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Re: SPACE - random thread about space stuff

Posted: Mon May 01, 2023 7:46 pm
by jztemple2
If you watch that first Manley video, towards the end there is a clip of all the SpaceX employees in the lobby at Hawthorne whooping and hollering as the rocket blows up :roll: . The video then switches to the control room and all you see there are somber faces :doh:

Re: SPACE - random thread about space stuff

Posted: Tue May 02, 2023 12:40 am
by Hrdina
jztemple2 wrote: Sun Apr 30, 2023 10:39 pm
jztemple2 wrote: Thu Apr 20, 2023 11:45 am Also there was something odd about the angle between the plume on ascent and the longitudinal axis of the vehicle, like they hadn't gone up far enough to start their gravity turn; anyone who's spend a lot of time in Kerbal Space Program might recognize that :wink:. It might have been planned to get the booster away from the coastline quicker.
I feel really smart about this, if you watched the first of the two Scott Manley videos, at about 5:20 he makes this same observations :D 8-)
Anyone who has played Kerbal has seen their own rockets flying like that. :D
jztemple2 wrote: Mon May 01, 2023 7:46 pm If you watch that first Manley video, towards the end there is a clip of all the SpaceX employees in the lobby at Hawthorne whooping and hollering as the rocket blows up :roll: . The video then switches to the control room and all you see there are somber faces :doh:
These guys were out in the lobby?

Re: SPACE - random thread about space stuff

Posted: Wed May 03, 2023 1:42 pm
by jztemple2
Elon Musk pushes for orbital goal following data gathering objectives during Starship debut
Following the maiden launch of the world’s most powerful rocket, SpaceX hopes to conduct a mirror test flight of the Starship rocket this summer.

Several requirements need to be satisfied before the flight of Booster 9 — and a to-be-decided Ship partner — ranging from repairing and improving the launch site to modification to the flight termination system (FTS). However, the launch of Booster 7 and Ship 24 achieved numerous objectives to add confidence in the system and provide a stepping stone to the key milestone of Starship reaching orbital velocity.
More on the new thrust plate:
“We’re going to be putting down a lot of steel. The debris is really just sand and rock, so it’s not toxic at all or anything. It’s like a sandstorm, essentially — basically a human-made sandstorm. But, we don’t want to do that again, so we’re putting down a very strong steel sandwich that is basically a water-jacketed sandwich.

“It’s two layers of very thick plate steel that are also sort of perforated on the upper side so that you have what is basically a massive, super strong steel showerhead pointing up. And then, the water pressure coming out of there has to exceed the pressure that the engines’ thrust is exerting on the steel plate on the vehicle launch stand.

Re: SPACE - random thread about space stuff

Posted: Wed May 03, 2023 1:48 pm
by jztemple2
Some more from the article linked to and quoted above:

About the initial engine start and liftoff:
Musk explained that the launch took place with 30 engines running instead of the full set of 33.

“There were three engines that we chose not to start, or hit aborts. (So), we actually lifted off with 30 engines, which is the minimum number of engines.

“Those engines did not explode, but they were just, the system didn’t think they were healthy enough to bring them to a full thrust,” added Musk during a post-flight Twitter spaces call, adding that is why the vehicle appeared to lean away from the Tower during ascent.

It was assumed the lean could have been related to pad avoidance, but Musk quickly noted that it is undesirable due to the “blowing torch” of the Raptor 2 engines on the OLM ring.

“If you move sideways sooner, you are moving that big, cutting torch across the launch ring. So, you can think of this thing like the world’s biggest cutting torch, basically. Depending on how close the engines are, they erode that steel at a roughly — I think half an inch to an inch per second of high strength steel is eroded by the cutting torch.”

“(The lean was actually) related to the engines out, and we do not normally expect to lean. It should be aspirationally going straight up.”
More about the Flight Termination System (FTS) which turned out to be not up to the job:
The loss of the TVC resulted in Booster 7 losing steering authority, which in turn led to the rocket starting its tumbling motion. The Flight Termination System (FTS) was activated soon after the vehicle started to tumble, but it failed to destroy the vehicle. Therefore, this item will require additional modifications before the next flight and is deemed the long lead item.

“The longest lead item on that is probably the requalification of the flight termination system. Because we did initiate the flight termination system, but it was not enough to, it took way too long to rupture the tanks,” Musk noted.

“So, we need basically a much — we need more detonation cord to unzip the tanks at altitude and ensure that the rocket explodes immediately if a flight termination is necessary.”
Finally, Starship and Super Heavy Booster production:

Re: SPACE - random thread about space stuff

Posted: Wed May 03, 2023 11:17 pm
by jztemple2

Re: SPACE - random thread about space stuff

Posted: Wed May 03, 2023 11:27 pm
by Isgrimnur
:o :ugeek:

Re: SPACE - random thread about space stuff

Posted: Tue May 09, 2023 2:24 pm
by jztemple2
NASA platform used to launch Apollo 11 to the moon set for demolition
The historic steel platform from which the first astronauts departed Earth to fly around and land on the moon now, itself, only has a limited time left on the planet.

Mobile Launch Platform-3 (MLP-3), or Mobile Launcher-1 (ML-1) as it was known when NASA used it for the Apollo 8 and Apollo 11 lunar missions more than 50 years ago, is set to be demolished, having recently been moved out of the Vehicle Assembly Building (VAB) to a nearby yard at Kennedy Space Center in Florida.

"MLP-3 has been moved out to the midfield park site and is awaiting demolition by a salvage contractor," John Giles, engineering operations manager for the crawler-transporters and other large equipment in NASA's Exploration Ground Systems program at Kennedy, said in an interview with collectSPACE.com. "[The work] should be beginning within two weeks."
When I came to LC-39 Pad A for my job interview in 1977, MLP-3 (then ML-1) was sitting at the pad with the Milkstool in place that was used for all the manned Skylab launches and also for Apollo-Soyuz. And it was there the last day I worked on the program in 2011, although by then the Milkstool had been scrapped but the now MLP-3 was still sitting somewhere on the site.

Re: SPACE - random thread about space stuff

Posted: Tue May 09, 2023 5:05 pm
by Unagi
That's a bummer.

Re: SPACE - random thread about space stuff

Posted: Tue May 09, 2023 11:45 pm
by Kraken

Re: SPACE - random thread about space stuff

Posted: Wed May 10, 2023 12:25 am
by jztemple2
Snake! Snake! :D

So I was thinking some more about this quote from Elon Musk about the recent Super Heavy launch:
The loss of the TVC resulted in Booster 7 losing steering authority, which in turn led to the rocket starting its tumbling motion. The Flight Termination System (FTS) was activated soon after the vehicle started to tumble, but it failed to destroy the vehicle. Therefore, this item will require additional modifications before the next flight and is deemed the long lead item.

“The longest lead item on that is probably the requalification of the flight termination system. Because we did initiate the flight termination system, but it was not enough to, it took way too long to rupture the tanks,” Musk noted.

“So, we need basically a much — we need more detonation cord to unzip the tanks at altitude and ensure that the rocket explodes immediately if a flight termination is necessary.”
Let's assume on this launch that a few more of the gimbaling engines were lost (only the interior engines on the Super Heavy gimbal), not a difficult assumption due to all the debris. And lets also assume that the engines that were lost caused the vehicle to head on a northern trajectory; again, not an outrageous assumption seeing as Musk did mention that the initial launch is completely vertical to avoid having the exhaust plume cut across the launch mount, therefore going off-course isn't as unlikely as it might seem.

So the vehicle starts heading to the north, almost immediately going outside of the safety envelope. The Flight Termination System (hereafter FTS) issues the destruct order but as we now know from Musk, the FTS failed to destroy the vehicle. So we have this rocket following a ballistic trajectory to the north...

And to the north, only six miles away, is the city of Port Isabel, population about five thousand.

I'm really surprised that there hasn't been more uproar in the press about this rather large SNAFU, that all the design by SpaceX and certification by the FAA failed to catch that the FTS wasn't up to the job and that the launch site is pretty damn close to a populated area. Just thinking...

Re: SPACE - random thread about space stuff

Posted: Wed May 10, 2023 7:50 am
by Unagi
So, a few more specific engine failures could have even tilted it further off course and straight at the nearby population… while the FTS sat by on idle (I realize it probably didn’t fail to trigger, rather it triggered and didn’t do enough)

Is that about right ?

