With the Federal Aviation Administration and US Fish and Wildlife Service approving the final signoff and license and SpaceX saying the rocket is ready, Starship is a go for its second test flight. Liftoff is targeted for a 20 minute launch window that opens on Nov. 18 at 7:00 AM CST, following a one day slip to fix an issue with Booster 9’s grid fin actuators.
During Starship’s first test flight, which took place on April 20, 2023, SpaceX experienced several issues that led to the loss of control and, ultimately, the loss of Booster 7 and Ship 24. For this second flight, SpaceX made several changes to the booster, ship, and the launch pad.
Starship Flight Test One:
During the first flight, Booster 7 experienced fires in its engine compartment due to a build-up of methane, which was a result of propellant leaks in the aft section of the vehicle. These fires led to wire bundles melting and burning, leading to loss of control of most of the booster’s engines from the flight computer.
To mitigate the engine fires and loss of control of each vehicle, SpaceX upgraded the engine section purge system with larger supply tanks and more vents to allow the gasses to be vented out and away from the vehicle.
The second biggest upgraded system is the flight termination system on both vehicles, as SpaceX added larger explosive charges and relocated them to a more effective location for the termination of the flight.
Starship’s maiden flight – via Max Evans for NSF.
An exciting change for this flight will be the introduction of hot staging. This is where the ship will ignite its engines and separate from the booster while some of its engines are still running. This will add some more payload capacity to the ship, and keep the separation system simpler.
Orbital Pad Changes
After the first flight test, the Orbital Launch Pad (OLP) had a massive crater dug into it while the engines ramped up to full power. Then, even more damage was done because at liftoff Booster 7 was only running with 30 engines at 90% throttle, which put its Thrust-to-weight ratio (TWR) at just above one. This resulted in a slower initial ascent and the stack taking longer to clear the pad than SpaceX predicted.
The orbital pad after the maiden launch – via Jack Beyer for NSF
To prevent something like this from occurring again, SpaceX had been working on a water deluge system before the first flight. However, Elon indicated shortly after the first flight that this system wouldn’t have been ready in time for that first flight. After the first launch, SpaceX got to work quickly on repairing the damage, along with the preparations for redoing the entire foundation of the launch pad.
These launch pad upgrades started with reinforced concrete pilings in and around the pad. Once these were completed, SpaceX dug a couple of meters into the ground under the Orbital Launch Mount (OLM) and started to lay very large amounts of rebar for what would become the new foundation. After the foundation had been poured, SpaceX laid out the rebar for the pile cap on top and then welded embeds on the top, where the deluge plate would be welded to once installed.
After everything was installed and all the concrete was poured, SpaceX installed the water deluge flame deflector, significantly increasing the robustness of the launch pad.
The water pressure for this system is very high, which is expected to protect the steel plate itself from the Raptors’ exhaust. This will prevent the “rock tornado” that was seen during the last launch.
With these pad upgrades and SpaceX CEO Elon Musk saying that the launch sequence will be modified to reduce the engine ramp-up time from six seconds to three seconds, the pad is expected to survive with significantly less damage than after Starship’s first integrated test flight.
Flight Test Two
So far, there has been no indication that SpaceX is changing the countdown other than the engine ramp-up time mentioned earlier. Also, the trajectory of this flight test will be the same as what the first test flight was supposed to be. If Ship 25 separates and reaches orbital velocity, it is slated to glide and reenter. And if it survives reentry, it will splash down just north of Hawaii.
Booster 9, assuming it survives its flight up to and including stage separation, will perform a boost back burn and splash down in the Gulf of Mexico just off the coast of Texas. Neither vehicle will be recovered.
SpaceX is targeting Nov. 18 as the primary launch date with backup launch opportunities available on Nov. 19 and Nov. 20. The road closures are the same as for the first flight — starting at 00:00 AM CST (06:00 UTC) and running all the way to 2:00 PM CST (20:00 UTC).
The launch window for the primary opportunity, Nov. 18, is set to begin at 7:00 AM CST (13:00 UTC) and will last for 20 minutes. The launch windows for the backup dates are currently unknown. If SpaceX were to go far into the count and have a scrub while Starship is fully loaded with propellants, then a 48-hour turnaround would be required to refill the tank farm, assuming no time is needed to fix whatever issues may have caused a scrub on that day.
Expectations
For this launch, the hope is for the upgrades to Booster 9 to be effective, allowing the stack to reach stage separation without many issues. The main goal of the first few test flights is to test the booster and work out potential issues with its design. Once this goal is achieved, SpaceX is expected begin testing reentry and booster recovery.
S28 and B10 at Masseys. (Credit: Jack Beyer for NSF)
Flight Test Three and Beyond
The vehicles for the third flight are slated to be Ship 28 and Booster 10, both of which have several upgrades already over the current stack. After the third flight, it is expected that SpaceX will follow up with booster/ship pairings in sequential order. For example, Ship 29 would fly with Booster 11, Ship 30 would fly with Booster 12, etc. It is unclear, however, if this sequential order will be kept going forward as SpaceX could be planning for ground test vehicles at a later point.
To get approval for the third flight, SpaceX will still have to get a launch license modification, as Revision 1 of License No. VOL 23-129 for the second flight notes “For the Orbital Flight Test 2 mission only unless this license is modified to remove this term.” Additionally, if there is any sort of anomaly during this second flight, a mishap investigation will be required before another launch.
Ships 28 through 32 have many similarities, although as more upgrades are made to ships, some of the changes are being retrofitted to the older ships. Regarding boosters, Boosters 10 through 13 have decent changes between them as SpaceX continues to upgrade.
(Lead Image: B9/S25 fully stacked ahead of the second test flight. Credit: Sean Doherty for NSF)
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