Saturday, November 4, 2023

SpaceX - Starlink Group 6-26

Screenshot from X-Twitter of Starlink Grp. 6-26 launch. Soon a million sonic booms will be heard

Mission Rundown: SpaceX Falcon 9 - Starlink Grp. 6-26

Written: November 4, 2023 

Lift Off Time

November 3/4, 2023 – 20:37:20 EDT | 00:37:20 UTC

Mission Name

Starlink Group 6-26

Launch Provider

SpaceX

Customer

SpaceX

Rocket

Falcon 9 Block 5 serial number B1058-18

Launch Location

Space Launch Complex 40 – SLC-40

Cape Canaveral Space Force Station, Florida

Payload

23 Data Relay Satellites – Starlink v2.0 mini

Payload mass

18 400 kg ~ 38 760 pounds – About 800 kg each

Where did the satellites go?

Low Earth Orbit – 284 km x 294 km x 43,0°

Recovery of the first stage?

Yes – Crosby Skipper towed ASOG downrange

Where will the first stage land?

A Shortfall Of Gravitas awaits 612 km downrange

Recovery of the fairings?

Yes – Recovery ship Doug is 682 km downrange

Are these fairings new?

No. Type 3.1 fairing with 4x2 venting ports, thermal steel tip, lowered protrusion and no acoustic tiles

This will be the:

– 269th flight of all Falcon 9 rockets

– 202nd re-flight of all Falcon 9 boosters

– 213th flight of a Falcon 9 Block 5 rocket

– 188th re-flight of a Falcon 9 Block 5 booster

– 151st SpaceX launch from SLC-40

– 240th booster landing overall

– 79th mission for SpaceX in 2023

Where to watch

Where to read more in depth

NasaSpaceFlight YouTube linkX Twitter link

Want to know or learn more go visit or see Tim Dodd


Launch debriefing

(This did happen)

Falcon 9 at Mach One at about T+00.01:02

Horizontal velocity by 1st stage is usually 7000 km/h at MECO

A fast ascent with a small dogleg to avoid a flyover of Bahamas

Video to Bermuda wasn’t lost at SECO

Jumps in telemetry data acquisition/loss of signal from rocket

T-00:04:59

No host:

T 00:00:00

T+00:01:09

T+00:02:28

T+00:02:35

T+00:02:41

T+00:03:12

T+00:04:22

T+00:06:15

T+00:08:08

T+00:08:45

T+00:09:05

T+00:54:05

-

T+01:05:23

T+01:30:17

T+02:10:17

Space Dev feed at 1:26 – Their high resolution link

Hawthorne Control Room – audio only

Liftoff at 6:25 – 00:37:20 UTC – Fourth backup window

MaxQ at 7:34 – Maximum aerodynamic pressure

MECO at 8:54 – B1058-18 stops after 148 seconds

Stage separation at 9:00 – Just losing 90% weight

SES-1 at 9:06 – Green TEA-TAB ignition visible

Fairing separation at 9:37 – No acoustic tiles inside

1st stage apogee at 10:47 – 7 104 km/h at 117 km

Reentry burn at 12:40 by 3 Merlin 1D# for 22 seconds

Landing burn at 14:33 by 1 Merlin 1D# for 21 seconds

SECO at 15:10 – Coasting in a elliptical earth orbit

Cut off from Hawthorne Control Room at 15:29

SES-2 to SECO-2 for 3 seconds at 01:31:25 UTC gives a velocity boost from 27 060 km/h to 27 236 km/h ish…

Starlink Group 6-26 deployed at 01:42:43.480 UTC

Deorbit burn performed over Texas, North America

2nd stage does a 44g oceandive south of Madagascar


Go loudly into the night

SpaceX’s Starlink Group 6-26 will launch 23 Starlink v2.0 ‘Mini’ satellites atop of the 208th Falcon 9 Block 5 rocket. The booster B1058-18 will lift off from Space Launch Complex 40 at Cape Canaveral Space Force Station in Florida, United States.

The launch of Starlink Group 6-26 became delayed with technical issues. The mission lifted off Friday evening on November 3/4, 2023 at 20:37:20 EDT − 00:37:20 UTC.

Starlink Group 6-26 will mark the 118th operational Starlink mission, boosting the total number of Starlink satellites launched to 5,399, of which ~4,982 will be in a functional order in their orbit around the Earth, adding 23 more once this mission is launched.

