
I want this in X plane 11( or 12) and multistage option like Kerbal space program, and autopilot that can do this things and option to tweak autopilot for certain things, or maybe something in airplane editor that can allow user to create different autopilot programs or program the autopilot from scratch... Something like that
In my opinion Earth's Moon should be the first "lily pad". I wonder if it's easier to launch a rocket to Alpha Centauri from Moon or Mars in terms of delta-V.
While Mars being a launch pad to Jupiter or Saturn makes some sense ... the tech needed for interstellar travel would be so powerful and so fast it would not matter 1% to stop at Mars.
mars belongs to life in an infinite universe it makes sense to catch solar wind - pull cables from pole to pole slightly offset for the dynamo effect (to master a solar system)
In short yes. Long answer: vacuum raptor was successflly fired on Earth at essentailly sea level pressure. It can't be throttled, though on Earth. Mars has low enough pressure that practically any vacuum engine could be fired.
I BET IT MIGHT BE, because the atmo pressure on mars is soooooooo low! i don't engage the engines, but maybe i SHOULD????? if anyone figures it out let me know!
@@austinmeyer Simple way of thinking about this is considering that over 100x less pressure means that over 100x higher nozzle expansion ratio vs sea level engines could be tolerated. For example 1:15 Merlin cold tolerate over 1:1500 expansion nozzle on Mars. Raptor which is around 1:40 at sea level could go beyond 1:4000 before ambient pressure on Mars would become a problem.
@@SebastianKaliszewski right of course... i should engage all 6 engines on mars to save time (and fuel, with less time spent 'hovering' against gravity)... will do app update that does this... i just treated the term 'vacuum engine' as gospel without considering how close to vacuum mars is
@@austinmeyer From PoV of rocket engines 20km up is pretty much vacuum. A side note: Vacuum engine test stands don't produce perfect vacuum, they produce pressure more or less like 30km up -- which happens to be pretty close to Martian surface).
Re: Artificial gravity. To get to Mars requires several refuellings in Earth Orbit. That entails 2 ships connecting back-to-back, since that's how it's fueled on the ground to begin with. If you were going to 2 ships spin, leaving two bolted engine-to-engine would be a lot more stable than cabling - the connectivity is already present - it would "just" have to be strong enough.
Ships so close would have to spin lots faster.... vomit ensues. And, connected at the tail, as the song says "oh what a feeling.. dancing on the cieling"
@@austinmeyer Agreed, but, I think the bigger issue would be making sure each ship had equal mass to prevent an uneven spin that would throw them off track or have to constantly corrected. Everything aboard each ship would have to be accounted for mass wise and be perfectly even which is why they probably won’t attempt that idea although it is favorable for the physiological issue you brought to light.
@@austinmeyer Assuming two equal masses, to feel 1G acceleration even at only 1RPM wouldn't it require an 1800 meter cable (900m radius)? I'm not a mechanical engineer, but I imagine there might be some problems trying to keep a long cable under a constant tension. I suspect there might be problems with oscillations - a cosmic twang ;-) If the radius were only 50 meters (the length of a Starship), then they'd rotate every 15 seconds. However, so you don't look out the window you wouldn't actually be aware you were rotating, constant rotation shouldn't produce vomiting when everything around you is moving in the same frame of reference. As for the ceiling - it's all relative isn't it? If it feels like the floor, then it's the floor. Might be a good place to experiment with "how much G force is enough to maintain bone mass, though better to try on the way coming home". Great program BTW.
Hey... those fins are, without question, PLANES (the definition of PLANE is pretty clear!) and without question they PLANE through the AIR! I rest me case! Also after 35 years of flying I can't call it anything else.
Gotta be 3 engines since none of them are center; they're all offset. They'll need to do a hoverslam due to extra thrust but all 3 for the most controlled landing.
It’s extremely interesting that you turned out to be wrong about what orientation the vehicle wants to be in. Remember the fluids inside makes up at least 50% of the mass. When it ascends, the vehicle remains upright with minimal corrections due to being aerodynamically stable when going upwards. Then it hovers, losing that stability and uses one engine to keep it flying. Then upon descent, the fluids fall towards the windward side, giving starship aerodynamic and CoM stability. It uses the header tanks to survive not having propellant that can be sourced from the main tanks since that propellant is not going to be able to be pumped through the pipes if it’s against the side of the tank and not the bottom. Then when it flips, the main tank propellant, when it doesn’t slosh too much to condense the autogenous gas pressurizing it, comes against the valves, allowing the raptors to quickly switch to them shortly before the header tanks drain empty.
if they land where the martian air is thicker (twice as thick), at the bottom of that huge martian canyon, valles marinaris, 23000 feet below "sea level" (datum on mars), they can save even more fuel. there is evidence of mud (water) there also (to make more methane fuel and oxygen using co2 in atmosphere and water)
I disagree with the “no human can function” there. The problems associated with coming back from space are mostly with the vestibular system and the heart having some trouble adjusting to 1G in a vertical position. The delicate handling of astronauts coming back from the ISS is mostly precautionary; falling over is their biggest risk. This is different here; the astronauts would be taking the 5 Gs through their back, and would only need to be operating controls within easy reach.
The drag equation you listed is only true for subsonic flight though. Supersonic drag doesn't have turbulent flow like you showed and the drag equation is different..
OK.. show me the math! I would love to see the supersonic drag equation for both cylinders and planes! Give me a link and I can roll the improvements into the next update for sure!!! But, of course, I need a link to experimental dat with proof, not just a vague mention of 'different drag'. I always code X-Plane to experimentally-proven data for constants like these, so I need to see the experimental data and proof.
@@austinmeyer I used to log back in the 70s'. I could break a 1.5" steel cable pulling in a big log. The idea sounds great. But I'm still curious what size cable it would take.
@@phillipzx3754 Whatever size cable it would take to lift the rocket up on the pad and put it on top pf the booster. Not an ounce more. Not an ounce less. Enough to suspend the rocket under 1G. No more, and no less.
Why not do a landing flip on mars like in mission 2? I tried this during the hyperbolic entry mission and it somewhat worked... only thing is that the engines were more coded for the other way you mentioned in the video.
Let me tell you how physics works. Landing with 3 active engines surprisingly saves fuel. Probably, each engine ignition spends some fuel too, but this is not that big. Let's make some math... 70% generates 1g, so 100% generates a little less than 1.5g, and 300% generates roughly 4.3g. Wich means that we are decelerating at 0.5g with one engine, and at 3.3g with 3 engines. So, about 7 times shorter burst (actually, 230 / 30 = 7.67 times). Since we are using 3 engines, we are gaining something close to 2.5x profit in fuel... Which IS a big deal! So, most probably you lost you bet.
There is no single center engine, lading on one engine means landing with off-center thrust. They pulled that off for the first test flights but this causes the vehicle to 'slide' off the pad on launch and forces it to either land at an angle or with some horizontal velocity left. That guarantees some damage to the vehicle and pad, which was fine for the initial tests but is not sustainable in the long run. I'm confident they'll land on three engines (assuming they hopefully make it that far).
@@softb I mean i KIND OF did, in the mission video in the sim, and the sim itself... did you download x-plane starship and watch the mission video for mission 2?
A SpaceX engineer from the SN9 mission said that the landing burn would be conducted with only 1 engine seconds before it crashed. I do believe the off center thing could be very minimal since the engine itself can just move around how it wants to, to correct it, plus if that was so, then SN5 and SN6 would have landed very strangely.
@@OortCloud landing didn't look quite like I think most of us expected. At this point I'd neither call it a one nor three engine landing. More like a three-two-one landing.
Very interesting video, but there are a couple of conceptual errors. There is no reason to launch to Mars orbit if you want to land elsewhere on Mars; just use a suborbital ballistic trajectory. And you don't actually slow down to enter Mars orbit on arrival; you speed up. With a patched conic approach, it looks like you're speeding up, but in reality, the orbital velocity at apogee of a Hohmann transfer from Earth is much slower than Mars' orbital velocity. You are actually doing a circularization burn/aerobrake, just like a satellite going to GEO needs to do from GTO.
where are the important updates from X-plane mobile, so far only solves bugs that don't exist and now where are the updates that change something in the simulation
I guess I'm thinking it need not be many tons... just a cable and some connectors... assembled with space walks at the beginning, and dis-assembled at the end of the trip... i dont think a cable need weigh many tons... the existing reaction control system could be used to get the spin going...
OHHH wait... see my comment in the video description I just added after thinking about your post... I forgot that the ENTIRE SHIP would have to be strong enough to hang from a cable under 1 G! The nose would have to be strong enough to literally hang the entire ship from it, the structural loads being carried all the way through to support the entire ship at 1 G! Hmm... that might add up to tons after all... it's a whole new structural requirement not existing on the ship as designed right now: I bet they have NOT designed the whole ship to be hung from its' nose under 1 G!!!! ;-P Wow this video is stirring up a lot of critical thinking and bringing up things I missed!
@@austinmeyer Don't forget that the ship has to be able to be stacked by a crane (hooked up to its nose) on Earth to the top of its booster before the launch! So they can use the same ports if they want a tether articifical-g
@@alvianchoiriapriliansyah9882 Oh yah cool! BUUUUT... now we have to carry the WHOLE SHIP (not just the nose!) from that crane! Argh! (BUUUT, we only need to do it when the fuel is MOSTLY empty)
@@austinmeyer I'm talking about the entire ship, not just the nose. And this is literally the process that has to be done for every single ship that will go to orbit (because of the booster). And after Trans Mars Injection the fuel is indeed almost empty anyways (only a little bite reserved for landing) I have added a timestamp here for stacking animation ua-cam.com/video/0qo78R_yYFA/v-deo.htmlm2s
But there is a "problem" with mission 2? If we take this flight path, it means that SN8 will fly in-land and not towards the gulf, which I doubt they will. So something doesn't add up there ?
I cn get back to the pad! You gotta hold the nose up by tilitng the pad back to you, rotate the pad AND HOLD IT left or rite to aim the nose back to the pad, then lower the nose a LOT to glide like a plane, then pull up as you approach the path you left going up... i can get back to the launch pad! kind of tricky but can do it!
UNSURE! We are still cranking on V11 to get vulkan/metal working perfectly, but are without question cranking on next-gen X-Plane stuff as well behind the scenes, to roll in when the time is right. It makes sense for Microsoft and X-Plane to release on alternating years or so, of course, so there is something new every year or so, and that type of schedule seems fine to me.
@@austinmeyer i have a aircraft suggestion for X-Plane 10 mobile can you add the Boeing 787-9 Dreamliner to mobile please this aircraft is much requested but can you please add it if you can or not
@@Geo001yt oh yah i like that plane and want to add it but we have to do some airbuses first to get those... so we are doing some airbus work now and will do dreamliner some day i hope cause i think that plane is really cool. its just all a matter of what order we do stuff in of course.
