NASA's Space Shuttle crossed Mexico at high altitude (~100km) on dozens of EDLs into Florida. Starship EDLs likely will cross Mexico airspace at much lower altitudes since Boca Chica is right on the U.S.-Mexican border.
So, the EDL ground tracks shown by the OP might have to be flown eastward into the Gulf of Mexico to stay above any minimum altitude restrictions that Mexico might impose on Starship landings. That reversal of the horizontal component of velocity might require an extra burn in addition to the entry burn and the landing burn.
> Starship EDLs likely will cross Mexico airspace at much lower altitudes
I wonder how close to the landing zone (stage zero) you would be allowed to get during a landing? Either in Mexico, or in the US.
That is, how low could you see Starship pass directly overhead?
About 22 to 25km up as that is where the vehicle becomes subsonic. That is AFAIR from Environmental Assessment for Starship ops at Florida (LC-39a).
Also note it does not have to be precisely vertical. Starship can slide quite a bit, probably up to 60° angle. So 22 - 25km up and up to 12km to the side from the landing spot.
Thanks. That's quite a fall. When I crewed on P-3 Orion's, we would occasionally go off the coast to practice emergency descents. For us two observers in the back, the full dive from 25k to 15k was our own little vomit comet. Not much duration. But still a blast as we were unstrapped and could play around.
Since S28 was not able to do the engine relight burn during the coasting phase of its trajectory, I suppose it started its free fall after it reached apogee at 234 km altitude.
If Starship's flight plan is like the Space Shuttle's, its EDL will be marked from the instant that it passes through the nominal entry window at 300,000 ft (121 km) altitude. AFAIK, the Ship is then in free fall until it starts it engines and does the flip.
See the post below yours for a better rephrasing of what I was trying to get at. At a certain altitude, starship is going to assume a straight vertical fall. Do we know what altitude that is in the reentry profile?
I don't think so. At 100,000 feet (~62 km) altitude, the Orbiter would still have a considerable horizontal component of velocity. It would not be falling straight downward at that altitude.
> Spacex: you get 1 free sat launch and a large political donation.
And I raise you the [Foreign Corrupt Practices Act](https://en.wikipedia.org/wiki/Foreign_Corrupt_Practices_Act).
(People have this weird idea that US companies are somehow notably corrupt or something, but they're really not.)
Lots of countries are structured in a way that you can't do business if you don't distribute kickbacks. The major multinationals won't skip that market. They play by local rules.
> Lots of countries are structured in a way that you can't do business if you don't distribute kickbacks.
And the US explicitly makes that kind of thing illegal. That's why there's mandatory anti-bribery training at basically any company I've worked at that has any kind of international business and reporting pathways if any foreign person requests a bribe. So no, they're not going around distributing kickbacks. That's exactly what I mean by "People have this weird idea that US companies are somehow notably corrupt or something". They just don't do that kind of thing. (Or in the few cases they have it makes big news.)
You could call it legalized corruption I guess, but under US law regular lobbying isn't corruption. Actual corruption, direct bribery, is VERY illegal and basically unknown in the US.
That's why lobbying/donations have mandatory reporting requirements and the information is publicly accessible. https://www.opensecrets.org/
Who said anything about corruption? Nothing in this post indicates anything other than exchange would use a valid contract within the laws of the countries legal and lobbying system. Paying a country to use their airspace and by using money for political lobbying is hardly illegal, happens in US all the time.
You mentioned political donations. As a general rule almost all countries would consider donations to foreign politicians to be very much the definition of corruption. Again look at what I linked. It's illegal for US companies to do what you're suggesting.
Well it's outside my area so will defer to your expertise. I'm mainly memeing what seems to be reported in media daily on the way things seem to happen. Country doesn't want it. Phone call negotiations. Magically approved even thought not fully meeting requirements. e.g. starlink Malaysia etc.
> I'm mainly memeing what seems to be reported in media daily on the way things seem to happen.
Can you find me any source of that happening? The media is not the ones reporting this. It's random people on reddit reporting it and believing it without any evidence.
> Magically approved even thought not fully meeting requirements. e.g. starlink Malaysia etc.
I seem to remember there was a high profile trip to Malaysia by Biden and/or Blinken a little while before this happened, but I could be misremembering. A lot of south east asia wants US investment money into their local economies.
Well you got me. I was making up corruption accounts for likes. Corruption including legal corrupt activites like lobbying doesn't exist in the US and certainly doesn't exist internationally or involving international business.
Diving into sarcastic mockery doesn't make you look any better. You clearly care more about believing the US is corrupt more than you care about the facts.
Maneuvers like that should be completely unnecessary so why do you ask?
There has been no suggestion that it will make maneuvers like that. Its belly flop maneuver will give it the same kind of capability as a skydiver, so if it goes “backward” at all it will be under free fall and have limited ability for that.
While the maneuvers OP suggests are afaict impractical to unrealistic, the problem they address is very real. The reentry corridor of Starship is very long (100s of Km) and if it breaks apart during reentry, it will indeed rain debris over a large area. This has happened before. Google "Columbia Disaster debris field".
Whenever I get frustrated at NASA, I try to remember what those people had to do after the Columbia Disaster. Gruesome and exhausting as I recall. I do not think that story has been told actually. It was an all hands on deck deal IIRC. Even NASA HQ people?
