Review of 4th Superheavy/Starship flight; FAA clears SpaceX for next flight
Link here. The article provides a detailed step-by-step review of everything that happened on the fourth Superheavy/Starship orbital test flight on June 6, 2024, as well as describing the changes being applied to Starship and Superheavy due to that flight.
However, the article also included this announcement from the FAA, stating that it will not do its own mishap investigation on that flight.
The FAA assessed the operations of the SpaceX Starship Flight 4 mission. All flight events for both Starship and Super Heavy appear to have occurred within the scope of planned and authorized activities.
While this decision means SpaceX can go ahead with the fifth test launch as soon as it is ready — no longer delayed while it waits for the FAA to retype SpaceX’s investigation and then approve it — it is unclear whether this FAA decision will allow SpaceX to attempt a tower landing of Superheavy, with the tower’s arms catching the rocket.
If the FAA has not yet approved a tower landing, I suspect SpaceX will forgo that attempt on the next launch in order to get it off the ground as soon as possible, even as it pushes the FAA for such an approval for a subsequent launch.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
Link here. The article provides a detailed step-by-step review of everything that happened on the fourth Superheavy/Starship orbital test flight on June 6, 2024, as well as describing the changes being applied to Starship and Superheavy due to that flight.
However, the article also included this announcement from the FAA, stating that it will not do its own mishap investigation on that flight.
The FAA assessed the operations of the SpaceX Starship Flight 4 mission. All flight events for both Starship and Super Heavy appear to have occurred within the scope of planned and authorized activities.
While this decision means SpaceX can go ahead with the fifth test launch as soon as it is ready — no longer delayed while it waits for the FAA to retype SpaceX’s investigation and then approve it — it is unclear whether this FAA decision will allow SpaceX to attempt a tower landing of Superheavy, with the tower’s arms catching the rocket.
If the FAA has not yet approved a tower landing, I suspect SpaceX will forgo that attempt on the next launch in order to get it off the ground as soon as possible, even as it pushes the FAA for such an approval for a subsequent launch.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
The license for IFT4 explicitly called out the vehicle configuration, so a license modification to remove/update that entry is required. As the article states, SpaceX is already in the process of making major adjustments to the heat shield on the IFT5 spaceship, so the FAA will have to evaluate whether this is a simple “change the numbers” or not. I would think that if they want to fly the same profile with an improved heat shield, that should be a very quick evaluation on the FAA’s part. Whether they can get that done in the “one month” that Elon is projecting for readiness would depend entirely on how soon SpaceX officially asks for it, I would think.
If they want a flight profile change to bring the booster back for a catch attempt, I would again guess it depends on when they ask. If they put in their application the moment the FAA said that no mishap investigation is required, I could see the FAA being ready at close to the same time SpaceX is. It has, as we’ve seen, historically taken the FAA around 2-3 weeks to grant a license from the date they announce that SpaceX has given them the complete finalized request.
I suspect that SpaceX has not yet reached that point, and won’t until the heatshield is back in place and the ship is headed out to the launch site for tests, and as a result SpaceX will be “ready” a week or two before they get their license.
Robert Zimmerman wrote: “If the FAA has not yet approved a tower landing, I suspect SpaceX will forgo that attempt on the next launch in order to get it off the ground as soon as possible, even as it pushes the FAA for such an approval for a subsequent launch.”
I suspect that SpaceX is more interested in getting in flight time to learn as much as possible about its improvements to its hardware. Although a return to launch site is an important goal, it is not yet urgent, as the company is still improving its launch vehicles. Right now, return to launch site is for development purposes, not for reuse purposes. Performing these mid-air catches can wait for a few months.
___________________
David Eastman wrote: “The license for IFT4 explicitly called out the vehicle configuration, so a license modification to remove/update that entry is required.”
I noticed this, too. The license for IFT4 specified the specific hardware by serial number, not generic Super Heavy and Starship vehicles. This was a change from the IFT3 license. Whether or not the first stage booster returns to launch site or is disposed in the same location in the Gulf of Mexico, this requires a new license for the IFT5 test flight.
https://behindtheblack.com/behind-the-black/points-of-information/faa-issues-launch-license-for-the-fourth-test-orbital-launch-of-starship-superheavy/
follow the link to:
https://drs.faa.gov/browse/excelExternalWindow/DRSDOCID173891218620231102140506.0001%3FmodalOpened%3Dtrue%3FmodalOpened%3Dtrue%3FmodalOpened%3Dtrue%3FmodalOpened%3Dtrue?modalOpened=true
From the Revision History, June 4, 2024 :
The scuttlebutt is that Elon wants some ablatives under the tiles as a fall-back.
The extensive rework of the TPS indicates to me that IFT4 showed some significant lack of performance, perhaps revealed by the deliberate gaps in the tiles. The rapid response also indicates that these shortcomings were to some extent anticipated.
Overall, this and the fin-gap issue are a bit surprising, given SpaceX’s reputation for accurate simulation.
Ray Van Dune wrote: “The extensive rework of the TPS indicates to me that IFT4 showed some significant lack of performance, perhaps revealed by the deliberate gaps in the tiles. The rapid response also indicates that these shortcomings were to some extent anticipated. Overall, this and the fin-gap issue are a bit surprising, given SpaceX’s reputation for accurate simulation.”
A simulation is a kind of model. Think of physical models in wind tunnels or think of computer models. Models only tell us what we tell them to say, so if we do not make them right then they don’t tell us what we need to know but may only tell us what we want to hear.
The basic concept that SpaceX is pursuing with their tiles is to fasten them in a way that makes them very easy and fast to replace or repair. Gluing them to the more difficult locations is a good short-term fix, allowing them to fly now and continue learning the other lessons they need, but it is a poor long-term solution.
So, here is a question that has been bugging me for days: If the fin melted down because hot gasses got past the thermal protection, what happened to the body, the hull, in that same region?