ptfrd

joined 1 year ago
[–] ptfrd@sh.itjust.works 1 points 22 hours ago

The capsule landed pretty close to the booster!: https://youtu.be/JH4_bghcTjg?t=41m15s (41:15)

I'm guessing this is not supposed to happen?

Either way, I wonder how close the capsule would have to be before it would have led to a significant delay in the passengers being allowed to exit. Ground crew having to maintain their distance until booster 'safing' was complete, etc.

[–] ptfrd@sh.itjust.works 1 points 1 week ago

Indeed.

I assumed the comment was satirising one common form of misguided critique of SpaceX's "hardware-rich" approach to this development programme. But yes, now I'm not so sure.

[–] ptfrd@sh.itjust.works 2 points 1 week ago

Groaning:

  • in pain
    • space fans
  • in pleasure
    • pyromaniacs
    • elon h8ers

And of course, some of us contain multitudes ...

 
[–] ptfrd@sh.itjust.works 3 points 1 week ago (1 children)

Definitely saved the best 'til last. (The Bibbidi-Bobbidi-Boom clip!)

[–] ptfrd@sh.itjust.works 1 points 1 week ago

Until now I've been too lazy to look into what rules/guidelines exist for this community. Am I now right in thinking there aren't any? (If so, I'm not complaining!) Or am I just not finding them (as an inexperienced Lemmy user)?

The thing I was going to look into was any posting guidelines. How significant should something be to warrant its own post? For example, this tweet includes a video with an F9 barge landing perspective that I don't remember seeing before.

FWIW, my own feeling is that I'd like a quarterly "General Discussion Thread" (as with the equivalent Subreddit), to gather up all the minor stuff.

Are posts automatically 'published' or do they go through moderation first? (If this is something I should be able to determine myself, if I knew more about Lemmy, LMK and I'll go & do some reading!)

P.S. My thanks to you and all the team for all your efforts.

[–] ptfrd@sh.itjust.works 2 points 1 month ago

I'm a rocket ship on my way to Mars [in a sense]

I'm burnin' through the sky, yeah [over Namibia, at about ~3:43:11 for about a minute]

[–] ptfrd@sh.itjust.works 3 points 1 month ago

LMK if you find anything interesting! My guess is that if there is any melting & re-solidifying going on, it will be nothing larger than a droplet.

[–] ptfrd@sh.itjust.works 3 points 1 month ago

Dan Huot jinxed it by invoking Kubrick on the livestream. It was subsequently inevitable that SpaceX's hardware abstraction layer (HAL) would claim not to be able to do it. I just hope it was telling the truth.

HAL: I'm sorry, Dan. I'm afraid I can't do that.
Dan: What's the problem?
HAL: I think you know what the problem is just as well as I do.
Dan: What are you talking about, HAL?
HAL: It's right there on your screen Dan, the actuators are stuck.
Dan: Oh yeah. Anyway, do you know any songs? You might want to start singing in about 27 minutes.
[–] ptfrd@sh.itjust.works 3 points 1 month ago (2 children)

Make a good reef.

Hope so!

Though I believe that it was the Gulf of Mexico that received (large chunks of) B14.

Whereas the Indian Ocean has probably some small bits of S35 debris. (Unless it fully vapourised on re-entry? You've also got me wondering whether any of the materials merely melt, and then re-solidify as solid lumps, either in the lower atmosphere or after hitting the ocean.)

And while I'm being pedantic, @threelonmusketeers@sh.itjust.works, the table above says "Soft water landing" for the booster, which isn't how I'd describe the plan they had for it.

[–] ptfrd@sh.itjust.works 2 points 1 month ago* (last edited 1 month ago)

Where do you get the information from that he deleted videos?

Well here's one example of the accusation ("deleted videos where he said spacex would never be able to re-fly a 1st stage"). Two replies seem to endorse it (e.g. "I recall him saying something like that") and another seems to be fairly familiar with his output and to endorse the general point ("later tried to delete and cover up"). One of the replies links to a different video, which I haven't looked at.