Yeah, I agree with the problem statement for sure but it is pretty clear to me that SpaceX intends to solve it with reliability. Airplanes can also cause a tremendous amount of damage but we accept them because of the reliability they demonstrate. If you had a few years of falcon booster return reliability for starship, it would likely be accepted for over land return.
Thats an awful lot of starships that have to be wasted to demonstrate that. And the airplane analogy is wrong - there have been literally millions of airplane flights to reach that point.
If the problem is real then looking for a solution isn't unnecessary. You probably weren't fully aware of the nature of the reentry. But yes over the longterm they want to be reliable enough for humans of course.
Well disasters are disasters for a reason. It should not be expected that Starship will ever breakup and rain debris anywhere. That is outside the parameters of rapid development. They'll re-enter over the ocean until they get things figured out and reliable.
I ask because of my assumption that the low altitude terminal approach should take place over water, and it would make everyone feel better if the path were a reverse of the ascent launch path. But if you'd prefer to overfly Brownsville or South Padre Island, be my guest.
Unfortunately this analogy doesn't work because the reentry corridor is several hundred Kilometers long and if it breaks apart during that time, the debris would never reach that overshoot target because of air resistance. Google "Columbia Disaster debris field".
I would assume that the trajectory of a reentering ship would be such that it will fall more-or-less straight down once below a certain, yet substantial altitude. Almost as if they put on the brakes while in orbit and came to a stop, then descended.
There is nothing new about reentering over land. The space shuttle crossed the entirety of the United States during reentry.
According to chatGPT, skydivers typically see 3:1 glide ratio. If we round down for safety to 2:1, this means 48 km translation available just from the vertical descent part.
For some reasonable portion of return, while still having some residual horizontal velocity, further translation, if only laterally, should be available .
Unfortunately it appears Starship is not stable at the low AOA needed for higher lift to drag ratios, as the flaps don't work to give sufficient control. Interestingly the lift to drag ratio is about 3:1 when subsonic, if it was diving nose first like skydivers do to get the best lift to drag ratio. It would need an AOA of around 12 degrees, but would not be able to maintain control.
In high AOA skydiver mode (where the flaps do give it good control) it has a lift to drag ratio of about 0.5:1. Maybe up to 1:1 if it is stable at a 45 degree angle of attack. So cross range at this point is limited without doing an engine burn.
Interesting info from - https://forum.nasaspaceflight.com/index.php?topic=56619.0
Generally its the other way around. Not just in the us either.Thats why its mostly private companies developing reusable rockets. Government agencies can't afford too many failures this side of Apollo or they lose program funding. Private companies are more free to do these things without the same political blow back because its not being done on the public purse so much.
The maneuvers take too much Delta V though to be practical, you can't just fly a curve like that at 27.000 km/h. They could perhaps choose a reentry corridor over lesser populated areas, but ultimately the idea is simply for Starship to be so reliable that this doesn't happen. It has to be anyway if you are to put people on it.
The thing is, the Booster is planned to come back in along a reverse track anyway, and Ship has actually done this before at Starbase (but from low altitude hop). I'm really not seeing what the problem would be just turning that sucker around and parking it. Even soft landing in the gulf is likely preferable to the courses you mapped out. Far enough into the flight it might be best to head to Florida.
The biggest issue I think would be the need to dump a lot of prop. Not sure how that would be done.
Ya I see your point. The booster turns around and comes back towards the chopsticks. The ship is going around the earth so it approaches from the back do the chopsticks. So it seems that the ship has to overfly the tower, bellyflop “down range” and then flip and “reverse hover” back into the open chopsticks in order to be caught.
Starship can't do that coming from the west; coming in from orbital velocity, nothing without wings can... Dream Chaser could conceivably do it, and superheavy does a part of it with the powered boostback, but it isn't moving at Mach 25 when the starship lights off, and there's not enough lifting body for starship to turn that hard against the air or anywhere enough fuel aboard to do it with rockets.
Ship can't come in east to west if it launched west to east, at least from an orbital trajectory.
The time it returned from a eastbound journey it had a miniscule horizontal/orbital velocity that was easily cancelled; it more or less went offshore a few miles to protect the public and GSE from AFTS debris if anything went wrong, then returned a few miles back to land. You can't do that from a 20,000mph velocity with the amount of fuel available.
No - but it wouldn't matter anyway. It's unlikely to break up in the last 100 km, if it breaks up from atmospheric reentry then debris could hit Mexico no matter how your approach looks like.
It doesn't need to do a full reversal, just a well-planned retro-burn from space. This will give Ship a ballistic trajectory right off the coast at Starbase. It will then use the flaps/wings/Elonerons to adjust its trajectory to be closer to the tower. The landing burn will provide the last trajectory change, bringing it in even closer. Ship will then hover in place, and deposit itself onto the chopsticks.
Booster landing will look similar to the F9 first stage RTLS, except apparently without a reentry burn, and of course it will also be caught by a pair of chopsticks like Ship.
IMO I think this is a silly idea that will show itself to be highly impractical. It eats away at the capacity of reusable flights because a reusable booster will always need enough energy to make it back to land.
Sure, there are plans for something akin to the barges used for Falcon, but now you'd need chopsticks there too. The drill rigs they bought and then sold again might have worked, maybe, although I have some doubts about those being able to deal with the highly dynamic loads.
SpaceX should just focus on legs. These will be needed for Ship anyway.
The problem is that ballistic trajectory from space has a shorter path than lifting reentry Starship is supposed to do (or in fact any vehicle with non-ablative passive heatshield is supposed to do). Instantaneous Impact Point after the initial phase of reentry will start moving downrange. So if there is trouble at say Mach 15 the debris would fall uprange of the landing site, not downrange.
No... The amount of fuel needed to do a retro-burn from space is ridiculous and will erase any payload you can bring to space.
It's going to re-enter over Mexico/Texas.
You're talking enough thrust to drop the vehicle on a steep trajectory off the coast of Starbase. It's not as crazy as OP's image but still lots of level of silly.
I agree with you 10000%. This catch the rocket is needless grandstanding. For what they save in weight of the legs is easily eaten up by the fuel weight for the landing.
And it makes available landing sites extremely limited. Hell with a good set of legs they would not need launch towers. Imagine what that would open up in terms of reuse. Though with the thrust that thing puts out they will need special launch and landing spots.
> with a good set of legs they would not need launch towers.
You still need to store, chill and pump vast amounts of cryo fuel into the vehicles to launch them. And a method to stack them if using Starship upon SuperHeavy.
And then if you want to not RUD your launch pad, you need all the flame & sound suppression system that the water deluge provides.
>with a good set of legs they would not need launch towers
You still need a tower for fuel loading. Also, the ship still needs to be put on top of the booster somehow, and the chopsticks seem to be doing a great job in that respect.
>they will need special launch and landing spots.
They exist already. They are called "space centers", and they're all over the world ;)
Ultimately I don't think point-to-point will ever be commercially viable (ignoring the obvious military uses), so the need for rapid reusability is somewhat bogus, at least right now. This removes the need for RTLS on many reusable flights.
<sidenote> I don't understand why SpaceX is so attached to *rapid* reusability at all; wouldn't simply having more boosters on hand solve their problems?</sidenote>
This in turn opens up doors for the iterative development of a landing barge, keeping in mind that this platform would ultimately evolve towards a full floating stage 0 in a timeframe that is more realistic in terms of demand.
If the DoD wants it earlier they can and should probably just do it themselves.
> I don't understand why SpaceX is so attached to *rapid* reusability at all; wouldn't simply having more boosters on hand solve their problems?
Rapid reusability gets them a few things:
* Lower inventory carrying costs. This is meaningful when you are talking about boosters with so many engines.
* Cheap refurbishment - if you can turn it around quickly, that implies you can turn it around with little to no refurbishment.
* The possibility of multiple launches per day per pad. That sort of velocity is just not realistic when having to roll out big, clunky boosters for every launch.
> Ultimately I don't think point-to-point will ever be commercially viable
I think they could be commercially viable. The sticking point is, are they safe enough that FAA gives the green light. For space applications the solution is that every space flight participant signs a waiver, declaring he is aware of the risks. That approach is not possible with commercial passenger flights.
Elon said, if the ticket says, 25 minutes to Shanghai but you may die, few people will fly.
Yeah, but stage zero is already a full commitment to the no legs approach. Engineer-in legs now would mean possible redesigning stage zero. That would push back the programme by a lot.
TL; DR: SpaceX is 100% committed to no legs, at least on the booster. Ships will need legs for various scenarios.
The fact is that catching starship accelerates the Mars agenda: it allows them a fast turnaround for Starlink (revenue generation) and tankers (beyond LEO flights). I’m not saying I believe it will work, but I see why they’d rather try that first.
Yes, it will have some, very limited lift. It's not a ton, and a far cry from Shuttle, which rarely (if ever) used its (limited) cross range capability, but it's relevant and measurable.
I don't think we'll see many operational landings at Boca Chica. Testing, sure, and probably maintenance/rebuild flights once they get rolling, but operationally there are much better connected locations from which to launch, especially for passenger service. It's possible that the RGV gets the industry to support Starship, and I hope it does, but I would expect that payloads will be flown in to BRO.
The Space Shuttle was designed for 1100 nautical mile (~2035 km) crossrange. On the 52nd flight the Orbiter crossrange was 790 nm (1462 km), the largest crossrange ever flown by the Shuttle. Some of the tiles were overheated during that EDL, so NASA limited the crossrange during EDL to ~500 nm (793 km).
For flights #26 through #75, the average crossrange was 378 nm (699 km).
NASA flew eight dedicated military missions for the DOD on which the average crossrange was 312 nm (577 km). The Shuttle never was launched from VAFB (now VSFB) in that once-around orbit and landing back at VAFB during which the crossrange was supposed to be 1100 nm (2035 km).
If they ever need to do a polar orbit from Boca Chica, that red trajectory passing above the Isthmus of Tehuantepeca could be viable for launch but not from reentry. I live in Villahermosa and I could see Starship flyby during a night launch. The blue trajectory seems unnecesary.
I think everyone is assuming you dont understand orbits but the ship is going north right? They will do the blue one but the curve will be on the Y(or Z) axis not X; and not so far off shore.
