Live coverage: SpaceX launches two Intelsat communications satellites

Live coverage of the countdown and launch of a SpaceX Falcon 9 rocket from Space Launch Complex 40 at Cape Canaveral Space Force Station, Florida. The Falcon 9 rocket will launch Intelsat’s Galaxy 33 and Galaxy 34 geostationary communications satellites. Follow us on Twitter.

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A pair of TV broadcasting satellites for Intelsat launched aboard a SpaceX Falcon 9 rocket from Cape Canaveral Saturday at 7:05 p.m. EDT (2305 GMT). SpaceX aborted a countdown Thursday due to a small helium leak, then called off another launch attempt Friday evening for allow time for additional vehicle checkouts.

The launch attempt Thursday night automatically aborted at T-minus 30 seconds after the Falcon 9’s on-board computer, which controls the final minute of the countdown, detected a higher than expected pressure decay rate in the first stage’s helium system.

“Tiny helium leak (just barely triggered abort), but we take no risks with customer satellites,” tweeted Elon Musk, SpaceX’ founder and CEO. “Standing down to investigate.”

SpaceX confirmed Friday evening it would not try again to launch the Falcon 9 rocket until Saturday, when the company had a 70-minute launch window available opening at 7:05 p.m. EDT.

The launch occurred a few minutes after sunset, and with mostly clear skies, spectators enjoyed dazzling views of the Falcon 9 climbs into space at twilight.

The launch Saturday night was the third flight of a Falcon 9 rocket this week, following a Falcon 9 launch at noon EDT (1600 GMT) Wednesday from pad 39A at Kennedy Space Center carrying a four-person crew to the International Space Station. Then SpaceX launched a Falcon 9 rocket from Vandenberg Space Force Base in California at 7:10 p.m. EDT (4:10 p.m. PDT; 2310 GMT) Wednesday with 52 Starlink internet satellites, just seven hours after the astronaut launch from Florida.

With those missions complete, a few miles south of Kennedy Space Center, SpaceX personnel prepared another Falcon 9 rocket for launch from pad 40 on a commercial flight for Intelsat.

SpaceX’s mission for Intelsat Saturday was also be the third space launch from Florida’s Space Coast in five days. An Atlas 5 rocket from United Launch Alliance kicked off the string of launches from Cape Canaveral on Tuesday with a commercial satellite delivery mission for SES.

The Galaxy 33 and 34 satellites are setting off on 15-year missions to relay C-band video and television programming for media networks and cable providers across North America. They will replace two aging Intelsat satellites, Galaxy 12 and Galaxy 15, that have been in space since 2003 and 2005.

SpaceX ground crews rolled the Falcon 9 rocket and its commercial satellite payload to pad 40 earlier this week, and raised it vertical in the launch mount at pad 40 for final checkouts early Thursday. During Saturday’s countdown, the 229-foot-tall (70-meter) launcher was filled with a million pounds of kerosene and liquid oxygen propellants in the final 35 minutes of the countdown.

After teams verified technical and weather parameters were all “green” for launch, the nine Merlin 1D main engines on the first stage booster flashed to life with the help of an ignition fluid called triethylaluminum/triethylborane, or TEA-TEB. Once the engines ramped up to full throttle, hydraulic clamps opened to release the Falcon 9 for its climb into space.

The nine main engines produced 1.7 million pounds of thrust for about two-and-a-half minutes, propelling the Falcon 9 and Intelsat’s Galaxy 33 and Galaxy 34 communications satellites into the upper atmosphere. Then the booster stage — tail number B1060 in SpaceX’s fleet — shut down and separated from the Falcon 9’s upper stage.

SpaceX’s Falcon 9 rocket standing on pad 40 at Cape Canaveral Space Force Station before launch of the Galaxy 33 and 34 satellites. Credit: Stephen Clark / Spaceflight Now

The booster extended titanium grid fins and pulsed cold gas thrusters to orient itself for a tail-first entry back into the atmosphere, before reigniting its engines for a braking burn and a final landing burn, targeting a vertical descent to the drone ship “A Shortfall of Gravitas” parked about 400 miles (about 640 kilometers) east of Cape Canaveral.

The successful rocket landing on the drone ship marked the completion of the booster’s 14th flight to space, tying another Falcon 9 booster as SpaceX’s fleet leaders.

SpaceX had previously launched a mission with a booster making its 14th flight to space, but that launch carried a batch of the company’s own Starlink internet satellites. The mission for Intelsat on Saturday night was the first time SpaceX has launched a booster with more than 10 flights on a dedicated flight for a customer.

“It’s the same price if you’re the first or the 14th,” said Jean-Luc Froeliger, Intelsat’s senior vice president of space systems.

SpaceX has qualified its reusable Falcon 9 boosters for at least 15 missions, up from the 10-mission goal the company stated when it debuted the Block 5 booster — the latest iteration of the Falcon 9 — in 2018, the trade magazine Aviation Week & Space Technology reported in June.

The magazine reported SpaceX put booster components through vibration testing to four times the fatigue life of what they would experience over 15 flights, giving engineers confidence that the rockets will continue to fly successfully.

