Starlink's effects on Astronomical Observations
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Submitted January 12, 2020 at 12:40AM by LukeWilson59
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Slow motion liftoff and timelapse video of Starlink 2
https://youtu.be/F-D0Zbsb8wA

Submitted January 13, 2020 at 03:28PM by learntimelapse
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Crew Dragon | Launch Escape Animation
https://www.youtube.com/watch?v=qObBRM4euxk&feature=emb_title

Submitted January 13, 2020 at 06:32PM by sn__parmar
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Some legs retracted some removed on B1049. Footage by USLaunchReport
https://youtu.be/zDkGWwD56bY

Submitted January 13, 2020 at 09:39PM by PrimarySwan
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<b>Starlink-3 Launch Campaign Thread</b>
<a href="https://pbs.twimg.com/media/D7TjU7DXkAAqtVZ.jpg"></a><a href="https://www.reddit.com/r/spacex/comments/eof5pr/starlink3_launch_campaign_thread/#siteTable_t3_eof5pr">JUMP TO COMMENTS</a>OverviewStarlink-3 (a.k.a. Starlink v1.0 Flight 3, Starlink Mission 4, etc.) will launch the third batch of Starlink version 1 satellites into orbit aboard a Falcon 9 rocket. It will be the fourth Starlink mission overall. This launch is expected to be similar to the <a href="/r/spacex/wiki/launches#wiki_78_.2013_starlink-2_.28v1.0.29">previous Starlink launch</a> in early January, which saw 60 Starlink v1.0 satellites delivered to a single plane at a 290 km altitude. Following launch the satellites will utilize their onboard ion thrusters to raise their orbits to 350 km. In the following weeks the satellites will take turns moving to the operational 550 km altitude in three groups of 20, making use of precession rates to separate themselves into three planes. Due to the high mass of several dozen satellites, the booster will land on a drone ship at a similar downrange distance to a GTO launch.Liftoff currently scheduled for:Late January TBDStatic fireTBDPayload60 Starlink version 1 satellitesPayload mass60 * 260 kg = 15 400 kg (presumed)Deployment orbitLow Earth Orbit, 290 km x 53° expectedOperational orbitLow Earth Orbit, 550 km x 53°, 3 planesVehicleFalcon 9 v1.2 Block 5CoreunknownPast flights of this coreunknownFairing reuseunknownFairing catch attemptLikelyLaunch site<a href="https://www.reddit.com/r/SpaceX/wiki/pads">SLC-40</a>, Cape Canaveral Air Force Station, FloridaLandingASDS: 32.54722 N, 75.92306 W (628 km downrange)Mission success criteriaSuccessful separation & deployment of the Starlink Satellites.Previous and Pending Starlink MissionsMissionDate (UTC)CoreDeployment OrbitNotesSat Update1<a href="/r/spacex/wiki/launches#wiki_71_.2013_starlink_v0.9">Starlink v0.9</a>2019-05-241049.3440km 53°60 test satellites with Ku band antennas<a href="https://twitter.com/planet4589/status/1216198537265975298">Jan 11</a>2<a href="/r/spacex/wiki/launches#wiki_75_.2013_starlink-1_.28v1.0.29">Starlink-1</a>2019-11-111048.4280km 53°60 version 1 satellites, v1.0 includes Ka band antennas<a href="https://twitter.com/planet4589/status/1216201828150513664">Jan 11</a>3<a href="/r/spacex/wiki/launches#wiki_78_.2013_starlink-2_.28v1.0.29">Starlink-2</a>2020-01-071049.4290km 53°60 version 1 satellites, 1 sat with experimental antireflective coating<a href="https://twitter.com/planet4589/status/1216204441306779649">Jan 11</a>4Starlink-3This Mission290km 53°60 version 1 satellites-5<a href="/r/SpaceX/wiki/launches/manifest#wiki_upcoming_falcon_launches">Starlink-4</a>Jan/Feb290km 53°60 version 1 satellites-Watching the LaunchSpaceX will host a live webcast on YouTube. Check the upcoming launch thread the day of for links to the stream. For more information or for in person viewing check out the <a href="https://www.reddit.com/r/spacex/wiki/faq/watching">Watching a Launch page</a> on this sub's FAQ, which gives a summary of every viewing site and answers many more common questions, as well as <a href="http://www.launchphotography.com/Delta_4_Atlas_5_Falcon_9_Launch_Viewing.html">Ben Cooper's launch viewing guide</a>, <a href="https://launchrats.com/">Launch Rats</a>, and the <a href="https://scla.space">Space Coast Launch Ambassadors</a> which have interactive maps, photos and detailed information about each site.Links & ResourcesGeneral Launch Related Resources:<a href="https://www.patrick.af.mil/About-Us/Weather/">Launch Execution Forecasts</a> - 45th Weather Squadron<a href="https://www.spacexfleet.com/next">SpaceX Fleet Status</a> - SpaceXFleet.comLaunch Viewing Resources:<a href="http://www.launchphotography.com/Delta_4_Atlas_5_Falcon_9_Launch_Viewing.html">Launch Viewing Guide for Cape Canaveral</a> - Ben Cooper<a href="https://launchrats.com/">Launch Viewing Map</a> - Launch Rats<a href="https://scla.space/">Launch…