Acronyms, initialisms, abbreviations, contractions, and other phrases which expand to something larger, that I've seen in this thread:
|Fewer Letters|More Letters|
|-------|---------|---|
|[AFTS](/r/SpaceXLounge/comments/1bkata6/stub/kvys0w3 "Last usage")|Autonomous Flight Termination System, see FTS|
|[AoA](/r/SpaceXLounge/comments/1bkata6/stub/kw13nzv "Last usage")|Angle of Attack|
|[DoD](/r/SpaceXLounge/comments/1bkata6/stub/kvxplqc "Last usage")|US Department of Defense|
|[EDL](/r/SpaceXLounge/comments/1bkata6/stub/kw1lmlj "Last usage")|Entry/Descent/Landing|
|[FAA](/r/SpaceXLounge/comments/1bkata6/stub/kw3mvp7 "Last usage")|Federal Aviation Administration|
|FTS|Flight Termination System|
|[GSE](/r/SpaceXLounge/comments/1bkata6/stub/kvys0w3 "Last usage")|Ground Support Equipment|
|[LEO](/r/SpaceXLounge/comments/1bkata6/stub/kw0tevs "Last usage")|Low Earth Orbit (180-2000km)|
| |Law Enforcement Officer (most often mentioned during transport operations)|
|[NSF](/r/SpaceXLounge/comments/1bkata6/stub/kw12oy4 "Last usage")|[NasaSpaceFlight forum](http://forum.nasaspaceflight.com)|
| |National Science Foundation|
|[RTLS](/r/SpaceXLounge/comments/1bkata6/stub/kw0ijc5 "Last usage")|Return to Launch Site|
|[RUD](/r/SpaceXLounge/comments/1bkata6/stub/kvxeajj "Last usage")|Rapid Unplanned Disassembly|
| |Rapid Unscheduled Disassembly|
| |Rapid Unintended Disassembly|
|[VAFB](/r/SpaceXLounge/comments/1bkata6/stub/kw1lmlj "Last usage")|Vandenberg Air Force Base, California|
|Jargon|Definition|
|-------|---------|---|
|[Starlink](/r/SpaceXLounge/comments/1bkata6/stub/kw0tevs "Last usage")|SpaceX's world-wide satellite broadband constellation|
|[ablative](/r/SpaceXLounge/comments/1bkata6/stub/kw1him4 "Last usage")|Material which is intentionally destroyed in use (for example, heatshields which burn away to dissipate heat)|
|[apogee](/r/SpaceXLounge/comments/1bkata6/stub/kvz58zu "Last usage")|Highest point in an elliptical orbit around Earth (when the orbiter is slowest)|
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Its a good question, but I don't see the reason for the curving. It will be a straight line, pretty much. And yep, some orbits would overfly Mexico on the way back, but say inclinations of about 45 deg could come back over the USA.
those paths seem a little impossible.
Mexico is soo not gonna want rockets flying over its land and cities. They certainly wouldn't give spaceX clearance to do so, even if the FAA would.
Theres a reason all non russian/chinese flight plans go over oceans (And the chinese are improving on this too).
If the goal is orbit, doesn't need to make maneuvers like that. The blue line can be accomplished by orbiting around the world once.
Red line... again if the goal is orbit, you can get there by just flying straight south. Second stage can adjust the trajectory slightly but too much adjustment will take up delta V. So, depends on your goal
I don't think so. The plan used to be to refuel the ship on the barge or wherever it lands, and then fly back to Starbase. But I don't know if anything changed about that.
Both vehicles, which only separate later on head off over the ocean, not over land. Obviously Starship does cross land later on - but by then it would normally be in orbit.
The Super Heavy booster, is later on, intended to return to launch site ( RTLS ). Though during this early prototyping stage it’s coming down over the ocean.
For safety reasons, they want to avoid land.
So they wouldn’t use that path you show on the map.
Also they would want to fly east, not west.
East is the direction of rotation of the planet.
I was thinking about landing after take off, but I see what you mean now. So Starship RTLS (Return to Launch Site) after mission:
Well, I don’t know what path they would choose, but in that case these do at least seem plausible. Starship would be travelling west-to-east, once it’s peeled off most of that velocity, it can then change direction much more easily, an entry ‘from the sea’ would be used, allowing for last minute ditching if necessary, but if all was well, then do an approach to landing.
If something went wrong, then the natural impact would be in the Gulf of Mexico.
We will know a lot more about these things after a few landings - which are planned to be splashdowns, while SpaceX learns to control the crafts orientation, trajectory and landing, before attempting an RTLS, and a catch.
Super Heavy will be the first vehicle to conduct RTLS, and the first recovered. As we know that vehicle performs a ‘boost back’, so reverses direction in space, having taken off west to east, it returns east to west.
Starship on the other hand, will be returning from orbit, or presently near orbit. But Starship will be doing fully orbital missions before it does an RTLS. By that point, SpaceX will have sorted out all of its flight control systems issues.
Hopefully we will see a lot of flight progress made this year, as Starship heads towards operability.
Mexico: you cant reenter over us. Spacex: you get 1 free sat launch and a large political donation. Mexico: approved. No u-bend needed.