“They’re very impressive,” Froeliger, a longtime satellite industry manager, said of SpaceX. “They have found a model where their reusable first stage and reusable fairing allow them to launch on a very rapid cadence, they have two launch complexes here, plus Vandenberg. So yes, they get a lot of business.”

Froeliger said SpaceX’s Falcon 9 launcher is the “workhorse of the industry” after SpaceX pioneered recovery and reuse of commercial rockets. With Saturday’s mission, the company has launched 46 times so far this year, far outpacing any of its rivals in the launch business.

This map illustrates the predicted ground track for the Falcon 9 rocket on the Galaxy 33/34 mission, with the locations of pad 40 and the drone ship “A Shortfall of Gravitas” labeled. Credit: Spaceflight Now

On Saturday’s mission, the Falcon 9 rocket fired its upper stage engine two times to inject the Galaxy 33 and 34 spacecraft into an elliptical “sub-synchronous” transfer orbit with an apogee, or high point, short of the satellites’ final 22,000-mile-high operating altitude in geostationary orbit.

The lower-than-usual deployment orbit for a geostationary mission allowed the Falcon 9 rocket to lift both satellites on one mission, and gave the Falcon 9’s reusable first stage booster enough reserve propellant to return to landing on a drone ship in the Atlantic Ocean.

Galaxy 33 and 34 separated from the Falcon 9 rocket one at a time about 33 minute and 38 minutes into the mission.

“They’re bolted on top of each other and encapsulated inside the fairing,” Froeliger said in a pre-launch interview. “At separation, it’s actually the upper satellite that separates from the lower satellite first. So Galaxy 33 will be separated from the lower satellite by firing a pyrotechnic device to release a clamp band that maintains the two satellites together. Once Galaxy 33 separates, then Galaxy 34 separates from the launch vehicle.”

The dual satellites had a combined weight at launch of about 16,200 pounds (7,350 kilograms), according to Northrop Grumman, which manufactured Galaxy 33 and 34.

The spacecraft will use their own hydrazine-fueled engines to raise their orbit to geostationary altitude. The orbit-raising maneuvers will take about 10 to 11 days, Froeliger said.

The two satellites are similar, but not identical. Galaxy 33 carries a C-band communications payload, plus steerable Ka-band and Ku-band beams. Galaxy 34 is a dedicated C-band relay satellite for video relay services.

Galaxy 33 will replace the Galaxy 15 communications satellite in an operating position at 133 degrees West longitude. Intelsat lost control of Galaxy 15 in August after it was likely damaged during a geomagnetic storm, the company said. Galaxy 15 was already due for replacement before Intelsat lost contact with spacecraft.

Intelsat plans to deploy the Galaxy 34 satellite to 129 degrees West longitude, where it will replace Galaxy 12.

The Galaxy 33 and 34 satellites are the first two of seven planned Intelsat satellites to replenish the company’s fleet of C-band television broadcast satellites, replacing C-band capacity being transitioned to 5G cellular network services by the Federal Communications Commission. The remaining C-band replacement satellites will launch on a mix of Falcon 9 and Ariane 5 rockets.

The Galaxy 33 and Galaxy 34 (top and bottom) satellites stacked in launch configuration at SpaceX’s payload processing facility at Cape Canaveral Space Force Station. Credit: Intelsat

ROCKET: Falcon 9 (B1060.14)

PAYLOAD: Galaxy 33 and 34 communications satellites

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

LAUNCH DATE: Oct. 8, 2022

LAUNCH WINDOW: 7:05-8:15 p.m. EDT (2305-0015 GMT)

WEATHER FORECAST: 90% probability of acceptable weather

BOOSTER RECOVERY: “A Shortfall of Gravitas” drone ship

LAUNCH AZIMUTH: East

TARGET ORBIT: Sub-synchronous transfer orbit

LAUNCH TIMELINE:

  • T+00:00: Liftoff
  • T+01:12: Maximum aerodynamic pressure (Max-Q)
  • T+02:33: First stage main engine cutoff (MECO)
  • T+02:37: Stage separation
  • T+02:41: Second stage engine ignition
  • T+03:25: Fairing jettison
  • T+06:27: First stage entry burn ignition (three engines)
  • T+06:48: First stage entry burn ends
  • T+08:15: Second stage engine cutoff (SECO 1)
  • T+08:18: First stage landing burn ignition (one engine)
  • T+08:40: First stage landing
  • T+26:19: Second stage engine restart
  • T+27:06: Second stage engine cutoff (SECO 2)
  • T+32:57: Galaxy 33 separation
  • T+38:07: Galaxy 34 separation

MISSION STATS:

  • 180th launch of a Falcon 9 rocket since 2010
  • 188th launch of Falcon rocket family since 2006
  • 14th launch of Falcon 9 booster B1060
  • 154th Falcon 9 launch from Florida’s Space Coast
  • 99th Falcon 9 launch from pad 40
  • 154th launch overall from pad 40
  • 121st flight of a reused Falcon 9 booster
  • 2nd SpaceX launch for Intelsat
  • 46th Falcon 9 launch of 2022
  • 46th launch by SpaceX in 2022
  • 44th orbital launch attempt based out of Cape Canaveral in 2022

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Follow Stephen Clark on Twitter: @StephenClark1.