Quote from: meekGee on 12/10/2012 01:58 amThey didn't call it v1.1 or v1.5. They called it 2.0, and I think this means that went back and designed it from scratch. Sigh... In other words, you ignore what evidence is out there (CCiCap, statements by informed people like Jim) and decide to make stuff up. Well, prepare to be disappointed.And BTW, since you seem to care so much about determining meaning in numerology - I believe Musk called in "Dragon 2", not "Dragon 2.0". There is a fine difference there, if you care to see it.
They didn't call it v1.1 or v1.5. They called it 2.0, and I think this means that went back and designed it from scratch.
Quote from: Lars_J on 12/10/2012 04:54 amQuote from: meekGee on 12/10/2012 01:58 amThey didn't call it v1.1 or v1.5. They called it 2.0, and I think this means that went back and designed it from scratch. Sigh... In other words, you ignore what evidence is out there (CCiCap, statements by informed people like Jim) and decide to make stuff up. Well, prepare to be disappointed.And BTW, since you seem to care so much about determining meaning in numerology - I believe Musk called in "Dragon 2", not "Dragon 2.0". There is a fine difference there, if you care to see it. Seriously - the version # is the least important bit in that post... And what evidence are you talking about that I'm supposedly ignoring? That the pressure vessel hasn't changed? I'd love to hear about any such evidence, one way or the other, since just like the rest of us here, I don't know....But how about the rest of my list of changes - did anyone show evidence in this entire thread to the contrary? Can you even argue that they won't be there?How's about you answer the original question - why is changing the pressure vessel so much more significant than all those other changes?
Quote from: cambrianera on 12/09/2012 07:12 pmA question to the people that believes that Dragon 2.0 will be similar to cargo Dragon: where is SpaceX going to fit SuperDracos?Some models seen on displays or in artworks seems incompatible with dragon pressure vessel.No, look closer, it is compatible. (both that display model and the rendering you attached are at least) Notice the raised areas around the thrusters. The SD's would be mounted on the outside of the pressure vessel, and the raised area/fairing would protect them during ascent.
A question to the people that believes that Dragon 2.0 will be similar to cargo Dragon: where is SpaceX going to fit SuperDracos?Some models seen on displays or in artworks seems incompatible with dragon pressure vessel.
Quote from: Lars_J on 12/10/2012 04:54 amQuote from: meekGee on 12/10/2012 01:58 amThey didn't call it v1.1 or v1.5. They called it 2.0, and I think this means that went back and designed it from scratch. Sigh... In other words, you ignore what evidence is out there (CCiCap, statements by informed people like Jim) and decide to make stuff up. Well, prepare to be disappointed.And BTW, since you seem to care so much about determining meaning in numerology - I believe Musk called in "Dragon 2", not "Dragon 2.0". There is a fine difference there, if you care to see it. Seriously - the version # is the least important bit in that post...
And what evidence are you talking about that I'm supposedly ignoring? That the pressure vessel hasn't changed? I'd love to hear about any such evidence, one way or the other, since just like the rest of us here, I don't know....
But how about the rest of my list of changes - did anyone show evidence in this entire thread to the contrary? Can you even argue that they won't be there?
{snip}I think Dragon 2 will have a warp drive without any evidence. Can you disprove it?
Yet it is your (apparently) entire basis for thinking that it is designed from scratch.
- Both Dragon & Falcon 9 were designed from inception to readily accommodate crew- Existing Dragon systems designed to accommodate escape system, including abort loads- Thermal Control System & radiator are sized for crew requirements- >210 days orbital life span: Positive energy balance...
Found another picture of "Naked Dragon".Seriously, I can't see enough space to fit 8 SuperDracos, except for having very big external bulges, with lot of implications on airflow and load path.
In addition to the other references previously posted, you might want to look at this presentation, in particular slides 18, 19 and 29.Quote from: SpaceX- Both Dragon & Falcon 9 were designed from inception to readily accommodate crew- Existing Dragon systems designed to accommodate escape system, including abort loads- Thermal Control System & radiator are sized for crew requirements- >210 days orbital life span: Positive energy balance...There doesn't appear to be anything to suggest "from scratch"; everything SpaceX has said strongly suggests otherwise.edit: In short, based on SpaceX's statements; from your list...No substantive changes:- Structural changes to capsule to support SDs- Larger propellant tanks- Power system to support life support system- Shape of internal vesselExpected/nominal changes:- Docking mechanism- Life support system (per SpaceX "up-rated... add CO2 & Humidity control")- Internal design for crew (per SpaceX "Seats, displays and controls")
Quote from: joek on 12/16/2012 10:27 pmIn addition to the other references previously posted, you might want to look at this presentation, in particular slides 18, 19 and 29.Quote from: SpaceX- Both Dragon & Falcon 9 were designed from inception to readily accommodate crew- Existing Dragon systems designed to accommodate escape system, including abort loads- Thermal Control System & radiator are sized for crew requirements- >210 days orbital life span: Positive energy balance...There doesn't appear to be anything to suggest "from scratch"; everything SpaceX has said strongly suggests otherwise.edit: In short, based on SpaceX's statements; from your list...No substantive changes:- Structural changes to capsule to support SDs- Larger propellant tanks- Power system to support life support system- Shape of internal vesselExpected/nominal changes:- Docking mechanism- Life support system (per SpaceX "up-rated... add CO2 & Humidity control")- Internal design for crew (per SpaceX "Seats, displays and controls")Are you saying the current propellant tanks for the Dracos are already large enough for landing and LAS?And that you can see where the SD's fit and attach?I agree with you about the power system maybe being large enough already.As always, my take about what SpaceX says is that it often reflects what's on the drawing boards, not what is currently flying. Case in point - engine out capability on F9, as articulated by Elon, matches what the Merlin 1D can do, but at the time he said it only the 1C existed as far as we knew.Either way - most of the list still stands even if one or two of the bullets is already in the Dragon 1.0
Dragon is thought to have about 500 m/s delta-v, which should be more than enough for either a launch abort or a thruster-assisted touchdown after a mission. A purely propulsive touchdown might be more than that can handle.
Either way - most of the list still stands even if one or two of the bullets is already in the Dragon 1.0
A merged upper stage and Dragon will only make sense once there is a significant flight history to prove that aborts at launch are only a statistical anomaly and can be ignored.Otherwise you are back to creating a separating cabin and/or ejection seats, and you forfeit the advantage of a merged unit anyway.
For landing, in principle, you only need as much as your terminal velocity, which for a largely empty aluminum can will be (IIANM) some 100 m/s. Cynically speaking, the rest will only make it easier for S&R to find the capsule if the landing went badly. OK - so if the stored impulse is already 500 m/s, I'm taking the "larger fuel tanks" out of the list.
How much extra margin will NASA require in case of extra wind, malfunctions, etc ? Looks like they're planning to land it near populated areas, important launch facilities, jet flight paths, etc., and NASA wouldn't let SpaceX attempt to place that secondary payload with CRS1 into correct orbit because the oxygen only gave 95% instead of 99% chance of success. Granted the parachutes would make it less of a bullet, but they still don't want it suddenly dropping into middle of a city.