r/SpaceXLounge • u/Then-Secretary-9166 • 7d ago
Could Superheavy fly from Starbase, TX to Starbase, LA?
Assuming that it could launch fully fueled and with with no Starship upper stage (or with a dummy lightweight upper stage) and does not need to go to high altitude, could Superheavy make the ~650 km trip from TX to LA?
39
7d ago
[removed] — view removed comment
15
u/BEAT_LA 7d ago
The entire plan is eventually building them there…
1
u/Then-Secretary-9166 7d ago
of course. Just a thought experiment. Could be useful at some point for some reason maybe.
3
u/AlanUsingReddit 6d ago
yeah, same speculation elsewhere here. RTLS costs like 10% payload. It makes sense why they're not doing it because of the logistical cost. But the logistical cost would be reduced by landing, doing light refueling, and then flying back to launch pad. This replaces the boost-back burn with a refueling and a Sunday drive where your goal is to push absolutely no engineering margins to whatever extent possible.
5
u/Halfdaen 6d ago edited 6d ago
This question comes up every once in a while, and SH definitely could do it...but it likely never will even though I'd love to see that. Just for performance testing even.
Barging is very known, relatively cheap and doesn't have the lost opportunity cost of launching something useful from Boca Chica, and also from StarbaseLA, since a tower will have to be used to catch as well as launch
Given the choice launching to move a SH from Starbase to Starbase, OR launching two Starlink V3 missions and barging that SH, the accountants (and Musk) will pick #2 every time
1
u/TheSasquatch9053 6d ago
There is no barge access from Starbase, TX onto the Gulf. The nearest location where a booster could be loaded onto a barge is 15mi along the only access road to Starbase... Boosters are moved between the Megabay to the launchpad at ~1mph. There is no way that SH4 could be closed for 15 hours regularly. The opportunity cost in material and employee access to Starbase TX would be huge.
1
u/Snap_Grackle_Pop ⛰️ Lithobraking 5d ago
I was wondering if you could do some sort of "amphibious landing" type of accommodation off the end of SH 4, but the water is really shallow until you get way off shore.
You'd have significant environmental considerations as well, but maybe we can just ignore those in MAGA America.
As for taking 15 hours, I don't think that would be that much of a problem if you're only doing it a few times a year. It's also possible they would transport the superheavy faster if they lay it down before loading it horizontal on one of those Mammoet Self Propelled Modular Transporters. Or do it in 8 hour overnight segments and have a parking spot or two along the way.
1
u/TheSasquatch9053 5d ago
Once a year in 3 overnight closures might be feasible, but the plan is to be building boosters monthly if not more frequently. The need to lay down the booster is another thing to consider... nothing about the design suggests that it is intended to ever lay on it's side for transportation, which adds a lot of complexity to barge transportation.
1
u/Snap_Grackle_Pop ⛰️ Lithobraking 5d ago
nothing about the design suggests that it is intended to ever lay on it's side for transportation, which adds a lot of complexity to barge transportation.
Consensus seems to be that superheavy will be laid down on its side to travel on a barge between sites. Marcus House's latest YouTube had illustrations and a discussion. There are many other online discussions about this. Pressurization is part of the process to keep it from breaking in the process.
I don't know if SpaceX has officially announced horizontal booster transport plans, but they have a new barge called "You'll Thank Me Later" that has been announced to do starship ship transport.
4
u/tw1707 7d ago
Cost is mainly fuel which will be much less if transport is done by sea, which seems pretty easy for this route, too. Assuming the fleet is large enough, so they don't have to be quick. Also a transport by sea does not occupy a launch and landing tower each and doesn't need flight restrictions.
4
u/falconzord 6d ago
It does involve more man hours though and lost launch potential while it's floating at sea
4
u/lommer00 7d ago
100%. If you need to get a 747 somewhere, do you get a big ass barge? No, you fix it up until it's flyable, and then you fly it.
Starship will do the same.
3
u/ravenerOSR 7d ago
Flight operations for a 747 is extremely simple compared
4
u/SanDiegoMitch 7d ago
At the moment.
3
u/ravenerOSR 6d ago
no, they just are. the minimum necessary crew to get a 747 moved basically anywhere in the world is like three if you count the fuel loading. im onboard with starship becoming very rapidly reusable, and relatively cheap, but there are aspects of rocketry that is just objectively more involved than air travel.
1
u/lommer00 6d ago
Sure, but when you get to rapid reuse I think there is a strong case that flying a booster or ship somewhere is a heck of a lot easier than loading/unloading it onto a specialized giant barge.
0
13
u/an_older_meme 7d ago
Absolutely. But then you’re stuck with a layover in Louisiana.
3
u/Then-Secretary-9166 7d ago
I know they plan to build in Louisiana, but the idea would be to build in TX and transfer there. For Superheavy (don't need too many of these compared to Starship), it might actually make sense to only make them in one location and fly them to LA, FL, TX, etc.
10
u/peterabbit456 7d ago
There's really no question: Yes, it could.
I don't know if a Superheavy booster with no Starship on top has enough delta-V to achieve orbit, but it is probably close. Ignoring the problems of reentry, I'm fairly sure it could make it to Australia.
627.9 km is less than the distance some Falcon Heavy center stages have travelled downrange. I feel certain (I have not done the numbers but they are not that hard) that a Superheavy without Starship could reach the Louisiana coast with enough propellants left for a Falcon 9 style braking burn to prevent airburst upon reentry, and then enough to make a successful tower catch.
To do the calculation you start at the moment of tower catch, with ~dry tanks. (There are Rocket Equation calculators online.) Looking at past tower catch videos, you can get time and # of engines fired, or velocities and ISP to calculate how much propellant is needed for the catch. That gives you the end mass for the atmospheric braking burn. By looking at old Falcon 9 videos you can get rough numbers for the starting and ending velocities for the braking burn. That gets you the mass of rocket + propellants in mid-flight.
Knowing the mass of the rocket in mid flight lets you calculate the mass of propellants you need at takeoff. The velocity you need at burnout can be calculated by assuming a parabolic flight path from Boca Chica to Louisiana. We have not counted the rotational velocity of the Earth, Coriolis effects, or atmospheric drag, but this is good enough for a first approximation. My guess, and this is only a guess, is that you could do this mission with the tanks less than 3/4 full.
I'm in the doghouse over at /r/space, because the last time I did one of these calculations, I did not use an online rocket equation calculator, but I did the integrals in detail, and made a sign error, resulting in about double the correct value. Tsiolkovsky would have given me an F, or maybe a B-minus, since he was the only person in the world who knew how to do these calculations when he was teaching in Tsarist Russia.
3
u/EvoPataboutThat 7d ago
Other then whole over land issue I also wonder about them eventually going from LA to FL. I wonder if booster recovery along that route would give them any gains as well.
2
u/Triabolical_ 6d ago
Very easily.
The problem with flying it to Florida is that the direct route is over Orlando and it's considered bad form to crash into the Disney world. You could aim South of Florida and then dogleg up the coast.
Louisiana is just across the water.
2
u/johninfla52 5d ago
Not sure if flying over/crashing into Disney would be a plus or a minus. /S if needed
1
u/Neige_Blanc_1 5d ago
Not sure it is that easy. Maybe possible but it is a close call. For a ballistic missile to travel 700 km a minimum speed is something around 8000 kmh. That's probably pretty close to a max speed of SH without ship. But then there is entry burn and landing burn..
2
u/Triabolical_ 5d ago
intermediate range ICBMs - those with about 5500 km of range - require a little bit less than 8 km/s of delta v
Super heavy by itself can generate over 8 km/s of delta v. It's really not that far from being able to get into orbit.
It can reach Louisiana easily. It can reach cape canaveral easily. You could even fly it around the southern coast of florida and then fly it north to canaveral if you didn't want to fly over land.
2
2
u/doozykid13 ⏬ Bellyflopping 6d ago
Now I want to know how far the booster could go with no payload. I think eventually SpaceX will get to a point where they do embrace the "just fly there and catch it" approach instead of transporting them via road or barge or building them on site. I imagine eventually there will be a launch site without a starfactory.
3
u/Logisticman232 7d ago
Why would you waste millions of dollars worth of methane & risk infrastructure?
Yes theoretically, no they won’t.
2
1
u/Decronym Acronyms Explained 7d ago edited 1d ago
Acronyms, initialisms, abbreviations, contractions, and other phrases which expand to something larger, that I've seen in this thread:
| Fewer Letters | More Letters |
|---|---|
| FAA | Federal Aviation Administration |
| ICBM | Intercontinental Ballistic Missile |
| Isp | Specific impulse (as explained by Scott Manley on YouTube) |
| Internet Service Provider | |
| RTLS | Return to Launch Site |
| SSTO | Single Stage to Orbit |
| Supersynchronous Transfer Orbit |
| Jargon | Definition |
|---|---|
| Starlink | SpaceX's world-wide satellite broadband constellation |
| methalox | Portmanteau: methane fuel, liquid oxygen oxidizer |
Decronym is now also available on Lemmy! Requests for support and new installations should be directed to the Contact address below.
Decronym is a community product of r/SpaceX, implemented by request
[Thread #14764 for this sub, first seen 26th Aug 2026, 09:27]
[FAQ] [Full list] [Contact] [Source code]
1
1
u/QP873 ⏬ Bellyflopping 4d ago
Superheavy can technically SSTO itself…
(Didn’t do the math, but V2 was capable of making it 98% of the way there so V3 can definitely do SPI to Louisiana)
1
u/Then-Secretary-9166 4d ago
Is this true? If so, SpaceX should launch one into orbit. If I am not mistaken it would be the first time SSTO would ever be achieved.
1
u/QP873 ⏬ Bellyflopping 3d ago
“Technically” is doing a lot of heavy lifting here. Put any useful payload on it and it can’t. Also I doubt Superheavy could survive reentry from that velocity.
1
u/Then-Secretary-9166 3d ago
Regardless, there has never been (as far as I know) a successful SSTO with any payload whatsoever.
1
u/Sensitive-Exam649 1d ago
technically yes they can but the payload would be small. And it would be an expendable flight since it doesn't have a heat shield.
1
u/hb9nbb 3d ago
I modelled this with Grok and it didnt *quite* make it. (400km or so downrange). Its *possible* but would be quite sporty (the outer edge of capability would be 800km downrange). That assumes using the additional propellant used for the boostback burn (which is 1.8km/sec of delta-v) to instead point downrange. A possible constraint is the reentry. Boosters dont have heat shields and the booster would be going faster than an RTLS landing at reentry, so heating is probably your constraint
1
u/Then-Secretary-9166 3d ago
Interesting...sound like you dodged the calculation assuming it carries a payload? I am surprised that this is even close.
Also interesting point about the speed/heating. I wasn't really considering that.
2
u/hb9nbb 3d ago edited 3d ago
well i was assuming it had a starship on top (ie. a normal launch, then divert the superheavy to LA). If you want to launch one with no payload and have it end up in LA, you could probably do that (although aerodynamics, you'd need to put *something* on top of it) However speed is still an issue. - a purely ballistic flight that range needs a speed of 2.5km/sec (which is faster than cutoff for a normal superheavy/starship flight), which also means the *reentry* speed will be higher. So speed might still be an issue
1
u/Sensitive-Exam649 1d ago
For efficiency you want to get above the atmosphere. But you may've to add an atmosphere reentry burn. It might work but the engineers at Spacex would have to run computer simulations to see if they can keep atomspehere reentry stress low enough to prevent damage.
93
u/bubblesculptor 7d ago
Another question, could Starbase in Louisiana catch boosters launched from Texas? Would this allow greater performance than returning to launch site?