Why aim for a 1 G spin? Surely there must be some advantage to a lower G value, say 0.3 G like Mars? Though I believe we have no data on this yet, which is a shame.
I’m not entirely sure this adds up, but I think one of the big reasons for creating artificial gravity is so your astronauts stand a chance of thinking during the 5G braking manoeuvre. If that’s the case, while they’d be better off with 0.3G than 0G, the reentry G-forces are now ~17 times what you’re used to. With a 1G spin, it’d be 5 times what you’re used to. That’s still a lot; I’d want to lift weights on the way there to be able to move my arms during that, and to remain conscious I’d want to be sitting flat against the acceleration. But it’s a lot more likely I could do it than if I were trying to do it from 0.3G
13:05 But using only one engine, how do you control roll for example? In that case I think you would need stronger control thrusters. Also.. if one of your engines fail during that manuver, the question is "it can restart another engine fast enough?" 29:44 I love it all your presentation, but I kinda disagree with your last point. For a trip to another star, you need a lot of deltaV to achieve the trip in a descent amount of time. Even 1/4 of light speed means around 20 years to a closest star, if you can achieve that deltaV, escaping sun gravity represent an infinitesimal % of that. There are a lot of points to colonize mars or venus, but the point to use those places to reduce deltaV to reach other places (even in the solar system) seem quite silly, more taking into account how cheap this would be with a fully reusable rocket.
A few notes: -Look at the first test-flite: It was done with one engine. No roll control from the engine was needed. -Look at all falcon-9's: They all land with 1 engine. So single-engine ops are normal... or crap my airplane only HAS one engine! :-O So yes there is a safety-loss, but it has been judged acceptable in many cases. They COULD use 2 or 3 of course... BUT would have to be that much more accurate with WHEN they light up to make sure they.... still MAKE IT TO THE GROUND BEFORE SHOOTING UP AGAIN! :-O
@@austinmeyer Ok.. you are right.. yes, seem that is possible to do roll because they are offset from the center, if that is the case then not sure how the roll is achieved on the falcon9, maybe they use the cold thrusters in that case, because I can not imagine how to roll with one engine in the center (of course it could be a way, I am just ignorant about it). Thanks for the reply.. great work!
@@angellestat2730 Oh yes you can roll with 1 engine since it is offset, that is true. BUT, it will cause pitch and/or yaw as well... which is NOT going to be the same as the roll you want just by luck. so you wind up not being able to use it for roll since it would mess up your pitch and yaw
All I can say after trying XPlane Starship is I am glad the computers are running the operation instead of me! Great video!!
any chance this translates to windows/android? either way this is super cool :)
Please in PC too! ❤
Do note that Scott Kelly was in zero-G for 340 days = >11 months in there (while Mars crew will be 6 months) in 2016, and then he reentered using Soyuz at around 4.5 gs on reentry (the explanation is like implying that the crew in LEO would move from 0 to 1 g which is not, they have to reenter into atmosphere with more g-load too, like Mars crew would!) Obviously he can't walk when just arrived at the Earth's surface, but once in a few days he return back to normal
www.nbcnews.com/mach/science/astronauts-emergency-descent-was-harrowing-high-g-ordeal-ncna919246
Ofc they would reduce the amount of g load possible to the acceptable level for crew during Mars reentry, that's presumably why Elon mentioned around ~70° Angle of Attack during entry, but once landed there the crew can have an adaptation mode where they could just sit there for a few days until they're more suitable. Base construction, Mars exploration, etc can start later, they have a lottt of time anyway :D
And oh, the Mars gravity is only ~38% of Earth right, thus the Mars crew should actually feel better after touchdown even than LEO one would!
That being said, as always your explanations of the physics is fantastic, and I know even more about this upcoming flight!
This is a nicely made video which explains things well to layman. Few nits though :P :
1. You could use lift at Mars during capture phase. Just use it the other way! i.e. produce negative lift instead of positive one. That way you could keep your vehicle longer without escaping back to hyperbolic orbit. In fact this is what Elon has shown during 2017 presentation (flying about 60-70° AoA, but inverted). This in turn allows one to tune down g-loads
2. You only need to slow down to 18000km/h at Mars. Mars escape velocity is slightly above 18000km/h. If you're moving at 18000km/h you're in orbit, just not a circular one (such orbit would be called HEMO - Highly Eccentric Mars Orbit).
3. Tethers certainly are not free. They are hard to set-up, they mess up thermal design, comms design, etc. Moreover you'd have to dismantle it few days before landing. Few days is enough to mess up your vestibular system anyway.
4. Hoverslam/suicide burn is a thing -- F9 can't hover, it has TWR > 1 during landing, yet it lands. It's extremely hard to do manually, so hand flight simulator must dispense with that (but computer controlled rocket doesn't)
Oh yes the sim is set up to let you explore inverted flight during hyperbolic, entry, etc. The sim is there to let you experiment. As for the cable, you get 6 months of 1-G for basically zero fuel cost, and you worry about dis-assembling it a day or two before landing? No way: Not a concern compared to the benefit!
@@austinmeyer WRT cost & benefit - the major issue for humans after flight is actually vestibular system readjustment to gravity -- few days of microgravity messes it enough. But the cost of artificial gravity system is much more than just a cable and hooks: radiation shielding design is messed up, thermal design is messed up, your comms system is now more complex and fragile, your navigation system is more complex and fragile (to manual backup anymore), solar panel design is changed, setup is risky and hard (previous in-space attempts of various wire systems had roughly 50:50 failure rate). It essentially means major redesign of the vehicle.
