SpaceX tests a Falcon 9 rocket for Sunday launch from Florida – Spaceflight Now

The Falcon 9 rocket conducted a test launch of its nine Merlin main engines at 9 a.m. EDT (1300 GMT) Saturday in preparation for the Starlink 4-25 mission. Credit: Spaceflight Now

SpaceX tested its Falcon 9 rocket at NASA’s Kennedy Space Center Saturday in preparation for takeoff on Sunday with the company’s next batch of 53 Starlink internet satellites.

Test launches on the launch pad have been a familiar part of every SpaceX launch campaign, but the company is phasing out static fire tests for most missions as the Falcon 9’s launch rate has risen to an average of one flight per week.

A few hours after launching a Falcon 9 rocket with 46 Starlink wide-range satellites from Vandenberg Space Force Base in California, SpaceX rolled another Falcon 9 to Platform 39A at Kennedy Space Center Friday to prepare for Sunday’s launch with 53 internet relay nodes. other.

But first, the SpaceX launch team prepared the rocket for a static test-fire Saturday morning.

Kerosene and liquid oxygen flow into the Falcon 9 starting 35 minutes before the ignition time. SpaceX engineers in Fire Room 4 of the Kennedy Launch Control Center monitored and managed the operation.

The Merlin engines fired for about 7 seconds at 9AM EDT (1300 GMT) on Saturday while the Falcon 9 hydraulic clamps kept the ground firmly in place. The engines were throttled to generate 1.7 million pounds of thrust, briefly sending a plume of exhaust out of the trench of flame.

SpaceX drained propellant from the rocket after a test launch, and the company confirmed the mission was on track for liftoff Sunday at 9:38 a.m. EDT (1338 GMT). The mission will mark SpaceX’s 33rd launch of the year, and Starlink’s 53rd dedicated launch.

Friday’s launch of the Falcon 9 from California was the 32nd Falcon 9 launch in 2022, breaking the company’s record of 31 launches in a given year in 2021.

Including static firing on Saturday, SpaceX has conducted a test fire on the launch pad ahead of six of the 33 Falcon 9 missions so far this year. SpaceX conducted pre-launch testing before each Falcon 9 launch through 2020, then gradually reduced the use of stationary fire.

SpaceX used to require a steady launch every time an engine was removed between flights of one of the Falcon 9’s reusable boosters. This requirement has been changed for pre-launch testing only when three or more engines are removed between missions, according to a report published last month by Aviation Week & Space Technology.

Static launches were originally part of every SpaceX launch campaign to ensure engineers spot any problems with the rocket before launch day. But SpaceX has improved its on-time launch performance as shooting experiences become less common.

The last-minute miscarriage before a planned launch in California earlier this week was the first time a Falcon 9 launch in the station’s countdown has been called off due to a technical issue since December 2020. SpaceX has recorded 62 consecutive launches from December 2020 through this month without Countdown abort due to rocket problem.

SpaceX has accomplished 141 successive missions since an explosion during a static fire test in 2016 destroyed a Falcon 9 rocket and the Israeli communications satellite Amos 6.

SpaceX continues to test-fire its new Falcon 9 rockets on a test stand at the company’s facility in Central Texas, after the boosters leave its Hawthorne, California factory.

A view of a group of Starlink satellites packed flat into orbit after the previous launch. Credit: SpaceX

Sunday’s launch of the Starlink 4-25 mission will introduce 53 Starlink Internet satellites from SpaceX into low Earth orbit. Falcon 9 will climb off platform 39A and head northeast over the Atlantic Ocean, flying in a path parallel to the east coast of the United States.

The first stage of the rocket’s booster will shut down after two and a half minutes of mission. After separating from the upper stage at the edge of space, the first stage of the Falcon 9 will head toward the SpaceX drone ship “A Shortfall of Gravitas” parked 400 miles (650 kilometers) in the Atlantic, using cold gas engines and titanium mesh fins to help control in the course of his journey.

Engine burns will slow the missile down as it lands on the drone ship. The booster spacecraft flying on the Starlink 4-25 mission, known as B1062, will launch on its eighth flight into space. It debuted with the launch of the US military GPS navigation satellite in November 2020, and launched the entire Inspiration4 and Axiom-1 crewed missions in September 2021 and in April of this year.

Recently, the booster rocket flew on June 8 with the Egyptian geostationary communications satellite Nilesat 301.

As the first stage descends toward landing on Sunday, the upper stage of Falcon 9 will burn for about six minutes to put 53 Starlink satellites packed into a transfer orbit between 144 miles and 210 miles (232 kilometers by 338 kilometers), at an inclination of 53.2 degrees. to the equator.

The Falcon 9’s reusable payload width will be discarded during second stage combustion. There is also a salvage ship at a station in the Atlantic to retrieve the halves of the nose cone after falling under the parachutes.

The satellites – each weighing more than a quarter of a ton – will separate from the rocket’s upper stage at T+ plus 15 minutes and 24 seconds. Four detention rails will be phased out to allow the satellites to fly free of the Falcon 9 into orbit. The rails hold the spacecraft onto the rocket during the ascent into space.

Starlink satellites will open their solar panels and use ion propulsion to reach their operating altitude of 335 miles (540 kilometers). Orbit-raising maneuvers usually take anywhere from a few weeks to a few months, depending on the target orbital plane of each spacecraft.

SpaceX launched 2,904 Starlink satellites on Sunday’s mission, including prototypes and designs for previous spacecraft that are no longer in service. The company says Starlink broadband service is currently available in 36 countries around the world.

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