Re: SPACE - random thread about space stuff

Posted: Wed May 10, 2023 12:44 pm
by jztemple2
Unagi wrote: Wed May 10, 2023 7:50 am So, a few more specific engine failures could have even tilted it further off course and straight at the nearby population… while the FTS sat by on idle (I realize it probably didn’t fail to trigger, rather it triggered and didn’t do enough)

Is that about right ?
Yes, that's right. The FTS was ineffectual. A properly designed FTS should have opened the booster like a zipper.

Re: SPACE - random thread about space stuff

Posted: Thu May 11, 2023 3:08 pm
by Unagi
jztemple2 wrote: Wed May 10, 2023 12:44 pm opened the booster like a zipper.
This is so weird. I had breakfast with my mother this morning, and one of the topics was this launch. I told her about the failed FTS and was 'son-splaining how important that system is on any rocket...

One of my sentences was something like this:
"Now, technically speaking getting a rocket to explode isn't that hard... They are already exploding... the FTS just needs to start it, and the rocket should open up like a zipper."
:D

Re: SPACE - random thread about space stuff

Posted: Thu May 11, 2023 3:49 pm
by jztemple2
The External Tank on the Shuttle program had a linear shaped charge that ran the length of the hydrogen tank, and maybe the LOX tank too, but I don't remember. And that was what is was supposed to do, essentially unzip the tank.

Re: SPACE - random thread about space stuff

Posted: Sun May 14, 2023 11:31 pm
by Kraken
Skylab at 50 is a quick, comprehensive history of the program. I actually learned something I had forgotten or never knew:
NASA had hoped to reactivate the station once the Space Shuttle became operational. Ultimately this was prevented by a combination of increased atmospheric drag causing Skylab to decay from orbit more quickly than expected, and delays to the Shuttle program.

Under early plans, the third Space Shuttle mission would have been flown by astronauts Jack Lousma and Fred Haise, who would have deployed a module called the Teleoperator Retrieval System (TRS). TRS would have then been docked with Skylab via remote control from the Shuttle. Once docked, its thrusters would have been used to raise the space station into a higher orbit — or to deorbit it to a controlled re-entry if deemed necessary. TRS was later moved to the second Shuttle mission as the program began to fall behind schedule, but would be abandoned when it became clear that Skylab was going to re-enter before the Shuttle would be ready to fly.
Image

In 1979, I was a college student in a rock band that reviewers called "punk" because that term was still fluid (we weren't punks) and we didn't really fit into any category except maybe Artsy Basement Band. Anyway, we wrote and performed a song called "Skylab" that slightly predated its reentry and benefited from the hoopla. I can still hear the tune in my head, but only remember snippets of lyrics.

Re: SPACE - random thread about space stuff

Posted: Sun May 14, 2023 11:46 pm
by jztemple2
Kraken wrote: Sun May 14, 2023 11:31 pm In 1979, I was a college student in a rock band that reviewers called "punk" because that term was still fluid (we weren't punks) and we didn't really fit into any category except maybe Artsy Basement Band. Anyway, we wrote and performed a song called "Skylab" that slightly predated its reentry and benefited from the hoopla. I can still hear the tune in my head, but only remember snippets of lyrics.
No demo? Shame, we could have made it an official OO Space Thread song :D

I was going to post about that same article. One of the earliest anticipated Shuttle missions was to booster Skylab to a higher orbit, as noted in the article, and when I joined the program in 1977 there was still some talk about being able to make that mission, but it soon was apparent that Shuttle was going to be way too late :roll:

Re: SPACE - random thread about space stuff

Posted: Mon May 15, 2023 1:33 am
by Kraken
jztemple2 wrote: Sun May 14, 2023 11:46 pm
Kraken wrote: Sun May 14, 2023 11:31 pm In 1979, I was a college student in a rock band that reviewers called "punk" because that term was still fluid (we weren't punks) and we didn't really fit into any category except maybe Artsy Basement Band. Anyway, we wrote and performed a song called "Skylab" that slightly predated its reentry and benefited from the hoopla. I can still hear the tune in my head, but only remember snippets of lyrics.
No demo? Shame, we could have made it an official OO Space Thread song :D

I was going to post about that same article. One of the earliest anticipated Shuttle missions was to booster Skylab to a higher orbit, as noted in the article, and when I joined the program in 1977 there was still some talk about being able to make that mission, but it soon was apparent that Shuttle was going to be way too late :roll:
It was probably for the best. Skylab was a stepping stone that was already stepped.

