mersenneforum.org "Born too late for earth exploration, Born too early for space exploration"
 Register FAQ Search Today's Posts Mark Forums Read

2019-12-20, 20:29   #12
Dr Sardonicus

Feb 2017
Nowhere

2·2,677 Posts

Quote:
 Originally Posted by ewmayer Why NASA’s Annoyed About Elon Musk’s Giant Rocket - LiveScience Hey, NASA - didja include any penalty-for-nondelivery clauses in that contract? Of cooooooooourse you didn't ... but I'm sure the MuskMan is quaking in his self-driving loafers at thw thought of your being "annoyed".
Boeing's Starliner Mission Flops Due To A Broken Clock
Quote:
 By Keith Cowing on December 20, 2019 11:33 AM. Keith's note: Boeing's Starliner was launched on time this morning. ULA gave it a perfect flight up to the point where the spacecraft separated. Then things started to go wrong. A planned engine burn did not happen because the spacecraft's clock was wrong and the spacecraft thought that it was somewhere else. Boeing tried to do a burn to fix the situation but a gap between several TDRSS satellites meant that the command would have been sent too late to allow the mission to have a chance to reach ISS. Boeing says that it has no idea why the clock was wrong. The curent orbital path will bring Starliner into a position to do a landing at White Sands in 48 hours. In talking about this problem NASA and Boeing tried to spin the mission as a success even though a prime objective was to dock with the ISS. It is too soon to know if a repeat flight to accomplish the original objectives will be required or if the next flight - with a crew - will be the first time that a Starliner docks with ISS.

2019-12-22, 23:44   #13
Dr Sardonicus

Feb 2017
Nowhere

123528 Posts
Followup on fouled-up Starliner mission...

Boeing capsule returns to Earth after aborted space mission
Quote:
 Managers will review all the data before deciding whether to do another test flight or go straight to flying astronauts, said NASA’s Steve Stich.
I'm not a rocket scientist or even an engineer, but wouldn't it be good to make sure the thing can dock with the ISS before sending it there with astronauts aboard?
Quote:
 Even though not all goals were met including a station docking, "in my eyes, it was a huge success," said Boeing flight director Richard Jones.
"A huge success?" Docking with the station was the primary mission!

The landing was a huge success. Since the space craft is intact, there's a good chance they can figure out why the mission clock did not sync up with the rocket and was off by 11 hours until they were able to reset it.

The following cost-related statements may be of interest:
Quote:
 As its space shuttle program was winding down, NASA looked to private industry to take over cargo and crew deliveries to the space station. SpaceX kicked off supply runs in 2012. Two years later, NASA hired SpaceX and Boeing to ferry astronauts to the orbiting lab. SpaceX got $2.6 billion under NASA’s commercial crew program, while Boeing received more than$4 billion. The goal was to launch NASA astronauts by 2017. Because of delays, NASA is looking to buy another two seats on Russian rockets in 2020 and 2021 to guarantee a continuing U.S. presence on the space station. Even when private companies are regularly carrying up astronauts for NASA, the space agency always will reserve a seat for a Russian in exchange for a free U.S. seat on a Soyuz. Over the years, these Soyuz rides have cost NASA up to \$86 million apiece, with the tab totaling in the billions. A recent audit by NASA’s inspector general found a Starliner seat will cost slightly more than that, with a Dragon seat going for just over half the price.

2019-12-23, 09:18   #14
xilman
Bamboozled!

"𒉺𒌌𒇷𒆷𒀭"
May 2003
Down not across

2B7C16 Posts

Quote:
 Originally Posted by Dr Sardonicus I'm not a rocket scientist or even an engineer, but wouldn't it be good to make sure the thing can dock with the ISS before sending it there with astronauts aboard?
As was done with Soyuz and the Shuttle you mean?

You may have a point there.

2019-12-23, 13:42   #15
Dr Sardonicus

Feb 2017
Nowhere

2×2,677 Posts

Quote:
Originally Posted by xilman
Quote:
 Originally Posted by Dr Sardonicus Boeing capsule returns to Earth after aborted space mission I'm not a rocket scientist or even an engineer, but wouldn't it be good to make sure the thing can dock with the ISS before sending it there with astronauts aboard?
As was done with Soyuz and the Shuttle you mean?

