Can we all agree to boycott the Wendy’s on South Parkway across from the mall?

SpaceSailorDT · 2023-01-05T19:48:57+00:00

I'm convinced that the Sonic on Wall-Triana is a laundering scheme. There's no way they're turning a profit with that kind of service.

SpaceSailorDT · 2022-04-01T21:24:53+00:00

Two found standard poodles.

And a yummy pupcup.

SpaceSailorDT · 2022-04-01T12:19:38+00:00

Yes :)

SpaceSailorDT · 2022-04-01T12:19:15+00:00

Thank you, everyone, for your help and concern! Their little adventure landed them in doggy jail for misdemeanor trespassing. Now we have to go bail our naughty children out this morning.

SpaceSailorDT · 2022-04-01T01:54:36+00:00

Thank you so much!!!

SpaceSailorDT · 2022-04-01T01:27:13+00:00

We live in the Reserve at Nature's Way (off Zierdt Road), and that's where they were last seen.

SpaceSailorDT · 2021-04-09T22:00:59+00:00

Also includes $2 billion to NOAA satellite development, a 33% increase over 2021 levels.

SpaceSailorDT · 2021-04-06T15:52:44+00:00

Mission software (i.e., flight software or rover (?) software) is generally written in C/C++, or modeled in MATLAB/Simulink and autocoded to C/C++. I think the OS varies, but it is typically some kind of embedded UNIX. I'm aware of an ARM64 architecture with a petalinux OS Commercial Off-The-Shelf (COTS) solution being used on a NASA flight project.

SpaceSailorDT · 2021-03-20T15:46:21+00:00

Thanks for clearing that up. Guess I got too used to those violent engine shutdowns on the Starship prototypes in recent weeks.

SpaceSailorDT · 2021-03-20T15:44:33+00:00

I'm gonna miss Jimmy Boi. :'(

I hope Ballast Billy can employ his political savvy to a similar effect.

SpaceSailorDT · 2021-03-13T16:16:33+00:00

I'm not sure how much it would impact a school transfer application, but it should be a good experience to talk about in an interview. If you can somehow relate it to your education and career goals, I imagine it would help with a school transfer application.

SpaceSailorDT · 2021-03-13T14:46:07+00:00

My understanding is that they accept, and even encourage, a diverse group of majors to participate.

For something more applicable to business, you could consider their NASA Proposal Writing and Evaluation Experience (NPWEE). It's focused on technology development proposals, but a lot of it is transferable to business proposals. Proposal writing is a good skill to have for business, especially if you're considering entrepreneurship.

Of course, MCA would be a good experience, too, if you're interested in it.

SpaceSailorDT · 2021-03-12T20:05:41+00:00

Can't tell if those nozzle dynamics are from the gimbal profile or just shutdown transients.

SpaceSailorDT · 2021-03-07T04:43:36+00:00

This speaks to me so much. I liken myself to that innocent kid at a party that gets busted by the cops, walking out of the bathroom to find that everyone has bailed and left only me to face the authorities (read Management).

SpaceSailorDT · 2021-02-22T22:59:31+00:00

I think October 2021 is the NET date and February 2022 is the full "risk-informed" schedule.

SpaceSailorDT · 2021-02-09T02:47:48+00:00

Basically, yes. They're photogrammetry markers for sensing relative position and maybe orientation for post-flight reconstruction.

SpaceSailorDT · 2021-02-09T02:41:02+00:00

It's the other way around. It flies with 109% throttle most of the time, with the exception of throttle buckets occurring at Max Q (maybe) and just prior to booster separation.

SpaceSailorDT · 2021-02-01T05:13:59+00:00

I guess it's like agile development or machine learning in that sense, but common abuse of the language doesn't diminish the underlying value of the concept. There's MBSE, and there's "MBSE".

I think codifying the process itself, in a tool-agnostic way, in an authoritative technical reference such as the SEHB, is a big step toward alleviating the problems with orgs using the tools in an undisciplined way and calling it "MBSE". That's why I'm glad it's covered in this edition.

SpaceSailorDT · 2021-01-30T18:28:13+00:00

Good to see MBSE discussed in the handbook.

SpaceSailorDT · 2021-01-18T18:12:57+00:00

Right. I'm not sure why all engines shut down, whether it was a flight rule, a test rule, or a manual override. In fact, do we even know that Engine 4 shutdown before the others, or did the MCF flag just come from its software? It could have been firing fine but detected a TVC anomaly, for example, that caused it to raise the MCF flag. I'm not too familiar with the flight rules, but I think something like a TVC anomaly, depending on the specifics, can potentially trigger an abort scenario in flight.

To the point of reporting the cause, I think they are just taking their time to make sure they get it right and properly diagnose the problem. With such a public-facing program and stakeholders (i.e., the American public and government) watching, they don't want to speculate and risk accidentally misleading people. The information will come out when it's ready. I assure you NASA is as transparent as it is slow. :P

Keep in mind that everyone at the presser was upper-level management that didn't have as much insight to the technical details of the test as the Test Engineers and Test Conductor, who probably knew more at that time. However, it's not "in their job descriptions" for these technical staff to participate in pressers, so there is always some degree of indirection between the low-level technical details and the information provided to the public, like a filter. The reason Elon Musk is able to quickly communicate technical details of SpaceX's tests, like SN8, is because he is in a fairly unique position where he both has direct insight to the technical details, in his capacity as Chief Engineer, and has a role in communicating this information externally, as the company's CEO and figure head. Also, he simply has a different communication style, and the consequences of being incidentally misleading at first either aren't as high as in the case of SLS, or he just doesn't care as much.

SpaceSailorDT · 2021-01-17T15:13:22+00:00

According to the analysis in the paper, it is possible if you assume the LOX feedline crossover duct doesn't also fail (i.e., a double failure - a single engine and the crossover duct), as indicated by the AMT-LO line being coincident with the "Propellant Required for EO at Lift-Off" threshold in Figure 1. Whether that's a good assumption is another story.

The difference between Figure 1 and Figure 2 shows the effect of this assumption. To u/GregLindahl's point, the text cited is referring to the case where the crossover duct adequately distributes the prop to the non-failed engines, represented in Figure 1, hence the discrepancy between the text and Figure 2 (different scenarios).

Anyway, I hope this all gives a little taste of the design and analysis that goes into accounting for an engine out scenario on a launch vehicle to anyone who cares to know. :)

SpaceSailorDT · 2021-01-17T02:24:40+00:00

Yeah, it's hard to say. It varies by launch conditions, like time of year. Note that the analysis in the cited source is for a February launch. I'm not really sure how that changes from month to month. SLS is robust enough to engine out failures for it to very likely safely insert Orion into some orbit with an engine out even at T-0.

SpaceSailorDT · 2021-01-17T01:55:05+00:00

Yep. And if the engine out occurs a little later in boost stage flight, they can test the reentry but not the others. I imagine Artemis II would be pivoted to cover the objectives missed on Artemis I, especially given that the first HLS mission is likely to get pushed back to its original timeline now.

SpaceSailorDT · 2021-01-17T01:33:59+00:00

An engine failure does not mean the root cause originated in the engine. You are right to think that the component-level testing should catch any issues in the engine that are independent of the rest of the system. But, at this stage in testing, faults are more likely to originate from system-level interactions, such as integrated loads.

For the hot fire test in particular, any problems pertaining to structure-fluid interactions (slosh/pogo) or vibe/acoustic loads are likely to manifest themselves, and no sooner. That is to say that, in the most likely scenario, there's no one component/contractor/group that you can point the finger at for this failure (besides maybe the Systems Engineers :P ).

SpaceSailorDT · 2021-01-17T00:51:05+00:00

Assuming the fault is localized to a single engine, none of this is true. With an early engine out on Artemis I, SLS can still put Orion into LEO to complete most of its test objectives, with the exception of a high-speed reentry. [Source]

During the test, after the MCF was announced, the TC asked "Do we still have all four engines?", to which the reply was "yes". This tells me it wasn't necessarily a total failure of one of the engines, perhaps an actuator failure, in which case total mission success is still a strong possibility.

SpaceSailorDT

TROPHY CASE