Starlink Group 6-26 will mark the 26th launch of Starlink v2.0 satellites (launching in the Mini variation) to be placed into a 43° low earth orbit at 530 km.

B1058-18 will have made its eighteenth flight after launching its next mission:

SpaceX Demo-2

May 30, 2020

Transporter-3

January 13, 2022

ANASIS-II

July 20, 2020

Starlink Group 4-8

February 21, 2022

Starlink V1.0 L12

October 6, 2020

Starlink Grp 4-17

May 6, 2022

CRS-21

December 6, 2020

Starlink Grp 4-21

July 7, 2022

Transporter-1

January 24, 2021

Starlink Grp 4-2

Sept. 10/11, 2022

Starlink V1.0 L20

March 11, 2021

Starlink Grp 4-37

December 17, 2022

Starlink V1.0 L23

April 7, 2021

Starlink Grp 6-5

July 9/10, 2023

Starlink V1.0 L26

May 15, 2021

Starlink Grp 6-17

September 19/20 2023

Starlink Group 4-1

November 13, 2021

Starlink Grp 6-25

November 3, 2023

NGA of Falcon 9’s flight path, landing zone with ASOG’s position and Doug’s fairing recovery area

Following stage separation, the Falcon 9 will conduct a reentry burn lasting 20 seconds and a 22 second landing burn. These two burns aim to land the booster softly on SpaceX’s Autonomous Spaceport Drone Ship − A Shortfall Of Gravitas.

B1058-18 didn’t perform a static fire test after its refurbishment while waiting for an east coast launch out of Cape Canaveral. SpaceX has omitted this safety precaution many times. It isn’t required to perform a static fire test on inhouse missions like Starlink or if the external private customers wish to save time.

The used fairings, which will fly for an unknown time, will be retrieved by Doug some 682 km downrange in the Atlantic Ocean near Bahamas.

The first v1.0/v1.5 Starlink satellites

Starlink is SpaceX’s internet communication satellite constellation. The low-Earth orbit constellation delivers fast, low-latency internet service to locations where ground-based internet is unreliable, unavailable, or expensive. The first phase of the constellation consists of five orbital shells, but the fifth shell changed to a semi second generation.

Shell

Type

Inclination

Orbit (km)

Planes

Sats.

Flights

Launched

1

V1.0

53.0o

550

72

22

28

1,665

2

V1.5

70.0o

570

‘36’

‘20’

8

408

3

V1.5

97.6o

560

‘6’

‘58’

5

243

4

V1.5

53.2o

540

72

22

28

1,637

5

V1.5E

43.0o

530

?

?

13

699

Starlink is currently available in several countries, allowing anyone in approved regions to order or preorder. After 28 launches, SpaceX achieved near-global coverage, but version 1 of the constellation will not be complete until all five shells are filled.

Starlink generation 1 has undergone several design developments in version 0.9 testbed, v1.0 regular, v1.5 regular and v1.5 enhanced while reaching a mass of 307 kg.

SpaceX developed a flat-panel design, allowing them to fit as many satellites as possible into the Falcon 9’s 5.2 meter internal wide payload fairing.

Due to this flat design, SpaceX was able to fit up to 60 Starlink satellites and the payload dispenser onto the second stage, while still being able to recover the first stage. This is near the recoverable 16 ton payload capacity of the Falcon 9 to LEO.

As small as the first generation Starlink satellites are, each is packed with high-tech communication and cost-saving technology. Each Starlink satellite is equipped with four phased array antennas, for high bandwidth and low-latency communication, and two parabolic antennas. The satellites also include a star tracker, which provides the satellite with attitude data, ensuring precision in broadband communication. 

Starlink v1.5 satellites are also equipped with a satellite laser communication system. This allows any satellite to communicate directly with other satellites, not having to go through ground stations. This reduces the number of ground stations needed, allowing coverage of the entire Earth’s surface, including the poles.

The Starlink satellites are also equipped with an autonomous collision avoidance system, utilizing the US Department of Defense (DOD) debris tracking database to autonomously avoid collisions with other spacecraft and space junk. 

Each satellite has a single solar panel, which simplifies the manufacturing process. To cut costs, Starlink’s propulsion system, an ion thruster, uses krypton as fuel, instead of xenon. While the specific impulse (ISP) of krypton is significantly lower than xenon’s, its purchase price is far cheaper, which further decreases the satellite’s manufacturing cost.

Each Starlink satellite is equipped with the first Hall-effect krypton-powered ion thruster. This thruster is used for both ensuring the correct orbital position, as well as for orbit raising and orbit lowering.