Anyway, Elon explicitly said they are not going to do that.
NB. ISS missions are half a year with some nearly full year and some of them ended up with 7.5g reentry (if Soyuz guidance systems fail and they sometimes to, they use backup procedure which ends up in fully ballistic reentry) - so we have a strategy to deal with return to gravity after 6 months of microgravity. The drug + exercise regime works reasonably well to keep astronauts healthy. And artificial gravity doesn't solve other problems like radiation. Spinning actually makes radiation shielding less effective (significant fraction of charged particle radiation comes from the Sun, so so called shadow shielding works reasonably against it; spining messes up shadow shielding)
@@SebastianKaliszewski " spinning messes up shadow shielding" ...You can spin with shadow shielding... the normal vector to the plane of rotation simply points at the sun.... shadow shielding un-affected... imagine rotation with heat-shield bellies always turned to the sun... shadow effect not compromised... system is neutrally stable with no energy input of any sort to maintain it... unless gyroscopic precession starts altering the plane of rotation... not sure if that even HAPPENS with 2 masses on a cable.. feel free to do a youtube video laying it all out...
@@austinmeyer You then need a new shield along the side of the spacecraft, then (or expose the crew to increased radiation). A side of Starship crew cabin is bigger than its base so any added shielding is less efficient per area. And you get no benefit from shielding provided by thrust structure, methane header tank, main tank bulkheads, floors, etc. Those provide 30-40g/cm^2 of shielding (and methane header tank provides >100g/cm^2 but it's pretty small and far away from the cabin). 30-40g//cm^2 is probably good to go without adding much more.
While, on the side you have about 8g/cm^2 -- the rest you must provide separately.
@@SebastianKaliszewski oh yah you have to shield maybe half the walls instead of all the floors... may indeed be more shielding...
By the way, I REALLY liked this highly informative video. I feel smart after watching this. Thank you!
Brilliant explanation of everything
Some of the comments add a ton more info though that I did not think of so be sure to read those as well!
We need this in the main release of X-Plane.
great to see you two back together again. thnx guys. (I failed at mission zero, plugging the ipad charger into the wall)
2 Starships tethered and generating artificial gravity has been theorized for sure.
It's not even as preposterous as it seems, they need to hang it from the nose for stacking anyway
@@zchris13 Nobody says it's preposterous. But the idea that it doesn't cost you anything as Austin says is not accurate either. It will cost you the weight of the steel cable and the mechanism to tether two Starships together. Because it has to be very strong, it will be a great deal of mass that has to get to orbit, which means less mass for your human cargo. Nobody knows what that trade off will be until the Starship is at least in the 3rd phase of testing. So the tether idea is a good one, but very unproven at the moment.
This video answered so many of my question regarding starship, thank you so so much for this awesome video
@LabPadre recommendation: That was exceptionally informative. The enthusiasm just radiates from the presenter. Would love to see a collaboration with LabPadre . Can't wait for StarShip belly-flop test. Subscribed.
I really enjoyed the sim, good job!
Just a note, Converting CO2 and H2O to O2 and CH4 is a process that can be carried out at conditions which can be achieved using solar power.
23:32 Hooray!
I've been saying for quite some time that they ought to tether two Starships together for the trip, and I haven't heard it batted around the media either. It's nice to finally hear someone else say it. I've been assuming that they would want less than a full g. A cable does have mass that could have been used for other payload items, and you want it to be rather long to minimize the Coriolis effect.
Starships have the hardware to connect to a cable anyway, so that they can be lifted onto the booster (or the test stand, at this point) with a crane. So the cable itself is the only extra hardware.
thank god, someone with an explanation as to how this thing is going to work.
Mars is meant to be the kickstarter for us to become a truly space fairing civilization. Mars is not meant to be the final destination, but its gonna push os toward having the need to improve spacetravel in orders of magnitude. Ever seen "The Expanse" ? That would be the next step with going interstellar after that. But you have to go to mars first and build a colony in order to start it.
Came here on a @LabPadre recommendation. Very informative.
Came here on a @LabPadre recommendation. Very informative. Very well presented!
Brilliant description. Ive been thinking about this a lot working on a KSP mod for Realism Overhaul which considers all these factors. So important to get vertical very late which is very scary of Mars
Very informative! This is never mentioned by others.
Nice contribution for the community!
Thanks Austin, nice explanations. The artificial gravity had already been imagined by the von Braun team long ago. (We had von Braun, Korolev and now Musk).
*slaps box* this bad boy can fit so many sim planes in it
Nope, it’s definitely three engines for the touchdown burn. It allows for engine-out capability and provides more control authority. It’s also more efficient because the engines can start later. The concept is demonstrated by the Falcon 9 landings; even at minimum thrust, the Merlin engine has a TWR well over 1.
Yes, suicide burn is also saving fuel. But for SN8 particular case, according to NSF they will use one engine for the flip, and then two for the rest of the burn
@@alvianchoiriapriliansyah9882 Oh I didn't know that, thanks. The rest of the logic still applies; more than one engine.
New to this channel but this video was GREAT and a joy to watch! More please :)
Thank you for uploading. I got the chance to see a rocket launch in 2018. Incredible experience. I uploaded a pretty cool montage of the journey to my channel.
you can toss a link to it here in the comments i dont mind!
