Rdivine Posted January 28, 2016 Share Posted January 28, 2016 (edited) A new rocket already? I haven't seen much progress regarding the falcon heavy, yet they are starting on another one. p.s. Elon Musk looks different and aged... I suspect meth stress. Edited January 28, 2016 by Rdivine Link to comment Share on other sites More sharing options...
Albert VDS Posted January 28, 2016 Share Posted January 28, 2016 46 minutes ago, Rdivine said: A new rocket already? I haven't seen much progress regarding the falcon heavy, yet they are starting on another one. It's not a rocket which is going to replace the Falcon 9 or the Falcon Heavy but a rocket to transport people to Mars. Link to comment Share on other sites More sharing options...
Nibb31 Posted January 28, 2016 Share Posted January 28, 2016 4 hours ago, fredinno said: Probably. Also cost. Link to comment Share on other sites More sharing options...
Albert VDS Posted January 28, 2016 Share Posted January 28, 2016 25 minutes ago, Nibb31 said: Also cost. Also cost what? Do you mean reduced cost, how would that work if you increase the nr. of parachutes? Link to comment Share on other sites More sharing options...
Frozen_Heart Posted January 28, 2016 Share Posted January 28, 2016 Really hyped to see his Mars ideas, even though I don't believe it will ever happen. Link to comment Share on other sites More sharing options...
Mitchz95 Posted January 28, 2016 Share Posted January 28, 2016 This should be interesting. Link to comment Share on other sites More sharing options...
Wingman703 Posted January 28, 2016 Share Posted January 28, 2016 9 hours ago, Rdivine said: Why does the crew dragon have 4 parachutes instead of 3? Is it a redundant feature? Can't have to many backups for the backup. Link to comment Share on other sites More sharing options...
Nibb31 Posted January 28, 2016 Share Posted January 28, 2016 2 hours ago, Albert VDS said: Also cost what? Do you mean reduced cost, how would that work if you increase the nr. of parachutes? 4 medium-sized parachutes are likely cheaper than 3 large ones. It's likely that these smaller chutes are a more commonly used off-the-shelf design. Higher volume = lower cost. Link to comment Share on other sites More sharing options...
Wjolcz Posted January 28, 2016 Share Posted January 28, 2016 (edited) 11 hours ago, Rakaydos said: On the full scale separation test, on the counterweight... is that a Thwomp? Like from Mario? Yup. http://i.imgur.com/oawldKV.gifv Edited January 28, 2016 by Veeltch Link to comment Share on other sites More sharing options...
sgt_flyer Posted January 28, 2016 Share Posted January 28, 2016 1 hour ago, Nibb31 said: 4 medium-sized parachutes are likely cheaper than 3 large ones. It's likely that these smaller chutes are a more commonly used off-the-shelf design. Higher volume = lower cost. one possibility is that it comes from Dragon's design itself, with the 4 superdraco pods. 4 smaller parachutes instead of 3 big ones might be less hassle to give housings, and using only two main chutes instead of 3 might not be enough to prevent life threatening injuries in case one of the parachute fails. (after all, they need to have a way to ensure the parachutes won't get damaged in case of a superdraco failure, maybe on top of the already existing special hpusing for the dracos. Link to comment Share on other sites More sharing options...
KerbonautInTraining Posted January 28, 2016 Share Posted January 28, 2016 1 minute ago, sgt_flyer said: one possibility is that it comes from Dragon's design itself, with the 4 superdraco pods. 4 smaller parachutes instead of 3 big ones might be less hassle to give housings, I'm pretty sure the parachutes are all in one compartment on the side of the capsule, that's how they did it on the cargo version and it's what appears to be in the pad abort test. Link to comment Share on other sites More sharing options...
Albert VDS Posted January 28, 2016 Share Posted January 28, 2016 38 minutes ago, KerbonautInTraining said: I'm pretty sure the parachutes are all in one compartment on the side of the capsule, that's how they did it on the cargo version and it's what appears to be in the pad abort test. Yeah, and besides it's going to have a back up set too. It would need 8 compartments and 8 drogue chutes if the parachutes were stored separately and it would increase complexity. Link to comment Share on other sites More sharing options...
sojourner Posted January 28, 2016 Share Posted January 28, 2016 I don't think there is another backup set of chutes. 4 is it. Link to comment Share on other sites More sharing options...
Albert VDS Posted January 28, 2016 Share Posted January 28, 2016 9 minutes ago, sojourner said: I don't think there is another backup set of chutes. 4 is it. In this interview Elon says that the Dragon 2 will have redundant and redundant chutes, although he talks about 3 main chutes: Link to comment Share on other sites More sharing options...
Wingman703 Posted January 28, 2016 Share Posted January 28, 2016 (edited) Ok, I'm all for backups for the backup, but backups for the backups for the backup seems excessive. Seriously, if enough has gone wrong that 1. Eight Superdracos fail 2. Four main chutes fail 3. Your pretty screwed by now anyway. Not sure how much four MORE chutes are going to help. Edited January 28, 2016 by Wingman703 Link to comment Share on other sites More sharing options...