At the end of the satellite’s life, this thruster is used to deorbit the satellite.

Second generation v2.0 starlink satellites

Starlink’s second generation starlink satellites in the sixth shell will host 3 360 satellites in a 530 km orbit with a 43° inclination. These satellites will cover most of the area between Japan/Oregon in the north and almost all of New Zealand to the south.

SpaceX will put 120 starlink v2.0 satellites in each of the 28 planes in the 6th shell which with this launch currently will host 558 ‘mini’ v2.0 starlink satellites.

Stack of 21/22 Starlink v2.0 Mini’s ready to be encapsulated in its fairing prior to be launched with the last stack of now out fazed Starlink v1.5 satellites standing over in the corner.

Each Starlink v2.0 ‘Mini’ satellite has a compact design and a mass of ~800 kg.

Due to delays in the Starship launch vehicle, SpaceX is preparing (and has filed for permission) to launch Starlink v2 “Mini” satellites that will launch on the Falcon 9 rocket.

These satellites have a powerful phased array antenna and utilize the E-band for backhaul. This allows each satellite to provide 4x more capacity than Starlink v1.0 and v1.5.

The Starlink v2.0 ‘Mini’ satellites are equipped with a new Argon Hall thruster for on-orbit maneuvering. These generate 2.4 times as much thrust as the thrusters on v1.5 satellites and have 1.5 times the specific impulse. The Starlink v2.0 ‘Mini’ satellites will be the 26th shell 6 satellite batch to use Argon thrusters in-orbit.

SpaceX’s ‘Starship Class’ Starlink V2.0 satellites are even larger, more powerful satellites meant to be launched with the Starship launch vehicle.

While little is known about these satellites thus far, it is known that they mass roughly 1,200 kg and feature a twin-solar array design, to increase power delivered to the satellite.

And according to SpaceX CEO and CTO Elon Musk, the satellites will have an order of magnitude more bandwidth, higher speeds, and with 10x better performance.

In the future, Starlink V2.0 satellites will act as cell towers, providing worldwide cell phone coverage to T-Mobile customers. Musk has stated that each of these satellites will have roughly 2-4 Mb/s of bandwidth per cell phone zone, which will allow for tens of thousands of SMS text messages per second or many users placing phone calls.

While this technology is primarily meant for contacting emergency services worldwide (similar to Apple’s connect to satellite feature on the iPhone 14 series), it will also be able to be used for sending non-emergency-related messages.

Starlink 2nd Generation Orbital Shells

Generation two consists of 29,988 satellites–this is roughly 20 times more satellites than were ever launched before the start of Starlink in 2019.

These satellites will primarily be launched by Starship; however, as previously mentioned, Falcon 9 will launch some of these satellites while Starship isn’t operational.

Due to the vast number of Starlink satellites, many astronomers are concerned about their effect on the night sky. However, SpaceX is working with the astronomy community and implementing changes to the satellites to make them harder to see from the ground and less obtrusive to the night sky.

The Starlink 2nd generation constellation consists of nine orbital shells. It is currently unclear how these shells will be named. This batch is called 6-26 after the shell.

Shell

Flights

Angel

Altitude

Orbit Planes

Sats./Plane

Sats. total

1


53.0°

340 km

48

110

5,280

2


46.0°

345 km

48

110

5,280

3


38.0°

350 km

48

110

5,280

4


96.9°

360 km

30

120

3,600

5


33.0°

535 km

28

120

3,360

5?

13

43.0°

530 km

v1.5+

?

699/?

6

26

43.0°

530 km

28

120

558/3,360

7

6

53.0°

525 km

28

120

127/3,360

8


148.0°

604 km

12

12

144

9


115.7°

614 km

18

18

324

It looks like the information highway needs a whole lot of traffic cops when this is completed

Confused? Well. The 1st generation five Shell’s seem to mix in with the 2nd generation table sets as the fifth shell launches continue with Starlink Shell’s 6 and 7 launches.

The 1st Shell of Starlink v1.0 satellites is about to face an end-of-service-life replacement after five years in orbit. Shell 7 satellites are in the same orbit as the L01-L28 Starlink v1.0 satellites but they are flying lower and are several times more powerful.

The Shell 1 with L01-L28 Starlink v1.0 satellites will be deorbited and not replaced. The beta ‘Better than Nothing’ customers might be moved to Shell 7 for downlink service.