Note that the first ever booster re-use was around March 2017 so we're probably talking about a deletion that happened no later than April 2017. And I'd expect he'd not be so stupid as to wait that long; he'd have probably deleted any such videos as soon as SpaceX announced that they'd found a willing customer (and insurance company), at the latest. So probably by late 2016 or early 2017.


Other stuff I just found ...

Seems he had some argument with another unreliable You Tube 'personality' called Sargon who made a response video back in May 2017. That video is unavailable now but apparently it was still available in 2022 and convinced one person who had until then been unconvinced, that Thunder Foot "apparently just made up shit about someone which was completely false".

I've just looked at one of his more recent "BUSTED!!" videos (July 2021, about Starlink) and I didn't notice any outright falsehoods, so perhaps he's being more circumspect these days. Also, he hasn't deleted that one, even though it's pretty embarrassing for him. So credit where it's due.

That said, the simplest example I've come across of an apparently uncorrected falsehood from him is also from 2021: https://x.com/thunderf00t/status/1364020482572492801 It's hardly a big deal, but he clearly knew that his followers believed the claim to be false, so it seems that at best he was lazy in not bothering to go back and read the 3 replies that proved they were correct.

Some general "debunkings" of more of his SpaceX claims:

https://old.reddit.com/r/SpaceXLounge/comments/lrhwxq/i_fact_checked_thunderf00ts_spacex_busted_part_1/

https://old.reddit.com/r/thunderf00t/comments/lthowt/some_fundamental_errors_in_thunderf00ts_spacex/ and https://old.reddit.com/r/thunderf00t/comments/lu6evm/a_more_casual_fact_check_on_thunderf00ts_spacex/

https://x.com/kedarus/status/1398785312567054336

 

Steve Stich states at today's Crew-9 news conference that Dragon has a new contingency capability if all 4 parachutes fail; the SuperDracos will ignite prior to splashdown.

The Crew-8 return to Earth will also have this capability.

(He said this about 20 minutes after the start of the stream.)

 

A Youtuber called Ellie in Space claims that a NASA source sent her the following message. It was in response to a question about when NASA knew that the Boe-CFT mission's Starliner vehicle would not be able to undock and return to Earth autonomously without being reconfigured.

So if you want to know when??? Well always, but it wasn't a reasonable consideration to retain the unmanned Starliner capsule software to work in the manned version of the capsule as a contingency. Would you call that a mistake?? Maybe, but let's think about the need to really ever plan to send folks up to space and leave them there with no way to fly home... they would always chose to risk the ride vs having no way home.

No one really considered this very unique and dynamic situation would happen.

Background

I believe this issue was first brought to light by Eric Berger.

Regardless, sources described the process to update the software on Starliner as "non-trivial" and "significant," and that it could take up to four weeks. This is what is driving the delay to launch Crew 9 later next month.

A couple of days later, NASA held a press teleconference in which they emphasized that what was needed was merely a "data load", not a software change. But they indicated timelines that do seem consistent with the "up to four weeks" claim by Berger's source.

My questions

Aren't there several realistic scenarios where you'd want to undock a crew vehicle, without its crew (or at least without them being in a fit state to operate the vehicle), in less than 4 weeeks?

Can Crew Dragon do it? Soyuz?

 

Relevant portion of the video is 18:06 - 22:22.

Key quote: "We'll move a Dragon recovery vessel to the Pacific some time next year, and we'll use SpaceX facilities in the Port of Long Beach for initial post-flight processing".

Although this was revealed in a Crew-9 briefing, it doesn't actually apply to Crew-9.

The announcement has just now been posted to the SpaceX website.

Key excerpts:

During Dragon’s first 21 missions, the trunk remained attached to the vehicle’s pressurized section until after the deorbit burn was completed. Shortly before the spacecraft began reentering the atmosphere, the trunk was jettisoned to ensure it safely splashed down in unpopulated areas in the Pacific Ocean.

