insert_name Posted February 29, 2016 Share Posted February 29, 2016 2 hours ago, gooddog15 said: I find it sort of hilarious and aggravating that Space X's main arch enemies are now boats. Also, that was one of closest aborts I've ever saw. how did a boat cause this again? Link to comment Share on other sites More sharing options...
gooddog15 Posted February 29, 2016 Share Posted February 29, 2016 21 minutes ago, Meithan said: Well, the flight computer commanded the abort automatically after determining that the thrust levels were not as expected. It's not like it had to time it just right or the rocket would launch. The rocket only launches if the flight computer OKs everything after the engines are lit. Yeah I know that. It's just that haven't seen this type of abort scenario play out live before. Actually, come to think of it, I've never seen an abort before, only scrubs. Link to comment Share on other sites More sharing options...
StrandedonEarth Posted February 29, 2016 Share Posted February 29, 2016 A ship strayed into the mo-go zone of the launch range, causing the range safety people to call a hold. The delay caused caused all sorts of problems with the super-chilled LO2 warming up, and so on. According to the twitter there was a helium bubble too. Elon Musk puts the blame on that hold Link to comment Share on other sites More sharing options...
DerekL1963 Posted February 29, 2016 Share Posted February 29, 2016 9 minutes ago, StrandedonEarth said: A ship strayed into the mo-go zone of the launch range, causing the range safety people to call a hold. The delay caused caused all sorts of problems with the super-chilled LO2 warming up, and so on. According to the twitter there was a helium bubble too. Elon Musk puts the blame on that hold Countdowns routinely get held for all kinds of reasons. If your rocket can't withstand a hold anytime after fueling but before ignition, your design is flawed. Time to go back to the drawing board. Link to comment Share on other sites More sharing options...
Motokid600 Posted February 29, 2016 Share Posted February 29, 2016 A helium bubble in what exactly? Link to comment Share on other sites More sharing options...
fredinno Posted February 29, 2016 Share Posted February 29, 2016 (edited) 28 minutes ago, DerekL1963 said: Countdowns routinely get held for all kinds of reasons. If your rocket can't withstand a hold anytime after fueling but before ignition, your design is flawed. Time to go back to the drawing board. That's what I meant that SpaceX whould never have bothered with the F9FT. They probably will regress to F91.1 due to this flaw, as it can cost them quite a bit of money and business, or find a way to detank and refuel a F9 in only a few minutes. Edited February 29, 2016 by fredinno Link to comment Share on other sites More sharing options...
Streetwind Posted February 29, 2016 Share Posted February 29, 2016 (edited) 2 hours ago, DerekL1963 said: Countdowns routinely get held for all kinds of reasons. If your rocket can't withstand a hold anytime after fueling but before ignition, your design is flawed. Time to go back to the drawing board. Keep in mind that this launch is scraping the absolute bottom of the barrel of the F9's capability in reusable mode. When the SES-9 contract was initially penned, it was expected to fly expendable. And now, even though the vehicle is upgraded, they are still forced to resort to measures like skipping the post-separation boostback burn entirely because the satellite is just that heavy. It's the heaviest payload SpaceX has ever tried to send to geostationary orbit, on any mission. If they were sending up a dragon, or a smaller satellite, I'm fairly sure they would have already launched, because losing a few hundred kg's of LOX to boiloff would simply not have mattered. The repeated scrubs here are all going to be down to having pretty much no margins for suboptimal conditions if they want any shot at all at recovering the stage. Edited February 29, 2016 by Streetwind Link to comment Share on other sites More sharing options...
