SpaceX cancels Starlink 3-2 launch attempt - NASASpaceFlight.com

SpaceX cancels Starlink 3-2 launch attempt – NASASpaceFlight.com

SpaceX is set to break several records on the Starlink Group 3-2 mission. Departing from Space Launch Complex 4 East (SLC-4E) at Vandenberg Space Force Base in California, the Falcon 9 Block 5 will place 46 Starlink Internet communications satellites in the constellation’s third shell.

Takeoff was scheduled for July 21, 2022, at 10:39 AM PST (17:39 UTC), but the T-46’s countdown was aborted. The launch is now targeted no later than the same time on July 22, and will mark SpaceX’s 32nd launch in 2022, with an average launch every 6.31 days. This will break SpaceX’s 2021 record for most launches in a year when it launched 31 times.

With the ultimate goal of being able to convert the SLC-4E as quickly as the SLC-40 in Florida, SpaceX has made a large number of upgrades to the Transporter/Erector (T/E) and the pad infrastructure in the Pad 4E. T/E is responsible for moving the Falcon 9 vehicle from horizontal to vertical. Once vertical, it provides the vehicle and payload with structural support, power and telemetry, and is used to refuel the vehicle through Quick Disconnects (QDs).

Unlike the T/E at SpaceX’s two other Falcon 9 launch sites – the LC-39A and SLC-40 – the SLC-4E uses an outdated design: the powerful back drops 13 degrees away from the rocket, starting at T-4 minutes, and ends moving by a T- 3 minutes. From this position, the T / E does not move further and remains stationary during takeoff. This is radically different from the “recoil” T/E pattern, which moves just under 2º away from the vehicle in about T-4 minutes, then drops the remaining distance from the vehicle (~45°) after takeoff.

By falling away from the vehicle after takeoff, the T/E also avoids the Falcon 9’s exhaust, reducing the amount of regeneration required between launches. The LC-39A has featured a recoil pattern T/E since SpaceX’s first launch from the board (CRS-10), and the T/E was upgraded from the SLC-40 to recoil pattern after the AMOS-6. However, SpaceX currently has no plans to replace the T/E of the SLC-4E with a recoil pattern T/E.

SpaceX’s upgrades to the SLC-4E allowed a significant reduction in the time between launches to just 10 days and 16 hours between Starlink Group 3-1 and Starlink Group 3-2. The previous record was 22 days, 11 hours and 20 minutes between SARah-1 and Starlink Group 3-1. This will also determine the fastest T/E response time with no bounce.

The booster supporting this mission is B1071-4, which has done three previous missions. This launch will see the 166th launch of the Falcon 9 and the 104th launch with the flight-proven booster.

B1071’s assignments Launch date (UTC) Response time (days)
trolley -87 February 2, 2022 20:27 Unavailable
trolley -85 April 17, 2022 13:13 73.70
Sarah 1 June 18, 2022 14:19 62.05
Starlink 3-1 . group July 22 2022 17:39 34.14

The B1071-4 will attempt to land on the West Coast of SpaceX Autonomous Spaceport Unmanned Aerial Vehicle (ASDS) Of Course I Still Love You (OCISLY), positioned at a distance of 635 km. As usual on West Coast launches, OCISLY is pulled by Scorpius, and GO Quest serves as ASDS support. On a successful landing – which would mark the 132nd and 58th year SpaceX landings respectively – the booster designation would change to B1071-5.

SpaceX will attempt to recover both halves of the aero with its 635 km NRC Quest recovery assets. Both rheology will be restored from the water about 50 minutes after launch.

Interior of a Falcon 9 gift recovered from the Starlink Group 3-1 mission. (credit: Jack Baer for NSF)

The Starlink Group 3-2 mission will raise another 46 satellites into the third shell of the Starlink constellation. Assuming none of the satellites failed, this would take 3 shell completion to 27.3% (in terms of operating satellites) and the total completion of the first five Starlink deployments to 59.32%.

shells slope (°) Orbital altitude (km) Planes Satellites in every plane number of satellites working satellites % complete
shell 1 53 550 72 22 1,584 1,534 94.5
Shell 2 70 570 36 20 720 51 7.1
Shell 3 97.6 560 6 58 348 49 14.1
Shell 4 53.2 540 72 22 1,584 972 61.4
Shell 5 97.6 560 4 43 172 0 0

Assuming SpaceX carries the current launch cadence, the company is expected to complete Shells 3 and 4 by the end of the year, as Shell 3 will require about eight launches to fill up Shell 4 and Shell 4 will require about 32 launches to fill it up. After these two projectiles are completed, it is not clear whether SpaceX will prioritize the 70-degree tilt angle Shell 2 or Shell 5 which orbits around the pole.

SpaceX currently offers several Starlink packages, including Starlink for home, business, RV, and marine. In addition to the services already provided, De Havilland Aircraft of Canada has announced its partnership with SpaceX to offer high-speed internet on their planes thanks to Starlink.

launch sequence

Waiting for a “kick-off” from the T-38’s technical reconnaissance, the Falcon 9 begins the T-35’s refueling sequence when the vehicle begins loading semi-cooled RP-1 on both stages and super-cooled liquid oxygen (LOX) in the first stage.

By the T-20 minutes, the Falcon 9’s second stage is fully refueled with RP-1, and the T/E is unloaded to prepare for the second stage’s LOX loading. Due to the cooler temperature of LOX, it is loaded after RP-1 in the second stage to reduce boiling/expansion.

By T-16 min, T/E is cleared and LOX loading begins in the second stage.

Seven minutes before launch, the craft begins cooling the engines in the first stage. This is done to reduce thermal shock to the engines as LOX flows through them upon ignition. In T-4 minutes, the T/E rotates back to the launch position –13° from the vehicle.

One minute before launch, the vehicle goes into start-up — a process in which computers on board the rocket control the launch sequence. Three seconds before launch, the rocket commands the ignition of all nine first-stage engines, which is done in a staggered manner to reduce crossovers on the vehicle.

Assuming all nine engines report a token start, at T0 the car will command the hydraulic release clamps to release them, allowing it to take off.

The first stage will burn for 2 minutes and 32 seconds before separating from the second stage. While the second stage completes a burn of just over six minutes, the aerodynamic will separate from the car and the first stage will complete two burns to land on OCISLY.

The second stage will end after that ~45 minutes, before igniting again for just under a second. The stage will then start rotating from end to end to deploy satellites in T + 1: 03: 03 in low Earth orbit.

After the payload is deployed, the MVac will perform a third burn to eject itself from orbit over the South Pacific.

SpaceX has another launch planned for July: The Starlink Group 4-25 will launch on July 24 from LC-39A in Florida. The Korean Pathfinder Lunar Orbiter (KLPO) will then be launched on the Falcon 9 from the East Coast on August 2.

(Main image: Falcon 9 B1071 at SLC-4E prior to the SARah-1 mission in June 2022. Credit: Pauline Acalin for NSF)


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