In-Flight Abort simulation from Flight Club - lots of info in comments!
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Submitted January 14, 2020 at 08:05PM by TheVehicleDestroyer
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@elonmusk: Exactly. We’ve had good discussions with leading astronomers. One way or another, we’ll make sure Starlink doesn’t inhibit new discoveries or change the character of the night sky.
https://twitter.com/elonmusk/status/1217175688228159488?s=19

Submitted January 15, 2020 at 12:22AM by Alvian_11
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@ElonMusk: "Advancing humanity’s understanding of the Universe is a fundamental motivator for SpaceX! Starship can put giant 🔭 in orbit & on moon. With an occluder, could image 🌏 in other star systems."
https://twitter.com/elonmusk/status/1217178315540140032

Submitted January 14, 2020 at 09:58PM by ChristianM
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NASA to Provide Coverage of SpaceX Crew Dragon Launch Escape Test
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Submitted January 14, 2020 at 10:14PM by jamesgalb
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NASA to Provide Coverage of SpaceX Crew Dragon Launch Escape Test (includes pre/post launch briefings)
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Submitted January 14, 2020 at 10:15PM by CProphet
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Falcon 9 Stage One: Under the Skin
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Submitted January 15, 2020 at 09:29PM by Reeceeboii_
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Elon Musk on Twitter: Starship orbital vehicle SN1, liquid oxygen header tank & nosecone
https://twitter.com/elonmusk/status/1217742268393607168

Submitted January 16, 2020 at 10:36AM by OccupyMarsNow
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Starlink might face a big problem...
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Submitted January 16, 2020 at 03:59PM by RaphTheSwissDude
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Starship design goal is 3 flights/day avg rate, so ~1000 flights/year at >100 tons/flight, so every 10 ships yield 1 megaton per year to orbit
https://twitter.com/elonmusk/status/1217989066181898240

Submitted January 17, 2020 at 03:08AM by vinodjetley
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SpaceX abort test serves as practice run for astronauts, rescue teams
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Submitted January 17, 2020 at 01:07PM by yoweigh
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In-Flight Abort Test Press Kit
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Submitted January 17, 2020 at 02:10PM by Straumli_Blight
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SpaceX on Twitter: Falcon 9 and Crew Dragon vertical ahead of tomorrow’s in-flight demonstration
https://twitter.com/SpaceX/status/1218153687429705730

