Falcon 9 launches Starlink satellites, Boeing rideshare 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 launches SpaceX’s next batch of 51 Starlink broadband satellites and a rideshare payload for Boeing to demonstrate broadband communications technology. follow us on Twitter.

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SpaceX is counting down to the launch of 51 more Starlink internet satellites and a rideshare payload that will use a Spaceflight-built orbital transport vehicle to maneuver into another orbit to test broadband communications technology for Boeing.

Launch of Space Launch Complex 40 at Cape Canaveral Space Force Station aboard a Falcon 9 rocket is scheduled for Sunday, 10:09 p.m. EDT (Monday, 0209 GMT), marking SpaceX’s 40th launch of the year.

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

The main payload for Sunday night’s mission, dubbed Starlink 4-20, is SpaceX’s next batch of Starlink internet satellites. The rocket will carry 51 flat-packed Starlink spacecraft, less than the number carried on a typical Starlink launch from Florida, to accommodate a rideshare payload.

The secondary passenger is the chemically powered Sherpa-LTC orbital transport vehicle that rides on the Starlink payload stack in the cockpit of the Falcon 9 payload. Built by Spaceflight, a Seattle-based developer of spacecraft and rideshare launchers, the Sherpa-LTC orbital transfer vehicle is designed to carry small satellites and host experiments to various heights and inclinations after an initial ride into orbit from a large rocket ship.

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 aims to demonstrate technologies and conduct space performance testing for a V-band communications system, a proposed 147 satellite constellation to provide broadband connectivity to commercial and U.S. government users.

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

The mission patch for the Sherpa-LTC mission shows an illustration of the orbital transfer vehicle built by Spaceflight. Credit: Spaceflight

The Falcon 9 rocket will place the Sherpa-LTC transfer vehicle carrying the Varuna tech demo mission into near-circular orbit at an average elevation of about 192 miles (310 kilometers) above Earth, with an inclination of 53.2 degrees. relative to the equator.

The Sherpa-LTC will first deploy approximately 49 minutes into the flight, followed by separation from the 51 Starlink satellites at T+plus 72 minutes.

Spaceflight’s solar-powered orbital transfer vehicle will perform a series of burns to reach a circular orbit around 620 miles (1,000 kilometers) above Earth, where the Varuna tech demo mission will kick off. Varuna’s technical demo payload was designed and built by Astro Digital, which also provided the command and control system for the Sherpa-LTC transport vehicle.

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

“Sherpa-LTC’s transportation capabilities combined with the reliability and consistency of Starlink missions create an ideal solution for customer’s unique mission needs,” said Curt Blake, CEO and president of Spaceflight. “Our OTV eliminates the barriers that make it more difficult for spacecraft to access unusual orbits in LEO and beyond. We are eager to continue providing innovative, cost-effective and reliable transportation services in space for our customers and partners such as Astro Digital. ”

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

Stationed at a launch control center just south of Cape Canaveral Space Force Station, the SpaceX launch team will begin loading supercooled, compressed kerosene and liquid oxygen propellants into the 70-meter-tall Falcon 9 vehicle at T-minus 35 minutes.

Helium pressure medium will also flow into the rocket in the last half hour of the countdown. In the final seven minutes before launch, the Falcon 9’s Merlin main engines are thermally conditioned for flight through a procedure known as “chilldown.” The Falcon 9’s guidance and range protection system will also be configured for launch.

After launch, the Falcon 9 rocket will send its 1.7 million pounds of thrust — produced by nine Merlin engines — across the Atlantic to the northeast.

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 launch. The booster stage detaches from the Falcon 9’s top stage, then fires pulses from cold throttle control engines and extended titanium grille fins to send the vehicle back into the atmosphere.

Two brake burns slowed the rocket before landing on the drone ship “Read the Instructions” down about 400 miles (650 kilometers), about eight and a half minutes after launch.

The first stage for Sunday’s launch is designated as 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 and was then converted to fly as the first stage on the Falcon 9 rocket starting earlier this year.

The reusable fairing from the Falcon 9’s payload is jettisoned during the second stage. A salvage ship is also on station in the Atlantic to retrieve the two halves of the nose cone after they crashed under parachutes.

The landing of the first stage on Sunday’s mission will occur moments after the Falcon 9’s second stage engine shuts down to put the Starlink satellites into tentative orbit. A second burn of the upper stage, about 45 minutes after launch, will put the charges in orbit for separation.

After releasing the Sherpa-LTC payloads, the upper stage will release retention bars of the Starlink payload stack, allowing the flat-packed satellites to fly free of the Falcon 9’s upper stage into orbit. The 51 spacecraft will deploy solar panels and go through automated activation steps, then use krypton-powered ion engines to maneuver into their operational orbit.

The satellites will use the onboard 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” with different inclinations for SpaceX’s global internet network. After reaching operational orbit, the satellites will enter commercial service and begin beaming broadband signals to consumers, who can purchase the Starlink service and connect to the network with a SpaceX-provided ground terminal.

ROCKET SHIP: Falcon 9 (B1052.7)

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

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

LAUNCH DATE: September 4, 2022

LAUNCH TIME: 10:09 PM EDT (0209 GMT)

WEATHER FORECAST: 80% chance of acceptable weather; Low risk of wind at the highest level; Low risk of adverse booster recovery conditions

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


TARGET JOB: 188 miles by 196 miles (304 kilometers by 316 kilometers), 53.2 degrees grade


  • T+00:00: Launch
  • T+01:12: Maximum aerodynamic pressure (Max-Q)
  • T+02:29: First stage main engine shutdown (MECO)
  • T+02:33: Stage separation
  • T+02:39: Engine ignition second stage (SES 2)
  • T+03:13: Cockpit edging
  • T+06:05: First stage entry burn ignition (three engines)
  • T+06:36: First stage entry burn cutoff
  • T+08:05: First stage landing ignition (one engine)
  • T+08:27: Landing first kick
  • T+08:45: Second stage engine shutdown (SECO 1)
  • T+45:25: Engine ignition of the second stage (SES 2)
  • T+45:27: Second stage engine shutdown (SECO 2)
  • T+49:28: Sherpa-LTC separation
  • T+1:12:23: Starlink satellite separation


  • 174th Falcon 9 rocket launch since 2010
  • 182nd launch of the Falcon family of rockets since 2006
  • 7th launch of Falcon 9 booster B1052
  • 149th Falcon 9 Launch from Florida’s Space Coast
  • 96th Falcon 9 launch from pad 40
  • 151st launch overall from pad 40
  • 116th flight of a repurposed Falcon 9 booster
  • 59th Falcon 9 Special Launch with Starlink Satellites
  • 40th Falcon 9 Launch of 2022
  • 40th SpaceX launch in 2022
  • 38th orbital launch attempt from Cape Canaveral in 2022

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