Last Thursday, SpaceX performed its first full-blown fairing recovery test during the Falcon 9 launch of PAZ and two Starlink demonstration satellites. The attempt involved a new addition to the SpaceX recovery fleet, Mr. Steven, complete with a giant net that is designed to catch returning fairings. While the catch during the PAZ mission was unsuccessful, the other phases of the recovery process showed significant progress.
The fairing is a nose cone structure which encapsulates the payloads on the rocket. It not only protects the payloads during ascent, but it also keeps the vehicle aerodynamic. Once the rocket is in the vacuum of outer space, the fairing is no longer needed. Therefore, it separates into two halves and falls back to Earth.
To reduce the cost of launch, SpaceX hopes to recover and reuse the fairing which represents an estimated $6 million – about 10% of the Falcon 9’s launch cost. Since the five meter diameter fairing splits into two halves when jettisoned, two recoveries are required per launch – with each saving about $3 million worth of hardware.
Currently, SpaceX’s fairing recovery routine works as follows.
Shortly after separation, the two fairing halves use cold gas thrusters and a guidance system to control themselves as they plummet back to Earth at up to eight times the speed of sound.
After entry into Earth’s atmosphere, a parafoil is deployed. The fairing halves are then able to steer themselves towards a general location in the ocean.
The parafoil has been one of the largest challenges with fairing recovery. Just a few weeks ago, SpaceX CEO Elon Musk stated, “It turns out that when you pop the parachute on the fairing, you’ve got this giant awkward thing. It tends to interfere with the airflow on the parachute. It gets all twisty.”
The final portion of recovery involves a vessel. The boat is tasked with positioning itself beneath the fairing, in order to catch it with a net located on the deck. This prevents the fairing from entering the corrosive salt water environment.
The first significant sign of progress came during the Falcon 9 launch of SES-10 in March of 2017. Due to the historic nature of the launch – it was the first reflight of a Falcon 9 booster – SpaceX held a post-launch press conference usually reserved for NASA launches such as Dragon missions. During the conference, Musk announced that not only had SpaceX successfully reused and recovered a Falcon 9 first stage, but they had also successfully recovered a portion of the fairing.
While impressive, the fairing sustained damage, and it had spent time in the corrosive salt water environment. If SpaceX were to reuse a fairing, they were not only going to need to keep it in one piece, but they were going to need a way to keep it out of the water.
To do so, Musk said that something like a “bouncy castle” would be used to capture the fairing halves. In reality, the platform turned out to be more like a catcher’s mitt than a bouncy castle.
In the fall of 2017, a new ship named Mr. Steven appeared at the SpaceX dock in Port Canaveral.
— Julia (@julia_bergeron) November 2, 2017
Mr. Steven has a large 136 x 27 foot wide deck. At the same time, it is also fast and nimble for a vessel of its size. Mr. Steven’s top speed is listed at 32 knots (approximately 37 miles per hour). The versatility of the ship makes it the perfect candidate for fairing recovery operations.
The boat was constructed by Louisiana based Gulf Craft in 2015. Then, it was delivered to Seatran Marine, an operator of over a dozen similar class vessels.
In 2017, SpaceX began leasing Mr. Steven. Interestingly, the vessel now has the logo for Guice Offshore painted on its side. Guice Offshore is the same operator who owns several other recovery vessels in SpaceX’s fleet including GO Pursuit, GO Searcher, and GO Quest. However, official licensing and Seatran’s website all state that Seatran is the current owner of Mr. Steven. Therefore, it is possible that Seatran still owns the vessel and Guice Offshore is just operating it for SpaceX.
Brian Herbert, a Senior Dynamic Positioning Officer (SDPO) on a Well Intervention Vessel has had personal interactions with Mr. Steven and its crew before SpaceX leased the ship. In an interview with NASASpaceflight.com, Herbert stated that Mr. Steven “is definitely one of the newest and best looking Fast Supply Vessels (FSVs) I’ve seen. She was well maintained…”
When asked what a ship like Mr. Steven would normally be used for, Herbert explained, “FSVs are usually contracted to haul deck cargo to larger vessels working on the outer continental shelf in the oil/gas exploration and production industry. They’re great, versatile work boats. A majority of that niche is filled with Offshore Supply Vessels (OSVs) which are generally larger (in the 300′ range) but much slower than FSVs like Mr. Steven.”
In terms of how much it would cost to lease Mr. Steven, Herbert notes that ships of that class typically go for about $7,500 per day. However, if SpaceX were to sign a long term lease, they would likely be able to reduce that number significantly. While the exact number will never be known, even at $7,500 per day SpaceX would only be spending about $2.7 million a year on Mr. Steven. If each recovery saves $3 million, SpaceX will cover the cost of the lease with a single recovery.
That being said, it is important to note that there are numerous other fees associated with recovery including development costs and rent on the dock space. Nonetheless, the economics for fairing recovery seem to make sense, especially since SpaceX launches multiple times a month.
Another perk is that unlike with Falcon first stage recoveries, significant mass does not have to be added to the overall vehicle to recover the fairings. Unfortunately, there is also an additional challenge.
Unlike with first stage boosters which can land on an autonomous spaceport drone ship (ASDS) in a set location, fairing halves are unable to land on a stationary target. Therefore, Mr. Steven will have to move into position on short notice.