I've posted our super-low-rez public-access TV video before, but that was before we wrote Skylab. Our song was about a depressed person who aspires to suicide by Skylab. The first lines went "I sit and wait for Skylab/Don't know when it's gonna fall" and the last lines went "Paint an inviting bullseye/Climb in and close my eyes". There were a bunch of nihilistic lines in between. :wink:

Re: SPACE - random thread about space stuff

Posted: Mon May 15, 2023 11:20 am
by Zaxxon

Re: SPACE - random thread about space stuff

Posted: Mon May 15, 2023 11:39 am
by jztemple2
Yeah, my company also hired some ex-NASA bigwigs, it didn't always work out :roll:.

Re: SPACE - random thread about space stuff

Posted: Fri May 19, 2023 5:19 pm
by jztemple2
Blue Origin will build NASA's new moon lander for Artemis astronauts. It's the second Artemis crew lander after SpaceX's Starship, which was selected in 2021.
Image

A moon lander built by Jeff Bezos' Blue Origin will be the second system that takes NASA astronauts to the lunar surface, agency officials announced today (May 19).

A consortium led by Blue Origin won the second Human Landing System (HLS) contract issued by NASA for the Artemis program, the agency said during a livestreamed announcement from Washington, D.C. today. Under the $3.4 billion award, Blue Origin will provide a second astronaut moon-landing option for NASA beyond SpaceX's Starship, which was selected in 2021.

"An additional, different lander will help ensure that we have the hardware necessary for a series of landings to carry out the science and technology development on the surface of the moon," NASA Administrator Bill Nelson said during the press conference.

Blue Origin representatives said that the lander, called Blue Moon, will be ready for the planned landing of the Artemis 5 mission in 2029, after test launches and landings.

Re: SPACE - random thread about space stuff

Posted: Mon May 22, 2023 5:15 pm
by jztemple2
From Scott Manley, Why Blue Origin's Lunar Lander Is A Radical Rethink. Illustrated with a conjectural craft in KSP2.


Re: SPACE - random thread about space stuff

Posted: Wed May 24, 2023 4:20 pm
by jztemple2
More news for virgins, oops, Virgin news!

Meet the 8 people flying on Virgin Galactic's 5th spaceflight on Thursday
Virgin Galactic's next crewed spaceflight will include eight people, six of whom will make it to suborbital space.

Virgin Galactic will send its next crew to space no earlier than Thursday (May 25) at 10 a.m. EDT (8 a.m. MDT) from Spaceport America in New Mexico. The events will not be livestreamed, but you will likely be able to follow along live on Virgin Galactic's Twitter feed.

This will be the fifth time that Virgin Galactic has flown to space, and the first since July 11, 2021, a mission that featured billionaire Virgin Group founder Richard Branson as one of the passengers. The company has been upgrading, and then testing, its VSS Unity space plane and VMS Eve carrier aircraft for the last two years or so.
Virgin Orbit shuts down after selling key assets to 3 aerospace companies
Enlarge Image

Virgin Orbit, the beleaguered satellite launch company that filed for bankruptcy close to two months ago, said it has agreed to sell key assets worth over $35 million to three aerospace companies and will cease operations.

The piecemeal sale of the California-based company — which was operating at a $50.5 million loss and filed for bankruptcy in early April, days after failing to secure long-term financing and furloughing all but 100 staff members — is subject to court approval today (May 24), "with the transactions expected to close shortly thereafter," according to a company statement on Tuesday evening (May 23).

California-based aerospace companies Stratolaunch, Rocket Lab and Launcher are the winning bidders of a weeks-long sale process that ended in a bankruptcy auction held on Monday (May 22), according to a new court filing. Six rockets in assembly stages are still pending sale, a Virgin Orbit spokesperson told CNBC's Michael Sheetz.

Re: SPACE - random thread about space stuff

Posted: Wed May 24, 2023 9:32 pm
by Kraken
"Unity then fires up its rocket motor to go even higher, beyond 50 miles (80 kilometers) — high enough, by some definitions, to reach space."

The most widely used definition says space starts at 100 km (62 miles).

Re: SPACE - random thread about space stuff

Posted: Wed May 24, 2023 9:49 pm
by jztemple2
Kraken wrote: Wed May 24, 2023 9:32 pm "Unity then fires up its rocket motor to go even higher, beyond 50 miles (80 kilometers) — high enough, by some definitions, to reach space."

The most widely used definition says space starts at 100 km (62 miles).
From wikipedia,
Up until 2021, the United States designated people who travel above an altitude of 50 mi (80 km) as astronauts. Astronaut wings are now only awarded to spacecraft crew members that "demonstrated activities during flight that were essential to public safety, or contributed to human space flight safety"

Re: SPACE - random thread about space stuff

Posted: Fri May 26, 2023 6:36 pm
by jztemple2
NASA's Artemis moon rocket will cost $6 billion more than planned: report
An independent report looking into the development of NASA's new moon rocket has found significant cost overruns and delays that could harm the agency's plans to put astronauts back on the moon.

Development of the Space Launch System (SLS) began in November 2011. It had a successful test flight in November 2022, six years after its first targeting a debut launch in late 2016. The SLS megarocket is intended to return humans to the moon as part of NASA's Artemis program, but increases in costs related to contracts awarded to Aerojet Rocketdyne and Northrop Grumman for SLS's propulsion systems could threaten that objective.

That's according to a 50-page report by NASA Inspector General Paul Martin published by the Office of Inspector General (OIG) on May 25. Altogether, the four contracts for the rocket's booster and engine were initially projected to cost $7 billion over a span of 14 years, but are now projected to cost at least $13.1 billion over nearly 25 years.

Re: SPACE - random thread about space stuff

Posted: Fri May 26, 2023 6:39 pm
by Daehawk
Shame when money stands in the way of a civilizations ability to evolve and grow.

Re: SPACE - random thread about space stuff

Posted: Fri May 26, 2023 7:09 pm
by Kraken
initially projected to cost $7 billion over a span of 14 years, but are now projected to cost at least $13.1 billion over nearly 25 years
So projected at $0.5B per year, actual $0.524 per year. What's an extra $24M between friends?

Re: SPACE - random thread about space stuff

Posted: Fri May 26, 2023 10:03 pm
by Isgrimnur
Hakuto-R
The private Japanese moon lander Hakuto-R crashed in late April during its milestone landing attempt because its onboard altitude sensor got confused by the rim of a lunar crater.

Representatives of Tokyo-based company ispace, which built the spacecraft, revealed that the unexpected terrain feature led the lander's onboard computer to decide that its altitude measurement was wrong and rely instead on a calculation based on its expected altitude at that point in the mission. As a result, the computer was convinced the probe was lower than it actually was, which led to the crash on April 25.

"While the lander estimated its own altitude to be zero, or on the lunar surface, it was later determined to be at an altitude of approximately 5 kms [3.1 miles] above the lunar surface," ispace said in a statement released on Friday (May 26). "After reaching the scheduled landing time, the lander continued to descend at a low speed until the propulsion system ran out of fuel. At that time, the controlled descent of the lander ceased, and it is believed to have free-fallen to the moon's surface."
...
Ispace stressed that the mission successfully completed eight of its nine mission milestones and only failed in the final stages of its powered descent.

Re: SPACE - random thread about space stuff

Posted: Fri May 26, 2023 10:50 pm
by Daehawk
3.5 miles? geez how deep are craters on the moon. If it registered the rim and took that to be the ground then its depth was 3.5 miles more ? Wow. That doesn't seem possible. Thats just 2 miles less than Mt Everest.

Re: SPACE - random thread about space stuff

Posted: Fri May 26, 2023 11:59 pm
by Isgrimnur
Shortly after the Moon formed, an asteroid smacked into its southern hemisphere and gouged out a truly enormous crater, the South Pole-Aitken basin, almost 1,500 miles across and more than five miles deep.

Re: SPACE - random thread about space stuff

Posted: Sat May 27, 2023 11:07 am
by Max Peck
Since the altitude was estimated via calculation rather than measurement, the altitude it was at doesn't really reflect anything about the local lunar geographical features. It just tells us that the calculation was off by 5 km.