The Falcon 9 launch

A typical Falcon 9 mission begins with the countdown that has a traditional 35-minute long propellant load sequence which begins with RP-1 (a refined form of kerosene) loading on both stages and liquid oxygen (LOX) loading on the first stage only.

Loading of RP-1 on the second stage wraps up first at the T-20 minute mark followed by the usual “T-20 minute vent” as the oxygen purging begins on the pipelines of the Falcon 9 Transporter/Erector (T/E) that supplies fluids and power to the vehicle. LOX load on the second stage begins about four minutes after that at T-16 minutes.

Engine chill commences at the T-7 minute mark with a small flow of LOX going into the turbopumps on all nine Merlin engines on the first stage. RP-1 loading on the booster then wraps up about a minute later at the T-6 minute mark.

LOX load on the first and second stages ends at around the T-3 minute and T-2 minute mark respectively, and the rocket takes control of the countdown at the T-1 minute mark.

Engine ignition is commanded at T-3 seconds allowing them to achieve maximum thrust and pass final checks before committing to launch and if engine checks look correct, the ground clamps release the rocket for liftoff at the expected T0 time.

After liftoff, Falcon 9 climbs steeply away from the launch site, pitching downrange as it maneuvers along its pre-programmed trajectory. Approximately 72 seconds into the flight, the vehicle passes through Max-Q — the point of maximum dynamic pressure, where mechanical stresses on the rocket are the greatest.

The nine first-stage engines continue to power Falcon 9 for the first two minutes and 30 seconds of the mission, until the time of main engine cutoff (MECO), at which point all nine engines shut down near-simultaneously.

Stage separation normally occurs four seconds later, with the ignition of the second stage’s Merlin Vacuum engine coming about seven seconds after staging.

While the second stage continues onward to orbit with its payload, the first stage coasts upward to apogee — the highest point of its trajectory — before beginning its trip back to Earth. The booster refines its course toward the landing zone before attempting to softly touch down on the deck of one of SpaceX’s three drone ships.

Two or three burns are required to secure a safe landing of a Falcon 9 booster depending on the chosen landing site. A boost back burn nullifies the horizontal speed from about 7000 km/h positive to a 1000 km/h negative if a return to launch site is chosen.

Normally a free fall trajectory is chosen which requires a re-entry burn designed to break the speed into the denser atmosphere. The Merlin 1D# engines start in a 1-3-1 sequence with the center engine 9 starting 4 seconds before lighting up engine 1 and 5 in a burn lasting 14-16 seconds ending with a 2 second center engine solo burn.

The re-entry burn last 20-22 seconds and the booster is now falling and steering through the denser atmosphere with the 4x5 feet grid fins. A last landing burn performed by the Merlin 1D# center engine is timed to the last millisecond securing the aiming and breaking of the boosters speed. The booster landing has now been performed over 220 times.

Using a drone ship for booster recovery allows SpaceX to launch more mass in a payload on Falcon 9 than it would be able to launch on a return-to-launch-site mission.

In the meantime, the second stage carries on with the primary mission. After stage separation and Merlin Vacuum engine ignition, the payload fairing halves are jettisoned, thereby exposing the satellites to space. The fairings can be recovered and reused, using a system of gas thrusters and parachutes to make a controlled descent into the ocean.

Second-stage engine cutoff (SECO-1) takes place just over eight and a half minutes into the flight. Other engine burns to modify or increase the deployment orbit will follow if the mission requires it. Starlink Group 6-26 will require a second circularization burn.

The Starlink satellites are deployed into a low orbit so any faulty or non-functional spacecraft will quickly re-enter the atmosphere and be destroyed. Working satellites will raise themselves into a more stable orbit, where they will undergo checkouts before heading to their final operational orbits.

After spacecraft separation, the second stage will perform a disposal deorbit burn, ensuring that reentry takes place in the Indian Ocean south of Madagascar.

When the second stage comes in contact with ground control in either Hawthorne, California or Boca Chica, Texas after one orbit. The deorbit burn command is given within sight of Fort Worth, Texas simultaneously with a blow out of the propellant tanks. 40-45 minutes later the second stage re-enters and crashes into the Indian Ocean.

The Falcon 9 rocket

The Falcon 9 Block 5 is SpaceX’s partially reusable two-stage medium-lift launch vehicle. The vehicle consists of a reusable first stage, an expendable second stage, and, when in payload configuration, a pair of reusable fairing halves.