This was cool to watch!
oh good!
Hi Austin,
* What do you think would be a tolerable tethered-spin RPM?
* Would you target earth or mars weight?
* What cable length would be required?
* What would be the required energy (fuel weight) for spin-up and de-spin?
Sure hope our cable doesn’t snap on the way to mars.
The longer cable, the better. Why? Because the longer the cable, the less the motion-sickness possibility from rotation, because the rotation rate is lower.
I can answer the bit about energy; for a given radius and a target 'gravity', you end up needing to hit a certain RPM. This RPM has an associated tangential velocity, which is equal to the delta V necessary to spin up or spin down. For example, if we wanted to simulate 1 g with a 500 meter tether, we would need an RPM of about 1.3 and end up with a tangential velocity of 70 m/s. The total delta V necessary to spin up and then spin down later is therefore 140 m/s, which is totally doable. Also, this radius should be big enough to eliminate pretty much all of the nausea-inducing effects of living inside a centrifuge.
@@sycodeathman Exactly! The longer the cable, the less the 'living in a centrifuge' effect. Delta-V is negligible compared to space flight, and when you impart it once, you enjoy 1 g all the way to mars!
Great video as always, this simulator would be great on PC
23:30
tether two craft to each other using cable.
really nice idea, i hope it gets explored.
maintaining g in space, could make the difference.
I think you would need to mount the human in a gimballed enclosure, such that you were not spinning relatively to each other. a bit like a Ferris wheel.
Well done ✅👍. Lab sent me
Best thing since sliced bread :-D
The idea of two starships connected by cable and rotating to create "gravity" has been discussed quite a bit. Do a google search.
Yep, and I'd be wanting three separate cables in case the other two broke, otherwise you'd be flung off into deep space forever
You should try to make the starship a default "aircraft" in x-plane... that would be pretty fun to fly!
The artificial gravity scheme you proposed is similar to Zubrin's. And if you want to reduce the loading on the airframes, just pick a percentage of 1G that can be supported. Anything will be better then being in free-fall for 6 months.
This is a very cool app and the video was super informative. Amazing, that for the time you must put into this that you offer it for free. Thank you, and Happy New Year!
Yah I have about 2 months in it I would say... but I just HAD to see how this thing would fly!
I have always thought that the tethering of two ships enroute to Mars is a good idea, but only do 0.38 g rotation. The ship already has hard attachment points on the nose that can support the entire front half of the ship in earth gravity so no major added structure required. The ship is already configured for occupancy in vertical orientation on mars. Once enroute there is almost no fuel onboard, so ship is not too heavy. Astronauts will arrive acclimated to Mars gravity.
very cool video!
Well, regarding the structural strenght of the ship required to be hung by a cable, I would point that's precisely how the current prototypes are lifted and mounted over the test structures (hung by a cable at 1G). At most you'll have to ensure the nose structure can distribute the load nicely onto the upper rings.
Well there ya go then!
I don't think the solar arrays and radiators will be able to handle 1G when deployed.
@@silenterection They do OK on the roof of my house right now......
Great Video.
Great Video!! Bravo!
You would use water from mars. There is no colony without that.
i love the idea of the artificial gravity, that definitely will happen
Great video! It definitely filled some gaps in my understanding of the ship's aerodynamics. One thing I haven't seen discussed too much is mission #6, leaving Mars and returning to Earth. Is there enough delta V lifting off from Mars with full tanks for Mars escape and transfer orbit to Earth? Do you slam into Earth's atmosphere at roughly 40,000 kph or use fuel to enter Earth orbit before committing to reentry at a slower 28,000 kph?
i haven't dived into that yet...once i did thos emars missions, i just was not that excited about coming back to earth....
If you added the falcon heavy and falcon 9 and the super heavy and cleaned up the graphics a little bit it would be awesome also add a full flight mode
I have 1200 hours in Kerbal Space Program, this is not a challange to me
Coming back after the spectacular BOOM .BTW also the flip over after shutting down the engine is quite different :)
Yah the way >>I
@@austinmeyer So will the next update have a throttle control option to manually hover?
@@playerjeblemontea1568 I dont think so cause it will be impossible to land.. .trust me i have tried
@@austinmeyer what if we do it in KSP style control or add it in computer edition if there will be? :)
Exactly!
I want this in X plane 11( or 12) and multistage option like Kerbal space program, and autopilot that can do this things and option to tweak autopilot for certain things, or maybe something in airplane editor that can allow user to create different autopilot programs or program the autopilot from scratch... Something like that
In my opinion Earth's Moon should be the first "lily pad".
I wonder if it's easier to launch a rocket to Alpha Centauri from Moon or Mars in terms of delta-V.
While Mars being a launch pad to Jupiter or Saturn makes some sense ... the tech needed for interstellar travel would be so powerful and so fast it would not matter 1% to stop at Mars.
mars belongs to life
in an infinite universe it makes sense to catch solar wind - pull cables from pole to pole slightly offset for the dynamo effect
(to master a solar system)
Is it possible for the vacuum raptors to fire on the surface of mars increasing thrust at takeoff?
In short yes.
Long answer: vacuum raptor was successflly fired on Earth at essentailly sea level pressure. It can't be throttled, though on Earth. Mars has low enough pressure that practically any vacuum engine could be fired.
I BET IT MIGHT BE, because the atmo pressure on mars is soooooooo low! i don't engage the engines, but maybe i SHOULD?????
if anyone figures it out let me know!
