CBase

This will improve with scaling of starship. Falcon 9 booster has 152 m² side area and 25t dry mass, SH 639 m² and estimated 200t dry mass. For commercial planes size makes it easier in bad weather as well.

quality of video feed during reentry and landing is really amazing If just his streaming company could hold up with higher res quality

There are quite some studies available: https://www.gnedenko.net/Journal/2009/022009/RATA_2_2009-05.pdf At least the german wikipedia webiste has the Francise scott key bridge listed to use floating protections at ~100m distance from the pier, which can be run over by very large vessels like that container ship.

I am physicist and no engineer, so take my guess with a grain of salt. When the passage and safety margins are big enough, you could probably build concrete islands around the piers and divide crash forces off them. Basically the crash should happen somewhere else. A ramp does a great job to transform velocity to lift the vessel, use its mass to increase friction and push the static structure not only away, but into the ground. Maybe with crash boxes and structures to divert forces could be build in smaller locations as well. But I doubt building stronger is a viable solution.

We can actually look up what triggers a mishap investigation at https://www.faa.gov/space/compliance_enforcement_mishap (with emphasis by me): Since the official flight plan probably did not contain a a disassembly at the actual altitude, formally both conditions match for either stage. At least somewhere I read that booster did not splash down, but expierenced a RUD at ~400m altitude (however I can not find the source right now). So

I am curious how SpaceX will change the ship for IFT-4. If I had this playing Kerbal, I would probably integrate an overkill of control thrusters and accept temporarly a reduced payload. Any payload to destination is better than none. When piloting is mastered, I would reduce thrust limits to see what I actually need and then refine build to match actual demand for control.

You are absolutely right, the payload costs are not the dicisive factor. The question is will next flight be orbital or stay suborbital. But thinking of it, maybe you are right: Even on a suborbital flight testing with a real Starlink satelite is probably much faster, realistic and therefore cheaper than trying to mock the satelite.

My guess is that they will put a dummy payload about the size and weight of starlink 2 into IFT-4 while still staying in a suborbital trajectory. That way they can test payload dispensing during coast, improve attitude control and engine relight while staying inside a flight envelop that keeps FAA happy. Depending on the result they might go for orbital trajectory and actual starlink payload in IFT-5.

By all the fancy targets of SpaceX let us not forget what the primary objective of rockets is: delivering a payload to its target orbit. Shown with IFT-3: ✔ Liftoff ✔ 1st stage burn ✔ stage seperation ✔ 2nd stage engine start ✔ 2nd stage burn ❌ control authority during coast phase ? second stage engine relight (some of us might conclude that the capability was demonstrated with 1st stage, few experts on this forum see it as raptors major issue) ✔ payload door opening ? payload seperation / dispense In my personal view they are damn close to having an operational, ultra heavy, orbital class rocket. So true. Just like Falcon 9 all the fancy reuse stuff will come as they use it for delivering payload and start to get return on investment.

From https://www.nasa.gov/image-article/nasa-spacex-test-starship-lunar-lander-docking-system/, emphasis by me. Nice progress

I am not sure I want to fly on Boeing planes anymore. Most recent information from an internal source: https://leehamnews.com/2024/01/15/unplanned-removal-installation-inspection-procedure-at-boeing/#comment-509962 (you have to scroll for part 2).

SpaceX was required to submit a mishap report for IFT-2, if I recall it right. The last time when FAA accepted the mishap report it took SpaceX 2 days to submit all paperwork that corrections are performed and FAA 7 weeks for 63 issues to check the paperwork. If I read above statement as by end of Jan they will have the latest mishap report completed, it will depend on how many issues are on the list. Certainly less than last time, so 1-2 weeks should be realistic for checking all paperwork that all corrective tasks are completed. And finally it might take SpaceX as well some days to find ideal conditions. Yeah last week of Febuary sounds likely.

Seriously how antique is Boeing manufacturing ? From automotive I do know that all "A" quality class screws are fastened with an eletric screwdriver which documents final torque and angle in a quality system. No way you could skip any screw or not reach appropiate torque. I do understand that 737 MAX production shutdowns made it hard to get good production line worker, but that is a poor excuse for lack of quality systems in place. And in 2023/24 another person with a pen to set a checkmark on paper is not industry standard quality control.

Congrats to ULA for successful launch After hundreds of SpaceX launches it is strange not to see any telemetry, see animations instead of live feed. Except for liftoff you could follow it on the radio Oh and is ULA really all imperial or just translating it ?

I doubt the header tanks contain 10 metric tons of liquid hydrooxygen. According to multiple sources that is the amount to transfer. More likely something is installed inside payload area.

My point is that they were probably right to go for IFT-1 without the deluge system. Real life testing showed a point where stage 0 simulations missed a critical point. By moving fast to IFT-1 they got the correction early. Beyond technical issues I guess the biggest change was to adopt risk assessment to align more with goverment oversight. I do think SpaceX attitude to taking risk is beneficial to space industries. Elon did prepare SpaceX for loosing a lot of vehicles as they go. But the mishap reports seem more painful than loosing a booster.

maybe, maybe not. CSI Starbase had a pretty good analysis that the ground shockwaves and breaking foundation caused stage 0 failure in first place. The steel plate might have been strong enough to support the foundation, but might have failed as well. And failing after installation of the deluge system would have made foundation upgrades more difficult. rotational impulse was my first thought as well, as it is preserved. Actually the moving CoM betweent 2 ships might help as the donator tanks spins more the less fuel it has. For IFT-3 demonstration they could place 4 tanks in rotational symmetry with full tanks vis-a-vis and full and empty side by side. This way during ascent load is balanced and for the first attempt CoM stays at center.

Several medias like arstechnica meanwhile provided information that the tank to tank demonstration should amount 10 metric tons ! Small compared to starship scale, but definetly breaking grounds in microgravity.

Just curious, but how do you demostrate propellant transfer with a single vehicle ? Any idea what we could observe during IFT-3 ? My kerbal conception would have been rendeveaus of two spacecraft, docking and fuel transfer via docking port. But I doubt we see this with IFT-3, so there must be something else to expect.

The idea of SH central engines to fire was to keep positive acceleration. Instead of backing off from this: Could they increase thrust and keep acceleration high enough ? Maybe add some perforated sheet inside the tank bottom to reduce lateral movement as long as there is positive pressure.

Are there yet any rumors about the FAA mishap report on IFT-2 ? I would love to see an IFT-3 this year and for sure SpaceX would have the vehicle ready in time. So any news on bureaucracy ?

Propably wouldn't matter if you place CoL close enough to CoM. Wings could translate vertical speed to horizontal speed on return, whichs saves fuel for a boostback. But they add weight which costs fuel on ascend. My gut feeling is that mostly the TWR difference makes it way more expensive at launch.

Booster...actually at the moment I do not care. It looked great until stage seperation and that is the responsibility of a booster to me. Anything beyond is cost optimisation that they eventually get right. Loss of telemetry triggers AFTS: Is that something unique for starship ? Especially before starlink loosing occasionally contact to ground control was expected if I remember the first falcon 9 launches.

I am still struggeling with the details Scott Manley found about starships end. Everything he concluded seems right, but why would after 5 minutes the LOX plumbing fail ? At the end of stage 2 burn the G forces are at maximum. For sure they expected this G forces, so some material failed due to the stress. However throttling starship to limit g force might be a quick fix. Some added fuel should be able to compensate gravitational loss. Although no permanent solution it might be enough to reach target trajectory until plumbing is improved. And there were some talks about FAA rating this flight as mishap since both FTS were used. If this is true a december launch does not seem believable to me.

For me the biggest question is why did thy trigger FTS on starship ? Seems likely. At T+5:00 they reported nominal trajectory. Starship already picked up 9500 km/h velocity. With (speculated) gimbal control it is extremly unlikely that the trajectory was messed up until SECO. Starship had even some fuel left. So either SECO was too early or shutdown was not happening evenly and therefore attitude lost. It might be that flight programm was not fexible enough to adjust for any unplanned loss during stage separation, but hey SpaceX should have a quite mature flight control loop. So even without seeing plume anomalies I would agree RCgothic: starship was tumbling. But overall it seems like a major success: They managed to get into safe territority with a nice launch and FTS was working as intended. There is no reason why test pace should not pick up and pretty soon we will see a reentry.