CAPE CANAVERAL, Fla. — Nine minutes before the launch of SpaceX’s new Starship spacecraft and Super Heavy rocket from Texas Monday morning, the company called it off due to a “pressurization issue.”

In a tweet, SpaceX founder Elon Musk said that a pressurant valve seemed to have froze, which seems to have caused the delay.

SpaceX is now calling Monday’s launch a “wet-dress rehearsal” and is hoping to have another attempt in 48 hours.

“Things look a little different on launch time,” said Kate Tice, the quality systems engineering manager at SpaceX.

While not much was given about the “pressurization issue,” it did happen in the first-stage of the rocket, Tice said during a live teleconference of the launch.

Musk called the scrub a learning experience. 

The Super Heavy rocket dwarfs the Statue of Liberty by nearly 100 feet stands stacked and it is still on the launch pad at the southern tip of Texas. After years of development and hundreds of days of regulatory evaluation, SpaceX will once again prepare to launch its Starship and Super Heavy rocket.

Known collectively as Starship, SpaceX’s super-heavy lift rocket was aiming to make its launch debut Monday, April 17, after receiving its launch license from the Federal Aviation Administration (FAA).

The company had to change the opening of its 150-minute launch window for Monday, which was set to begin at 8:20 a.m. CT (9:20 a.m. ET), which the company updated Monday morning. Late Sunday night, the window was going to be 20 minutes earlier. The window was originally set to launch at 7 a.m. CT (8 a.m. ET).

Spectrum News asked about the previous launch window, but SpaceX has not yet responded.

No detailed information has been given for the new launch attempt.

When it does launch, the 33 Raptor engines will ignite, fueled by a combination of liquid methane and liquid oxygen. Starship is designed to be a fully reusable rocket, with both the Super Heavy booster and the Starship spacecraft being capable of multiple flights. However, both pieces for this first test flight, Starship 24 and Booster 7, are planned to be expended in the Pacific Ocean and the Gulf of Mexico respectively.

In a tweet Sunday morning, SpaceX stated it was “completing final checkouts and reviews ahead of Starship’s first flight attempt.” The company also noted that while the weather Monday morning “is looking pretty good,” it is also “keeping an eye on wind shear.”

However, weather was not the issue on Monday.

This will mark SpaceX’s first launch from Texas since the high-altitude flight test of Starship Number 15 (SN15) in May 2021. That test saw the successful launch and landing of the Starship spacecraft.

The FAA issued the long-awaited launch license on Friday afternoon. Prior to that decision, an FAA official spoke with members of the press on background regarding the mission and said the pre-launch work didn’t stop once the license was granted to SpaceX.

The FAA official said inspectors would be on-site at Boca Chica, the location of SpaceX’s Starbase, where manufacturing and launch operations of Starship are conducted. Among those present will be Dan Murray, the FAA’s executive director in the Office of Operational Safety.

“To date, we’ve had more than 530 FAA-licensed activities, none of which have resulted in a fatality, injury or significant damage to public property,” the official said.

Safety First

As is the case of any rocket launching for the first time, not everything may go according to plan, as many saw on Monday's attempt. If all goes smoothly when the launch does happen, the flight director will conduct a poll to begin loading the 3,400 tons of propellant into the Super Heavy booster followed by the 1,200 tons of propellant into Starship.

After more than an hour of fuel, the teams will begin cooling the engines just under 17 minutes ahead of liftoff. The startup sequence begins eight seconds before launch.

In a fully successful flight, the rocket will reach the point of greatest stress, known as "Max Q," about 55 seconds into flight. The Super Heavy booster will separate at about 2:52 minutes into the mission. The booster will conduct a boostback burn, followed by a landing burn and splash down in the Gulf of Mexico about eight minutes after liftoff.

Starship itself won’t reach orbit (about 146 miles in altitude expected), but will instead splash down off the coast of Hawaii about an hour and a half after leaving Texas. Again, if everything goes according to plan.

“This is a test activity. This is not an operational program and SpaceX is trying to collect data and find out things about this particular vehicle,” an FAA official said. “So, a mishap, as I mentioned, is part of our business and it’s a pretty realistic possibility.”

The official stated that there in general a mishap with rocket launches about 11% of the time. The FAA has an Office of Compliance, Enforcement and Mishap that monitors all space launches and investigates when things don’t go fully according to plan.

If something were to happen that causes human injury or death or significant public property damage, the National Transportation Safety Board (NTSB) would take lead on the investigation. The two agencies formalized this agreement last September.

The launch license for this test flight of Starship requires SpaceX to have $48 million in liability insurance “for covered claims resulting from pre-flight ground operations” and $500 million “for covered claims resulting from the flight of the Starship-Super Heavy launch vehicle.”

The FAA official said there’s no part of the mission, pre-, during or post-flight that is considered to be the point of greatest risk. Rather they said, “It all bears equal risk to us and we look at all of it.”