@@austinmeyer Simple way of thinking about this is considering that over 100x less pressure means that over 100x higher nozzle expansion ratio vs sea level engines could be tolerated. For example 1:15 Merlin cold tolerate over 1:1500 expansion nozzle on Mars. Raptor which is around 1:40 at sea level could go beyond 1:4000 before ambient pressure on Mars would become a problem.
@@SebastianKaliszewski right of course... i should engage all 6 engines on mars to save time (and fuel, with less time spent 'hovering' against gravity)... will do app update that does this... i just treated the term 'vacuum engine' as gospel without considering how close to vacuum mars is
@@austinmeyer From PoV of rocket engines 20km up is pretty much vacuum. A side note: Vacuum engine test stands don't produce perfect vacuum, they produce pressure more or less like 30km up -- which happens to be pretty close to Martian surface).
Where to download the 3d model of the spaceship, I would like to 3d print one myself?
Re: Artificial gravity. To get to Mars requires several refuellings in Earth Orbit. That entails 2 ships connecting back-to-back, since that's how it's fueled on the ground to begin with. If you were going to 2 ships spin, leaving two bolted engine-to-engine would be a lot more stable than cabling - the connectivity is already present - it would "just" have to be strong enough.
Ships so close would have to spin lots faster.... vomit ensues. And, connected at the tail, as the song says "oh what a feeling.. dancing on the cieling"
@@austinmeyer Agreed, but, I think the bigger issue would be making sure each ship had equal mass to prevent an uneven spin that would throw them off track or have to constantly corrected. Everything aboard each ship would have to be accounted for mass wise and be perfectly even which is why they probably won’t attempt that idea although it is favorable for the physiological issue you brought to light.
@@austinmeyer Assuming two equal masses, to feel 1G acceleration even at only 1RPM wouldn't it require an 1800 meter cable (900m radius)? I'm not a mechanical engineer, but I imagine there might be some problems trying to keep a long cable under a constant tension. I suspect there might be problems with oscillations - a cosmic twang ;-) If the radius were only 50 meters (the length of a Starship), then they'd rotate every 15 seconds. However, so you don't look out the window you wouldn't actually be aware you were rotating, constant rotation shouldn't produce vomiting when everything around you is moving in the same frame of reference. As for the ceiling - it's all relative isn't it? If it feels like the floor, then it's the floor. Might be a good place to experiment with "how much G force is enough to maintain bone mass, though better to try on the way coming home". Great program BTW.
@@CandyInAPinata that's as easy as a vertical weight and pulley system.
@@VerisonMember Is it though when your end goal is just to get to Mars? Every pound counts and costs hundreds of thousand of dollars.
I find it sorta funny how this guy keeps calling Starship an airplane
Hey... those fins are, without question, PLANES (the definition of PLANE is pretty clear!) and without question they PLANE through the AIR! I rest me case! Also after 35 years of flying I can't call it anything else.
Oh yah and i spend more time FLYING it on the PLANES than GUIDING it when in rocket mode in this app sooooo.........
Love the CFD sim of the nozzle dynamics...any chance that is a preview of new capabilities in X-Plane 12?
Gotta be 3 engines since none of them are center; they're all offset. They'll need to do a hoverslam due to extra thrust but all 3 for the most controlled landing.
The Starhsip hop tests have been done with one off-center enginge. So it's not totally impossible.
They will use one for flip, then two for the rest. And again, SN5 & 6 hop proved that the thrust vector control is totally capable for off-center
It’s extremely interesting that you turned out to be wrong about what orientation the vehicle wants to be in.
Remember the fluids inside makes up at least 50% of the mass. When it ascends, the vehicle remains upright with minimal corrections due to being aerodynamically stable when going upwards. Then it hovers, losing that stability and uses one engine to keep it flying. Then upon descent, the fluids fall towards the windward side, giving starship aerodynamic and CoM stability. It uses the header tanks to survive not having propellant that can be sourced from the main tanks since that propellant is not going to be able to be pumped through the pipes if it’s against the side of the tank and not the bottom.
Then when it flips, the main tank propellant, when it doesn’t slosh too much to condense the autogenous gas pressurizing it, comes against the valves, allowing the raptors to quickly switch to them shortly before the header tanks drain empty.
Adventure of Tintin before 1969 = information Tintin by Nasa = old dream = Gyroscope Hight Technic
Niiiiice!!! Score
if they land where the martian air is thicker (twice as thick), at the bottom of that huge martian canyon, valles marinaris, 23000 feet below "sea level" (datum on mars), they can save even more fuel. there is evidence of mud (water) there also (to make more methane fuel and oxygen using co2 in atmosphere and water)
I disagree with the “no human can function” there. The problems associated with coming back from space are mostly with the vestibular system and the heart having some trouble adjusting to 1G in a vertical position. The delicate handling of astronauts coming back from the ISS is mostly precautionary; falling over is their biggest risk. This is different here; the astronauts would be taking the 5 Gs through their back, and would only need to be operating controls within easy reach.
Can you make an x place game for the f35b?
Umm,...the cable idea for artificial gravity has been bounced around since Mars Direct with Robert Zubrin.
Hello Austin how is the Leminar team doing i hope you guys are doing well😄
The drag equation you listed is only true for subsonic flight though. Supersonic drag doesn't have turbulent flow like you showed and the drag equation is different..