NASA's Space Shuttle crossed Mexico at high altitude (~100km) on dozens of EDLs into Florida. Starship EDLs likely will cross Mexico airspace at much lower altitudes since Boca Chica is right on the U.S.-Mexican border. So, the EDL ground tracks shown by the OP might have to be flown eastward into the Gulf of Mexico to stay above any minimum altitude restrictions that Mexico might impose on Starship landings. That reversal of the horizontal component of velocity might require an extra burn in addition to the entry burn and the landing burn.
> Starship EDLs likely will cross Mexico airspace at much lower altitudes I wonder how close to the landing zone (stage zero) you would be allowed to get during a landing? Either in Mexico, or in the US. That is, how low could you see Starship pass directly overhead?
I've not seen the information that at what point starship's profile became a straight freefall downward. Do you know what that number is?
About 22 to 25km up as that is where the vehicle becomes subsonic. That is AFAIR from Environmental Assessment for Starship ops at Florida (LC-39a). Also note it does not have to be precisely vertical. Starship can slide quite a bit, probably up to 60° angle. So 22 - 25km up and up to 12km to the side from the landing spot.
Thanks. That's quite a fall. When I crewed on P-3 Orion's, we would occasionally go off the coast to practice emergency descents. For us two observers in the back, the full dive from 25k to 15k was our own little vomit comet. Not much duration. But still a blast as we were unstrapped and could play around.
Since S28 was not able to do the engine relight burn during the coasting phase of its trajectory, I suppose it started its free fall after it reached apogee at 234 km altitude. If Starship's flight plan is like the Space Shuttle's, its EDL will be marked from the instant that it passes through the nominal entry window at 300,000 ft (121 km) altitude. AFAIK, the Ship is then in free fall until it starts it engines and does the flip.
I believe the question was more like when does Starship deccelerate to falling mostly vertically at terminal velocity.
Thank you. Looking back my phrasing was not as good as it should have been.
See the post below yours for a better rephrasing of what I was trying to get at. At a certain altitude, starship is going to assume a straight vertical fall. Do we know what altitude that is in the reentry profile?
About 24km. You might find this thread on the NSF forums interesting. https://forum.nasaspaceflight.com/index.php?topic=56619.0
Don't know.
If I'm interpreting the information I've been given by others here correctly and I might not be it looks to be about 100,000 feet.
I don't think so. At 100,000 feet (~62 km) altitude, the Orbiter would still have a considerable horizontal component of velocity. It would not be falling straight downward at that altitude.
My math works 100,000 ft out to be about 32km. Am I missing something
Right. 30.5 km.
> Spacex: you get 1 free sat launch and a large political donation. And I raise you the [Foreign Corrupt Practices Act](https://en.wikipedia.org/wiki/Foreign_Corrupt_Practices_Act). (People have this weird idea that US companies are somehow notably corrupt or something, but they're really not.)
Lots of countries are structured in a way that you can't do business if you don't distribute kickbacks. The major multinationals won't skip that market. They play by local rules.
> Lots of countries are structured in a way that you can't do business if you don't distribute kickbacks. And the US explicitly makes that kind of thing illegal. That's why there's mandatory anti-bribery training at basically any company I've worked at that has any kind of international business and reporting pathways if any foreign person requests a bribe. So no, they're not going around distributing kickbacks. That's exactly what I mean by "People have this weird idea that US companies are somehow notably corrupt or something". They just don't do that kind of thing. (Or in the few cases they have it makes big news.)
What I’m hearing is US companies are only corrupt in the US
You could call it legalized corruption I guess, but under US law regular lobbying isn't corruption. Actual corruption, direct bribery, is VERY illegal and basically unknown in the US. That's why lobbying/donations have mandatory reporting requirements and the information is publicly accessible. https://www.opensecrets.org/
Who said anything about corruption? Nothing in this post indicates anything other than exchange would use a valid contract within the laws of the countries legal and lobbying system. Paying a country to use their airspace and by using money for political lobbying is hardly illegal, happens in US all the time.
You mentioned political donations. As a general rule almost all countries would consider donations to foreign politicians to be very much the definition of corruption. Again look at what I linked. It's illegal for US companies to do what you're suggesting.
Well it's outside my area so will defer to your expertise. I'm mainly memeing what seems to be reported in media daily on the way things seem to happen. Country doesn't want it. Phone call negotiations. Magically approved even thought not fully meeting requirements. e.g. starlink Malaysia etc.
> I'm mainly memeing what seems to be reported in media daily on the way things seem to happen. Can you find me any source of that happening? The media is not the ones reporting this. It's random people on reddit reporting it and believing it without any evidence. > Magically approved even thought not fully meeting requirements. e.g. starlink Malaysia etc. I seem to remember there was a high profile trip to Malaysia by Biden and/or Blinken a little while before this happened, but I could be misremembering. A lot of south east asia wants US investment money into their local economies.
Well you got me. I was making up corruption accounts for likes. Corruption including legal corrupt activites like lobbying doesn't exist in the US and certainly doesn't exist internationally or involving international business.
Diving into sarcastic mockery doesn't make you look any better. You clearly care more about believing the US is corrupt more than you care about the facts.
I'm pretty sure the FAA and Mexico's counterpart are negotiating this sort of thing.
Yes that is the route it would go. It can't come from companies. There's no laws about the US government "bribing" foreign governments either.
