We know the Starship can fly – now it’s time to see if it can return to Earth

The Federal Aviation Administration approved the commercial launch license for the fourth test flight of SpaceX’s Starship rocket on Tuesday, with liftoff from South Texas targeted for just after sunrise Thursday.

“The FAA has approved a license authorization for SpaceX Starship Flight 4,” the agency said in a statement. “SpaceX met all safety and other licensing requirements for this test flight.”

Shortly after the FAA announced the launch license, SpaceX confirmed plans to launch the fourth test flight of the world’s largest rocket at 7:00 a.m. CDT (12:00 UTC) on Thursday. The launch window lasts two hours.

This flight follows three previous demonstration missions, each progressively more successful, of SpaceX’s privately developed mega-rocket. The last time Starship flew — on March 14 — it completed an eight-and-a-half-minute ascent into space, but the craft was unable to maneuver itself after landing nearly 150 miles (250 km) above Earth. This controllability problem caused the rocket to explode during re-entry.

On Thursday’s flight, SpaceX officials will expect the ascent portion of the test flight to be just as successful as the March launch. The objectives this time will be to demonstrate the Starship’s ability to survive the most extreme heat of re-entry, when temperatures peak at 2,600° Fahrenheit (1,430° Celsius) as the vehicle plunges through the atmosphere at more than 20 times the speed of sound.

SpaceX officials also hope to see the Super Heavy booster guide itself to a soft landing in the Gulf of Mexico, just offshore from the company’s launch site, known as Starbase, in Cameron County, Texas.

“The fourth flight test shifts our focus from achieving orbit to demonstrating the ability to return and reuse the Starship and Super Heavy,” SpaceX wrote in a mission summary.

Last month, SpaceX completed a “wet suit test” at Starbase, where the launch team fully loaded the rocket with cryogenic methane and liquid oxygen propellants. Before the practice countdown, SpaceX tested the booster and shuttle at the launch site. Recently, technicians installed components of the missile’s self-destruct system, which would activate to blow up the missile if it flew off course.

Then on Tuesday, SpaceX lowered Starship’s upper stage from the top of the Super Heavy booster, apparently to make final touches on the ship’s heat shield, made up of 18,000 hexagonal ceramic plates to protect its steel structure. stainless steel during reentry. Ground crews were expected to lift the shuttle, or upper stage, back atop the booster sometime Wednesday, returning the rocket to its full height of 397 feet (121 meters) before the Thursday morning launch window.

Starship’s fourth flight point

If all goes according to plan, the SpaceX launch team will begin loading 10 million pounds of supercooled propellant onto the rocket about 49 minutes before liftoff on Thursday. Methane and liquid oxygen will first flow into smaller tanks in the ship, then into larger tanks in the booster.

The rocket must be fully charged about three minutes before launch and, after a sequence of automated checks, the computer controlling the countdown will give the command to fire the booster’s 33 Raptor engines. Three seconds later, the rocket will begin its vertical climb from the launch pad, its engines capable of producing more than 16 million pounds of thrust at full power.

Launching east from the Texas Gulf Coast, the rocket will exceed the speed of sound for about a minute, then begin shutting down its 33 main engines about 2 minutes and 41 seconds after liftoff. Then, just as the Super Heavy booster jets begin a descent back to Earth, the Starship’s six Raptor engines will fire up to continue propelling the rocket’s upper part into space. Starship’s engines are expected to burn up to T+ 8 minutes and 23 seconds, accelerating the rocket to near-orbital speed with enough energy to fly an arcing trajectory halfway around the world to the Indian Ocean.

All of this will be similar to the events of the last Starship launch in March. What changes to the flight plan this time involves trying to steer the booster and send it back to Earth. This is important to lay the groundwork for future flights, when SpaceX wants to bring the Super Heavy booster — the size of the fuselage of a Boeing 747 jumbo jet — to a landing on its launch pad. Eventually, SpaceX also aims to recover reusable Starships back to the Starbase or other spaceports.

Based on the results of the March test flight, SpaceX still has a lot to prove in these areas. On that flight, the engines in the Super Heavy booster were unable to complete all the necessary burns to propel the rocket toward the crash site in the Gulf of Mexico. The booster lost control as it plummeted toward the ocean.

Engineers traced the blockage failure to a filter where liquid oxygen flows into the Raptor engines. Notably, a similar problem occurred on Starship’s second test flight last November. The Super Heavy booster expected to launch Thursday has additional equipment to improve fuel filtration capabilities, according to SpaceX. The company also implemented “operational changes” to the booster for the upcoming test flight, including removing the Super Heavy’s stage ring, which sits between the booster and the spacecraft during launch, to reduce the mass of the rocket during descent.

SpaceX has plenty of experience recovering its fleet of Falcon 9 boosters. The company now boasts a streak of more than 240 successful rocket landings in a row, so it’s reasonable to expect SpaceX to rise to the challenge of booster recovery. big Super Heavy.