CBase

Since they claimed it was too much ice clogging the filters, @Ultimate Steve is probably right that unlike the 777 RR Trent issue this is about having so much ice returned to the tank. Either they need improved filters to better cope with the amount of ice or reduce the amount. Any heat exchanger at Raptors mean actually 39 more parts while inside tanks you have at most 8 of them, probably less as header tanks might not need them. I could even image that you could alter the flow in the pre burner to have a lower burned fuel ratio being fed back at the autogenous pressurization inlet. I mean any remaining ice after landing would slow down reuse. They would have to drain the tanks, let them heat up enough for any ice to melt and then drain it as well until refuel could start. So reducing the amount of ice sounds more attractive.

Ahh sorry missed your update in ULA thread. Too many companies involved

Now targeting May 21th. Issue is helium leak, which is assumed to be acceptable but tests pending. Otherwise another date slip is likely. https://arstechnica.com/space/2024/05/boeing-is-troubleshooting-a-small-helium-leak-on-the-starliner-spacecraft/

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.