After seven years of successful recovery operations on the U.S. West Coast, Dragon recovery operations moved to the East Coast in 2019, enabling teams to unpack and deliver critical cargo to NASA teams in Florida more efficiently and transport crews more quickly to Kennedy Space Center. Additionally, the proximity of the new splashdown locations to SpaceX’s Dragon processing facility at Cape Canaveral Space Force Base in Florida allowed SpaceX teams to recover and refurbish Dragon spacecraft at a faster rate [...]

This shift required SpaceX to develop what has become our current Dragon recovery operations, first implemented during the Demo-1 and CRS-21 missions. Today, Dragon’s trunk is jettisoned prior to the vehicle’s deorbit burn while still in orbit, passively reentering and breaking up in the Earth’s atmosphere in the days to months that follow. [...]

When developing Dragon’s current reentry operations, SpaceX and NASA engineering teams used industry-standard models to understand the trunk’s breakup characteristics. These models predicted that the trunk would fully burn up due to the high temperatures created by air resistance during high-speed reentries into Earth’s atmosphere, leaving no debris. The results of these models was a determining factor in our decision to passively deorbit the trunk and enable Dragon splashdowns off the coast of Florida.

In 2022, however, trunk debris from NASA’s Crew-1 mission to the International Space Station was discovered in Australia, indicating the industry models were not fully accurate with regards to large, composite structures such as Dragon’s trunk. [...]

After careful review and consideration of all potential solutions – coupled with the new knowledge about the standard industry models and that Dragon trunks do not fully burn-up during reentry – SpaceX teams concluded the most effective path forward is to return to West Coast recovery operations.

To accomplish this, SpaceX will implement a software change that will have Dragon execute its deorbit burn before jettisoning the trunk, similar to our first 21 Dragon recoveries. Moving trunk separation after the deorbit burn places the trunk on a known reentry trajectory, with the trunk safely splashing down uprange of the Dragon spacecraft off the coast of California.

 

That's 27 hours from now.

SpaceX is targeting Saturday, July 27 for a Falcon 9 launch of 23 Starlink satellites to low-Earth orbit from Launch Complex 39A (LC-39A) at NASA’s Kennedy Space Center in Florida. Liftoff is targeted for 12:21 a.m. ET, with backup opportunities available until 4:21 a.m. ET.

And here is their blogpost, dated 2024-07-25, announcing that the mishap report has been submitted to the FAA, and discussing some of the details.

During the first burn of Falcon 9’s second stage engine, a liquid oxygen leak developed within the insulation around the upper stage engine. The cause of the leak was identified as a crack in a sense line for a pressure sensor attached to the vehicle’s oxygen system. This line cracked due to fatigue caused by high loading from engine vibration and looseness in the clamp that normally constrains the line.

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submitted 11 months ago* (last edited 11 months ago) by ptfrd@sh.itjust.works to c/spacex@sh.itjust.works
 

During tonight’s Falcon 9 launch of Starlink from Space Launch Complex 4 East at Vandenberg Space Force Base in California, the second stage engine did not complete its second burn. As a result, the Starlink satellites were deployed into a lower than intended orbit. SpaceX has made contact with five of the satellites so far and is attempting to have them raise orbit using their ion thrusters.

There's also a tweet saying the same thing in fewer words.

This is the affected mission: Starlink 9-3 launch bulletin

Let's hope it was due to SpaceX pushing the envelope on their in-house Starlink missions in some way, though I have no specific guesses along those lines. Perhaps a manufacturing defect or an operational mistake are more likely to be the leading candidates for the cause.

 

Quote from Bill Nelson:

... SpaceX, by having the return of the first stage, has brought the cost down significantly. That has affected the entire launch industry. We'll be seeing attempts at bringing the second stage down on some missions.

The key sentence is (currently) 52 minutes and 48 seconds into the video. Approximately 49 minutes after the event started.

No other mention is made of this. Should we assume he's specifically referring to the 2nd Stage of the Falcon 9? What is the likelihood that he is mistaken? Could he just be thinking of the existing deorbit procedure? Or could SpaceX be putting parachutes on some of their 2nd Stages in the near future?

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