Quote from: MP99 on 01/09/2012 02:56 pmImplied, but not explicit in your response is that the 5KW array will be operating on a 50% duty cycle (day/night).Presuming there are charging losses on the batteries, Dragon will see a bit less than 2.5KW of continuous power. Anyone have any data what those losses are likely to be (ie estimate the actual continuous power available to Dragon systems from that array).Assuming perfect panel illumination, 50%. More likely much less than 50% in practice. Don't forget depending on the season and inclination of the orbit, you can get much less than 50% daylight per orbit.
Implied, but not explicit in your response is that the 5KW array will be operating on a 50% duty cycle (day/night).Presuming there are charging losses on the batteries, Dragon will see a bit less than 2.5KW of continuous power. Anyone have any data what those losses are likely to be (ie estimate the actual continuous power available to Dragon systems from that array).
Quote from: Robotbeat on 01/08/2012 05:46 amIn addition to being a vertically integrated rocket company, they're becoming a vertically integrated satellite manufacturer ... Probably more profit margin there, anyway, compared to being a launch company.What do you think is keeping OSC in the black? It's certainly not Pegasus and Taurus...
In addition to being a vertically integrated rocket company, they're becoming a vertically integrated satellite manufacturer ... Probably more profit margin there, anyway, compared to being a launch company.
Quote from: kevin-rf on 01/09/2012 03:10 pmQuote from: MP99 on 01/09/2012 02:56 pmImplied, but not explicit in your response is that the 5KW array will be operating on a 50% duty cycle (day/night).Presuming there are charging losses on the batteries, Dragon will see a bit less than 2.5KW of continuous power. Anyone have any data what those losses are likely to be (ie estimate the actual continuous power available to Dragon systems from that array).Assuming perfect panel illumination, 50%. More likely much less than 50% in practice. Don't forget depending on the season and inclination of the orbit, you can get much less than 50% daylight per orbit.Why does season matter since you are aiming at the Sun (not at an angle)? The further you are from Earth, the more daylight you will get, so if you have good aim, you should get GREATER than 50% sunlight, not less.
Dragon PDF says 1,500-2,000 W average, 4,000 W peak
On the topic of solar panels, what are your thoughts on plume impingement concerns raised by NASA (?). Eyeballing the geometry, the thrusters look like they wouldn't pose issues, but the diffuse component of the plume (rapidly expanding outward, not the "main" jet) of downward pointing Dracos looks like it could impact the panels. Is it correct to assume the impingement concern is mainly due to exhaust droplets and if so are they mostly concentrated in a narrow jet?
Are cold gas thrusters much better when it comes to plume impingement?
Electrical Power– Unregulated 28 VDC and 120 VDC– ~2000 W avg. payload power– ~4000 W peak payload power– ~16 kWh storage on-board
Updated Erin Beck PDF from August 2010 on NASA's site....QuoteElectrical Power– Unregulated 28 VDC and 120 VDC– ~2000 W avg. payload power– ~4000 W peak payload power– ~16 kWh storage on-board
Page 17 "CRS Late Load, Early Access" says "Access through side hatch up to L-9 hours". This implies that they were at either planning some access to the Dragon after it is erected on the launch pad like the two man bucket lift used to send in the guys with the tin snips on F9 #1, or they plan to roll out and launch in <9 hrs for CRS.
Successful WDR Wed. Rehearsed everything from Falcon 9 roll 2 pad, tanking, tests, countdown to T-3 sec, done in <6 hrs
At the risk of creating a firestorm: Is the C2/3 schedule being held back by the ISS schedule or is the ISS schedule being held back by the C2/3 schedule? I'm interested in the factual answer, not apologia for either side.
