Tuesday, September 27

SpaceX successfully launches Starlink mission on sixth try – Spaceflight Now

Live coverage of the countdown and launch of a SpaceX Falcon 9 rocket from Space Launch Complex 40 at Cape Canaveral Space Force Station in Florida. The Starlink 4-34 mission will launch SpaceX’s next batch of 54 Starlink broadband satellites. Follow us on Twitter.

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SpaceX launched a Falcon 9 rocket from Cape Canaveral Sunday night after five days of weather delays, hauling 54 more Starlink satellites to orbit as the company continues its push toward completing more than 60 missions this year.

Liftoff of the 229-foot-tall (60-meter) Falcon 9 rocket occurred at 8:18:40 p.m. EDT Sunday (0018:40 GMT Monday) to begin SpaceX’s Starlink 4-34 mission. The Falcon 9 took off powered by nine kerosene-fueled Merlin 1D engines, firing into a nighttime sky as it soared northeast from pad 40 at Cape Canaveral Space Force Station.

The mission finally got off the ground after five days of delays, which began Tuesday night when the launch team called off a countdown just before starting to load propellants into the Falcon 9 rocket. Lightning flashes lit up the sky over Florida’s Space Coast throughout the evening. Similar weather conditions Wednesday night forced officials to call another scrub before tanking, and SpaceX stopped the countdown at about T-minus 30 seconds Thursday night as weather remained “no go” for launch.

It was a similar story Friday night as SpaceX loaded propellants into the Falcon 9, but stopped the countdown just inside of T-minus 60 seconds. Teams initially targeted another launch attempt Saturday, but SpaceX announced Saturday evening the mission would be delayed to Sunday night.

This flight marked SpaceX’s 42nd Falcon 9 launch so far in 2022. It was the 40th space launch attempt overall from Florida’s Space Coast this year, including launches by SpaceX, United Launch Alliance, and Astra.

SpaceX’s Falcon 9 rocket launches on the Starlink 4-34 mission. Credit: Stephen Clark / Spaceflight Now

About 15 minutes after liftoff, the Falcon 9 rocket’s upper stage released 54 Starlink satellites over the North Atlantic Ocean traveling at a velocity of some 17,000 mph. The satellites totaled about 36,800 pounds, or 16.7 metric tons, in payload mass.

The Starlink 4-34 mission was the third of as many as five Falcon 9 missions on SpaceX’s schedule this month. Tom Ochinero, SpaceX’s vice president of commercial sales, said last week at the World Satellite Business Week conference in Paris that the company aims to complete more than 60 launches this year, with the goal of 100 rocket missions in 2023, continuing a dramatic uptick in SpaceX’s launch cadence.

The higher launch rate has been aided by shorter turnarounds between missions at launch pads in Florida and California, and SpaceX’s reuse of Falcon 9 boosters and payload fairings. Launches carrying satellites for SpaceX’s own Starlink internet network, like the mission Sunday night, have accounted for about two-thirds of the company’s Falcon 9 flights so far this year.

The next Falcon 9 launch for the Starlink network was scheduled for Sept. 19 from Cape Canaveral, but is likely to be delayed until the last week of September as a ripple effect of the weather-related scrubs for the Starlink 4-34 mission.

SpaceX began flying 54 Starlink satellites on dedicated Falcon 9 flights last month, one more spacecraft than the company typically launched on previous missions. SpaceX has experimented with different engine throttle settings and other minor changes to stretch the Falcon 9’s performance.

A SpaceX Falcon 9 rocket stands on pad 40 at Cape Canaveral Space Force Station ahead of liftoff on the Starlink 4-34 mission. Credit: Stephen Clark / Spaceflight Now

SpaceX test-fired the Falcon 9 booster for the Starlink 4-34 mission at the launch pad Sept. 11. A static fire attempt Sept. 10 was aborted as a strong thunderstorm swept across the Cape Canaveral spaceport.

The booster that flew Sunday night is designated B1067 in SpaceX’s inventory of reusable rockets. The booster previously launched two astronaut missions toward the International Space Station, plus two resupply flights to the station. It also launched Turkey’s Turksat 5B communications satellite.

The first stage completed its sixth flight to space Sunday night, culminating in an on-target landing on SpaceX’s drone ship parked in the Atlantic Ocean.

With the Starlink 4-34 mission, SpaceX has now launched 3,347 Starlink internet satellites, including prototypes and test units no longer in service. The launch Saturday was the 61st SpaceX mission primarily dedicated to hauling Starlink internet satellites into orbit.

Stationed inside a launch control center just south of Cape Canaveral Space Force Station for Sunday night’s countdown, SpaceX’s launch team began loading super-chilled, densified kerosene and liquid oxygen propellants into the Falcon 9 vehicle at T-minus 35 minutes.

Helium pressurant also flowed into the rocket in the last half-hour of the countdown. In the final seven minutes before liftoff, the Falcon 9’s Merlin main engines were thermally conditioned for flight through a procedure known as “chilldown.” The Falcon 9’s guidance and range safety system were also configured for launch.

After liftoff, the Falcon 9 rocket vectored its 1.7 million pounds of thrust — produced by nine Merlin engines — to steer northeast over the Atlantic Ocean.

The rocket exceeded the speed of sound in about one minute, then shut down its nine main engines two-and-a-half minutes after liftoff. The booster stage released from the Falcon 9’s upper stage, then fired pulses from cold gas control thrusters and extend titanium grid fins to help steer the vehicle back into the atmosphere.

Two braking burns slowed the rocket for landing on the drone ship “Just Read the Instructions” around 400 miles (650 kilometers) downrange approximately eight-and-a-half minutes after liftoff.

Credit: Spaceflight Now

The Falcon 9’s reusable payload fairing jettisoned during the second stage burn. A recovery ship was also on station in the Atlantic to retrieve the two halves of the nose cone after they splash down under parachutes.

Landing of the first stage on Sunday’s mission occurred moments after the Falcon 9’s second stage engine cut off to deliver the Starlink satellites into orbit. Separation of the 54 Starlink spacecraft, built by SpaceX in Redmond, Washington, from the Falcon 9 rocket was confirmed at T+plus 15 minutes, 21 seconds.

Retention rods released from the Starlink payload stack, allowing the flat-packed satellites to fly free from the Falcon 9’s upper stage in orbit. The 54 spacecraft will unfurl solar arrays and run through automated activation steps, then use krypton-fueled ion engines to maneuver into their operational orbit.

The Falcon 9’s guidance computer aimed deploy the satellites into an elliptical orbit at an inclination of 53.2 degrees to the equator. The satellites will use on-board propulsion to do the rest of the work to reach a circular orbit 335 miles (540 kilometers) above Earth.

The Starlink satellites will fly in one of five orbital “shells” at different inclinations for SpaceX’s global internet network. After reaching their operational orbit, the satellites will enter commercial service and begin beaming broadband signals to consumers, who can purchase Starlink service and connect to the network with a SpaceX-supplied ground terminal.

ROCKET: Falcon 9 (B1067.6)

PAYLOAD: 54 Starlink satellites (Starlink 4-34)

LAUNCH SITE: SLC-40, Cape Canaveral Space Force Station, Florida

LAUNCH DATE: Sept. 18, 2022

LAUNCH TIME: 8:18:40 p.m. EDT (0018:40 GMT on Sept. 19)

WEATHER FORECAST: 40% chance of acceptable weather; Low risk of upper level winds; Low risk of unfavorable conditions for booster recovery

BOOSTER RECOVERY: “Just Read the Instructions” drone ship east of Charleston, South Carolina

LAUNCH AZIMUTH: Northeast

TARGET ORBIT: 144 miles by 208 miles (232 kilometers by 336 kilometers), 53.2 degrees inclination

LAUNCH TIMELINE:

  • T+00:00: Liftoff
  • T+01:12: Maximum aerodynamic pressure (Max-Q)
  • T+02:27: First stage main engine cutoff (MECO)
  • T+02:31: Stage separation
  • T+02:36: Second stage engine ignition
  • T+02:42: Fairing jettison
  • T+06:48: First stage entry burn ignition (three engines)
  • T+07:07: First stage entry burn cutoff
  • T+08:26: First stage landing burn ignition (one engine)
  • T+08:40: Second stage engine cutoff (SECO 1)
  • T+08:47: First stage landing
  • T+15:21: Starlink satellite separation

MISSION STATS:

  • 176th launch of a Falcon 9 rocket since 2010
  • 184th launch of Falcon rocket family since 2006
  • 6th launch of Falcon 9 booster B1067
  • 151st Falcon 9 launch from Florida’s Space Coast
  • 97th Falcon 9 launch from pad 40
  • 152nd launch overall from pad 40
  • 118th flight of a reused Falcon 9 booster
  • 61st dedicated Falcon 9 launch with Starlink satellites
  • 42nd Falcon 9 launch of 2022
  • 42nd launch by SpaceX in 2022
  • 40th orbital launch attempt based out of Cape Canaveral in 2022

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Follow Stephen Clark on Twitter: @StephenClark1.

source: spaceflightnow.com