Albert VDS Posted January 28, 2016 Share Posted January 28, 2016 18 minutes ago, Wingman703 said: Your pretty screwed by now anyway. Not sure how much four MORE chutes are going to help. If an in flight abort happens, which means they can't land with the SuperDraco's, and the chutes don't work then back up chutes are very welcome. It's common practice for parachutist, so why not for a capsule? And there is enough time to deploy the back up chutes if the main chutes fail to deploy, it's something which can easily be detected by the onboard computer and some sensors. Link to comment Share on other sites More sharing options...
Nibb31 Posted January 28, 2016 Share Posted January 28, 2016 There are 4 chutes. You can land safely with 3, and maybe even 2. You don't need 4 more. Link to comment Share on other sites More sharing options...
Wingman703 Posted January 28, 2016 Share Posted January 28, 2016 Ah, I was thinking only of re-entry, not an abort. With TWO sets of 'chutes then, how much do the Draco's really save vs an abort tower/RCS controls? Is it still a fair amount? I mean, the Draco's themselves can't be all that light. Link to comment Share on other sites More sharing options...
fredinno Posted January 28, 2016 Share Posted January 28, 2016 9 minutes ago, Wingman703 said: Ah, I was thinking only of re-entry, not an abort. With TWO sets of 'chutes then, how much do the Draco's really save vs an abort tower/RCS controls? Is it still a fair amount? I mean, the Draco's themselves can't be all that light. Probably very little. It's likely since Elon just wants to reduce costs and make everything land propulsively- a parachuted land landing needs a lot more space than a propulsive one to land. Link to comment Share on other sites More sharing options...
Nibb31 Posted January 28, 2016 Share Posted January 28, 2016 There won't be two sets of chutes, only one set and Dracos. Link to comment Share on other sites More sharing options...
Albert VDS Posted January 28, 2016 Share Posted January 28, 2016 31 minutes ago, Nibb31 said: There are 4 chutes. You can land safely with 3, and maybe even 2. You don't need 4 more. It's one of those things where one says "I wish we had a back up" when all main chutes fail. 8 minutes ago, Wingman703 said: Ah, I was thinking only of re-entry, not an abort. With TWO sets of 'chutes then, how much do the Draco's really save vs an abort tower/RCS controls? Is it still a fair amount? I mean, the Draco's themselves can't be all that light. SpaceX is planing to land the Dragon 2 propulsively with the SuperDracos, so it's fulfilling 3 roles for the weight of one system. I have no idea what the weight save is but it's I think it's a fair amount replacing replacing 3 systems with one. Link to comment Share on other sites More sharing options...
Nibb31 Posted January 29, 2016 Share Posted January 29, 2016 8 hours ago, Albert VDS said: It's one of those things where one says "I wish we had a back up" when all main chutes fail. If all the main chutes fail, then you have a fundamental systemic problem that is probably also present in your backup chutes. Redundancy is better served by providing different systems or repurposing existing systems than by duplicating everything. 8 hours ago, Albert VDS said: SpaceX is planing to land the Dragon 2 propulsively with the SuperDracos, so it's fulfilling 3 roles for the weight of one system. I have no idea what the weight save is but it's I think it's a fair amount replacing replacing 3 systems with one. Actually, for the first Commercial Crew missions, it will be landing on parachutes with SDs as a last second braking device (and maybe as a backup if the chutes fail, not sure). Link to comment Share on other sites More sharing options...
Albert VDS Posted January 29, 2016 Share Posted January 29, 2016 32 minutes ago, Nibb31 said: If all the main chutes fail, then you have a fundamental systemic problem that is probably also present in your backup chutes. Redundancy is better served by providing different systems or repurposing existing systems than by duplicating everything. It already has 2 different system and besides what the problem of have 2 sets of parachutes? Your reasoning about 1 failing and the other failing in the same way is very unlikely, even more so if it's an outside cause. 33 minutes ago, Nibb31 said: Actually, for the first Commercial Crew missions, it will be landing on parachutes with SDs as a last second braking device (and maybe as a backup if the chutes fail, not sure). Yes, that's why I said planning and not going to on the first flights. Link to comment Share on other sites More sharing options...
fredinno Posted January 29, 2016 Share Posted January 29, 2016 6 minutes ago, Albert VDS said: It already has 2 different system and besides what the problem of have 2 sets of parachutes? Your reasoning about 1 failing and the other failing in the same way is very unlikely, even more so if it's an outside cause. Yes, that's why I said planning and not going to on the first flights. More mass, meaning higher F9 performance needed to send it into space. I can't beleive you forgot one of the most basic concepts of spaceflight in a forum about a game about spaceflight Link to comment Share on other sites More sharing options...
KSK Posted January 29, 2016 Share Posted January 29, 2016 23 minutes ago, fredinno said: More mass, meaning higher F9 performance needed to send it into space. I can't beleive you forgot one of the most basic concepts of spaceflight in a forum about a game about spaceflight Back of the envelope calculation: Falcon 9 can put a little over 13,000 kg into LEO. Dry mass of Dragon 2 is about 4,200 kg and it can carry a payload of just over 3,300 kg to ISS. Leaving SpaceX with 6,500 kg of spare capacity for fuel, consumables and redundant systems, assuming that they're not already factored into that dry mass. In other words, SpaceX's current workhorse booster, which they're cheaply mass producing (inasmuch as rockets are ever mass-produced or ever cheap) has more than enough performance for the job. It's not like they have to develop a new, higher performance booster just for Dragon 2. Link to comment Share on other sites More sharing options...
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