Re: SPACE - random thread about space stuff

Posted: Sat May 27, 2023 12:20 pm
by Isgrimnur
NASA May Have Found Hakuto-R’s Crash Site
New images from NASA’s Lunar Reconnaissance Orbiter (LRO) appear to show the crash site where the Japanese Hakuto-R Mission 1 lunar lander impacted the surface of the Moon a month ago.
...
A day later, LRO flew over Hakuto-R’s targeted landing area and took ten images around the landing site with its Narrow Angle Cameras (NACs).
...
The LRO Camera (LROC) team said they identified an unusual surface change near the intended landing site, noting at least four prominent pieces of debris and several small changes. ... The camera team suggested the new objects could be a small crater at the center with different parts of the lander body surrounding it. They said this site will be analyzed more over the coming months as LROC has the opportunity to re-image the site under various lighting and viewing geometries.

Re: SPACE - random thread about space stuff

Posted: Tue May 30, 2023 9:46 am
by stessier
Fascinating look at what went wrong.


Re: SPACE - random thread about space stuff

Posted: Wed May 31, 2023 5:35 pm
by jztemple2
stessier wrote: Tue May 30, 2023 9:46 am Fascinating look at what went wrong.

I watched the video, which was generally well done, but I'll disagree with the phrase in the title, "Unbelievable Computer Bug" as well as when Scott repeatedly called it a software bug. It was neither. Both software and computer operated as intended by the requirements. The requirements were faulty, due to the failure (as Scott explains) to test the software against the selected final landing area. Had they done so, they would have found that their software requirements wouldn't be able to handle that 3km cliff the lander passed over. Because the software wasn't designed to accept that possibility, it thought that the radar altimeter had failed and took it out of the voting for assessing the lander location and velocity.

If the team had more money, or more payload capacity, it could have added a second radar altimeter and do a logic check. That way, if both altimeters registered that 3km sudden change, then the altimeters would have been kept in the voting logic.

I wonder how the software programmers feel with people like Manley saying "software bug" when it was nothing of the kind.

Re: SPACE - random thread about space stuff

Posted: Wed May 31, 2023 10:09 pm
by Isgrimnur
I agree with your assessment. However, I try not to get bent out of shape when people misuse terminology like that. Communication is hard. Calling it a bug makes it easier for people to understand what happened. Whether it was due to a conscious decision or not, the software did something that resulted in an abnormal event. And, as much as I love being pedantic, it doesn't serve a purpose in communicating inside baseball to the public.

Re: SPACE - random thread about space stuff

Posted: Wed May 31, 2023 10:25 pm
by jztemple2
Isgrimnur wrote: Wed May 31, 2023 10:09 pm I agree with your assessment. However, I try not to get bent out of shape when people misuse terminology like that. Communication is hard. Calling it a bug makes it easier for people to understand what happened. Whether it was due to a conscious decision or not, the software did something that resulted in an abnormal event. And, as much as I love being pedantic, it doesn't serve a purpose in communicating inside baseball to the public.
I'm not bent out of shape, I'm just communicating to the more enlightened members of this forum thread that Manley, who we know and respect, does occasionally use words and phrases that don't convey all the correct details.

And I love communicating inside baseball to others :wink:. It's the pedantic in me :D

Re: SPACE - random thread about space stuff

Posted: Thu Jun 01, 2023 8:09 pm
by jztemple2
Technical snags force another delay for Boeing’s Starliner crew capsule
Boeing and NASA officials said Thursday the first launch of astronauts on Boeing’s delay-prone Starliner crew capsule won’t happen in July after engineers recently discovered a problem with the spacecraft’s parachute system and identified flammable tape around wiring harnesses inside the vehicle.

The technical problems, which escaped detection for years, dealt another setback for Boeing’s Starliner program, already running years behind schedule after a series of issues with software, valves, and other parts of the spacecraft.
Regarding that flammable tape...
Boeing engineers will likely apply another layer of safe material around the flammable tape in certain parts of the crew capsule, which would require removal of covers already installed in different parts of the spacecraft. Nappi said the flammable tape is extensively used in the Starliner spacecraft, with hundreds of feet it scattered throughout the vehicle.
And this, in case anyone is thinking Boeing is making money off these delays
NASA’s firm-fixed price commercial crew contracts require the cost of delays to be paid by industry, so Boeing is on the financial hook for repairs and rework to remedy the Starliner technical problems. As of last October, Boeing said the Starliner delays have cost the company nearly $900 million.