The Falcon 9 first stage contains 9 Merlin 1D# sea level engines. Each engine uses an open gas generator cycle and runs on RP-1 and liquid oxygen (LOx). Each engine produces 845 kN of thrust at sea level, with a specific impulse (ISP) of 285 seconds, and 934 kN in a vacuum with an ISP of 313 seconds.

Due to the powerful nature of the engine, and the large amount of them, the Falcon 9 first stage is able to lose an engine right off the pad, or up to two later in flight, and be able to successfully place the payload into orbit.

The Merlin engines are ignited by triethylaluminum and triethylborane (TEA-TEB), which instantaneously burst into flames when mixed in the presence of oxygen. During static fire and launch the TEA-TEB is provided by the ground service equipment. However, as the Falcon 9 first stage is able to propulsively land, three of the Merlin engines (E1, E5, and E9) contain TEA-TEB canisters to relight for the boost back, reentry, and landing burns.

The Falcon 9 second stage is the only expendable part of the Falcon 9. It contains a singular MVacD engine that produces 992 kN of thrust and an ISP of 348 seconds. The Falcon 9 can put some or many payloads in different orbits on missions with many burns and/or long coasts between burns, the second stage is able to be equipped with a mission extension package.

When the second stage has this mission extension package it has a gray paint strip, which helps keep the RP-1 warm in sunlight, an increased number of composite-overwrapped pressure vessels (COPVs) for pressurization control, and additional TEA-TEB.

SpaceX is the first entity ever that recovers and reflies its fairings. After being jettisoned, the two fairing halves will use cold gas thrusters to orientate themselves as they descend through the atmosphere. Once at a lower altitude, they will deploy drogue chutes and parafoils to help them glide down to a soft landing for recovery.

The Falcon 9’s fairing consists of two dissimilar reusable halves. The first half (the half that faces away from the transport erector) is called the active half, and houses the pneumatics for the separation system. The other fairing half is called the passive half.

Comparison of Type 1 and 2 with measurements based on pixels - Type 2 are 5-6 inches thicker

As the name implies, this half plays a purely passive role in the fairing separation process, as it relies on the pneumatics from the active half. It’s suspected that the passive fairing unlocks the twelve hooks in the fairing hinge locking mechanism by rotating them.

SpaceX used boats with giant suspended nets to attempt to catch the fairing halves, however, at the end of 2020 this program was canceled due to safety risks and a low success rate. On Starlink Group 6-26, SpaceX will attempt to recover the fairing halves from the water with their recovery vessel Doug.

There are three known types of 34 x 17 foot fairings used by SpaceX to protect payload during ascent through the atmosphere. The first type had 10 evenly spaced ventilation ports in a circle on the bottom part of the fairings. This type was not aerodynamic enough to carry a parachute and ACS - Attitude Control System.

The aerodynamic balance during descent must have made them prone to stalling, or they burned up too easily. ACS gas tanks, flight orientation computers and ACS thrusters must have helped with these problems during development of type 2 fairings.

The second type is a slightly thicker fairing with only 8 evenly spaced ventilation ports in a circle on the bottom part of the fairings. The ventilation ports release the pressurized Nitrox gas during ascent, but was letting in seawater which makes it harder to refurbish the fairings after recovery from the ocean.

In 2021, SpaceX started flying a new “upgraded” version of the Falcon 9 fairing. The third type has 8 ventilation ports in pair’s near the edge of the fairings.

Some old type 2 fairings have been rebuilt and reused in Starlink launches. That have been a test program to develop the type 3 fairings to prevent saltwater from the ocean from flooding and sinking the fairing, and makes refurbishment toward the next flight easier.

Lately it’s apparent that the fairings are actively aiming for the droneship in order to speed up the recovery process and cut corners of the time table. The fairings are breaking their speed during reentry and before deploying the parachute at altitude or the last moment.

Another solution is a ‘vertical’ boost lifting the fairings apogee so the ballistic trajectory is changed aiming for a landing nearer the droneship. It’s equivalent to raising the angle on a water hose giving the water stream an higher arc but giving it a shorter reach.

It’s not clear whether or not the cold gas nitrogen thrusters alone are capable of doing a ‘boost back’ or a ‘push up’ so the fairings can alter their forward momentum mid-flight. Every landing close to the ASDS seems to be an aimed fairing landing.

Everyday Astronaut: Trevor Sesnic link

NasaSpaceFlight: Aaron McCrea link

Coauthor/Text Retriever Johnny Nielsen

SpaceX Launch list - ElonX stats link


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