Submitted January 17, 2020 at 02:09PM by xDeeKay
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<b>r/SpaceX In-Flight Abort Test Official Launch Discussion & Updates Thread</b>
<a href="/#%20MC%20//%20section%20intro">IntroductionWelcome, all the people of the subreddit! It is the mod team that is going to bring you live updates on the long awaited In-Flight Abort Test.Your host teamReddit usernameTwitter accountResponsibilitiesNumber of hosts<a href="/u/hitura-nobad">u/hitura-nobad<a href="https://twitter.com/HituraNobad">@HituraNobadMission updates, Community? Hostu/Nsooo<a href="https://twitter.com/TheRealNsooo">@TheRealNsoooThread format, Mission updates? HostAbout the missionSpaceX is going to simulate an abort around Max-Q, when Crew Dragon will use it's Superdraco engines to escape from the failing booster.The triple flown booster is going to be destroyed by aerodynamics.Scrub counterScrub dateCauseCountdown stoppedBackup dateNo scrubs!n/an/an/aLot of facts&#9745;&#65039; This will be the <strong>87th</strong> SpaceX launch.&#9745;&#65039; This will be the <strong>79th</strong> Falcon 9 launch.&#9745;&#65039; This will be the <strong>23rd</strong> Falcon 9 Block 5 launch.&#9745;&#65039; This will be the <strong>2nd</strong> SpaceX launch this year.&#9745;&#65039; This will be the <strong>2nd</strong> Falcon 9 launch this year.&#9745;&#65039; This will be the <strong>4th</strong> and last flight of the flight-proven Block 5 core B1046.&#9745;&#65039; This will be the heaviest payload launched on a <strong>suborbital trajectory</strong> by SpaceXVehicles usedTypeNameLocationFirst stageFalcon 9 v1.2 - Block 5 (Full Thrust) - B1056KSC, LC-39ASecond stageFalcon 9 v1.2 Block 5 (<em>No thrust this time</em>)KSC, LC-39A<em>Core data source: Core wiki by r/SpaceX</em><em>Ship data source: SpaceXFleet by u/Gavalar_</em>Live updates<a href="/#%20MC%20//%20section%20events">TimelineTimeUpdate<a href="/#%20MC%20//%20row%2029"> T-21:00:00Welcome everyone! Falcon 9 went vertical ahead of tomorrows launch attempt. Currently GO for launch!<a href="/#%20MC%20//%20section%20viewing">Mission's state&#9989; Currently <strong>GO</strong> for the launch attempt.Weather - Cape Canaveral, FloridaLaunch windowWeatherTemperatureProb. of rainProb. of weather scrubMain concernPrimary launch window<strong>&#127780;&#65039;</strong> <em>Partly Cloudy</em><strong>&#127777;&#65039;</strong> <em>No data</em><strong>&#128167;</strong> <em>No data</em><strong>&#128721;</strong> <em>10%</em><em>No data</em><em>Weather data source: Google Weather & 45th Space Wing.</em> <em>- The probability of a scrub due to weather does not includes the chance due to upper level winds, which are monitored by the SpaceX launch team itself using sounding balloons before launch.</em><a href="/#%20MC%20//%20section%20stats">Watching the launch liveLinkNote<a href="https://www.spacex.com/webcast">Official SpaceX Launch Webcast - embeddedstarting ~20 minutes before liftoff<a href="https://www.youtube.com/watch?v=sbXgZg9JmkI">Official SpaceX Launch Webcast - directstarting ~20 minutes before liftoff<a href="https://www.reddit.com/r/spacex/comments/ebfr9t/rspacex_jcsat18kacific1_official_launch/fb4kdie/">Webcast - relay<a href="/u/codav">u/codav<a href="/#%20MC%20//%20section%20mission">Useful Resources, Data, &#9835;, & FAQEssentialsLinkSource<a href="http://www.spacex.com/sites/spacex/files/in-flight_abort_test_press_kit.pdf">Press kit<a href="http://www.spacex.com">SpaceXLaunch weather forecast<a href="http://www.patrick.af.mil/About-Us/Weather/">45th Space Wing<a href="https://www.spacexfleet.com/next">SpaceX Fleet StatusSpaceXFleet.comSocial mediaLinkSource<a href="https://reddit.com/r/SpaceX">Reddit launch campaign thread<a href="/r/SpaceX">r/SpaceX<a href="https://twitter.com/rSpaceX">Subreddit Twitter<a href="/r/SpaceX">r/SpaceX<a href="https://twitter.com/SpaceX">SpaceX Twitter<a href="/r/SpaceX">r/SpaceX<a href="https://www.flickr.com/photos/spacex/">SpaceX Flickr<a href="/r/SpaceX">r/SpaceX<a href="https://twitter.com/elonmusk">Elon Twitter<a href="/r/SpaceX">r/SpaceX<a…