You may have a point there.
I guess it's down to making sure the docking mechanism works. I imagine that with astronauts aboard, a human pilot could do the required rocket burns.

Your mention of Soyuz brings to mind the point at which I thought we (the US) had finally caught up with and passed the Russians (USSR) in the "Space Race." It was during the Gemini program.

(Looks up details)

It was Gemini VIII in January 1966 which did the first "space docking," with an unmanned Agena "target vehicle." Some time after that, a Soviet mission tried and failed to perform a "space docking." They succeeded on a later mission, of course, but the fact remained, that the US had reached an important milestone in achieving a manned lunar mission before the USSR had.

Eventually (1975), pursuant to the policy of détente, there was an Apollo-Soyuz mission in which a US and Soviet spacecraft docked in orbit.

Of course, back in those days, having an unmanned craft perform such a delicate maneuver was out of the question.

In the general category of rushing the testing process, in 1963 NASA adopted the "all-up" testing concept, to be implemented on the as-yet-untested 3-stage Saturn V rocket. No methodical testing of each stage individually. Engineers at the Marshall Space Flight Center were appalled. Wernher von Braun himself had reservations, but acquiesced. Fortunately for all concerned, the tests were successful, saving a great deal of time in getting the Apollo missions to the moon.

This was mentioned in the NOVA episode TO THE MOON, which aired July 13, 1999 -- commemorating the 30th anniversary of the first manned lunar landing. The following is a quote from Adelbert "Del" O. Tischler, Director of the Chemical Propulsion Division at NASA. IMO it provides some explanation of why the "all-up" tests were successful.
Quote:
 A. TISCHLER: Some of the people in the headquarters referred to Marshall as the Chicago Bridge and Iron Works, and all of their vehicles were very conservatively designed with safety factors that I think were probably excessive by today's standards at least. However, there's one thing that has to be acknowledged. They worked.

 2019-12-23, 22:04 #16 tServo     "Marv" May 2009 near the Tannhäuser Gate 23·89 Posts Saturn V impressive record On one of the moon landing anniversary shows, they mentioned that EVERY Saturn V launch was a success !!
2019-12-30, 22:08   #17
ewmayer
2ω=0

Sep 2002
República de California

1168810 Posts

Re. the Boeing fubar, my money's on a software error, which will likely get spun in typical anodyne fashion as a "glitch". Funny how the Apollo-era missions didn't seem to have many of those, especially of the mission-failure-causing variety, despite the extreme programming/hardware constraints faced by the coders back then. Or perhaps better, I expect said missions didn't have catastrophic software errors *because* of the constraints, which forced the programmers to keep the code as simple and robust as possible, meaning every single line of code was precious and got more eyeballs than the any multi-million-line spaghetti-code project gets today. Note the "criticality mismatch issue" here - modern coders learn in an environment where bugs are to be avoided, but if your PeeCee hits one and gets BSODed, you just reboot it. Transfer that learned casual ethos to air and space travel, and you have a recipe for one disaster after another. And at Boeing that is exacerbated by the culture of extreme short-termism and cost-cutting of the last-few-decades, as exemplified by the ever-worsening 737 Max debacle. Thanks, Wall Street!

Quote:
 Originally Posted by tServo On one of the moon landing anniversary shows, they mentioned that EVERY Saturn V launch was a success !!
That's more than a bit disingenous - so they don't count the Apollo I oxygen-fire disaster as a failed launch because said mission never actually launched. And I'm guessing they count Apollo XIII as a mission success because "we brought the crew home safely". That having been said, the Saturn V was a remarkably robust piece of work, just that it doesn't help to pretend away the very real mission failures of the Apollo program. And of course NASA simply walked away from the thoroughly-debugged-by-the-end Saturn V program to focus on the shiny new Space Shuttle program, throwing away all that precious and hard-won expertise, as well as a crucial heavy-lift capability whose lack is still costing them today.

2019-12-31, 01:53   #18

"Sam Laur"
Dec 2018
Turku, Finland

4758 Posts

Quote:
 Originally Posted by ewmayer That's more than a bit disingenous - so they don't count the Apollo I oxygen-fire disaster as a failed launch because said mission never actually launched. And I'm guessing they count Apollo XIII as a mission success because "we brought the crew home safely".
The Apollo 1 (AS-204) mission used a Saturn IB rocket, because it was only going to be launched to Earth orbit. And the rocket was actually used during the unmanned Apollo 5 (also AS-204...) mission, which was to test the Lunar module descent and ascent engines. The Saturn launched smoothly, but there were glitches during the LM descent engine tests, however the mission was deemed enough of a success anyway, that another unmanned flight test was scrapped.

On the Apollo 13, the Saturn V second stage encountered some self-ampliifying oscillations called pogo, and the center engine (one of five) of the second stage shut down just before it would have destroyed itself with catastrophic results. Fortunately this did not have much of an effect on the mission, and the later tank failure in the service module was completely unrelated.

The earlier unmanned Apollo 6 mission had run into some oscillation problems of its own. That time it was the first stage that shook so much, that the fuel lines of two engines in the second stage were damaged, and those shut down during the second stage burn due to performance problems. Also the third stage engine, or systems related to if, were damaged, and the engine wouldn't restart for the trans Lunar injection burn.

And then there was the lightning strike during the Apollo 12 launch, which did not affect the Saturn V systems, but did knock many command and service module systems offline.

So every Saturn V launch was a success, if you define success as having no catastrophic failures caused by the launch vehicle. By the time of the crewed launches, it was robust enough, due to extensive (and expensive) testing and failures encountered during those tests. It is indeed somehow sad, that all that experience was just thrown away after the Apollo program.

2019-12-31, 02:56   #19
Dr Sardonicus

Feb 2017
Nowhere

2×2,677 Posts

Quote:
 Originally Posted by ewmayer Funny how the Apollo-era missions didn't seem to have many of those, especially of the mission-failure-causing variety, despite the extreme programming/hardware constraints faced by the coders back then. Or perhaps better, I expect said missions didn't have catastrophic software errors *because* of the constraints, which forced the programmers to keep the code as simple and robust as possible,
I generally agree, the best work with a technology is often done by those who push it to its limits. And this almost invariably done in learning what new technologies can do.
That said, Apollo 11 came fairly close to a landing abort because of an unanticipated computer problem. During the descent, the system began issuing "program alarms" that said, basically, there wasn't anywhere for new computer instructions to go. The system would then reboot. Luckily, this didn't happen often enough to lose vital navigation data.

Finally, Buzz Aldrin noticed the alarms seemed to come when they asked the computer for radar data from tracking the other craft, which they needed to keep current on in case they had to abort. (As it turned out, these requests were overloading the system.) So they started asking Houston for the data instead, and the program alarms ceased.
Quote:
 Originally Posted by tServo On one of the moon landing anniversary shows, they mentioned that EVERY Saturn V launch was a success !!
Quote:
 That's more than a bit disingenous - so they don't count the Apollo I oxygen-fire disaster as a failed launch because said mission never actually launched. And I'm guessing they count Apollo XIII as a mission success because "we brought the crew home safely".
Since the context of the original statement is not known, it is fatuous to call it "disingenuous" or claim that anyone was "pretending away" anything. As far as I know, the statement was only to the effect that the rocket did its job.

I would note that Alan Shepard made the first manned US space flight on May 5, 1961, three weeks after Yuri Gagarin became the first person in history to go into space. After Shepard's successful flight, on May 25, 1961 President Kennedy made the commitment "before this decade is out," to send a man to the Moon and return him safely to the earth.

That commitment was fulfilled on July 24, 1969, when the Apollo 11 capsule splashed down. That's eight years and two months. In the interim, there were other important matters on the national agenda.

The last Space Shuttle mission ended July 21, 2011. Eight years and five months have elapsed since then. So it has taken longer to regain the capacity to send US astronauts into low earth orbit, than it took from the dawn of manned space flight to land men on the Moon, starting from scratch. I don't think this is due to any lack of expertise or ability. I think the main reason is that most Americans just don't give a rat's patootie about manned space flight.

 Similar Threads Thread Thread Starter Forum Replies Last Post retina Lounge 32 2015-03-28 13:08 petrw1 Lounge 2 2011-05-24 06:11 petrw1 Lounge 0 2009-03-05 21:26 ewmayer Science & Technology 1 2008-12-03 03:27 mfgoode Lounge 4 2007-07-17 16:45

All times are UTC. The time now is 08:19.

Sat Jan 22 08:19:06 UTC 2022 up 183 days, 2:48, 0 users, load averages: 1.25, 1.28, 1.20