SpaceX postpones the first flight of the double cross-country Starlink to Tuesday

With five Falcon 9 launches and only one Falcon Heavy flight already under its belt so far in 2023, SpaceX is expected to wrap up in January and begin in February launching two Starlink missions. These launches will now take place one day apart at separate launch sites.

The first such mission – Starlink Group 2-6 – is now scheduled to fly from Space Launch Complex 4 East (SLC-4E) at Vandenberg Space Force Base in California on Tuesday, January 31 at 8:15 a.m. PST (16:15 UTC) after a delay from Monday “to allow more time for payments before launch”. This will be followed by the Starlink Group 5-3 mission, which will launch from historic Launch Complex 39A (LC-39A) at Kennedy Space Center in Florida, which is currently scheduled for Tuesday, February 1 at 3:02 a.m. EST (08:02 UTC).

These two missions will serve as the sixth and seventh Falcon 9 launches of the year, and the seventh and eighth overall launches for SpaceX in 2023. Both flights will use flight-proven Falcon 9 boosters and feature booster recovery attempts.

Vandenberg’s Starlink Group 2-6 will use the Falcon B1071-7 core, which previously supported launches of two missions for the US National Reconnaissance Office (NROL-87 and NROL-85), SARah-1 for Airbus, SWOT for NASA and CNES, and two other Starlink flights. After launching on Sunday morning, the first stage will attempt to land on the Autonomous Space Drone (ASDS) Of course I still love you, stationed about 647 km downstream in the Pacific Ocean. The boat NRC Quest should also be able to salvage the fairing halves for reuse.

Kennedy Space Center’s Starlink Group 5-3 will use Falcon booster B1069-5, which launched CRS-24, Starlink Group 4-23, Hotbird-13F and OneWeb #15. ASDS A lack of seriousness will be available for recovery from the first stage at an approximate distance of 665 km in the Atlantic Ocean.

The launch from California — Group 2-6 — will see the deployment of 49 Starlink satellites in an orbit inclined at 70 degrees to the equator, at a final altitude of 570 km. The initial parking orbit will be 327 km by 339 km, with the Falcon 9 flying on a south-southeast trajectory.

The final 570 km orbit corresponds to the “second shell” of the Starlink constellation: an eventual grouping of 720 spacecraft spread over 36 planes, with 20 spacecraft per aircraft. Monday’s launch will only be the third launch to target this second shell, as Group 2-2, 2-3, and 2-5 missions have yet to launch. The first launch to Shell 2, Group 2-1, was deployed in September 2021.

Rendering of an ION Satellite Carrier midway through the deployment of CubeSats in Low Earth Orbit. (Credit: D-Orbit)

The Starlink spacecraft will not be alone in the refit of the Group 2-6 mission. An ION Satellite Carrier Orbital Transfer Vehicle (SCV009 Eclectic Elena), developed and operated by Italian company D-Orbit, will serve as the carpool payload on Sunday’s flight.

The ION Satellite Carrier platform includes a customizable carrier capable of hosting a combination of different sized CubeSats. Throughout a mission, the vehicle can release its payloads individually, changing orbital parameters from one deployment event to the next. This adds a level of flexibility for missions that cannot be served by standard carpool launches.

Following the launch of Starlink Group 2-6, SpaceX will turn its attention to the East Coast for the launch of the Group 5-3 mission. This mission is expected to deploy a batch of Starlink satellites into an orbit with an inclination of 43 degrees. That means Falcon 9 will head on a southeasterly trajectory out of Florida — a common practice during the winter months, as rougher seas to the north tend to complicate recovery efforts.

The satellites themselves should be similar to the version 1.5 satellites that have been launched in the last few years.

A typical Starlink mission begins with Falcon 9 lifting off from its launch pad. The nine first-stage Merlin 1D engines begin their firing sequence at the second T-3 mark of the countdown, allowing them to reach maximum thrust and pass final checks before committing to launch.

A previous mission, Starlink Group 4-37, lifts off from LC-39A in December 2022. (Julia Bergeron for NSF)

After liftoff, the Falcon 9 will roll away from the launch site, pitching while maneuvering along its pre-programmed path. About 72 seconds into the flight, the vehicle will pass through Max-Q – the point of maximum dynamic pressure, where the mechanical stresses on the rocket are greatest.

The nine engines on the first stage will continue to power the Falcon 9 for the first two minutes and 27 seconds of the mission, until the moment of main engine cut-off (MECO), at which time all nine engines will shut down almost simultaneously. Stage separation normally occurs four seconds later, with ignition of the second stage Merlin Vacuum engine coming approximately seven seconds after stage.

As the second stage continues to orbit with its payload, the first stage will ascend to apogee – the highest point in its trajectory – before beginning its journey back to Earth. The thruster will refine its trajectory toward the landing zone before attempting to gently land on the deck of one of SpaceX’s three drones. Using a drone ship for surge recovery allows SpaceX to launch a more massive payload onto Falcon 9 than it could on a return mission to the launch site.

In the meantime, the second stage will continue with the main mission. After the stages separate and the Merlin Vacuum engine fires, the fairing halves of the payload will jettison, exposing the satellites to space. Similar to the Falcon 9 first stage, the fairing halves can be recovered and reused, using a system of thrusters and parachutes to perform a controlled descent into the ocean where they will be recovered by a recovery vessel.

Shutdown of the second stage engine (SECO-1) usually occurs just over eight and a half minutes into the flight. Further engine burns to modify the deployment orbit will follow if the mission requires it, such as on group 2-6 which will use a second burn before deploying SCV009 Eclectic Elena and Starlink satellites.

Starlink satellites are deployed in a low orbit so that any malfunctioning or non-functional spacecraft will quickly re-enter the atmosphere and be destroyed. Operating satellites will hoist themselves into a more stable orbit, where they will undergo checks before heading to their final operational orbits.

After separation from the spacecraft, the second stage will perform a deorbit burnup for proper disposal, ensuring reentry takes place over the ocean.

The Starship vehicle and Super Heavy booster, undergoing a wetsuit refueling test at Starbase. (Credit: SpaceX)

With two successful launches, Falcon 9 will reach a total of 200 orbital flights, with a launch success rate of 99%. The flights are part of a quick start to the year for SpaceX, which CEO Elon Musk says is aiming for the ambitious goal of reaching as many as 100 orbital launches in 2023. That would surpass its current record of 61 launches in a calendar. year, set in 2022.

In addition to the Falcon 9 and the Falcon Heavy, SpaceX hopes to introduce Starship into its orbital catalog this year with the first full-stack test flight (the Starship vehicle and its Super Heavy booster). At this time, Starship is still undergoing readiness testing at the company’s Starbase test and production facilities in South Texas, with a launch date yet to be officially announced.

(Main image: Falcon 9 on SLC-4E before SARah-1 launch in June 2022. Credit: Michael Baylor for NSF)

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