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SpaceX fires Falcon Heavy’s 27 booster engines ahead of “most difficult launch ever”
For the third time ever, SpaceX has successfully performed a critical static-fire test of an integrated Falcon Heavy, briefly igniting all 27 of its Merlin 1D engines to verify the health and readiness of the rocket.
Per SpaceX’s official confirmation, a “quick-look” inspection of static fire telemetry has indicated that the company’s Falcon Heavy rocket is ready for its second launch in less than three months, a milestone that could also allow both flight-proven side boosters to tie SpaceX’s own record for booster turnaround. Falcon Heavy Flight 3 is now scheduled to launch the US Air Force’s Space Test Program 2 (STP-2) mission no earlier than 11:30 pm ET (03:30 UTC), June 24th. According to SpaceX CEO Elon Musk, the mission will unequivocally be the company’s “most difficult launch ever”.
Coincidentally, on top of being Falcon Heavy’s first scheduled night launch, STP-2 has now also marked the massive rocket’s first nighttime static fire. During this critical test, Falcon Heavy briefly ignites all 27 of its three boosters’ Merlin 1Ds and throttles the engines up to full thrust, much like airliners sometimes set their brakes and throttle up before attempting to take off. The difference between Falcon Heavy and passenger aircraft is nevertheless rather significant, given that Falcon Heavy produces ~15x the thrust of an A380 – the world’s most powerful mass-produced passenger aircraft – at liftoff: 22,820 kN (5.1M lbf) to the massive jet’s meager 1,440 kN (0.3M lbf).
Despite all of that thrust, Falcon Heavy is held down during static fire by eight accurately-named hold-down clamps, themselves a part of a massive transport/erector, which is itself anchored directly to Pad 39A’s concrete foundation. In short, Falcon Heavy (and especially Falcon 9) is not going anywhere until those hold-down clamps are explicitly released. Thanks to SpaceX’s avoidance of the solid rocket boosters used by almost every other modern launch vehicle, Falcon 9 and Heavy rockets can abort at any point prior to clamp release, offering a uniquely broad abort capability.
As such, not only does SpaceX’s dedicated pre-launch static fire fully test the rocket’s health, but the same procedure is essentially repeated in the seconds before clamp release during an actual orbital launch attempt. If at any point Falcon 9’s autonomous onboard computer decides that it doesn’t like any of the thousands of channels of telemetry it’s constantly analyzing, it can command an engine shutdown and total launch abort even if all first stage engines have already ignited and reached full thrust. If routine McGregor, TX acceptance testing – also involving a full static fire – is accounted for, every single Falcon 9 booster technically completes three fully-integrated static fires before its inaugural liftoff. Falcon Heavy is slightly different, as each booster is independent test-fired in Texas but the integrated rocket can only perform static fires at Pad 39A.
After those three critical tests, flight-proven Falcon boosters are subjected to the less stringent few-second static fires SpaceX performs at the launch pad 3-7 days before a given launch. With Falcon Heavy Flight 3, the rocket’s center core, upper stage, and payload fairing are all brand new, fresh from either SpaceX’s Hawthorne factory or McGregor acceptance testing. However, both side cores – Block 5 boosters B1052 and B1053 – are flight-proven, having successfully completed their first launches and landings on April 11th, less than 70 days ago.
Set by regular old Falcon 9 boosters, SpaceX’s current record for booster turnaround time (time between two launches) is 71 days (set in June 2018), while the Block 5 upgrade’s record stands at 74 days (set in October 2018). If Falcon Heavy’s STP-2 launch holds strong on June 24th, B1052 and B1053 will simultaneously tie SpaceX’s Block 5 turnaround record. This would be accomplished despite the added pressure from the US Air Force’s decision to use STP-2 as a sort of dress rehearsal for certifying all flight-proven commercial rockets, an honor (and burden) that likely added extra work, oversight, and scrutiny to the process of refurbishing and relaunching B1052 and B1053.
“[T]he US Air Force has decided that STP-2 presents an excellent opportunity to begin the process of certifying flight-proven SpaceX rockets for military launches. The STP-2-related work is more of a preliminary effort for the USAF to actually figure out how to certify flight-proven commercial rockets, but it will still be the first time a dedicated US military mission has flown on a flight-proven launch vehicle. Down the road, the processes set in place thanks – in part – to STP-2 and Falcon Heavy may also apply to aspirational rockets like Blue Origin’s New Glenn and ULA’s “SMART” proposal for Vulcan reuse.”
— Teslarati.com, 06/16/2019
In a last-second surprise, SpaceX updated Falcon Heavy center core B1057’s planned drone ship landing site from a brief 40 km (25 mi) to more than 1240 km (770 mi) off the coast of Florida. SpaceX set its current record for recovery distance less than three months ago during Falcon Heavy’s commercial launch debut, in which Block 5 center core B1055 landed nearly 970 km (600 mi) offshore on drone ship Of Course I Still Love You (OCISLY). If all goes well, B1057 – the second finished Block 5 center core – will absolutely crush its predecessor’s record, implying that the booster will likely be subjected to SpaceX’s most difficult reentry and recovery yet.
For more on what CEO Elon Musk describes as “[SpaceX’s] most difficult launch ever”, check out these previous articles on an unexpected ultra-fast booster reentry and the extraordinary challenge facing Falcon upper stage.
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SpaceX’s Raptor engine family has steadily increased sea-level thrust while simultaneously reducing mass, turning iterative engineering gains into substantially higher performance for the Super Heavy booster. CEO Elon Musk shed more light on how powerful Raptor 4 will be, and it’s pretty crazy.
Raptor 1 delivered 185 metric tons of thrust at roughly 2,080 kilograms, while Raptor 2 raised that to 230 tons while cutting mass to about 1,630 kilograms. SpaceX data for Raptor 3 lists a target of 280 tons at 1,525 kilograms (with further reductions in associated vehicle hardware), while operational flight ratings have been cited near 250 tons.
This morning, Elon Musk stated that Raptor 4 is expected to reach 300 tons of sea-level thrust at roughly the same mass as Raptor 3. Across these versions, thrust has risen by more than 60 percent from the first engines while engine mass has fallen, producing a sharp improvement in thrust-to-weight ratio. This is a true testament to how great SpaceX engineering has been:
🚀 Elon says Raptor 4 will make 300 tons of thrust at sea level at roughly the same mass as Raptor 3.
How far Raptor has come:
Raptor 1: 185 tf, 2,080 kg
Raptor 2: 230 tf, 1,630 kg
Raptor 3: 250 tf, 1,525 kg
Raptor 4: 300 tf33 on Super Heavy = ~9,900 tf, nearly 3x Saturn V https://t.co/HQDswZhyvL
— TESLARATI (@Teslarati) October 26, 2026
With 33 engines on SuperHeavy, the jump from earlier versions to a 300-ton Raptor 4 would produce roughly 9,900 metric tons of total liftoff thrust, nearly three times the Saturn V’s approximately 3,400 metric tons from its five F-1 engines.
This is not just a larger number on a data sheet, either, as sea-level thrust is the force available the moment the vehicle leaves the pad. This is when it is heaviest and still deep in Earth’s gravity well and dense atmosphere.
Higher levels of sea-level thrust directly improves the initial thrust-to-weight ratio of the full stack. A higher ratio produces faster acceleration off the pad, which shortens the time the rocket has to spend fighting gravity, and gravity losses during the first minute or two of the flight are a major drain on total available delta-v. Every second shaved off of that early climb preserves more propellant energy for reaching orbital velocity or for carrying extra payload.
Because Super Heavy’s engine count is constrained by vehicle diameter and packing density, increasing thrust per engine is the most straightforward way to raise total liftoff performance without redesigning the booster structure or design.
The same-mass target for Raptor 4 is equally important. Holding engine mass roughly constant while raising thrust improves the engine’s own thrust-to-weight ratio and reduces the structural and propellant mass fraction that must be carried solely to support the engines.
Earlier Raptor iterations also simplified or eliminated extensive vehicle-side hardware such as heat shields. These gains compound: more force for less installed mass leaves additional capacity for propellant, payload, or operational margins such as engine-out capability.
For Starship’s architecture, the practical effects are large. Greater liftoff thrust supports heavier vehicles, larger propellant loads, and higher payloads to low Earth orbit, figures SpaceX has targeted in the 100-plus-ton reusable range. That capacity underpins orbital refueling, lunar missions, and eventual Mars cargo and crew flights.
Continued growth in sea-level thrust therefore tightens the gap between theoretical rocket performance and the high flight rates and reusability needed to make large-scale space transport practical.
Tesla has expanded its Tesla Assisted Driving (TAD) suite to its tenth European country, as Latvia joined a growing list of European Union member states authorizing the company’s advanced driver assistance technology.
Tesla Europe announced this morning that the system is now approved in Latvia, with a software rollout to begin soon.
The approval and rollout follow recognition of a provisional European type approval originally granted by the Netherlands’ RDW authority on April 10.
🚨 Latvia has just received approval for Tesla Full Self-Driving (Supervised)
This is the 10th country in the EU to gain approval:
1. Netherlands — 10 April 2026 (original RDW approval)
2. Lithuania — 20 May 2026
3. Estonia — 29 May 2026
4. Denmark — 9 June 2026
5. Belgium — 10 June 2026
6. Slovenia — 7 September 2026
7. Czechia — 21 September 2026
8. Croatia — 29 September 2026
9. Slovakia — 16 October 2026— TESLARATI (@Teslarati) October 26, 2026
Latvia’s Road Traffic Safety Directorate (CSDD) evaluated the Dutch documentation, coordinated with the other national authorities, and reviewed updates from Tesla. These included tightened limits on speed offsets, automatic resets of any manual speed adjustments after each trip, and stronger driver monitoring.
In Europe, the feature is marketed as Tesla Assisted Driving after a recent rule change that labeled the name “Full Self-Driving” as misleading.
The system remains an SAE Level 2 driver assistance tool, not unsupervised autonomy. It can control speed, steering, braking, lane changes, and intersections while following a navigation route. Drivers need not keep their hands on the wheel at all times, yet they must continuously monitor the road and be prepared to intervene immediately.
The sequence of EU recognitions began with the Netherlands in April and continued through Lithuania, Estonia, Denmark, Belgium, Slovenia, Czechia, Croatia, and Slovakia. Most have relied on mutual recognition of the single Dutch provisional approval rather than independent national testing.
These national clearances do not yet constitute bloc-wide authorization. An EU-wide decision requires a qualified majority in the Technical Committee on Motor Vehicles: at least 15 of 27 member states representing 65 percent of the EU population. Larger markets, like Germany, France, and Italy, remain under review, and a vote is expected this December.
However, for Latvian Tesla owners with compatible vehicles and software, the imminent rollout expands access to the supervised system while underscoring that attentive human oversight remains essential.
Tesla expanded its Robotaxi geofence in Houston, Texas, today, enlarging the service area and drawing a new rocket-shaped boundary across the city’s northwestern and central parts.
Although CEO Elon Musk said it was just a coincidence, the expansion seems to be an ode to SpaceX and its potential merger with Tesla.
🚨 Tesla has just expanded its Robotaxi geofence in Houston
It looks a lot like a rocket — we all remember the shape in Austin 🤣 https://t.co/cFOPEuiJ4u
— TESLARATI (@Teslarati) October 26, 2026
The official Tesla Robotaxi account announced the change with the lines “Houston, we have liftoff” and “Bigger service area now live,” pairing them with a map overlay.
The prior white geofence, roughly 25 square miles covering Jersey Village, Harvest Bend, and the Willowbrook corridor along U.S. 290 and State Highway 249, now sits inside a larger blue zone that stretches southeast toward Bellair and closer to central Houston.
Houston’s Robotaxi service launched on April 18, 2026, the same day as Dallas, as Tesla’s first unsupervised public expansion beyond Austin. From the start, the vehicles were Model Ys running without anyone in the front seats, booked through the dedicated Tesla Robotaxi app and open to the public inside the geofence.
Trackers measured the initial zone at about 25 square miles; by late September it had not grown substantially. Community and registry data indicated a modest local fleet of unsupervised Model Ys, while dozens to nearly 200 Cybercabs, the purpose-built, steering-wheel-free two-seaters, have been spotted staging and testing in Houston lots, though public Cybercab rides remain limited to Austin for now.
Across the broader Robotaxi program, Tesla began public Robotaxi rides in Austin in June 2025, as a small geofence and vehicles with safety monitors became available for a ride-hailing service. Later on, Tesla removed the monitors and steadily expanded the service area until it covered most of the Austin metro area.
Unsupervised Robotaxi services now run in six cities: Austin, Dallas, Houston, Miami, Orlando, and Tampa. Cumulative driverless miles reported by the company have reached several million. The Cybercab entered public service in Austin in early September 2026 and has scaled rapidly there. The company has also said that Dallas is next for Cybercab rides in November, with further cities and 24/7 hours targeted by year-end, plus fleet-operator sales of the vehicle.
Waymo also operates a fully driverless service in Houston, which has been open to the public since August of this year.
The Houston expansion continues Tesla’s pattern of starting with tightly controlled validation zones before widening coverage as real-world data accumulates, while the rocket motif on the map underscores the company’s habit of injecting visual flair into its autonomy rollout.
Riders inside the new boundary can request unsupervised Model Y trips in the Robotaxi app; exact operating hours and further Cybercab availability remain subject to app updates and company statements.
How SpaceX Is raising Raptor’s sea-level thrust while holding engine mass steady
Tesla Assisted Driving expands to tenth EU country