As an SDPO, Herbert is familiar with the types of control systems that are found on a ship like Mr. Steven. There are three primary modes.
The first mode is manual controls which can be used with “main propulsion to travel at a high rate of speed and steer like a ship.” Next, Dynamic Position (DP) mode is where “a computer system operates the thrusters and propulsion system to hold a location or make maneuvers.” The third and final method is joystick mode where “the vessel operator (captain or mate) uses a joystick to operate the thrusters and propulsion systems in unison.”
Herbert believes that the third mode is the most likely of the three to be utilized during a recovery attempt, as in his opinion “DP systems would not be able to respond fast enough to catch a moving target.”
Interestingly, the recovery operations must have a crew onboard, even if Mr. Steven were to have the ability to autonomously perform the maneuvers. As Herbert explains, “every inspected vessel that’s certified to operate has what’s called a Minimum Manning Certificate. It’s issued by the vessel’s flag state (in the case of Mr. Steven this would be American Bureau of Shipping as authorized by the United States Coast Guard).”
According to Herbert, such requirement is not a factor for an ASDS, as they are a converted barge.
While it is possible that SpaceX could try to get an exemption to the minimum manning regulations, the legal process to do so is not entirely clear. Regulatory agencies are still figuring out how to handle autonomous ships, as such technologies are relatively new.
However, all indications are that a crew were aboard Mr. Steven during the PAZ recovery attempt, which was the first test where the vessel tried to catch a fairing half with a net.
Before last Thursday, Mr. Steven had performed a few other experimental operations during missions without trying to perform a fairing catch.
The first test came during the Falcon 9 launch of Koreasat 5A from Kennedy Space Center on October 30th, 2017.
Before the launch, Mr. Steven set out with no significant modifications to its deck. A few days, later Mr. Steven returned to Port Canaveral with an object that seemed to resemble part of a payload fairing. However, the object was never confirmed to be a fairing, and it appeared too small to be an entire half. Regardless, the fairing half would have been pulled out of the water, as there was no equipment onboard to catch the expensive hardware.
Shortly after Thanksgiving, Mr. Steven made the journey from Port Canaveral to the Port of LA via the Panama Canal. Once in LA, SpaceX began performing significant modifications to the ship to allow it to catch a fairing.
Just before the Iridium-4 launch on December 22nd from Vandenberg Air Force Base, Mr. Steven was spotted with four large arms reaching out from its deck. These arms were designed to support a net to complete the “catcher’s mitt”.
In the end, Mr. Steven headed out to sea without a net attached, and it is since believed that this was a dress rehearsal for a fully fledged attempt at a later date.
This later date turned out to be the launch of PAZ. This time, Mr. Steven was outfitted with the net needed to capture a fairing half and thus was ready for its first attempt at a catch.
Additionally, the launch was also the first to feature Fairing 2.0 – an upgraded fairing designed for reusability.
With the conditions prime for the first full-blown fairing recovery attempt, Mr. Steven left the Port of LA approximately 18 hours before the initial launch time on February 21st.
The vessel then sailed about 300 miles down range from Vandenberg Air Force Base to a holding location off the west coast of Baja California.
After upper level winds caused the original launch attempt to be scrubbed, Mr. Steven moved to a new holding position slightly further west for the new launch date on the 22nd. This was likely due to a change in winds.
Liftoff occurred on February 22nd at 6:17 AM Pacific Time. Two minutes and fifty six seconds into launch, the payload fairing separated from the Falcon 9. The two halves then began to perform their recovery maneuvers.
While observers on the ground reported seeing thrusters firing on both fairing halves, SpaceX was only attempting to catch one of the halves with the recovery vessel.
Approximately 15 minutes into the launch, Musk tweeted that the parafoil had deployed and they were preparing for a catch.
Unfortunately, Mr. Steven was unable to reach the landing site in time. Musk announced in a follow-up tweet, “Missed by a few hundred meters, but fairing landed intact in water. Should be able catch it with slightly bigger chutes to slow down descent.”
Despite the final portion of recovery not going according to plan, the fact that a fairing half appeared to have successfully gone from eight times the speed of sound to a soft splashdown in the ocean demonstrates significant progress.
Similar to what happened with first stage recovery testing, it is not unexpected to not have a complete success on the first go. Lots of trial and error are required to refine the recovery process.
After Thursday’s attempt, Mr. Steven pulled the intact fairing half out of the water and placed it in a cradle for transport back to the port. Additionally, a piece of the half which was most likely not heading for the recovery boat was also found in the water.
A day after the launch, Mr. Steven arrived back at the Port of LA with the recovered hardware. Engineers will now have the opportunity to examine the fairing and learn from this test.
— Matt Hartman (@ShorealoneFilms) February 23, 2018
Once the fairing recovery process has been refined, SpaceX will need to add additional fairing recovery vessels to support its large manifest. With launches expected multiple times a month, there will not be enough time to move the ships between the east and west coasts.
This means that SpaceX will likely need at least four fairing recovery vessels (two for each coast). While there has been speculation that two fairing halves could be recovered with one ship, using a separate ship for each fairing half is currently the more likely option.
The next fairing recovery attempt is expected to occur during the Falcon 9’s Iridium-5 mission, which is currently scheduled for no earlier than March 29th.