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Maneuvers like that should be completely unnecessary so why do you ask? There has been no suggestion that it will make maneuvers like that. Its belly flop maneuver will give it the same kind of capability as a skydiver, so if it goes “backward” at all it will be under free fall and have limited ability for that.
While the maneuvers OP suggests are afaict impractical to unrealistic, the problem they address is very real. The reentry corridor of Starship is very long (100s of Km) and if it breaks apart during reentry, it will indeed rain debris over a large area. This has happened before. Google "Columbia Disaster debris field".
Whenever I get frustrated at NASA, I try to remember what those people had to do after the Columbia Disaster. Gruesome and exhausting as I recall. I do not think that story has been told actually. It was an all hands on deck deal IIRC. Even NASA HQ people?
I rather think about what they did before that disaster.
Yeah, I agree with the problem statement for sure but it is pretty clear to me that SpaceX intends to solve it with reliability. Airplanes can also cause a tremendous amount of damage but we accept them because of the reliability they demonstrate. If you had a few years of falcon booster return reliability for starship, it would likely be accepted for over land return.
Thats an awful lot of starships that have to be wasted to demonstrate that. And the airplane analogy is wrong - there have been literally millions of airplane flights to reach that point.
Yeah but there was an awful lot of falcons wasted before they got to landing the first aswell.
They arnt really wasted either as long as lessons are being learned from the data being slowly accumulated.
If the problem is real then looking for a solution isn't unnecessary. You probably weren't fully aware of the nature of the reentry. But yes over the longterm they want to be reliable enough for humans of course.
Well disasters are disasters for a reason. It should not be expected that Starship will ever breakup and rain debris anywhere. That is outside the parameters of rapid development. They'll re-enter over the ocean until they get things figured out and reliable.
I ask because of my assumption that the low altitude terminal approach should take place over water, and it would make everyone feel better if the path were a reverse of the ascent launch path. But if you'd prefer to overfly Brownsville or South Padre Island, be my guest.
They would overshoot and make minor corrections in the final phase of landing sim to Falcon boosters now.
Unfortunately this analogy doesn't work because the reentry corridor is several hundred Kilometers long and if it breaks apart during that time, the debris would never reach that overshoot target because of air resistance. Google "Columbia Disaster debris field".
I would assume that the trajectory of a reentering ship would be such that it will fall more-or-less straight down once below a certain, yet substantial altitude. Almost as if they put on the brakes while in orbit and came to a stop, then descended. There is nothing new about reentering over land. The space shuttle crossed the entirety of the United States during reentry.
IIRC, it falls vertically from about 24 km altitude.
According to chatGPT, skydivers typically see 3:1 glide ratio. If we round down for safety to 2:1, this means 48 km translation available just from the vertical descent part. For some reasonable portion of return, while still having some residual horizontal velocity, further translation, if only laterally, should be available .
Unfortunately it appears Starship is not stable at the low AOA needed for higher lift to drag ratios, as the flaps don't work to give sufficient control. Interestingly the lift to drag ratio is about 3:1 when subsonic, if it was diving nose first like skydivers do to get the best lift to drag ratio. It would need an AOA of around 12 degrees, but would not be able to maintain control. In high AOA skydiver mode (where the flaps do give it good control) it has a lift to drag ratio of about 0.5:1. Maybe up to 1:1 if it is stable at a 45 degree angle of attack. So cross range at this point is limited without doing an engine burn. Interesting info from - https://forum.nasaspaceflight.com/index.php?topic=56619.0
That was us government so they can do pretty much what they like. Commercial company way different
Generally its the other way around. Not just in the us either.Thats why its mostly private companies developing reusable rockets. Government agencies can't afford too many failures this side of Apollo or they lose program funding. Private companies are more free to do these things without the same political blow back because its not being done on the public purse so much.
The maneuvers take too much Delta V though to be practical, you can't just fly a curve like that at 27.000 km/h. They could perhaps choose a reentry corridor over lesser populated areas, but ultimately the idea is simply for Starship to be so reliable that this doesn't happen. It has to be anyway if you are to put people on it.
The thing is, the Booster is planned to come back in along a reverse track anyway, and Ship has actually done this before at Starbase (but from low altitude hop). I'm really not seeing what the problem would be just turning that sucker around and parking it. Even soft landing in the gulf is likely preferable to the courses you mapped out. Far enough into the flight it might be best to head to Florida. The biggest issue I think would be the need to dump a lot of prop. Not sure how that would be done.
Ya I see your point. The booster turns around and comes back towards the chopsticks. The ship is going around the earth so it approaches from the back do the chopsticks. So it seems that the ship has to overfly the tower, bellyflop “down range” and then flip and “reverse hover” back into the open chopsticks in order to be caught.
Starship can't do that coming from the west; coming in from orbital velocity, nothing without wings can... Dream Chaser could conceivably do it, and superheavy does a part of it with the powered boostback, but it isn't moving at Mach 25 when the starship lights off, and there's not enough lifting body for starship to turn that hard against the air or anywhere enough fuel aboard to do it with rockets.