OK.. show me the math! I would love to see the supersonic drag equation for both cylinders and planes! Give me a link and I can roll the improvements into the next update for sure!!! But, of course, I need a link to experimental dat with proof, not just a vague mention of 'different drag'. I always code X-Plane to experimentally-proven data for constants like these, so I need to see the experimental data and proof.
Wow
How strong/heavy would the cable need to be in order to withstand the tension it would be under?
For 1G, exactly enough to lift the starship on hold it on Earth. Not an ounce more, not an ounce less.
@@austinmeyer I used to log back in the 70s'. I could break a 1.5" steel cable pulling in a big log.
The idea sounds great. But I'm still curious what size cable it would take.
@@phillipzx3754 Whatever size cable it would take to lift the rocket up on the pad and put it on top pf the booster. Not an ounce more. Not an ounce less. Enough to suspend the rocket under 1G. No more, and no less.
Why not do a landing flip on mars like in mission 2? I tried this during the hyperbolic entry mission and it somewhat worked... only thing is that the engines were more coded for the other way you mentioned in the video.
Let me tell you how physics works. Landing with 3 active engines surprisingly saves fuel. Probably, each engine ignition spends some fuel too, but this is not that big. Let's make some math... 70% generates 1g, so 100% generates a little less than 1.5g, and 300% generates roughly 4.3g. Wich means that we are decelerating at 0.5g with one engine, and at 3.3g with 3 engines. So, about 7 times shorter burst (actually, 230 / 30 = 7.67 times). Since we are using 3 engines, we are gaining something close to 2.5x profit in fuel... Which IS a big deal! So, most probably you lost you bet.
Very good video! Can you put Spanish subtitles to can send this to my familiy?
Great video! But I’m really curious about where you got that Starship model. Did you build it? Or where can I get one? Haha
3d printed by a 3d printer
They are planning on using one engine for flipping and two for landing
I BEG YOU TO MAKE THIS FOR ANDROID!
There is no single center engine, lading on one engine means landing with off-center thrust. They pulled that off for the first test flights but this causes the vehicle to 'slide' off the pad on launch and forces it to either land at an angle or with some horizontal velocity left. That guarantees some damage to the vehicle and pad, which was fine for the initial tests but is not sustainable in the long run. I'm confident they'll land on three engines (assuming they hopefully make it that far).
OOOOOOOO!!!!!!!!!!!!!!!!!! OK good we have a bet then! (the off-center thing is all true... but I just don't think it MATTERS as much)
@@austinmeyer could you please do an analyzation of the sn8 landing?
@@softb I mean i KIND OF did, in the mission video in the sim, and the sim itself... did you download x-plane starship and watch the mission video for mission 2?
A SpaceX engineer from the SN9 mission said that the landing burn would be conducted with only 1 engine seconds before it crashed. I do believe the off center thing could be very minimal since the engine itself can just move around how it wants to, to correct it, plus if that was so, then SN5 and SN6 would have landed very strangely.
@@OortCloud landing didn't look quite like I think most of us expected. At this point I'd neither call it a one nor three engine landing. More like a three-two-one landing.
Very interesting video, but there are a couple of conceptual errors. There is no reason to launch to Mars orbit if you want to land elsewhere on Mars; just use a suborbital ballistic trajectory. And you don't actually slow down to enter Mars orbit on arrival; you speed up. With a patched conic approach, it looks like you're speeding up, but in reality, the orbital velocity at apogee of a Hohmann transfer from Earth is much slower than Mars' orbital velocity. You are actually doing a circularization burn/aerobrake, just like a satellite going to GEO needs to do from GTO.
Since Vulkan now supports ray tracing, will this be something that will be incorporated into the future X-Plane? Maybe x-plane 12?
Do we measure the martian interface maneuver G-load per earth G or martian G?
look at the g-meter in the sim... in the sim its' labelled as earth g. my discussion in this video is in earth g as well.
Musk has said he will use the Sebatier process to combine H20 from subsurface Mars and CO2 from the atmosphere to generate CH4, and O2.
It's on android ?
where are the important updates from X-plane mobile, so far only solves bugs that don't exist and now where are the updates that change something in the simulation
i'm guessing it's landing with two engines
Thanks for the 5g Mars entry number. Alas, tethers are tough to deploy and control, and many Tons of equipment
I guess I'm thinking it need not be many tons... just a cable and some connectors... assembled with space walks at the beginning, and dis-assembled at the end of the trip... i dont think a cable need weigh many tons... the existing reaction control system could be used to get the spin going...
OHHH wait... see my comment in the video description I just added after thinking about your post... I forgot that the ENTIRE SHIP would have to be strong enough to hang from a cable under 1 G! The nose would have to be strong enough to literally hang the entire ship from it, the structural loads being carried all the way through to support the entire ship at 1 G! Hmm... that might add up to tons after all... it's a whole new structural requirement not existing on the ship as designed right now: I bet they have NOT designed the whole ship to be hung from its' nose under 1 G!!!! ;-P
Wow this video is stirring up a lot of critical thinking and bringing up things I missed!
@@austinmeyer Don't forget that the ship has to be able to be stacked by a crane (hooked up to its nose) on Earth to the top of its booster before the launch! So they can use the same ports if they want a tether articifical-g
@@alvianchoiriapriliansyah9882 Oh yah cool! BUUUUT... now we have to carry the WHOLE SHIP (not just the nose!) from that crane! Argh! (BUUUT, we only need to do it when the fuel is MOSTLY empty)
@@austinmeyer I'm talking about the entire ship, not just the nose. And this is literally the process that has to be done for every single ship that will go to orbit (because of the booster). And after Trans Mars Injection the fuel is indeed almost empty anyways (only a little bite reserved for landing)
I have added a timestamp here for stacking animation
ua-cam.com/video/0qo78R_yYFA/v-deo.htmlm2s
Where did you get the model?
