SpaceX Launches Falcon 9 Booster Retiring on Intelsat Mission – Spaceflight Now

SpaceX will launch one of its reusable Falcon 9 rocket boosters for the last time on Saturday on a rare, replaceable mission for Intelsat, spending all of the launch vehicle’s thrust to place a pair of television broadcasting satellites in orbit. Intelsat says it paid SpaceX an additional fee for the expendable mission.

The Falcon 9 rocket has a two-hour launch window on Saturday at 11:06 a.m. EST (1606 GMT) for launch from pad 40 at the Cape Canaveral Space Force Station, Florida. Forecasters from the US Space Force’s 45th Weather Squadron predict a 90% chance of good weather for Saturday’s launch.

The launch was delayed from November 8 due to Hurricane Nicole.

The two Intelsat communications satellites atop the 70-meter-tall Falcon 9 rocket will go into geosynchronous orbit to launch missions expected to last more than 18 years and provide video broadcasting services over North America. The Galaxy 31 and 32 satellites are built by Maxar and are part of Intelsat’s program to replace older communications satellites as the Federal Communications Commission transitions a segment of the C-band spectrum for use by 5G cellular network services.

Intelsat launched the Galaxy 33 and 34 satellites on a Falcon 9 rocket on October 8, the first two of seven new C-band satellites that are part of the transition program. The company has three more new C-band broadcast satellites under construction for launches on Falcon 9 and Ariane 5 rockets in the coming months.

SpaceX’s Falcon 9 rocket will lift off from Cape Canaveral and head east across the Atlantic, targeting a “super synchronous” transfer orbit for the deployment of the Galaxy 31 and 32 satellites. The elliptical orbit will range from a few hundred miles above Earth to nearly 37,000 miles (60,000 kilometers) in elevation, according to Jean-Luc Froeliger, senior vice president of space systems at Intelsat.

The Galaxy 31 and 32 satellites are stacked on top of each other for launch, with the Galaxy 32 set to deploy first from the top position on the rocket at T+plus 33 minutes 31 seconds. Five minutes later, Galaxy 31 will separate from the upper stage of the Falcon 9.

Intelsat decided to pay SpaceX extra money to get all of the lift capacity from the Falcon 9, reducing the amount of fuel the Galaxy 31 and 32 satellites need to reach their final operational position in geostationary orbit. SpaceX usually reserves some of the booster’s propellant for landing maneuvers, but on this mission, all of the rocket’s fuel will be burned during its ascent to space. The first stage reusable booster, designated B1051, will make its 14th and final flight.

The booster debuted on March 2, 2019, with the first unmanned test flight of SpaceX’s Crew Dragon capsule, a precursor to SpaceX’s later astronaut missions. It was relaunched in June 2019 with Canada’s Radarsat Constellation Mission. Later in its career, the booster launched SiriusXM’s SXM 7 radio broadcast satellite and flew on 10 missions with SpaceX’s own Starlink internet satellites.

Most recently, the Falcon 9 booster was launched on July 17 during a Starlink mission.

The two satellites are based on Maxar’s 1300-series satellite design and are the first time two large Maxar-built communications vehicles have been launched in a stacked configuration on the same rocket. According to Froeliger, the dual-satellite stack weighs about 14,500 pounds or 6.6 metric tons, fully fueled for launch.

The Galaxy 31 and 32 satellites will use their own propellants to move from the Falcon 9 rocket’s elliptical orbit to a circular geostationary orbit directly above the equator, consuming fuel that could otherwise be used for stationing during their missions.

“SpaceX won’t be able to reuse the first stage, so you’ll have to pay a premium for a replaceable launch vehicle,” Froeliger said in a news conference Monday, giving a preview of the upcoming launch. “The replaceable launch vehicle was needed for this mission due to the properties of the Maxar satellites. This is the first time Maxar has launched a stack of two 1300s together. And to achieve a good orbital lifetime, i.e. more than 15 years, we had to go to a single-use Falcon 9, and a premium has to be paid for that.”

“You pay extra if it’s a one-off,” Froeliger said in an earlier interview with Spaceflight Now. always pay because you pay for the consumable.”

