Quote from: guckyfan on 05/14/2019 12:07 pmLaunch is 4:30 CEST, not 3:30.Ohh thank you! 2:30am UTC is 2 hours difference this time of the year. Thats just before sunrise, probably too bright to see satellites.. too bad.
Launch is 4:30 CEST, not 3:30.
Guess from the photos that Mr. Mask posted on Twitter. Perhaps it will repeat the discharge while pushing out with a separate spring alternately on each side. The photos also show thrusters that seem to be ion engines.
If you look at the solar panels for spacecraft applications on the top panel, you can see that the Starlink satellites are quite large, although you can not see them in the photos at all. It may be a feeling that components, heat instrumentation, and electricity are directly attached to the solar cell panel.
I'm thinking of the satellite. Since there is a possibility that another channel laser communication device will be installed, let's put in an optical path. I wonder if I can shake the laser by slightly moving the mirror at the edge of the structure.
Updated Launch Hazard Areas of SpaceX Mission 1488 Starlink-1Appropriate FCC application states planned ASDS position for booster landing 621km downrange.
Quote from: Raul on 05/14/2019 09:41 pmUpdated Launch Hazard Areas of SpaceX Mission 1488 Starlink-1Appropriate FCC application states planned ASDS position for booster landing 621km downrange.Now's the time where I wish I knew where a table was for previous ASDS locations. (AKA mass comparison for an estimate of the Starlink sat mass)
Quote from: intelati on 05/14/2019 09:50 pmQuote from: Raul on 05/14/2019 09:41 pmUpdated Launch Hazard Areas of SpaceX Mission 1488 Starlink-1Appropriate FCC application states planned ASDS position for booster landing 621km downrange.Now's the time where I wish I knew where a table was for previous ASDS locations. (AKA mass comparison for an estimate of the Starlink sat mass)From pure delta-v calculations and being a bit conservative the mass of the total payload might be between 15 and 16 metric tons depending on how much aggressive they want to be. If my conservative numbers are more conservative than I think then add an extra metric ton if you want but at least it gives you an idea of how massive this payload will be. It's amazing. In terms of mass you can be sure these sats have a mass less than 300kg, that would be crazy massive in total and I think over the limits for this type of recovery and destination orbit. Mass might quite be around the 250kg number give it or take 25kg.
...each Starlink satellite weighs approximately 227kg...
From press kit:QuoteWith a flat-panel design featuring multiple high-throughput antennas and a single solar array, each Starlink satellite weighs approximately 227kg, allowing SpaceX to maximize mass production and take full advantage of Falcon 9’s launch capabilities. To adjust position on orbit, maintain intended altitude, and deorbit, Starlink satellites feature Hall thrusters powered by krypton. Designed and built upon the heritage of Dragon, each spacecraft is equipped with a Startracker navigation system that allows SpaceX to point the satellites with precision. Importantly, Starlink satellites are capable of tracking on-orbit debris and autonomously avoiding collision. Additionally, 95 percent of all components of this design will quickly burn in Earth’s atmosphere at the end of each satellite’s lifecycle—exceeding all current safety standards—with future iterative designs moving to complete disintegration.* Autonomous debris avoidance* Star tracker from Dragon* Krypton thruster
With a flat-panel design featuring multiple high-throughput antennas and a single solar array, each Starlink satellite weighs approximately 227kg, allowing SpaceX to maximize mass production and take full advantage of Falcon 9’s launch capabilities. To adjust position on orbit, maintain intended altitude, and deorbit, Starlink satellites feature Hall thrusters powered by krypton. Designed and built upon the heritage of Dragon, each spacecraft is equipped with a Startracker navigation system that allows SpaceX to point the satellites with precision. Importantly, Starlink satellites are capable of tracking on-orbit debris and autonomously avoiding collision. Additionally, 95 percent of all components of this design will quickly burn in Earth’s atmosphere at the end of each satellite’s lifecycle—exceeding all current safety standards—with future iterative designs moving to complete disintegration.
Why would the Starlink satellites want to track on-orbit debris?
Why would the Starlink satellites want to track on-orbit debris?(Not a rhetorical question and please don't give the trite answer. Be practical.) Any object threatening collision seen by on-board systems would be approaching too fast to avoid, particularly with an ion engine.There is no reason to assume that debris approaching is a significant long term threat. Perhaps to another satellite, but then the entire constellation will spend it's resources tracking debris, predicting collisions, and sharing results.What are they really trying to say here?
Hi folks, sorry if I missed it, but was there any particular payload-related reason they are launching at this time? Or was it more related to range availability? Thanks!
Quote from: ArbitraryConstant on 05/12/2019 05:54 pmTo summarize, something this bus needs anyway (reaction wheels) may be able to substitute to some extent for the mechanical complexity of deployable solar tracking arrays etc. This would never normally make sense but they're using a novel design to fit such a large number of satellites without a dispenser and in that fairly unusual circumstance I think it might make sense. They're basically floating 1U servers with solar on top and antennas below.If you expect that these satellites won't unfold, that is quite a statement to make. I see it as rather obvious that some element(s) of this design will indeed unfold - certainly the solar arrays. But I guess we will see who is right.
To summarize, something this bus needs anyway (reaction wheels) may be able to substitute to some extent for the mechanical complexity of deployable solar tracking arrays etc. This would never normally make sense but they're using a novel design to fit such a large number of satellites without a dispenser and in that fairly unusual circumstance I think it might make sense. They're basically floating 1U servers with solar on top and antennas below.
Quote from: Lars-J on 05/12/2019 08:35 pmQuote from: ArbitraryConstant on 05/12/2019 05:54 pmTo summarize, something this bus needs anyway (reaction wheels) may be able to substitute to some extent for the mechanical complexity of deployable solar tracking arrays etc. This would never normally make sense but they're using a novel design to fit such a large number of satellites without a dispenser and in that fairly unusual circumstance I think it might make sense. They're basically floating 1U servers with solar on top and antennas below.If you expect that these satellites won't unfold, that is quite a statement to make. I see it as rather obvious that some element(s) of this design will indeed unfold - certainly the solar arrays. But I guess we will see who is right.The press kit[1] specifies a single solar array so I think the "solar panel with stuff on the back" architecture is basically correct. There was that Twitter post[2] with renders for antenna masts that fold out, I think that idea might make sense. The antenna masts could rotate as the solar panel/bus tracks the sun.1 - https://www.spacex.com/sites/spacex/files/starlink_press_kit.pdf2 - https://twitter.com/moffmiyazaki/status/1127883704330645505
227kg puts total stack mass at 13,620kg.
Crowdsourcing this. Correct me if I'm wrong, but at 13,620 kg, this is the heaviest payload launched by SpaceX to date?
