SpaceX Falcon 9 Block 5 - Starlink L01 - Launching November 11, 2019
Screenshot picture from Tim Dodds old Prelaunch Preview - It’s flying bareback - Amos-17?
Mission Rundown: SpaceX Falcon 9 B5 - Starlink L01
Written: January 6, 2021
Start spreading the News, Starlink is here
SpaceX will be launching 60 satellites on top of its workhorse Falcon 9 rocket from the Space Launch Complex (SLC-40) at Cape Canaveral Space Force Station, Florida.
The rocket will lift off at Space Launch Complex 40 - SLC-40 from Cape Canaveral Air Force Station (CCAFS) in Florida at 14:51:00 UTC and at 09:51:00 EST local time.
This will be the first operational launch of SpaceX’s near-global satellite constellation – Starlink, which aims to deliver a fast, low-latency broadband internet service to locations where access has previously been unreliable, expensive, or completely unavailable.
SpaceX plans to offer service in North America by the end of 2020 and estimates that once complete, its venture will make $30-50 billion annually. The funds from which will, in turn, be used to finance its ambitious Mars program.
Grafik: by Geoff Barrett - Webcast by Tim Dodd Everyday Astronaut screenshot
SpaceX will be launching their Starlink satellites on their flight-proven first stage B1048-4. This particular first stage has already flown thrice and will become the first booster to fly for the fourth time with Starlink V1.0 L01.
After boosting the second stage along with its payload towards orbit, the first stage will perform a reentry burn to slow the vehicle down in preparation for atmospheric reentry. The booster will then land 628 km downrange aboard SpaceX’s autonomous spaceport drone ship ‘Of Course I Still Love You.’
Update: SpaceX’ ships GO Ms. Tree and Go Ms. Chief will not attempt to catch both fairing halves because of high seas. Furthermore, this mission will also be the first to make use of previously caught fairings. The first stage will attempt to land on OCISLY, placed 628 km downrange from the launch pad.
The Starlink Payload
Inside the payload fairing for this launch were 60 Starlink satellites destined for Low Earth Orbit. The satellites are the first group of operational satellites for SpaceX’s satellite internet constellation following the launch of 60 test satellites on May 23.
The operational satellites most notably include Ka-band antennas, which were omitted from the test satellites. The operational satellites are also designed to be completely destroyed upon reentry, whereas about 5% of a Starlink test satellite’s components are expected to survive reentry.
Each satellite has a liftoff mass of 260 kilograms, which amounts to 15,600 kilograms of payload total. This is heavier than the first dedicated Starlink mission of 60 satellites measuring 227 kilograms each, for a total of 13,620 kilograms. This makes the Starlink L1 mission the heaviest payload SpaceX has ever launched.
After launch, the satellites will use their Krypton-fueled Hall Ion thrusters to maneuver into their operational orbits. The first phase of Starlink deployment is planned to include a “Shell” of 1,584 satellites in 550 kilometer altitude orbits, inclined 53 degrees. Additional deployment phases to different orbital altitudes will follow the completion of phase one.
On November 7, the Federal Communications Commission (FCC) granted SpaceX a Special Temporal Authority (STA) to change the deployment altitude of the satellites. Instead of deploying into a 440 kilometer orbit, like the 60 test satellites launched in May, the operational satellites will be deployed into a 280 kilometer orbit.
After launch, SpaceX will establish contact with each satellite and confirm each spacecraft’s health before maneuvering them to 350 kilometer orbits. Any satellites not functioning properly after launch will be left in the initial 280 kilometer orbit to naturally deorbit. Satellites that pass their health checks will use the 350 kilometer orbit to drift right or left to their orbit planes, from where they will maneuver up to their operational altitude of 550 kilometers for a period of 5 years.
SpaceX did note late on Sunday that at least one of the satellites may not make it to an operational orbit, but that issue won’t halt the launch. It's cheaper to go ahead than to unpack the stack just to replace one Starlink satellite.
About the Starlink constellation
SpaceX improved the Starlink 1.0 satellites by doubling the number of steerable faze array broadband beams, a 400 % increase of data put through in each satellite and a new KAA antenna system. The Starlink 0.9 will just serve as testbeds and eventually be retired, which means to be deorbited.
To achieve initial coverage, SpaceX plans to form a net of 12 000 satellites, which will operate in conjunction with ground stations, akin to a mesh network. Building that mesh network means at least 200 Starlink launches in the first constellation alone, each with 60 or fewer satellites in each orbit. There will be 24 hours x 60 minutes x 60 seconds divided by 200 orbits equal to (432 seconds) 7,2 minutes between longitudinal coverage and 90 to 100 seconds between orbital coverage.
So the Starlink satellite orbit will pass over from west to east every 7,2 minutes from southwest toward northeast and then pass from northwest to southeast on its return orbit also every 7,2 minutes. There will be a lot of intersections in the space above us, especially in the northern and southern hemispheres, where the orbits change direction coming up from the south and going down to the south and vice versa.
Furthermore, SpaceX recently filed for FCC permission on launching an additional 30000 spacecraft, which, if granted, could see the constellation amount to a lucrative 42000. This would octuple the number of operational satellites in earth orbit, further raising concerns regarding the constellation's effect on the night sky and earth-based astronomy. Such mega-constellations have only recently been made possible with the advent of reusable rocketry, pioneered by SpaceX. For more information on Starlink, I recommend watching the Real Engineering video listed below. And about Starlink orbits watch this.
Photo: Screenshot from Twitter and YouTube. “Do you play with a full deck of cards?”
100th launch from SLC-40.
With 55 previous Titan rockets launched and now 45 Falcon 9 rocket launches from Space Launch Complex 40 since June 4, 2010, and nobody bought a Cake? Or a lot of candles, at least a hundred? And I did count it right. It’s 55 Titan rockets previously launched from Space Launch Complex 40 since June 4, 2010.
I’m sorry, I might still be one rocket launch off. Does this also count?
The C201 Dragon capsule, dubbed DragonFly was a spacecraft abort test conducted by SpaceX on 6 May 2015 from the Space Launch Complex 40 at Cape Canaveral Air Force Station, Florida.
As part of the development of NASA's Commercial Crew Program, the test demonstrated the spacecraft's abort system capability, verifying the capsule's eight side-mounted SuperDraco thrusters' capability to quickly power itself away from a failing rocket while it is still on the ground.
It seems like everybody forgot to count rocket launches, and I know that people from NasaSpaceFlight have been keeping tabs on launches from Cape Canaveral Air Force Station and Kennedy Space Center next door a few kilometers further north.
They did celebrate the 100th launch from this historic Launch Complex LC-39A, because it only took 6 launches of Falcon 9 rockets to make it to one hundred. There had already been 12 Apollo Saturn V and 82 STS Space Shuttle launches, so it was an easy count down to celebrate the 100th rocket launch.
Now it's the only Space Launch Complex 4 East - SLC 4E on Vandenberg Air Force Base, which is in the launch countdown having reached 93 launches by November 21, 2020. There have only been 18 Falcon 9 launches so far since 29 September 2013.
Lose pipes? That’s a good question
In Superchat, Vlad Chompalov asked this question: What are those tubes/wires that break off at stage separation at T+2:40?
The Merlin 1D# Vacuum Engine has 6 tubes connected to the Black Interstage, which at least two uses to bleed vaporized oxygen from the LOX pipes, a second pair is used to chill the Turbopump and the Preburner by tapping and vaporizing liquid oxygen, and the third line pair is to bleed excess pressure from the propellant tanks.
During LOX loading prior to launch, two lines vent oxygen gas continuously, and even during flight they keep venting, building beautiful frozen LOX coral-like ice crystals on the vent pipes. There is the possibility that LOX is being sacrificed as a coolant in the LOX tank, which like in a freezer removes heat from the LOX tank.
Oxygen is pumped in pipes through radiators along the tank sides coming in contact with the ambient air temperature outside, the heat from outside transfers to the LOX, which transfers it again to the radiators, which removes the excess heat by venting it. Another method of cooling is using helium bubbles to speed up oxygen evaporation and thereby removing heat from the LOX tank.
Later I have noticed it’s six tube lines, three on each side of the Merlin 1D# Vacuum Engine, and I now guess, they are all there for LOX tank refrigeration, Turbopump engine chilling and venting of excess oxygen pressures in the engine pipes. The main pressure oxygen release valves are on top of the second stage LOX tank.
That’s my two cents worth on answering this question.
No comments:
Post a Comment