During Saturday morning’s countdown, the Falcon 9 launcher will be filled with a million pounds of kerosene and liquid oxygen in the final 35 minutes before launch.

After teams verify that the technical and weather parameters are all “green” for launch, the nine Merlin 1D main engines on the first stage booster will come to life using an ignition fluid called triethylaluminium/triethylborane, or TEA-TEB. Once the engines are running at full throttle, hydraulic clamps open to release the Falcon 9 for its ascent into space.

The nine main engines will produce 1.7 million pounds of thrust for more than two-and-a-half minutes, propelling the Falcon 9 and Intelsat’s Galaxy 31 and 32 satellites into the upper atmosphere. Then the booster stage is turned off and detached from the Falcon 9’s upper stage to begin an uncontrolled fall into the Atlantic Ocean.

The booster is not equipped with SpaceX’s recovery hardware, such as titanium grid fins or landing legs. And SpaceX hasn’t deployed any of its drone ships for the expendable mission.

SpaceX is expected to attempt to restore the cockpit of the Falcon 9 rocket after the two halves of the nose cone are lowered into the sea from Cape Canaveral. The payload fairing will be jettisoned about three and a half minutes into the rocket’s flight, shortly after the Falcon 9’s upper stage motor ignited.

For Saturday’s mission, the Falcon 9 rocket will fire its upper stage motor twice to inject the two Intelsat spacecraft into elliptical geostationary orbit. The satellites will be deployed from the rocket 33 minutes and 38 minutes after launch.

Galaxy 31 and 32 will deploy their solar panels and begin maneuvers with their own propulsion systems to orbit their orbits in a geostationary orbit more than 22,000 miles (nearly 36,000 kilometers) above the equator.

Intelsat will use the Galaxy 31 satellite in a slot at 121 degrees west, replacing the Galaxy 23 satellite launched in 2003. Galaxy 32 will replace the Galaxy 17 satellite launched in 2007 at 91 degrees west.

The orbital maneuvers needed to place the Galaxy 31 and 32 satellites in their circular geostationary orbit will take about two weeks. After in-orbit testing, Froeliger said Galaxy 31 will enter commercial service in January, followed by Galaxy 32 in February.

“Our customer base is made up of the media, so anyone who uses TV in the US can rest assured that your channel will be on one of these two satellites, or any other Galaxy satellite we have over the US,” said Froeliger . “These satellites are replacing older fuel-powered satellites, and they’re being replaced with a little more newer technology so they’ll have higher power, allowing the customer to use smaller receiving antennas and have better performance, especially in the event of bad weather. “

ROCKET SHIP: Falcon 9 (B1051.14)

LOAD: Galaxy 31 and 32 communication satellites

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

LAUNCH DATE: Nov 12, 2022

START WINDOW: 11:06 – 13:06 EST (1606-1806 GMT)

WEATHER FORECAST: 90% chance of acceptable weather

BOOSTER RECOVERY: No

LAUNCH AZIMUTH: East

TARGET JOB: Geostationary Transfer Orbit

LAUNCH TIMELINE:

• • T+00:00: Launch
  • T+01:12: Maximum aerodynamic pressure (Max-Q)
  • T+02:43: First stage main engine shutdown (MECO)
  • T+02:46: Stage separation
  • T+02:53: Engine second stage ignition
  • T+03:32: Cockpit ship
  • T+08:05: Second stage engine shutdown (SECO 1)
  • T+26:50: Restart engine second stage
  • T+28:00: Second stage engine shutdown (SECO 2)
  • T+33:31: Galaxy 32 separation
  • T+38:41: Galaxy 31 separation

MISSION STATS:

• 185th Falcon 9 rocket launch since 2010
• 194th launch of Falcon rocket family since 2006
• 14th launch of Falcon 9 booster B1051
• 158th Falcon 9 Launch from Florida’s Space Coast
• 103rd Falcon 9 launch from pad 40
• 158th launch overall from pad 40
• 126th flight of a repurposed Falcon 9 booster
• 3rd Launch of SpaceX for Intelsat
• 51st Falcon 9 Launch of 2022
• 52nd launch by SpaceX in 2022
• 49th orbital launch attempt from Cape Canaveral in 2022

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Follow Stephen Clark on Twitter: @StephenClark1.