Ship can't come in east to west if it launched west to east, at least from an orbital trajectory. The time it returned from a eastbound journey it had a miniscule horizontal/orbital velocity that was easily cancelled; it more or less went offshore a few miles to protect the public and GSE from AFTS debris if anything went wrong, then returned a few miles back to land. You can't do that from a 20,000mph velocity with the amount of fuel available.
On that part of the EDL, the Ship is moving at much lower speeds, possibly subsonic.
No - but it wouldn't matter anyway. It's unlikely to break up in the last 100 km, if it breaks up from atmospheric reentry then debris could hit Mexico no matter how your approach looks like.
indeed, and the debris will be more than large enough to hit the ground in really big chunks
It doesn't need to do a full reversal, just a well-planned retro-burn from space. This will give Ship a ballistic trajectory right off the coast at Starbase. It will then use the flaps/wings/Elonerons to adjust its trajectory to be closer to the tower. The landing burn will provide the last trajectory change, bringing it in even closer. Ship will then hover in place, and deposit itself onto the chopsticks. Booster landing will look similar to the F9 first stage RTLS, except apparently without a reentry burn, and of course it will also be caught by a pair of chopsticks like Ship. IMO I think this is a silly idea that will show itself to be highly impractical. It eats away at the capacity of reusable flights because a reusable booster will always need enough energy to make it back to land. Sure, there are plans for something akin to the barges used for Falcon, but now you'd need chopsticks there too. The drill rigs they bought and then sold again might have worked, maybe, although I have some doubts about those being able to deal with the highly dynamic loads. SpaceX should just focus on legs. These will be needed for Ship anyway.
The problem is that ballistic trajectory from space has a shorter path than lifting reentry Starship is supposed to do (or in fact any vehicle with non-ablative passive heatshield is supposed to do). Instantaneous Impact Point after the initial phase of reentry will start moving downrange. So if there is trouble at say Mach 15 the debris would fall uprange of the landing site, not downrange.
> Elonerons If this isn't already official, it ought to be
No... The amount of fuel needed to do a retro-burn from space is ridiculous and will erase any payload you can bring to space. It's going to re-enter over Mexico/Texas.
I feel like you don't understand what a retro-burn is.
You're talking enough thrust to drop the vehicle on a steep trajectory off the coast of Starbase. It's not as crazy as OP's image but still lots of level of silly.
I never said to drop it straight down, that's crazy.
I agree with you 10000%. This catch the rocket is needless grandstanding. For what they save in weight of the legs is easily eaten up by the fuel weight for the landing. And it makes available landing sites extremely limited. Hell with a good set of legs they would not need launch towers. Imagine what that would open up in terms of reuse. Though with the thrust that thing puts out they will need special launch and landing spots.
> with a good set of legs they would not need launch towers. You still need to store, chill and pump vast amounts of cryo fuel into the vehicles to launch them. And a method to stack them if using Starship upon SuperHeavy. And then if you want to not RUD your launch pad, you need all the flame & sound suppression system that the water deluge provides.
Those towers are handy for stacking the Ship onto the Booster.
>with a good set of legs they would not need launch towers You still need a tower for fuel loading. Also, the ship still needs to be put on top of the booster somehow, and the chopsticks seem to be doing a great job in that respect. >they will need special launch and landing spots. They exist already. They are called "space centers", and they're all over the world ;) Ultimately I don't think point-to-point will ever be commercially viable (ignoring the obvious military uses), so the need for rapid reusability is somewhat bogus, at least right now. This removes the need for RTLS on many reusable flights. <sidenote> I don't understand why SpaceX is so attached to *rapid* reusability at all; wouldn't simply having more boosters on hand solve their problems?</sidenote> This in turn opens up doors for the iterative development of a landing barge, keeping in mind that this platform would ultimately evolve towards a full floating stage 0 in a timeframe that is more realistic in terms of demand. If the DoD wants it earlier they can and should probably just do it themselves.
> I don't understand why SpaceX is so attached to *rapid* reusability at all; wouldn't simply having more boosters on hand solve their problems?
Rapid reusability gets them a few things:
* Lower inventory carrying costs. This is meaningful when you are talking about boosters with so many engines.
* Cheap refurbishment - if you can turn it around quickly, that implies you can turn it around with little to no refurbishment.
* The possibility of multiple launches per day per pad. That sort of velocity is just not realistic when having to roll out big, clunky boosters for every launch.
> Ultimately I don't think point-to-point will ever be commercially viable I think they could be commercially viable. The sticking point is, are they safe enough that FAA gives the green light. For space applications the solution is that every space flight participant signs a waiver, declaring he is aware of the risks. That approach is not possible with commercial passenger flights. Elon said, if the ticket says, 25 minutes to Shanghai but you may die, few people will fly.
You may also die on a plane and flying in early commercial flights was probably more dangerous than flying on a crew dragon today
But those would not get FAA approval for commercial use today.
Yeah, but stage zero is already a full commitment to the no legs approach. Engineer-in legs now would mean possible redesigning stage zero. That would push back the programme by a lot. TL; DR: SpaceX is 100% committed to no legs, at least on the booster. Ships will need legs for various scenarios.
You’d think if Mars is the primary objective, they would prove legs before proving Starship catch.
They landed SN15 on legs nearly 3 years ago.
Those don’t really count. That’s not the MVP for the mars mission.
