When Starship achieves decent cadence (probably sometime next year), I can see that the cost per single launch might be higher than F9’s for a bit, but surely FH’s market would be entirely covered within a year or so?
The full video from where this short have been cut from (only 4:24): https://youtu.be/\_meDQry3sf8?is=BZ6CjKDNE7R40EvD
Just some considerations on ball bearings vs. Hydrostatic bearings.
His previous video also has commentary on rocket engines: https://youtu.be/HCupuEVCGOU?is=F6-WekZcTpatq2tI
Source tweet: https://x.com/\_maxq\_/status/2072793203456008368
Comparing the startup sequences for the 6 engine static fires for Ship 40 vs Ship 39,
Ship 40 lit 2 Rvacs and the adjacent sea level Raptor before then lighting the remaining Raptors, which is very different from Ship 30, which lit the 3 Rvacs simultaneously, then one sea level Raptor (it seems, video cuts out before full ignition).
This lends credence to the theory that the timing of the Starship raptors led to the off-axis rotation of the Super Heavy after stage separation.
It will be interesting to see how the asymmetric thrust will affect the Starship as it lights and separates from the booster.
The calculations are done on an Excel spreadsheet.
Starship = the Booster (the first stage) and the Ship (the second stage)
The flight data are extracted from the information SpaceX provides on the video. The time step for analyzing the Booster flight data is 5 seconds and 10 seconds for the Ship. The time interval during the flight for the Booster extends from liftoff to staging and, for the Ship, from staging to the second-stage engine cutoff (SECO-1). I don't analyze the Booster return to launch site (RTLS) data. It's enough work just to analyze the launch to SECO-1 flight data.
That flight data includes the time after launch (Time At Launch (TAL) + x, seconds), altitude (km), speed (km/sec), flight path angle (FPA, radians), the propellant mass remaining at each time step during the engine burn (t, metric tons).
The flight path angle is used to calculate the gravity drag in meters per second using numerical integration. In IFT-12, time at staging is TAL + 135 seconds and SECO-1 time is TAL + 560 seconds.
The propellant mass flow rate (t/sec) is calculated from the propellant mass remaining divided by the time step. Engine thrust can be calculated from propellant mass flow rate and the engine specific impulse (sec), however, thrust is not explicitly needed in this analysis.
On the IFT-12 launch the Starship trajectory was vertical (FPA = 90 degrees) from liftoff to TAL + 20 sec and then the Booster flight computer started the gravity turn. The Booster flew on that trajectory until staging. Then the Ship flight computer took over and continued the flight on a gravity turn trajectory until SECO-1.
Since the Ship is the payload for the Booster, the Ship performance has to be calculated first, i.e. we need to estimate the Ship’s dry mass before the Booster analysis can begin. So, the calculation proceeds in a top-down fashion.
To calculate the Ship’s dry mass, we need an equation of motion (EoM) for the Starship. That’s the Rocket Equation, which is a result from Newtonian physics via the conservation of momentum equation. For this analysis the Rocket Equation, which is a transcendental equation (contains exponentials or logarithms), is written in its exponential form. The exponential is on the left side of the EoM and its argument contains the Starship dynamics (speeds and engine parameters). The right side of the EoM contains all of the masses that define the Starship (dry masses, payload mass, propellant masses, header tank mass, crew-related masses, etc.).
The two unknowns are the Booster dry mass and the Ship dry mass. You plug in all of the flight information on the left side and on the right side you plug in all of the mass information. Then you set up the equation
Diff = Left side - Right side.
Then the Excel “Goal Seek” operator uses iteration to drive the Diff to zero by changing the only independent variable, the dry mass. The Ship is analyzed first to calculate its dry mass. And then the Booster dry mass calculation is done in a similar fashion. Since the EoM is satisfied as long as the engines are providing thrust and the velocity is changing, you can select any time interval you like during the engine burn and run the analysis. For IFT-12, I chose the interval between TAL+25 sec and TAL+105 sec, which is the entire part of the Booster’s gravity turn trajectory. For the Ship I chose TAL+330 sec and TAL+450 seconds that’s roughly in the middle part of the Ship’s gravity turn.
Block 3 Ship IFT-12 flight data analysis IFT-12 AO98
Analysis starting time TAL + (sec) 330 AO99
Analysis ending time TAL + (sec) 450 AO100
Ship velocity at start of time interval (m/sec) 2628 AO101
Ship velocity at end of time interval (m/sec) 4383 AO102
Ship gravity drag during time interval (m/sec) 168 AO103
Boca Chica TX latitude (deg) 25.99 AO104
Earth rotation delta V at Boca Chica (m/sec) 418 AO105
AO106
Header tank mass (t) 35 AO107
Ship payload (t) 38.5 AO108
AO109
g0 (m/sec^2) 9.807 AO110
AO111
Number of Raptor 3 sealevel engines 3 AO112
Number of Raptor 3 vacuum engines 3 AO113
Raptor 3 sealevel engine Isp in vacuum (sec) 350 AO114
Raptor 3 vacuum engine in vacuum Isp (sec) 380 AO115
Average Raptor 3 Isp for Block 3 Ship (sec) 365 AO116
Ship propellant mass at end of interval (t) 661.3 AO117
AO118
Ship delta V in the time interval (m/sec) 1,755.0 AO119
Ship gravity loss during time interval (m/sec) 168.10 AO120
Isp (sec) 365 AO121
Ship propellant mass at start of time interval (t) 1,305.1 AO122
Ship propellant mass at end of time interval (t) 662.0 AO123
AO124
Block 3 Ship dry mass estimate (t) 168.7 AO125
Left 1.71128671 AO126
Right 1.71130161 AO127
AO128
Diff -1.4897E-05 AO129
LEFT=EXP((AO119+AO120)/(AO110*AO116)) RIGHT=(AO125+AO107+AO108+AO122)/(AO125+AO107+AO108+AO123) DIFF = LEFT - RIGHT
Since the information extracted from the flight data inevitably has noise contamination (errors), the dry mass estimate calculation is repeated numerous times by varying the propellant-remaining measurement at the end of the time interval by +/- 5% to determine a final estimate of the average dry mass and the standard deviation.
Block 3 Booster IFT-12 flight data analysis IFT-12
Analysis starting TAL + (sec) 25 AO27
Analysis ending TAL + (sec) 105 AO28
Booster velocity at start of time interval (m/sec) 405 AO29
Booster velocity at end of time interval (m/sec) 671 AO30
Booster delta V analysis TALs (m/sec) 266 AO31
Booster gravity loss TAL starting to ending (m/sec) 132 AO32
Booster propellant mass at analysis start TAL (t) 2,311 AO33
Booster propellant mass at analysis ending TAL (t) 1,851 AO34
AO35
IFT-12 Block 3 Ship mass at liftoff (t) 2,523 AO36
AO37
g0 (m/sec^2) 9.807 AO38
Isp (sec) 350 AO39
Booster dV at analysis TAL starting to ending (m/sec) 266 AO40
Booster gravity loss TAL starting to ending (m/sec) 132.2 AO41
Booster atmospheric drag loss (m/sec) 13 AO42
AO43
AO44
Booster propellant mass at analysis start TAL (t) 2,311 AO45
Booster propellant mass at analysis end TAL (t) 1,736 AO46
Ship liftoff mass (t) 2,523 AO47
Interstage ring mass (t) 11 AO48
AO49
AO50
IFT-12 Booster Block 3 estimated dry mass (t) 267 AO51
AO52
Left 1.12731 AO53
Right 1.12684 AO54
AO55
Diff 0.00047 AO56
LEFT: = EXP((AO40+AO41+AO42)/(AO38*AO39)) RIGHT: = (AO51+AO45+AO47+AO48)/(AO51+AO46+AO47+AO48) DIFF = LEFT - RIGHT
I reposted this from another thread cause it was getting ignored. I am genuinely puzzled by this.
For the BLUE Moon option, how does Orion get to LLO now? I don't think New Glenn has the delta-V to take Orion and Blue Moon to LLO. On top of that, Blue Moon appears to have its docking port on the side which would rule out New Glenn taking Orion and Blue Glenn together to LLO even if i had the delta-V.
Maybe Starship HLS goes on every Artemis mission? When Blue Moon lands, HLS starship hauls a bunch of cargo on a one way trip to the lunar surface?
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Purpose: To estimate the dry mass in metric tons of the B19 Booster and the S39 Ship.
-Results for Block3 Starship (IFT-12):
B19 Booster dry mass: 257t +/- 9.4t. S39 Ship dry mass: 172t +/- 5.3t.
-Results for Block 2 Starship (average of IFT-7 through IFT-11):
Booster dry mass: 281t +/- 11.4t. Ship dry mass: 161t +/- 3.6t.
-Results for Block 1 Starship (average of IFT-3 through IFT-6):
Booster dry mass: 279t +/- 9.3t. Ship dry mass: 149t +/- 6.5.
So one of the things they described as a use for Starfall was in space manufacturing, using Starship to deliver raw materials up to space then using Starfall to bring them back.
The problem is, I don't... entirely get why that would make any sense. Or more specifically, I don't get why that makes any sense logistically when we already have a ginormous, rapidly reusable and highly controllable reentry platform available; Starship.
If you are using Starship to send up raw materials to something like an LEO manufacturing facility, why not use that same Starship to bring it down? You don't have to send up a bunch of extra heat shield material since you are just using the heat shield Starship has, and you don't need any kind of sea based recovery system since you can just catch it in the chopsticks and unload the cargo on the surface and get it into trucks.
And even if you don't have a massive space factory, why not just do all the manufacturing internally in Starship? If it's just showing a proof of concept, why not just set up a system in Starship to make whatever it is you are making, then land and recover it on Earth? Why have a redundant reentry system in the first place? People love talking about the idea of just having Starship act as temporary space stations, and for this specific use case that would actually make a lot of sense, or at least more sense than using Starfall for it.
It just kinda feels like "LEO manufacturing" was one of those things thrown into the Starfall announcement to boost the IPO tbh. I'm not saying it won't have 0 use, I think the fact that SpaceX has gotten to the point of launching and testing them proves otherwise, however I just really doubt that LEO manufacturing is gonna actually be a major use for it
EDIT: also ignore the typo in the title I can't change it lol, meant to say "With starship available"