3-d printed by a friend of a friend... now we can 3-d print... i guess any shape
But there is a "problem" with mission 2? If we take this flight path, it means that SN8 will fly in-land and not towards the gulf, which I doubt they will. So something doesn't add up there ?
I cn get back to the pad! You gotta hold the nose up by tilitng the pad back to you, rotate the pad AND HOLD IT left or rite to aim the nose back to the pad, then lower the nose a LOT to glide like a plane, then pull up as you approach the path you left going up... i can get back to the launch pad! kind of tricky but can do it!
@@austinmeyer Not gonna lie... Not sure I understand what you just said 😅😂
@@MrRaph1260 did you watch the in0game mission-2 "BRIEF" video that i made to show how to do mission 2?
@@austinmeyer Just did ! Thanks now I understand much better... Basically has to do a 180 degrees steer while skydiving
When is the new X-Plane 12 coming out!
UNSURE! We are still cranking on V11 to get vulkan/metal working perfectly, but are without question cranking on next-gen X-Plane stuff as well behind the scenes, to roll in when the time is right. It makes sense for Microsoft and X-Plane to release on alternating years or so, of course, so there is something new every year or so, and that type of schedule seems fine to me.
@@austinmeyer i have a aircraft suggestion for X-Plane 10 mobile can you add the Boeing 787-9 Dreamliner to mobile please this aircraft is much requested but can you please add it if you can or not
@@Geo001yt oh yah i like that plane and want to add it but we have to do some airbuses first to get those... so we are doing some airbus work now and will do dreamliner some day i hope cause i think that plane is really cool. its just all a matter of what order we do stuff in of course.
@@austinmeyer alright and the 777-200 needs a rework and and the a320 needs one to and we need working airport gates
@@austinmeyer oh and why does X-Plane 10 mobile have to always download
Why aim for a 1 G spin? Surely there must be some advantage to a lower G value, say 0.3 G like Mars? Though I believe we have no data on this yet, which is a shame.
I’m not entirely sure this adds up, but I think one of the big reasons for creating artificial gravity is so your astronauts stand a chance of thinking during the 5G braking manoeuvre. If that’s the case, while they’d be better off with 0.3G than 0G, the reentry G-forces are now ~17 times what you’re used to. With a 1G spin, it’d be 5 times what you’re used to. That’s still a lot; I’d want to lift weights on the way there to be able to move my arms during that, and to remain conscious I’d want to be sitting flat against the acceleration. But it’s a lot more likely I could do it than if I were trying to do it from 0.3G
you would want to burn oil on mars for energy and to thicken the atmo
To close the ground landing it's imposible to reality vector fly be a 100.000 or more not to 10.000 close to ground it's one chance to slow down
Here is the first I heard of two ships "tethered" together - at the 18:53 mark
ua-cam.com/video/kRO_07nEi8g/v-deo.html&lc
13:05 But using only one engine, how do you control roll for example? In that case I think you would need stronger control thrusters. Also.. if one of your engines fail during that manuver, the question is "it can restart another engine fast enough?"
29:44 I love it all your presentation, but I kinda disagree with your last point.
For a trip to another star, you need a lot of deltaV to achieve the trip in a descent amount of time.
Even 1/4 of light speed means around 20 years to a closest star, if you can achieve that deltaV, escaping sun gravity represent an infinitesimal % of that.
There are a lot of points to colonize mars or venus, but the point to use those places to reduce deltaV to reach other places (even in the solar system) seem quite silly, more taking into account how cheap this would be with a fully reusable rocket.
A few notes:
-Look at the first test-flite: It was done with one engine. No roll control from the engine was needed.
-Look at all falcon-9's: They all land with 1 engine.
So single-engine ops are normal... or crap my airplane only HAS one engine! :-O
So yes there is a safety-loss, but it has been judged acceptable in many cases.
They COULD use 2 or 3 of course... BUT would have to be that much more accurate with WHEN they light up to make sure they.... still MAKE IT TO THE GROUND BEFORE SHOOTING UP AGAIN! :-O
@@austinmeyer Ok.. you are right.. yes, seem that is possible to do roll because they are offset from the center, if that is the case then not sure how the roll is achieved on the falcon9, maybe they use the cold thrusters in that case, because I can not imagine how to roll with one engine in the center (of course it could be a way, I am just ignorant about it).
Thanks for the reply.. great work!
@@angellestat2730 Oh yes you can roll with 1 engine since it is offset, that is true. BUT, it will cause pitch and/or yaw as well... which is NOT going to be the same as the roll you want just by luck.
so you wind up not being able to use it for roll since it would mess up your pitch and yaw
People who like this kinda stuff don't use iPhones. They use Android. Make this app for Android PLEASE!
No, people who like this stuff use PCs for anything that isn't just making a phone call or looking at memes in a toilet.
@@kazioo2 okay
Surprised you don’t work with space x, have you shown this to Elon?
Can you add a free Cessna Citation for X-Plane 10? Or no because you guys need money for development of this?
lol... following a failure of a software house it's not what i want to see on my YT frontpage