WuphonsReach Posted February 29, 2016 Share Posted February 29, 2016 3 hours ago, Streetwind said: Keep in mind that this launch is scraping the absolute bottom of the barrel of the F9's capability in reusable mode. When the SES-9 contract was initially penned, it was expected to fly expendable. And now, even though the vehicle is upgraded, they are still forced to resort to measures like skipping the post-separation boostback burn entirely because the satellite is just that heavy. It's the heaviest payload SpaceX has ever tried to send to geostationary orbit, on any mission. In addition, they're not putting SES-9 up in a standard Falcon 9 orbit where SES-9 would take months to get into final position. Because of the delays of the past year (SES-9 was supposed to launch last fall? or late summer?), they're going to put the payload into a much higher orbit which gets it a headstart on its final position. The combination of payload mass + target orbit altitude is pushing the limits of what F9 FT is capable of. Link to comment Share on other sites More sharing options...
Serpens Solidus Posted February 29, 2016 Share Posted February 29, 2016 Why did they scrub today's backup launch attempt? Link to comment Share on other sites More sharing options...
KSK Posted February 29, 2016 Share Posted February 29, 2016 Genuine question but how tolerant of normal LOX would an engine developed to use sub-cooled LOX be? I can imagine (quite probably wrongly) that a turbopump that's set up to work with a particular propellant density might have problems with suddenly being fed a lower density propellant mid-flight. Would this 'just' result in reduced thrust (which itself might be enough to scrub the mission), or could it result in a damaged/broken pump? Put another way, is sub-cooled LOX an all or nothing thing, or would F9-FT still be able to launch with warmer LOX if SpaceX were prepared to just forego any landing attempt for the sake of meeting customer demands? Link to comment Share on other sites More sharing options...
fredinno Posted February 29, 2016 Share Posted February 29, 2016 7 hours ago, Streetwind said: Keep in mind that this launch is scraping the absolute bottom of the barrel of the F9's capability in reusable mode. When the SES-9 contract was initially penned, it was expected to fly expendable. And now, even though the vehicle is upgraded, they are still forced to resort to measures like skipping the post-separation boostback burn entirely because the satellite is just that heavy. It's the heaviest payload SpaceX has ever tried to send to geostationary orbit, on any mission. If they were sending up a dragon, or a smaller satellite, I'm fairly sure they would have already launched, because losing a few hundred kg's of LOX to boiloff would simply not have mattered. The repeated scrubs here are all going to be down to having pretty much no margins for suboptimal conditions if they want any shot at all at recovering the stage. Well, they could justfly it expendab;, you know. TBH, what'staking Falcon Heavy so long? It's just 2 cores strapped to a 1st stage! 3 hours ago, Serpens Solidus said: Why did they scrub today's backup launch attempt? A damn boat. 2 hours ago, KSK said: Genuine question but how tolerant of normal LOX would an engine developed to use sub-cooled LOX be? I can imagine (quite probably wrongly) that a turbopump that's set up to work with a particular propellant density might have problems with suddenly being fed a lower density propellant mid-flight. Would this 'just' result in reduced thrust (which itself might be enough to scrub the mission), or could it result in a damaged/broken pump? Put another way, is sub-cooled LOX an all or nothing thing, or would F9-FT still be able to launch with warmer LOX if SpaceX were prepared to just forego any landing attempt for the sake of meeting customer demands? I remember hearing the SSME needed to be modified to handle the cooler, hgher-pressure fuel from the SLS core, as the Shuttle fuel lines were pretty long, and ended up heating the fuel quite a bit. So, i'd say not that much tolerance is available. So deep-cryo LOX is probably all or nothing. I could be wrong though. Link to comment Share on other sites More sharing options...
CatastrophicFailure Posted February 29, 2016 Share Posted February 29, 2016 1 minute ago, fredinno said: Well, they could justfly it expendab;, you know. TBH, what'staking Falcon Heavy so long? It's just 2 cores strapped to a 1st stage! The major failure last summer that's delayed EVERYTHING. Evolution is a slow process. this is all new technology, not like the Atlas that's been around for 50+ years. Link to comment Share on other sites More sharing options...
fredinno Posted February 29, 2016 Share Posted February 29, 2016 9 minutes ago, CatastrophicFailure said: The major failure last summer that's delayed EVERYTHING. Evolution is a slow process. this is all new technology, not like the Atlas that's been around for 50+ years. Falcon Heavy is about as far away from "new" as you can possibly get. Link to comment Share on other sites More sharing options...
Serpens Solidus Posted February 29, 2016 Share Posted February 29, 2016 20 minutes ago, fredinno said: A damn boat. That was what i call yesterday. I was referring to the backup mentioned in this tweet: What happened to that? Link to comment Share on other sites More sharing options...
KerbonautInTraining Posted February 29, 2016 Share Posted February 29, 2016 5 minutes ago, Serpens Solidus said: What happened to that? They got to the point of ignition, my guess is they have to check out the engines to make sure they're ready to go again. Link to comment Share on other sites More sharing options...
CatastrophicFailure Posted February 29, 2016 Share Posted February 29, 2016 22 minutes ago, fredinno said: Falcon Heavy is about as far away from "new" as you can possibly get. It's still an as-yet unflown design with significant enough changes to necessitate its own dedicated launch pad. All while SpaceX has to maintain its existing manifest at the same time. Link to comment Share on other sites More sharing options...
lincourtl Posted February 29, 2016 Share Posted February 29, 2016 Starting at about T -1:35 there's what looks like a sudden venting of fuel from the umbilical where it goes into the strongback, with an accompanying whoosh sound. Does anyone know what's going on at this point in the launch sequence? I hadn't seen this happen before on other Falcon 9 launches, and was just curious. Link to comment Share on other sites More sharing options...
fredinno Posted February 29, 2016 Share Posted February 29, 2016 30 minutes ago, CatastrophicFailure said: It's still an as-yet unflown design with significant enough changes to necessitate its own dedicated launch pad. All while SpaceX has to maintain its existing manifest at the same time. It didn't need LC-39A, FH was originally launching at LC-40. Link to comment Share on other sites More sharing options...
KSK Posted February 29, 2016 Share Posted February 29, 2016 46 minutes ago, fredinno said: Falcon Heavy is about as far away from "new" as you can possibly get. C'mon - that's not exactly fair. OK, Falcon Heavy is 'just' three F9 cores strapped together but F9 itself is pretty darn new as boosters go. The failure last summer will have delayed things, as CatastrophicFailure pointed out. I'm also wondering (and this is pure speculation) whether there's been any redesign work needed to strap three significantly upgraded F9 cores together. I think I remember hearing that F9 was designed to be modular from the outset (so that it could be used in a Falcon Heavy type design) but I don't know whether that's also true of the much taller F9 1.1. You would hope so but neither is it difficult to imagine that the taller core has necessitated a rethink or two. SpaceX have also recovered relatively well from last summer. Compared to Orbital Sciences who are still waiting for their return-to-flight. Or Virgin Galactic, who have taken way longer than expected to move beyond SpaceShipOne. Different companies with very different hardware and business models so a direct comparison isn't fair, but they do serve as reminder that it's easy to over-promise in spaceflight and all too easy for schedules to slip, regardless of which company you're talking about. Link to comment Share on other sites More sharing options...
DerekL1963 Posted February 29, 2016 Share Posted February 29, 2016 8 hours ago, Streetwind said: 11 hours ago, DerekL1963 said: Countdowns routinely get held for all kinds of reasons. If your rocket can't withstand a hold anytime after fueling but before ignition, your design is flawed. Time to go back to the drawing board. Keep in mind that this launch is scraping the absolute bottom of the barrel of the F9's capability in reusable mode. When the SES-9 contract was initially penned, it was expected to fly expendable. Then it should fly expendable. Seriously, delaying a customers payload (which has already been delayed because of an earlier LOV accident) because your experimental system has repeatedly failed does not strike me as good business. SpaceX already has a poor track record for meeting their schedule commitments, and no matter how cheap that's only going to be tolerated for so long. 8 hours ago, Streetwind said: If they were sending up a dragon, or a smaller satellite, I'm fairly sure they would have already launched, because losing a few hundred kg's of LOX to boiloff would simply not have mattered. Losing LOX to boiloff isn't the problem. The problem is the temperature rise of the subcooled LOX. Link to comment Share on other sites More sharing options...
Kerbart Posted February 29, 2016 Share Posted February 29, 2016 2 minutes ago, DerekL1963 said: SpaceX already has a poor track record for meeting their schedule commitments, and no matter how cheap that's only going to be tolerated for so long. I'm not so sure about that. I work in the transportation sector (albeit not spaceflight) and despite how much customers have their mouth full about “supply chain management” and “on time delivery,” they seem to be very eager to drop all that if it means shaving off $0.02 of transport cost per product for something that sells for $50 in a retail store (and no, this is not an exaggeration, sadly). In a business environment where “proven” bottom line savings are given much more significance than “vague” statements as long term viability or network impact (as much as you’d have highly accurate calculations of those) that price tag will remain a huge selling point. Link to comment Share on other sites More sharing options...
sgt_flyer Posted February 29, 2016 Share Posted February 29, 2016 20 minutes ago, Kerbart said: I'm not so sure about that. I work in the transportation sector (albeit not spaceflight) and despite how much customers have their mouth full about “supply chain management” and “on time delivery,” they seem to be very eager to drop all that if it means shaving off $0.02 of transport cost per product for something that sells for $50 in a retail store (and no, this is not an exaggeration, sadly). In a business environment where “proven” bottom line savings are given much more significance than “vague” statements as long term viability or network impact (as much as you’d have highly accurate calculations of those) that price tag will remain a huge selling point. guess it'll depend on how long the customers can wait before a satellite is launched depending on the launcher's price. you can't charge for the services of your satellite if it's still grounded - but you still paid a large sum upfront for building the satellite, so the sooner it's in position, the sooner you profit from the investment. Link to comment Share on other sites More sharing options...
fredinno Posted February 29, 2016 Share Posted February 29, 2016 44 minutes ago, KSK said: C'mon - that's not exactly fair. OK, Falcon Heavy is 'just' three F9 cores strapped together but F9 itself is pretty darn new as boosters go. The failure last summer will have delayed things, as CatastrophicFailure pointed out. I'm also wondering (and this is pure speculation) whether there's been any redesign work needed to strap three significantly upgraded F9 cores together. I think I remember hearing that F9 was designed to be modular from the outset (so that it could be used in a Falcon Heavy type design) but I don't know whether that's also true of the much taller F9 1.1. You would hope so but neither is it difficult to imagine that the taller core has necessitated a rethink or two. SpaceX have also recovered relatively well from last summer. Compared to Orbital Sciences who are still waiting for their return-to-flight. Or Virgin Galactic, who have taken way longer than expected to move beyond SpaceShipOne. Different companies with very different hardware and business models so a direct comparison isn't fair, but they do serve as reminder that it's easy to over-promise in spaceflight and all too easy for schedules to slip, regardless of which company you're talking about. Well, the Atlas V Heavy was said to already use 98% of the same stuff as Atlas V Medium... OSC needed new engines, so obviously that would take longer. Link to comment Share on other sites More sharing options...
Frybert Posted February 29, 2016 Share Posted February 29, 2016 Launch set for Tuesday at 6:46. Link to comment Share on other sites More sharing options...
Streetwind Posted February 29, 2016 Share Posted February 29, 2016 53 minutes ago, DerekL1963 said: Then it should fly expendable. Seriously, delaying a customers payload (which has already been delayed because of an earlier LOV accident) because your experimental system has repeatedly failed does not strike me as good business. SES has a high interest in SpaceX's reusability progress. They don't mind that much. (They have in fact said that they'll happily buy the first booster reflight, if SpaceX would go and refly one already.) Link to comment Share on other sites More sharing options...
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