<b>[Sources Required] What's preventing SpaceX from recovering B1046 in the In Flight Abort Test</b>
Elon <a href="https://twitter.com/elonmusk/status/1216148212085428224">said</a> that they've tried to find a way to recover the first stage but couldn't find any way to do it. Let's see why by trying to design a recovery trajectory.On T+1:33 Dragon aborts. The abort itself won't affect the Falcon 9 because Dragon will be lifted by the SuperDraco engines.But it exposes the second stage to the supersonic flow of air.Can the stack survive the supersonic flow or air?The force on the second stage before the abort:<code>Drag with Dragon = 0.5 * p * v^2 * Cd * Area = 0.5 * 0.04 * 666^2 * 0.25 * 10.8 = 24,000 N</code>[1] [2]<code>Dragon's weight = 9.8 * 9,525 = 152145 N</code> [3]=> Total force on stage 2 = drag + dragon's weight = <code>24000 N + 152145 N = 176,145 N</code><code>Drag without Dragon = 0.5 * p * v^2 * Cd * Area = 0.5 * 0.04008 * 666^2 * 0.8 * 10.8 = 76,800 N</code> [4]This means the total force on stage 2 after the abort will be half as much as it will with Dragon. This doesn't prove Falcon 9 will not be torn due to aerodynamic forces as the situation is FAR more complex than this simple force calculation. But what I can say is that <strong>Falcon 9 won't be crushed due to drag</strong>.Separation from Stage 2In order to simulate loss of thrust in case of a RUD, Stage 1 will shut off its engines. And only 3 engines are re ignitable, so it can't continue a normal ascent up to MECO like every flight (see "Trajectory after the abort" section). It also can't coast and do a normal landing burn because it has too much fuel (too heavy for the landing legs, wrong CoG) and has a second stage on top of it.Stage 1 has to separate from Stage 2 because it can't land with it (too heavy, ruins aerodynamics and moves the GoG too high), Stage 2 can't be separated on ascent because drag will cause it to slow down faster than stage 1.For example: If stage 1 were to separate from stage 2 right after Dragon's abort, it will headbutt the second stage <a href="https://www.youtube.com/watch?v=v0w9p3U8860&t=2m51s">Falcon 1 Flight 3 style</a> as the second stage decelerates 2.5 m/s2 faster than it.That means <strong>separation has to occur at, or close, to apogee</strong>. This is in addition to the fact the first stage is normally never exposed on ascent. And would probably require a nose cone if it were to be exposed.Trajectory after the abortAccording to FlightClub[2], on abort the first stage will contain 175 tons of propellant. An average landing burn requires ~15 tons of propellant. That means the booster needs to burn 150 tons of propellant in order to land.The Merlin 1D engine has a MFR of 279 kg/s. x3 engines = 837 kg/s.Total burn time = <code>150,000 [kg] / 873 [kg/s] = 171 seconds</code>Upper bound of gravity losses = <code>9.8 * 171 = 1675 m/s</code>Total burn delta v (with S2) = <code>282 * 9.8 * ln([22 + 116 + 150]/[116 + 22]) = 2033 m/s</code> [5]TWR = <code>3*845 [kN] / [9.8*(22,000 + 175,000 + 116,000)] = 0.82</code>This <strong>rules out any attempt to raise apogee</strong> in any major way. It's doubtful the booster can reorient itself engines first in the relatively dense atmosphere at ~50 km.The best approach seems to be a coast to apogee, stage separation the second stage and a continuous burn for the rest of the way.FlightClub[2] shows an apogee of 48 km.delta v (without stage 2) = <code>282 * 9.8 * ln([22 + 150]/22) = 5683 m/s</code>while it seems like the stage has enough performance to land, it would require major software and possible hardware changes. The stage would have to do an almost continuous burn from apogee to landing. The grid fins would have very limited control on the low speed flow, very high center of gravity and fuel sloshing. <strong>It's probably too much effort for SpaceX to try to recover B1046, even though it might be physically possible.</strong>[1] Density of air from: <a href="https://www.enginee…