Re: SPACE - random thread about space stuff

Posted: Thu Jun 01, 2023 9:23 pm
by Kraken
If Starliner flies before ISS retires that will be a win for Boeing.

Re: SPACE - random thread about space stuff

Posted: Sun Jun 04, 2023 7:49 pm
by Hrdina
jztemple2 wrote: Wed May 31, 2023 10:25 pm
Isgrimnur wrote: Wed May 31, 2023 10:09 pm I agree with your assessment. However, I try not to get bent out of shape when people misuse terminology like that. Communication is hard. Calling it a bug makes it easier for people to understand what happened. Whether it was due to a conscious decision or not, the software did something that resulted in an abnormal event. And, as much as I love being pedantic, it doesn't serve a purpose in communicating inside baseball to the public.
I'm not bent out of shape, I'm just communicating to the more enlightened members of this forum thread that Manley, who we know and respect, does occasionally use words and phrases that don't convey all the correct details.

And I love communicating inside baseball to others :wink:. It's the pedantic in me :D
I'm the lead SW designer for a different space project. I sent a bunch of information around to my team about this incident. I hope some of them actually read it. I got very little feedback. I sent that out before Scott's video, so that one was not included.

Scott Manley writes software, so should know the distinctions between software and requirements. My initial reaction was the expected "NOT A BUG - that's a requirements failure". That said, after some thought I've more toward what Isgrimnur wrote, in that an outside observer won't care about the why, only that the software made the lander run out of go-juice.

I object more to the word "unbelievable" in that title. :D

That said, part of my job is to recognize when I'm given an insufficient (to be charitable) requirement and to point out all the ways it could cause trouble.

One thing I found interesting was that the customer blamed themselves, not the software developer (Draper).
The lander used software developed by Draper, but Ujiie [Ryo Ujiie, chief technology officer of ispace] said ispace accepted blame for the failure, linking it to requirements ispace levied on the software. Besides their relationship on software for the lander, ispace’s U.S. subsidiary is designing a lander for a Draper-led lander mission for NASA’s Commercial Lunar Payload Services program.

Re: SPACE - random thread about space stuff

Posted: Mon Jun 05, 2023 10:25 am
by raydude
Hrdina wrote: Sun Jun 04, 2023 7:49 pm
jztemple2 wrote: Wed May 31, 2023 10:25 pm
Isgrimnur wrote: Wed May 31, 2023 10:09 pm I agree with your assessment. However, I try not to get bent out of shape when people misuse terminology like that. Communication is hard. Calling it a bug makes it easier for people to understand what happened. Whether it was due to a conscious decision or not, the software did something that resulted in an abnormal event. And, as much as I love being pedantic, it doesn't serve a purpose in communicating inside baseball to the public.
I'm not bent out of shape, I'm just communicating to the more enlightened members of this forum thread that Manley, who we know and respect, does occasionally use words and phrases that don't convey all the correct details.

And I love communicating inside baseball to others :wink:. It's the pedantic in me :D
I'm the lead SW designer for a different space project. I sent a bunch of information around to my team about this incident. I hope some of them actually read it. I got very little feedback. I sent that out before Scott's video, so that one was not included.

Scott Manley writes software, so should know the distinctions between software and requirements. My initial reaction was the expected "NOT A BUG - that's a requirements failure". That said, after some thought I've more toward what Isgrimnur wrote, in that an outside observer won't care about the why, only that the software made the lander run out of go-juice.

I object more to the word "unbelievable" in that title. :D

That said, part of my job is to recognize when I'm given an insufficient (to be charitable) requirement and to point out all the ways it could cause trouble.

One thing I found interesting was that the customer blamed themselves, not the software developer (Draper).
The lander used software developed by Draper, but Ujiie [Ryo Ujiie, chief technology officer of ispace] said ispace accepted blame for the failure, linking it to requirements ispace levied on the software. Besides their relationship on software for the lander, ispace’s U.S. subsidiary is designing a lander for a Draper-led lander mission for NASA’s Commercial Lunar Payload Services program.
Where I work we do preliminary and critical design reviews for all aspects of the mission, and these are attended by scientists and engineers. If a flight software lead presented that use-case where the software would switch to internal calculations in the event of an N-km difference you can bet a scientist would have raised their hand and said "you know our landing area has 3km cliffs right? What happens if the altimeter sees that?"