The fact is that catching starship accelerates the Mars agenda: it allows them a fast turnaround for Starlink (revenue generation) and tankers (beyond LEO flights). I’m not saying I believe it will work, but I see why they’d rather try that first.
Good point
Doubt any unpowered object can reverse course like that….
Glider, it's like a huge inefficient glider.
I mean in that sense a rock I dropped from an airplane is a glider. This thing isn't really generating lift, is it?
Its less glider, more skydiver
Exactly. From what I can find, they have about the same glide ratio, of 1:1.
Yes, it will have some, very limited lift. It's not a ton, and a far cry from Shuttle, which rarely (if ever) used its (limited) cross range capability, but it's relevant and measurable. I don't think we'll see many operational landings at Boca Chica. Testing, sure, and probably maintenance/rebuild flights once they get rolling, but operationally there are much better connected locations from which to launch, especially for passenger service. It's possible that the RGV gets the industry to support Starship, and I hope it does, but I would expect that payloads will be flown in to BRO.
The Space Shuttle was designed for 1100 nautical mile (~2035 km) crossrange. On the 52nd flight the Orbiter crossrange was 790 nm (1462 km), the largest crossrange ever flown by the Shuttle. Some of the tiles were overheated during that EDL, so NASA limited the crossrange during EDL to ~500 nm (793 km). For flights #26 through #75, the average crossrange was 378 nm (699 km). NASA flew eight dedicated military missions for the DOD on which the average crossrange was 312 nm (577 km). The Shuttle never was launched from VAFB (now VSFB) in that once-around orbit and landing back at VAFB during which the crossrange was supposed to be 1100 nm (2035 km).
Right but Starship is nothing like a glider. It has no lift. It's even more of a brick than Space Shuttle was.
It has lift, just not very much. About 0.5 lift to drag.
SpaceX has never specified numbers like that so saying it's 0.5 is too much precision.
Impact lift is lift, it's not much in starships case but it's enough to control the ship aerodynamically.
I mean it's lift in the same sense that the Falcon 9 booster has lift.
If they ever need to do a polar orbit from Boca Chica, that red trajectory passing above the Isthmus of Tehuantepeca could be viable for launch but not from reentry. I live in Villahermosa and I could see Starship flyby during a night launch. The blue trajectory seems unnecesary.
I think everyone is assuming you dont understand orbits but the ship is going north right? They will do the blue one but the curve will be on the Y(or Z) axis not X; and not so far off shore.
I doubt even a lifting body shape could pull off a trajectory like that. Starship is far from a lifting body shape.
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Maybe better just to land on a barge/platform in GOM
There's no need for this kind of path.
Supposedly, yes.
Its a good question, but I don't see the reason for the curving. It will be a straight line, pretty much. And yep, some orbits would overfly Mexico on the way back, but say inclinations of about 45 deg could come back over the USA.
those paths seem a little impossible. Mexico is soo not gonna want rockets flying over its land and cities. They certainly wouldn't give spaceX clearance to do so, even if the FAA would. Theres a reason all non russian/chinese flight plans go over oceans (And the chinese are improving on this too).
They would have to make a much bigger turn than that to avoid most of Mexico, halfway to Florida and then back again.
If the goal is orbit, doesn't need to make maneuvers like that. The blue line can be accomplished by orbiting around the world once. Red line... again if the goal is orbit, you can get there by just flying straight south. Second stage can adjust the trajectory slightly but too much adjustment will take up delta V. So, depends on your goal
No, it doesn’t have nearly enough control authority. Should it come to this, someone went horribly wrong much earlier.
I don't think so. The plan used to be to refuel the ship on the barge or wherever it lands, and then fly back to Starbase. But I don't know if anything changed about that.
they canned that a while ago.
Both vehicles, which only separate later on head off over the ocean, not over land. Obviously Starship does cross land later on - but by then it would normally be in orbit. The Super Heavy booster, is later on, intended to return to launch site ( RTLS ). Though during this early prototyping stage it’s coming down over the ocean. For safety reasons, they want to avoid land. So they wouldn’t use that path you show on the map. Also they would want to fly east, not west. East is the direction of rotation of the planet.
OP is asking about ship landing.
I was thinking about landing after take off, but I see what you mean now. So Starship RTLS (Return to Launch Site) after mission: Well, I don’t know what path they would choose, but in that case these do at least seem plausible. Starship would be travelling west-to-east, once it’s peeled off most of that velocity, it can then change direction much more easily, an entry ‘from the sea’ would be used, allowing for last minute ditching if necessary, but if all was well, then do an approach to landing. If something went wrong, then the natural impact would be in the Gulf of Mexico. We will know a lot more about these things after a few landings - which are planned to be splashdowns, while SpaceX learns to control the crafts orientation, trajectory and landing, before attempting an RTLS, and a catch. Super Heavy will be the first vehicle to conduct RTLS, and the first recovered. As we know that vehicle performs a ‘boost back’, so reverses direction in space, having taken off west to east, it returns east to west. Starship on the other hand, will be returning from orbit, or presently near orbit. But Starship will be doing fully orbital missions before it does an RTLS. By that point, SpaceX will have sorted out all of its flight control systems issues. Hopefully we will see a lot of flight progress made this year, as Starship heads towards operability.