Falcon 9 to launch Starlink satellites, Boeing’s ride-sharing payload – Spaceflight Now

Live coverage of the countdown and launch of a SpaceX Falcon 9 rocket from Space Launch Complex 40 at the Cape Canaveral Space Force Station in Florida. The Starlink 4-20 mission will launch SpaceX’s next batch of 51 Starlink broadband satellites and a rideshare payload for Boeing to demonstrate broadband communications technology. Follow us Twitter.

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SpaceX is on the countdown to launch 51 more Starlink internet satellites and a ride-sharing payload that will use a Spaceflight-built orbital transfer vehicle to maneuver into a different orbit to test broadband communications technology for Boeing. .

Liftoff from Space Launch Complex 40 at the Cape Canaveral Space Force Station aboard a Falcon 9 rocket is scheduled for Sunday at 10:09 p.m. EDT (02:09 GMT Monday), marking the launch SpaceX’s 40th issue of the year.

There is an 80% chance of favorable weather for the launch opportunity on Sunday night, according to the US Space Force’s 45th Weather Squadron.

The primary payload for Sunday night’s mission, designated Starlink 4-20, is SpaceX’s next batch of Starlink internet satellites. The rocket will lift 51 flat-pack Starlink spacecraft, fewer than the number carried in a typical Starlink launch from Florida, to accommodate a rideshare payload.

The secondary passenger is the chemically-powered Sherpa-LTC Orbital Transfer Vehicle that rides on the Starlink payload stack inside the Falcon 9’s payload fairing. Built by Spaceflight, a Seattle-based spacecraft developer and launch corridor The Sherpa-LTC Orbital Transfer Vehicle is designed to transport small satellites and experiments housed at different altitudes and inclinations after an initial trip into orbit from a large rocket.

The Sherpa-LTC Orbital Transfer Vehicle on the Starlink 4-20 mission will carry Boeing’s Varuna Technology Demonstration Mission, or Varuna-TDM. The mission is designed to demonstrate technologies and conduct in-orbit performance tests for a V-Band Communications System, a proposed 147-satellite constellation to provide broadband connectivity to US government and commercial users.

The Varuna-TDM mission will provide potential users of the broadband satellite constellation “an opportunity to assess the performance of V-band communications links and determine their attributes and acceptability for specific applications,” Boeing said.

The Sherpa-LTC mission patch shows an illustration of the Spaceflight-built Orbital Transfer Vehicle. Credit: spaceflight

The Falcon 9 rocket will deploy the Sherpa-LTC transfer vehicle with the Varuna technical demonstration mission into a nearly circular orbit at an average altitude of about 310 kilometers (192 miles) above Earth, with an inclination of 53.2 degrees with relative to the equator.

Sherpa-LTC will first deploy about 49 minutes after the flight, followed by separation of the 51 Starlink satellites at T+plus 72 minutes.

Spaceflight’s solar-powered orbital transfer vehicle will perform a sequence of power-ups to reach a circular orbit about 620 miles (1,000 kilometers) above Earth, where the Varuna technical demonstration mission will launch. The Varuna Technical Demonstration Payload was designed and built by Astro Digital, which also provided the command and control system for the Sherpa-LTC Orbital Transfer Vehicle.

The Sherpa-LTC vehicle uses a “green,” or non-toxic, twin-propeller propulsion system developed by Benchmark Space Systems.

“Sherpa-LTC’s transport capabilities coupled with the reliability and consistency of Starlink missions create an ideal solution for a customer’s unique mission needs,” said Curt Blake, CEO and president of Spaceflight. “Our OTV removes the barriers that make it difficult for spacecraft to access rare orbits in LEO and beyond. We look forward to continuing to provide innovative, cost-effective and reliable space transportation services for our customers and partners like Astro Digital.”

With Sunday’s Starlink 4-20 mission, SpaceX has launched 3,259 Starlink internet satellites, including prototypes and test units that are no longer in service. Sunday night’s launch will be SpaceX’s 59th mission dedicated primarily to putting the Starlink internet satellites into orbit.

Stationed inside a launch control center just south of the Cape Canaveral Space Force Station, the SpaceX launch team will begin loading liquid oxygen and supercooled densified kerosene propellants into the 229-foot Falcon 9 vehicle. height (70 meters) in T-minus 35 minutes

Pressurized helium will also flow into the rocket in the last half hour of the countdown. In the last seven minutes before liftoff, the Falcon 9’s Merlin main engines will thermally condition themselves for flight through a procedure known as “relaxation.” The Falcon 9’s range and guidance safety system will also be configured for launch.

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

The rocket will exceed the speed of sound in about a minute and then shut down its nine main engines two and a half minutes after liftoff. The booster stage will break free from the Falcon 9 upper stage, then fire pulses from the cold gas control thrusters and extended titanium grid fins to help steer the vehicle back into the atmosphere.

Two braking bursts slowed the rocket to land on the “Just Read the Instructions” drone about 400 miles (650 kilometers) about eight and a half minutes after liftoff.

The first stage for Sunday’s launch is designated B1052 in SpaceX’s inventory. The booster will make its seventh flight into space. This vehicle flew as a side booster on two Falcon Heavy rocket missions in 2019, then was converted to fly as a first stage on the Falcon 9 rocket, starting earlier this year.

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

Sunday’s mission’s first-stage landing will occur moments after the Falcon 9’s second-stage engine shuts down to place the Starlink satellites into a preliminary transfer orbit. A second upper stage burn about 45 minutes after launch will put the payloads into the proper orbit for separation.

After releasing the Sherpa-LTC payloads, the upper stage will release the Starlink payload stack retaining rods, allowing flat satellites to fly freely from the Falcon 9 upper stage into orbit. Spacecraft 51 will deploy solar panels and execute automated activation steps, then use krypton-fueled ion engines to maneuver into its operational orbit.

The satellites will use onboard propulsion to do the rest of the work and reach a circular orbit 540 kilometers (335 miles) above Earth.

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

ROCKET: Falcon 9 (B1052.7)

USEFUL LOAD: 51 Starlink and Sherpa-LTC satellites (Starlink 4-20)

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

RELEASE DATE: September 4, 2022

LUNCH TIME: 22:09 EDT (0209 GMT)

WEATHER FORECAST: 80% chance of fair weather; Low risk of high winds; Low risk of unfavorable conditions for reinforcement recovery

BOOSTER RECOVERY: “Just Read The Instructions” Unmanned Boat East of Charleston, South Carolina

LAUNCH AZIMUTH: northeast

TARGET ORBIT: 188 miles by 196 miles (304 kilometers by 316 kilometers), 53.2 degree incline

LAUNCH SCHEDULE: