Connect with us

News

How SpaceX is able to achieve its amazing rocket landing accuracy

Published

9 years ago

on

After SpaceX’s successful and uniquely exciting launch of Taiwan’s Formosat-5 remote sensing satellite, Elon Musk took to Twitter to reveal some fascinating details about the launch and recovery of the Falcon 9 first stage.

Unabashedly technical, the details Musk revealed demonstrate the truly incredible accuracy of Falcon 9’s recovery, honed over 20 landing attempts and numerous modifications to the launch vehicle. The accuracy is best understood within the context of Falcon 9’s scale and the general scope of orbital rocketry.

The first stage of Falcon 9 Full Thrust, currently the active version of Falcon 9, stands 140 feet tall and 12 feet in diameter. If you can, for a moment, picture a 737 airliner, the plane most people have likely flown aboard on domestic flights. The first stage of Falcon 9 is the same length or greater and the same diameter as Boeing’s workhorse airliner. If you are now imagining a 737 landing on its tail aboard an ocean-going barge, that is a great start. The most common version of the 737, the -800, has an empty weight of 91,000 lb, while Falcon 9’s empty first stage is a bit more than half as heavy. With a full load of fuel, Falcon 9 S1 (first stage) weighs nearly three times as much as the 737-800. A single Merlin 1D engine out of Falcon 9’s namesake nine rocket engines has nearly ten times the thrust of the airliner. In short, Falcon 9’s first stage is massive, both extremely light and extremely heavy, and has a mind-boggling amount of thrust.

Falcon 9’s ability to land as accurately as it does is due to a combination of multiple technologies and vehicle modifications. Most visible are S1’s cold gas maneuvering thrusters and aluminum or titanium grid fins, both of which are designed to provide some level of control authority and maneuverability to the first stage during its trip within and without Earth’s atmosphere. At the peak of its trips, the first stage is often completely outside of the vast majority of the atmosphere, meaning that aerodynamic forces are no longer relevant or useful for the vehicle. This is where the cold gas thrusters come in: by carrying their reaction mass with them (the gas), Falcon 9 can maneuver outside of the atmosphere. Once the stage descends into thicker atmospheric conditions, the grid fins deploy and are used like wings to guide the stage down to its landing location, be that on land or at sea. While the gas thrusters lose a lot of their utility once in the atmosphere, they can still be used to add a small amount of control authority when needed. They were famously seen fighting a futile battle to save a first stage aboard OCISLY in 2015.

Advertisement
-
-

With this in mind, we can take a closer look at Musk’s technical details. First off, we have a photo of the landed booster, Falcon 9 1038, clearly almost dead center on the droneship Just Read The Instructions. More specifically, Musk reports that 1038 landed less than a single meter off the center of the target, and it landed with less than a single meter per second of latent velocity. The first stage thus managed both a soft and deadly accurate landing after traveling to a height of 150 miles – well into what is technically “space” – at a maximum speed of 1.5 miles per second. Without delving further into the details, this is best summarized as “insanely fast”, and is a bit faster than the X-15 rocketplane’s fastest recorded speed. To better put this into context, Falcon 9 1038 traveled to an altitude of 240,000 meters at a top speed of 2,400 meters per second, turned around, and landed on an autonomous barge about two feet off of its optimal target. It is truly difficult to describe how impressive that kind of accuracy is.

The hypersonic X-15 and Falcon 9 S1, with a 737-800 on the right. All vehicles are to scale. (Wikipedia, SpaceX)

Mr. Musk nevertheless did not let 1038 steal all the fanfare, and revealed that the first stage responsible for launching BulgariaSat-1, 1029, had the honor of being the fastest first stage yet, clocking in at at a truly staggering Mach 7.9, or 2,700 meters per second. That speedy mission marked the stage’s second flight and was SpaceX’s second successful reuse of a Falcon 9. Indicative of the intense speed and heat the core experienced, one of the vehicle’s grid fins was noted to have almost completely melted through. Aluminum’s melting point begins at 1,221°F.

Related Topics:

Eric Ralph is Teslarati's senior spaceflight reporter and has been covering the industry in some capacity for almost half a decade, largely spurred in 2016 by a trip to Mexico to watch Elon Musk reveal SpaceX's plans for Mars in person. Aside from spreading interest and excitement about spaceflight far and wide, his primary goal is to cover humanity's ongoing efforts to expand beyond Earth to the Moon, Mars, and elsewhere.

Advertisement
Comments

Elon Musk

Tesla CEO Elon Musk denies ridiculous Gigafactory Shanghai rumor

Published

51 minutes ago

on

July 31, 2026

By

(Credit: Tesla)

Tesla CEO Elon Musk took to his social media platform X on Thursday night to deny a ridiculous rumor regarding the sale of the company’s Chinese vehicle production plant, Gigafactory Shanghai.

On Thursday, the Wall Street Journal, citing sources familiar with the matter, claimed in a scathing new report that Tesla was exploring a potential sale of the entire China business in an effort to help bolster a potential merger between SpaceX and Tesla.

Musk immediately denied the rumor not once but twice, initially calling it “fake news,” and then calling it “absurdly fake news” in a separate post just a few moments later:

The original poster of the Wall Street Journal article that Musk saw deleted the initial post sharing the headline and the rumored sale of Tesla’s China business.

The report seemed absolutely and unequivocally false to begin with; Tesla’s business in China is among the most important pieces of the company’s business. Not only does the factory supply vehicles for the domestic market, but also for various other markets in Asia and Europe.

China is also one of the largest automotive markets in the world, and Tesla has performed well there despite the robust competition.

The speculation regarding a Tesla and SpaceX merger has started to gain steam this year as the space exploration company went public just a month ago. There has been speculation that Musk will bridge all of his companies under one “umbrella company,” and analysts believe this could happen before the end of the decade.

The Tesla and SpaceX merger everyone is talking about is quietly building

Advertisement
-
-

This is the latest iteration of Musk’s very evident war on mainstream media. Reports regarding any of Musk’s companies are quick to get the dreaded “false” or “fake news” response from the CEO when they are unfounded.

Continue Reading

Elon Musk

Tesla AI boss reveals how big Optimus is going to get

Tesla’s Optimus chief corrected himself on X, confirming a staggering 10 million robot production target.

Published

9 hours ago

on

July 31, 2026

By

Tesla Optimus Gen 3 [Credit: Tesla]

Tesla’s Optimus program has a new number attached to it, after Ashok Elluswamy, the executive who has run the humanoid robot program since June 2025, posted a three word correction on X Thursday, “Correction, 10 million robots.”

The line clarifies the long term annual capacity Tesla is building toward its planned second Optimus production line at Gigafactory Texas, a figure Musk has cited repeatedly since last year’s shareholder meeting.

The scale is worth noting, because ten million robots a year would mean Tesla building more units annually than most countries sell in new cars. Tesla has framed this as a second line, not the first. The buildout is happening in two phases: a roughly one million unit per year line inside Tesla’s Fremont factory, installed on the floor space vacated when Model S and Model X production ended earlier this year, and a much larger dedicated facility under construction at Giga Texas that broke ground on its first steel structure in May. That Texas facility is the one Elluswamy’s correction refers to, and is expected to reach volume production sometime in 2027.

Tesla Optimus project fires up as Musk sees production line progress

Elluswamy took over Optimus from Milan Kovac last summer and has spent the months since talking up the program’s trajectory. Elon Musk has also floated the ten million figure at Tesla’s 2025 shareholder meeting.

Advertisement
-
-

Ending Model S and Model X production to make room for the first Optimus line was one of the more consequential manufacturing decisions in the company’s recent history, retiring two flagship vehicles in favor of a robot that has yet to enter mass production. Musk has previously estimated per unit production costs at $20,000 to $25,000 once Tesla reaches a million units a year, though he hasn’t said what that cost looks like at ten times the volume.

Continue Reading

News

Autonomous vehicle red tape gets slashed by Trump Administration

Published

20 hours ago

on

July 30, 2026

By

Credit: Zoox

The Trump Administration today made several key moves to help with the deployment of autonomous vehicles by cutting overreaching red tape that has stifled growth and innovation for years.

The moves, which were put forth by the National Highway Traffic Safety Administration (NHTSA), aim to grant temporary exemptions to at least one company currently, although that could expand in the coming months. Additionally, it will work with organizations to develop standards and a sound but efficient regulatory landscape.

Zoox is the only company mentioned explicitly by the Trump Administration in its press release announcing the new terms today. They will receive a temporary two-year exemption that will allow the commercial deployment of up to 2,500 vehicles annually for two years.

There is a potential exemption for Robomart, Inc., which “requests a temporary exemption from certain FMVSS No. 500 requirements for a low-speed vehicle operated by an ADS without a human driver onboard. NHTSA will publish a separate notice seeking public comment on its merits once the initial evaluation is complete,” the agency said.

Here are the five new terms that Secretary Sean Duffy has implemented through the NHTSA today:

  1. Allow Zoox to commercially deploy its robotaxis through a temporary exemption.
    This temporary exemption will allow the commercial deployment of up to 2,500 vehicles annually for two years, subject to an enhanced, adaptable oversight structure that can evolve as Zoox’s technology advances.
  2. Accelerate development of first-ever AV performance standards through a partnership with SAE Industry Technologies Consortia (ITC).
    This partnership will fund a three-year, $5 million “A2SCEND” consortium, bringing together experts to gather data and accelerate creation of the first-ever AV performance standards. This project will inform a single national standard for AV safety to eliminate the patchwork regulatory landscape that has stifled innovation for years.
  3. Publish an interim final rule that allows vehicles manufactured prior to an exemption to be eligible for a commercial deployment exemption.
    This rule will modernize the application process and improve access to exemptions for innovators, including AV developers, by granting the NHTSA Administrator the discretion to apply temporary exemptions to vehicles manufactured prior to the effective date of an exemption grant.
  4. Streamline the application process for Part 555 exemptions by updating guidance and soliciting feedback from the public.
    By updating the Part 555 exemption process—which allows automakers to temporarily sell a limited number of non-compliant vehicles, primarily to test new technologies—NHTSA is aiming to create a more flexible oversight structure for exemptions and summarize recent AV framework activities, including expanded exemption pathways, streamlined crash reporting, and ongoing efforts to modernize Federal Motor Vehicle Safety Standards (FMVSS).
  5. Establish a new Federal Docket for public feedback on NHTSA’s updated safe AV development and deployment guidance.
    NHTSA is updating its technical guidance for AVs for the first time since 2017—focusing on key safety areas like emergency responder interactions, safety management systems, remote assistance, and post-crash behavior to help the industry scale up driverless deployments safely.

Additionally, the NHTSA said it has modernized some safety standards by proposing updates to:

  • FMVSS 102 – Transmission shifting
  • FMVSS 103/104 – Windshield defrosting and wiping
  • FMVSS 110 – Tire placards
  • FMVSS 135 – Braking systems
  • FMVSS 101 – Controls and displays
  • FMVSS 108 – Vehicle lighting
  • FMVSS 111 – Mirrors and rearview display
  • FMVSS 126 – Electronic stability control systems
  • FMVSS 201/208 – Sun visors and warning labels

These changes aim to make the regulatory process for autonomous vehicles more streamlined and efficient, which could help the U.S. gain dominance over autonomous vehicle systems moving forward.

Continue Reading