Mitigating environmental impact

As part of the more than 500 days of evaluation leading up to SpaceX receiving its launch license, the FAA published a 122-page PDF described as the “Written Re-Evaluation of the 2022 Final Programmatic Environmental Assessment.”

The document outlined some of the changes SpaceX made since the Programmatic Environmental Assessment (PEA) was completed in June 2022.

“SpaceX has done a lot of tinkering along the way, I will say, and as a result of that, the application has undergone multiple changes,” the FAA official said. “And so, each time the application changes, we don’t have to do a complete restart, but we have to take a fresh look at different things in accordance to the regulations to ensure that we’re not missing anything.”

It included a description of the detonation suppression system, which would use about 3,000 gallons of water to reduce the risk of fire.

It also detailed an expansion of the possible splashdown of Starship. It would land no closer than 62 nautical miles north of Kauai, Hawaii, but the expanded landing area was boosted to include an additional 155 miles to the north.

The re-evaluation also points to one of the possible reasons for the timing of the issuance of the launch license in the form of a letter from the National Marine Fisheries Service (NMFS). That agency sent its letter of concurrence to the FAA on April 14, 2023, which agreed the alterations made since the PEA “may affect, but is not likely to adversely affect (Endangered Species Act)-listed species and designated habitat.”

Additionally, as part of the initial PEA, SpaceX was required to complete more than 75 actions “to mitigate environmental impacts of launching Starship.” The FAA official stated that some were completed prior to launch and some will be completed post-launch with others marked as “ongoing.”

“One example of the mitigations that remains ongoing is that SpaceX has to do beach cleanup in Boca Chica approximate to the area of launch as well as on the periphery of the area associated with the launch to ensure that some of the native species of birds and turtles in that area are protected and that predators to those native species of birds or other species are not attracted to that area as a result of the activities that would be going on down at Boca Chica,” the official said.

And while the Starship / Super Heavy rocket will eventually be reusable, this first flight, as well as the next two, will likely see the disposal of the rocket in ocean.

The Super Heavy booster is designed to take on water and sink following a soft landing in the Gulf of Mexico. SpaceX also has the ability to remotely open tank vents to allow water to seep in or try to roll the vehicle to force it to sink. If all that doesn’t work the re-evaluation document states that they could try and force it to sink by “puncturing the outer shell of the vehicle using a firearm or remote operating vessel.”

Similarly, Starship is intending to splash down in the ocean near Hawaii on its first launch and then “break up upon atmospheric entry” with the debris field landing significantly southwest of Hawaii.

All eyes on Texas

In a retweet Friday announcing the test flight targeting Monday, Musk said, “Success maybe, excitement guaranteed!” That excitement extends far beyond Texas.

While initial launches of Starship will happen in Boca Chica, SpaceX has also erected a Starship launch tower at Launch Complex 39A at NASA’s Kennedy Space Center in Florida in anticipation of future Florida-based flights. Assembly of that tower happened throughout 2022.

SpaceX also submitted proposals through the Land Use Notice of Availability to potentially “construct and operate a new launch complex (LC-49) as well as expand SpaceX’s existing operations near Roberts Road” to help support Starship work at KSC.

NASA has keen interest in Starship since it will serve as the first spacecraft that will take humans to the surface of the moon on the Artemis III mission, launching no earlier than 2025, as part of the Human Landing System program. It was awarded a $2.89 billion contract in April 2021.

Following the announcement of the Artemis II astronauts earlier this month, Nicole Williams, who is working with SpaceX on crew compartments and sustainability, spoke with Spectrum News and said the HLS office is also eagerly watching this first launch attempt.

“You can anticipate that as SpaceX designs and our teams partner with them, that that compartment’s going to have all of the different things that other spacecraft that have humans have, including life-support systems, places to get food ready, facilities, places for the crew to sleep,” Williams said. “So, that first Artemis III mission, they may be living in the Starship for up to a week, going out and doing extravehicular activities, other science, coming back. So, that will be their home base for Artemis III.”

Leading up to the Artemis III mission, SpaceX will conduct a demonstration landing mission with no humans on board no earlier than April 2025.

Last November, NASA awarded SpaceX a contract modification valued at $1.15 billion that would have SpaceX “provide a second crewed landing demonstration mission in 2027 as part of NASA’s Artemis IV mission.”

In that same interview with Williams, Lisa Hammond, the associate program manager in the HLS office, said NASA feels confident that SpaceX is working on a good timeline to get Starship certified for its use in the Artemis program.

“This orbital flight test that SpaceX is going to conduct is key in us working together, sharing data and being able to mature their design, their Starship design,” Hammond said. “They’ve flown. They’ve got Falcon, they’ve got Dragon and so, they’ve got lots of experience in flying crewed flights. This SpaceX HLS however is going to land on the Moon.”

“I think we’re in great shape, short answer, (but) there’s work to be done. We’ve got a ways to go,” she said.

Watch the launch broadcast here: