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Author
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Topic: [Discuss] SpaceX CRS-1 space station mission
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Robert Pearlman Editor Posts: 42988 From: Houston, TX Registered: Nov 1999
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posted 10-09-2012 02:16 PM
quote: Originally posted by garymilgrom: Didn't the STS have this capability?
Shuttle could get to orbit on two engines, but not the desired orbit. It only happened once during the program, STS-51F, and Challenger entered a lower than desired orbit (173 vs. the planned 211 nautical miles). The mission had to be extended 17 orbits in part due to the Abort-to-Orbit (ATO). |
Jay Chladek Member Posts: 2272 From: Bellevue, NE, USA Registered: Aug 2007
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posted 10-09-2012 02:43 PM
What orbit a shuttle ended up in depended entirely on where it lost an SSME in the ascent. If an engine quit close to MECO, the bird still could get enough Delta Vee from the remaining engines with the remaining fuel to typically park itself in the proper orbit. Down lower, it becomes a bit more of a problem (as with the STS-51F abort). The loss of more than one engine makes hitting ANY orbit very problematic at best.Technically though, the system shuttle used did much the same thing as what the Saturn did. Given the weight of an orbiter, sure it couldn't necessarily hit exactly the same orbit if it had to do an AOA, but it would at least be a survivable abort and mission objectives could still be achieved. Only reason why you likely don't see a similar system on other boosters such as Delta, Atlas or the Russian ones is due to how their engines are set up. So I admit Falcon 9 is kind of unique (and it beats the "Cluster's last stand" moniker of the Saturn 1 by a single engine... nine instead of eight). The Saturn 1B I believe had that capability as well with its first stage engines (and technically Saturn 1Bs were still flying after the Saturn V did, but that I admit is a case of nit picking). Second stage, not so much as it used a single J-2 engine (perhaps the original S-IV from the Saturn 1 could do it though). While I understand SpaceX is trying to point out that its booster has a capability to get to the proper orbit after losing a first stage engine, it is still a bit of a stretch mentioning the Saturn V in a blanket statement about the Falcon 9 without necessarily mentioning how it is like the Saturn, because people can assume it is more like a Saturn than it actually is. It is almost like doing what a political advertisement does, making you feel good or bad about something by mentioning a word or two and letting a viewer's knowledge (or lack thereof) fill in the blanks to get a point across. But, some people consider that a valid form of advertising and sales. My point is that SpaceX is better than that. They don't HAVE to keep making a Saturn V comparison, especially when Musk keeps harping that he can fly payloads into space for less money than what NASA legacy systems can. In this industry, people want to see RESULTS, not hear talk. This Falcon 9 abort with a successful primary mission is a nice result, even with the failure. Why try to grandstand more? Better yet, figure out what failed and do your best to correct it before the next one rather than crowing about the backup system's success. The success is good, but the failure STILL needs to be investigated. |
Robert Pearlman Editor Posts: 42988 From: Houston, TX Registered: Nov 1999
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posted 10-09-2012 02:51 PM
quote: Originally posted by Jay Chladek: ...it is still a bit of a stretch mentioning the Saturn V in a blanket statement about the Falcon 9 without necessarily mentioning how it is like the Saturn
Where have they done that? SpaceX's statement defined the relationship: Like the Saturn V, which experienced engine loss on two flights, Falcon 9 is designed to handle an engine out situation and still complete its mission. I think it's a stretch to label this grandstanding. Rather, it is using history to illustrate a modern feature, which is a common device when relating the new to a public only familiar with the old. quote: Originally posted by Jay Chladek: ...but the failure STILL needs to be investigated.
Of course it does — and it is — but it's day two, and reporting on what they know worked doesn't at all interfere in finding out what didn't. The latter just takes longer. |
Rusty B Member Posts: 239 From: Sacramento, CA Registered: Oct 2004
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posted 10-09-2012 04:58 PM
Saturn-Apollo 4 (SA-4), the fourth flight of the Saturn IB on March 29, 1963 did a deliberate engine out test of engine #5 (one of it's inboard engines, out of the eight 1st stage engines), 100 seconds into the the flight with no problem. |
Jay Chladek Member Posts: 2272 From: Bellevue, NE, USA Registered: Aug 2007
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posted 10-09-2012 05:11 PM
They are still referencing two engine failures that took place over 40 years ago on a different rocket system with a very different set of circumstances. It is a "bit" of a stretch to go THAT far back. It wasn't a point of discussion and it didn't need to be until they made it one. Why even mention it at all? Now if somebody asks about the guidance system and how it corrected the course of the rocket on ascent and Saturn as referenced, that is different. But to come right out and say it on the press release... why reference it at all?Granted this is my own opinion mind you as I am not intending this as a smear campaign against SpaceX. I'm just voicing my concerns about a comparison which in my opinion doesn't need to be made and it seems a little misguided. Now if Musk and or the PR department had said in a press release "Our Falcon 9 rocket shows it can stay on course and reach the proper orbit, even with a first stage single engine failure..." that would be different. It showcases that their rocket did something relatively unique which has never been demonstrated on an operational mission before (only in a planned test). Minor correction Rusty, SA-4 was a Saturn 1 Block 1 (live first stage, dummy upper stage). It was the original Saturn 1, not a Saturn 1B (originally known as the "Uprated Saturn 1) which didn't fly until SA-201, which flew on February 26, 1966. |
Robert Pearlman Editor Posts: 42988 From: Houston, TX Registered: Nov 1999
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posted 10-09-2012 06:10 PM
quote: Originally posted by Robert Pearlman: NASA has scheduled 10 minutes for collectSPACE.com to interview ISS Expedition 33 commander Suni Williams live from onboard the orbiting laboratory...
Just received word from NASA that the date of my interview is moving; it is now targeted for the morning of Oct. 19. Once a firm date is set, I will let readers here know. |
mikej Member Posts: 481 From: Germantown, WI USA Registered: Jan 2004
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posted 10-10-2012 06:47 PM
quote: Originally posted by Rusty B: Saturn-Apollo 4 (SA-4), the fourth flight of the Saturn IB on March 29, 1963 did a deliberate engine out test of engine #5 (one of it's inboard engines, out of the eight 1st stage engines), 100 seconds into the the flight with no problem.
Two flights later, an H-1 on SA-6 experienced a problem with its turbopump, resulting in an unplanned engine-out situation. It reached orbit without problem. |
Jim Behling Member Posts: 1463 From: Cape Canaveral, FL Registered: Mar 2010
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posted 10-10-2012 07:19 PM
quote: Originally posted by Jay Chladek: They are still referencing two engine failures that took place over 40 years ago on a different rocket system with a very different set of circumstances. It is a "bit" of a stretch to go THAT far back.
It isn't a stretch. They are only going back to the closest system to use the same capability. Also, of course, it is going to be a different rocket system, what else would they compare to? A fictional system. It is not a different set of circumstances. It is the exact same circumstance. Falcon 9 has multiple booster engines, Saturn V had multiple booster engines. Saturn V had engine out capability during certain portion of the flight, so does Falcon 9. Jeesh, when will people stop treating Saturn V, Apollo, Von Braun, the astronauts as untouchable? If the Saturn V was so, great? Why isn't it flying anymore? |
Robert Pearlman Editor Posts: 42988 From: Houston, TX Registered: Nov 1999
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posted 10-12-2012 12:54 PM
From SpaceX: NASA and SpaceX announce that they have jointly formed a CRS-1 Post-Flight Investigation Board. This board will methodically analyze all data in an effort to understand what occurred to engine 1 during liftoff of the CRS-1 mission on Sunday, October 7. While Falcon 9 was designed for engine out capability and the Dragon spacecraft has successfully arrived at the space station, SpaceX is committed to a comprehensive examination and analysis of all launch data, with the goal of understanding what happened and how to correct it prior to future flights. |
Robert Pearlman Editor Posts: 42988 From: Houston, TX Registered: Nov 1999
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posted 11-15-2012 07:44 AM
Space station program manager Michael Suffredini, addressing the NASA Advisory Council's human exploration and operations subcommittee, provided an update on the anomalies and problems experienced during the Dragon CRS-1 supply mission, Spaceflight Now reports. The mission's Falcon 9 booster suffered an engine failure moments after liftoff from Cape Canaveral, Fla., and investigators from SpaceX and NASA have found "no smoking gun" on the cause of the problem, according to Mike Suffredini, NASA's space station program manager. ...while the ship was berthed with the space station, a suspected radiation hit took out one of Dragon's three flight computers, Suffredini said. Dragon's flight computers are not hardened to resist radiation, according to Suffredini, but the craft is designed to function with only two main computers operating at one time. Engineers believe radiation also shut down one of Dragon's three GPS navigation units, a propulsion computer and an ethernet switch during the flight. Controllers at SpaceX's headquarters in Hawthorne, Calif., recovered those systems to full operability, Suffredini said. Engineers also believe that after splashing down, sea water leaked into electrical boxes, causing the Dragon's freezer and three cabin coolant pumps to lose power. The GLACIER freezer was set at minus 139 degrees Fahrenheit. When SpaceX's recovery team opened the capsule, the freezer's temperature was minus 85 degrees, according to NASA.Scientists are studying the medical samples, which were returned to NASA's Johnson Space Center, said Josh Byerly, an agency spokesperson. "It wasn't a severe impact in terms of the temperature increase," said Byerly, who added the power snafu would not affect any contractual payments to SpaceX. |
SkyMan1958 Member Posts: 867 From: CA. Registered: Jan 2011
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posted 11-15-2012 08:58 PM
Wow, that is bad news. I just assumed that they would have radiation hardened their craft. That just sounds sloppy to me in a space environment. |
issman1 Member Posts: 1042 From: UK Registered: Apr 2005
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posted 11-16-2012 11:20 AM
Not using radiation-hardened systems means avoiding an increase in cost and weight, which is why commercial redefines being on the cutting edge.But is it cutting corners? One can only presume at this juncture that DragonRider (the crew version) will utilize radiation-hardened or radiation-protected computers. Musk is about my age, which means he (and I) lived through Challenger and Columbia. | |
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