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Dragon - Why only 1001 pounds of cargo going up?
According to Spaceflight Now, the first operational cargo flight of the Dragon spacecraft is carrying 1001 pounds of cargo. On the other hand, on the same site it is mentioned that Dragon is capable of carrying 3310 kg. I assume that figure is for ISS flights since the Dragon data sheet on the SpaceX site says it can carry 6000 kg into LEO and up to 3000 kg down mass. So why only 1001 pounds of cargo on this flight and why only 1995 pounds of down mass? To this layman, it seems that the flight is underutilized.
References: http://spaceflightnow.com/falcon9/00...hmanifest.html http://spaceflightnow.com/falcon9/00...nmanifest.html http://www.spacex.com/downloads/dragonlab-datasheet.pdf |
#2
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Dragon - Why only 1001 pounds of cargo going up?
Maybe there is some cargo which is instruments measuring the flight
parameters or something like that. Brian -- From the Bed of Brian Gaff. The email is valid as Blind user. "Alejandro Zuzek" wrote in message ... According to Spaceflight Now, the first operational cargo flight of the Dragon spacecraft is carrying 1001 pounds of cargo. On the other hand, on the same site it is mentioned that Dragon is capable of carrying 3310 kg. I assume that figure is for ISS flights since the Dragon data sheet on the SpaceX site says it can carry 6000 kg into LEO and up to 3000 kg down mass. So why only 1001 pounds of cargo on this flight and why only 1995 pounds of down mass? To this layman, it seems that the flight is underutilized. References: http://spaceflightnow.com/falcon9/00...hmanifest.html http://spaceflightnow.com/falcon9/00...nmanifest.html http://www.spacex.com/downloads/dragonlab-datasheet.pdf |
#3
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Dragon - Why only 1001 pounds of cargo going up?
On Mon, 8 Oct 2012 07:38:35 -0700 (PDT), Alejandro Zuzek
wrote: According to Spaceflight Now, the first operational cargo flight of the Dragon spacecraft is carrying 1001 pounds of cargo. On the other hand, on the same site it is mentioned that Dragon is capable of carrying 3310 kg. I assume that figure is for ISS flights since the Dragon data sheet on the SpaceX site says it can carry 6000 kg into LEO and up to 3000 kg down mass. So why only 1001 pounds of cargo on this flight and why only 1995 pounds of down mass? To this layman, it seems that the flight is underutilized. Part of the reason is that the full Dragon capability has to wait for Falcon 9 v1.1 whicih debuts next year. But stiil, this is very lightly loaded. Brian |
#4
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Dragon - Why only 1001 pounds of cargo going up?
In article , bthorn64
@suddenlink.net says... On Mon, 8 Oct 2012 07:38:35 -0700 (PDT), Alejandro Zuzek wrote: According to Spaceflight Now, the first operational cargo flight of the Dragon spacecraft is carrying 1001 pounds of cargo. On the other hand, on the same site it is mentioned that Dragon is capable of carrying 3310 kg. I assume that figure is for ISS flights since the Dragon data sheet on the SpaceX site says it can carry 6000 kg into LEO and up to 3000 kg down mass. So why only 1001 pounds of cargo on this flight and why only 1995 pounds of down mass? To this layman, it seems that the flight is underutilized. Part of the reason is that the full Dragon capability has to wait for Falcon 9 v1.1 whicih debuts next year. But stiil, this is very lightly loaded. Considering the same launch carried Orbcomm?s O2G-1 communications satellite (313 lb), I'd say it's lightly loaded. Jeff -- "the perennial claim that hypersonic airbreathing propulsion would magically make space launch cheaper is nonsense -- LOX is much cheaper than advanced airbreathing engines, and so are the tanks to put it in and the extra thrust to carry it." - Henry Spencer |
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Dragon - Why only 1001 pounds of cargo going up?
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Dragon - Why only 1001 pounds of cargo going up?
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#7
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Dragon - Why only 1001 pounds of cargo going up?
JF Mezei wrote on 10/9/2012 :
http://www.spacex.com/press.php?page=20121008 says: ## Approximately one minute and 19 seconds into last night's launch, [jfm continues:] Would be interesting to know at what point (in seconds) after launch, they can afford to lose an engine. Wouldn't engines still be needed at 100% thrust at that point in time ? At 1m19s? Not necessarily. If you read the rest of the SpaceX posting, you'll see that they routinely shut down 2 engines earlier than the others -- one of those "let's tailor the acceleration profile to not smash anything or anyone on board" adjustments. At what time they normally do that, and how much they throttle the engines at what time, I'm not sure, but 1m19s is on the order of the time the Shuttle would throttle for MaxQ. I assume that they remained at 100% longer then planned in order to achieve the delta-V that the first stage is supposed to give ? Again, not necessarily. The total burn was longer than normal, but how that affected the throttle settings may be more complex than you assume. /dps -- Who, me? And what lacuna? |
#8
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Dragon - Why only 1001 pounds of cargo going up?
On Mon, 08 Oct 2012 17:27:49 -0400, JF Mezei
wrote: On 12-10-08 14:38, Jeff Findley wrote: Considering the same launch carried Orbcomm?s O2G-1 communications satellite (313 lb), I'd say it's lightly loaded. Is it possible that when you combine Progress, ATV, HTV and now Dragon, there is more uplift capacity than needed ? No, they're barely breaking even in comparison to Shuttle. Shuttle was intended to make four flights to the Station each year, each flight delivering about 15,000 lbs, or 60,000 lbs. per year. Dragon's payload is to be 7,000 lbs. once fully operational, Cygnus is to be 6,000 lbs. so we're looking at something like five flights of each per year to replace Shuttle. Progress, ATV and HTV were to be flying anyway, so they are not Shuttle replacements. Brian |
#9
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Dragon - Why only 1001 pounds of cargo going up?
Maybe the answer is in the last press release. It says this mission has the
capability to return frozen samples. Could it be that the equipment for keeping temperatures low is rather heavy? Brian -- From the Sofa of Brian Gaff Reply address is active "Snidely" wrote in message news:mn.4b787dcad7d7d03f.127094@snitoo... JF Mezei wrote on 10/9/2012 : http://www.spacex.com/press.php?page=20121008 says: ## Approximately one minute and 19 seconds into last night's launch, [jfm continues:] Would be interesting to know at what point (in seconds) after launch, they can afford to lose an engine. Wouldn't engines still be needed at 100% thrust at that point in time ? At 1m19s? Not necessarily. If you read the rest of the SpaceX posting, you'll see that they routinely shut down 2 engines earlier than the others -- one of those "let's tailor the acceleration profile to not smash anything or anyone on board" adjustments. At what time they normally do that, and how much they throttle the engines at what time, I'm not sure, but 1m19s is on the order of the time the Shuttle would throttle for MaxQ. I assume that they remained at 100% longer then planned in order to achieve the delta-V that the first stage is supposed to give ? Again, not necessarily. The total burn was longer than normal, but how that affected the throttle settings may be more complex than you assume. /dps -- Who, me? And what lacuna? |
#10
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Dragon - Why only 1001 pounds of cargo going up?
Well, its a clever system. I guess it was only shut down as a precaution.
could easily have been a sensor issue. If the craft had been near its limit in weight though, could this still have been achieved. Brian -- From the Sofa of Brian Gaff Reply address is active "JF Mezei" wrote in message eb.com... On 12-10-09 09:15, Jeff Findley wrote: One thing that only the "space media" seem to be reporting is that the Falcon 9 first stage suffered an engine failure. At least in this case, the redundancy in the design worked and Dragon made it into orbit without the "mainstream media" noticing. http://www.spacex.com/press.php?page=20121008 says: ## Approximately one minute and 19 seconds into last night's launch, the Falcon 9 rocket detected an anomaly on one first stage engine. Initial data suggests that one of the rocket's nine Merlin engines, Engine 1, lost pressure suddenly and an engine shutdown command was issued. We know the engine did not explode, because we continued to receive data from it. Panels designed to relieve pressure within the engine bay were ejected to protect the stage and other engines. Our review of flight data indicates that neither the rocket stage nor any of the other eight engines were negatively affected by this event. As designed, the flight computer then recomputed a new ascent profile in real time to ensure Dragon's entry into orbit for subsequent rendezvous and berthing with the ISS. This was achieved, and there was no effect on Dragon or the cargo resupply mission. ## Would be interesting to know at what point (in seconds) after launch, they can afford to lose an engine. Wouldn't engines still be needed at 100% thrust at that point in time ? I assume that they remained at 100% longer then planned in order to achieve the delta-V that the first stage is supposed to give ? |
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