# How Rockets Work > United Launch Alliance plans to fly its Vulcan rocket again on 13 November 2026, nine months after a solid-booster nozzle failed in flight. This film explains how any rocket works: why throwing exhaust backwards pushes it forwards even in empty space, how a nozzle turns hot gas into speed, how Tsiolkovsky's rocket equation sets the price of every kilometre per second, why rockets are mostly propellant and are built in stages, how liquid engines and solid boosters differ, what happens when a booster nozzle fails, and how it all adds up to orbit, from Goddard's 1926 flight and Thailand's Bun Bang Fai festival to Sputnik and today's satellites. Interactive film: https://www.planetpast.com/stories/how-rockets-work/ Publisher: PlanetPast (https://www.planetpast.com/) · d => T('readPublished', l, { d: dateIn(d, l) }) 2026-10-30 · Physics, Space, Technology ## Prologue ### Throwing mass backwards *Physics · Space* How rockets reach orbit. On the twelfth of February 2026, less than thirty seconds after liftoff, a nozzle failed on one of the four solid boosters strapped to a Vulcan rocket. The rocket still reached orbit, but it was grounded for nine months. Its maker, United Launch Alliance, now plans to fly it again on the thirteenth of November. Why does one small part matter so much? To answer that, start with a simpler question: what does a rocket push against? ![A rocket climbing on several solid boosters. AI-generated still.](https://assets.planetpast.com/a/b4/b438c2d9205641e3.jpg) - 12 Feb 2026: Booster nozzle fails on flight 4 (USSF-87) - Feb–Oct: Investigation; four military missions moved to other rockets - 13 Nov 2026: Planned return to flight - Why exhaust pushes a rocket forward - The rocket equation and staging - Liquid engines and solid boosters - What a nozzle failure does Prologue #### A rocket grounded Spaceflight Now (28 October 2026): United Launch Alliance says Vulcan will return to flight on Friday 13 November 2026 after a nine-month grounding, carrying 40 Amazon Leo internet satellites on its fifth flight, the first with six solid boosters; on the fourth flight (USSF-87, 12 February 2026) a nozzle failed on one of four boosters less than 30 seconds after liftoff, yet the rocket reached its intended orbits. Air & Space Forces Magazine: ULA called it a “significant performance anomaly”, the November flight will use a redesigned nozzle, and the Space Force moved four missions from Vulcan to SpaceX. The 3D rockets are generic teaching models, not copies of any real vehicle; sizes, flames and exhaust particles are drawn for clarity, not to scale. Sources: [Spaceflight Now (28 Oct 2026): United Launch Alliance announces mid-November return to flight for Vulcan](https://spaceflightnow.com/2026/10/28/untied-launch-alliance-announces-mid-november-return-to-flight-for-vulcan-rocket/); [Air & Space Forces Magazine (Oct 2026): ULA says Vulcan will launch again in November after a months-long pause](https://www.airandspaceforces.com/united-launch-alliance-vulcan-rocket-launch-again-november/) ## Chapter I · Push and push back ### Push and push back *Chapter I* A rocket pushes on its own exhaust. A rocket does not push against the ground or the air. It pushes against its own exhaust. Let go of an untied balloon and it flies off for the same reason: air rushes out one way, and the balloon goes the other. Inside the engine, fuel burns with an oxidizer, a substance that supplies the oxygen, to make hot gas, and the engine throws that gas out of the back at enormous speed. By Newton's third law, the gas pushes back on the engine just as hard. That push is thrust. Because a rocket carries its own oxidizer, it needs no air at all. That is why it works in the vacuum of space, where a jet engine or a propeller could not. ![A rocket engine firing on a test stand. AI-generated still.](https://assets.planetpast.com/a/33/33d4df0062cedf6c.jpg) > “Thrust is produced according to Newton’s third law of motion.” (NASA, “Rocket thrust”) $$F_{\text{rocket on gas}} = -\,F_{\text{gas on rocket}}$$ - $F$: force; equal in size, opposite in direction - A jet breathes oxygen from the air - A rocket carries fuel and oxidizer - So a rocket works in a vacuum Chapter I · Push and push back #### Action and reaction NASA Glenn Research Center: thrust is produced according to Newton’s third law; the engine accelerates hot exhaust out of the nozzle, and the reaction pushes the rocket forward. The rocket thrust equation has no term for incoming air, because a rocket carries its own oxidizer, which is why it works in a vacuum, unlike a gas turbine or a propeller. Try it: fire the engine and watch the exhaust go one way and the rocket the other. The 3D rockets are generic teaching models, not copies of any real vehicle; sizes, flames and exhaust particles are drawn for clarity, not to scale. Sources: [NASA Glenn Research Center: rocket thrust](https://www.grc.nasa.gov/WWW/K-12/airplane/rockth) ### How much thrust you get depends on two things: how much gas leaves each second, and how fast it goes. That is the job of the bell-shaped nozzle. The gas squeezes through a narrow throat, where it reaches the speed of sound. Then, unlike water in a hose, gas moving faster than sound speeds up as the passage widens, to several kilometres a second. Without a working nozzle, the thrust drops. Remember that for chapter four. Engineers rate engines by specific impulse: the total push each kilogram of propellant can give, counted against its weight, which comes out in seconds. The higher the number, the faster the exhaust and the less fuel the rocket needs. $$F = \dot{m}\,V_e + (p_e - p_0)\,A_e$$ - $\dot{m}$: mass of exhaust per second - $V_e$: exhaust speed at the nozzle exit - $(p_e - p_0)A_e$: pressure term; zero when exit and outside pressure match - Combustion chamber: hot, high-pressure gas - Throat: the narrowest point, at the speed of sound - Bell: supersonic gas expands and speeds up - **Mach 1**: at the throat, where the flow chokes - **Mach > 1**: in the bell, faster as it widens $$I_{sp} = \dfrac{V_{eq}}{g_0}$$ - $V_{eq}$: effective exhaust speed - $g_0$: 9.8 m/s², so the unit is seconds Chapter I · Push and push back #### Thrust and specific impulse NASA Glenn: thrust F = ṁ·Ve + (pe − p0)·Ae, where ṁ is the mass flow rate, set at the choked throat, Ve is the exit velocity, set by the area ratio from throat to exit, and the pressure term vanishes when the exit pressure equals the surrounding pressure. Specific impulse is the thrust per unit weight flow of propellant; dividing the effective exhaust velocity by g₀ gives it in seconds. NASA Glenn, nozzle design: the flow chokes at the throat, which makes it sonic; downstream, in supersonic flow an increase in area produces an increase in velocity, while subsonic flow would slow down. Try it: raise the flow or the exhaust speed and see the thrust change. The numbers are illustrative. The 3D rockets are generic teaching models, not copies of any real vehicle; sizes, flames and exhaust particles are drawn for clarity, not to scale. Sources: [NASA Glenn Research Center: rocket thrust](https://www.grc.nasa.gov/WWW/K-12/airplane/rockth); [NASA Glenn Research Center: nozzle design](https://www1.grc.nasa.gov/beginners-guide-to-aeronautics/nozzle-design); [NASA Glenn Research Center: specific impulse](https://www.grc.nasa.gov/www/BGH/specimp.html) ## Chapter II · Fire and fuel ### Fire and fuel *Chapter II* From gunpowder to liquid oxygen. The idea is old. Every May in Yasothon, in northeast Thailand, villagers launch homemade rockets of plastic pipe packed with gunpowder, to ask the rain god for rain at the start of the rice season. Those are solid rockets: the fuel and oxidizer are mixed in one solid charge that burns until it is gone. Liquid rockets keep the fuel and the oxidizer in separate tanks and pump them into the engine. On the sixteenth of March 1926, on a snowy farm in Auburn, Massachusetts, Robert Goddard flew the first rocket burning liquids: gasoline and liquid oxygen. It flew for about two and a half seconds, rose forty-one feet and landed a hundred and eighty-four feet away, in a cabbage field. ![Homemade rockets on a bamboo ramp. AI-generated still.](https://assets.planetpast.com/a/71/71ed954b450db1a4.jpg) - Solid: fuel and oxidizer premixed in one block - Liquid: kept in separate tanks, pumped into the engine - Goddard, 1926: gasoline + liquid oxygen ![A snowy farm field with an early rocket frame. AI-generated still.](https://assets.planetpast.com/a/f8/f8238e64fb363343.jpg) - **~2.5 s**: in the air - **41 ft**: about 12.5 m up - **184 ft**: about 56 m away Chapter II · Fire and fuel #### Solid and liquid Bangkok Post: in Yasothon province, every May, locals light home-made rockets to honour Phaya Thaen, the rain god, and ask for rain as the rice-farming season begins. Vice: the rockets are PVC pipes packed with gunpowder. NASA History: Robert Goddard’s first liquid-fuelled rocket flew on 16 March 1926 on a farm in Auburn, Massachusetts, burning gasoline and liquid oxygen; it flew for about 2.5 seconds, rose 41 feet and landed 184 feet away in a cabbage field. NASA (2026): snow covered the ground on the morning of the flight. The 3D rockets are generic teaching models, not copies of any real vehicle; sizes, flames and exhaust particles are drawn for clarity, not to scale. Sources: [Bangkok Post: rocket festival in Yasothon](https://www.bangkokpost.com/life/social-and-lifestyle/941813/rocket-festival-in-yasothon); [Vice Creators: shooting rockets into the heavens to please the rain god in Thailand](https://creators.vice.com/en/article/mba39b/shooting-rockets-into-the-heavens-to-please-the-rain-god-in-thailand); [NASA History: 95 years ago, Goddard’s first liquid-fueled rocket](https://www.nasa.gov/history/95-years-ago-goddards-first-liquid-fueled-rocket/); [NASA (2026): from cabbages to craters, NASA marks one century of modern rocketry](https://www.nasa.gov/centers-and-facilities/goddard/from-cabbages-to-craters-nasa-marks-one-century-of-modern-rocketry) ## Chapter III · The rocket equation ### The rocket equation *Chapter III* The price of speed. Twenty-three years before Goddard flew, in 1903, a Russian schoolteacher, Konstantin Tsiolkovsky, published a study of how rockets could reach space. It showed that a rocket's speed depends on how fast its exhaust leaves. It also proposed liquid propellants, two decades before anyone flew one. Today we write it as the rocket equation. The change in speed equals the exhaust speed times the natural logarithm of the mass ratio: the full rocket's mass divided by its mass once the fuel is gone. The logarithm is the catch. Doubling the fuel does not double your speed. Try raising the mass ratio and watch how slowly the speed grows. ![A teacher’s study in the early 1900s. AI-generated still.](https://assets.planetpast.com/a/b9/b9674a831b021475.jpg) - 1898: Submitted to a journal - 1903: Published: rockets for orbital spaceships, liquid propellants $$\Delta v = V_{e}\,\ln\!\left(\dfrac{m_{\text{full}}}{m_{\text{empty}}}\right)$$ - $\Delta v$: change in speed - $V_e$: exhaust speed - $m_{\text{full}} / m_{\text{empty}}$: the mass ratio - mass ratio 2: 2.4 - ratio 4: 4.8 - ratio 10: 7.9 - ratio 20: 10.3 Chapter III · The rocket equation #### Tsiolkovsky and the rocket equation US Centennial of Flight Commission: Tsiolkovsky (1857–1935), a schoolteacher in Kaluga province, submitted “Investigating Space With Rocket Devices” in 1898; it was published in 1903, described rockets launching orbital spaceships, showed that a rocket’s speed and range are limited by the exhaust velocity, and proposed liquid propellants. NASA Glenn, “Ideal rocket equation”: Δu = Veq·ln(MR), with MR the full mass over the empty mass and Veq = Isp·g₀; it neglects lift and drag, and gravity subtracts g₀ times the burn time. Try it: the readout uses an exhaust speed of 3.4 km/s, close to NASA’s example of a hydrogen–oxygen engine with Isp ≈ 350 s. The 3D rockets are generic teaching models, not copies of any real vehicle; sizes, flames and exhaust particles are drawn for clarity, not to scale. Sources: [US Centennial of Flight Commission: Konstantin Tsiolkovsky](https://centennialofflight.net/essay/SPACEFLIGHT/tsiolkovskiy/SP1.htm); [NASA Glenn Research Center: the ideal rocket equation](https://www1.grc.nasa.gov/beginners-guide-to-aeronautics/ideal-rocket-equation) ### To stay in a low orbit, about three hundred kilometres up, a satellite must travel at about seven point eight kilometres a second, roughly twenty-eight thousand kilometres an hour. NASA works an example. With a good hydrogen and oxygen engine, the rocket's full mass must be about ten times its empty mass. So about ninety percent of what stands on the pad is propellant, and the payload is about one percent. A rocket is mostly a flying fuel tank, with a small cargo on top. Every extra kilogram of cargo needs many more kilograms of fuel, and that fuel needs fuel of its own to lift it. - **7.8 km/s**: circular orbit at 300 km; one lap in about 90 min - **11.2 km/s**: escape velocity: leaving Earth for good ![A propellant tank section in a rocket factory. AI-generated still.](https://assets.planetpast.com/a/c1/c1f704a28e05058e.jpg) - Propellant: ~90% - Structure and engines: ~9% - Payload: ~1% - **~350 s**: specific impulse, hydrogen–oxygen engine - **~10**: mass ratio needed for a 200-mile orbit - More cargo needs more fuel - More fuel is more weight to lift - So the fuel needs fuel of its own Chapter III · The rocket equation #### The tyranny of the equation ESA: a satellite in a circular orbit 300 km above Earth needs about 7.8 km/s (28,000 km/h) and goes round in about 90 minutes; escape velocity is 11.2 km/s. NASA Glenn: for a liquid hydrogen–liquid oxygen engine with an Isp of about 350 s, reaching a 200-mile orbit (Δu ≈ 25,000 ft/s) needs a mass ratio of about 10, so about 90% of the launch weight is propellant and the payload only about 1%. “Structure and engines” is what remains of NASA’s example once propellant and payload are taken out. The 3D rockets are generic teaching models, not copies of any real vehicle; sizes, flames and exhaust particles are drawn for clarity, not to scale. Sources: [ESA Kids: space velocity](https://kids.esa.int/space_velocity/); [NASA Glenn Research Center: the ideal rocket equation](https://www1.grc.nasa.gov/beginners-guide-to-aeronautics/ideal-rocket-equation) ### There is a way to cheat the equation a little: throw away weight you no longer need. Tsiolkovsky studied multistage rockets too. When the first stage empties its tanks, it drops away with its heavy engines. The smaller second stage then lights, and it no longer has to carry all that dead weight. Compare the two: the same total mass, the same engines, the same payload. Built in two stages, the rocket gains about thirty percent more speed. ![A first stage falling away above Earth. AI-generated still.](https://assets.planetpast.com/a/9a/9a387571bfb51ff4.jpg) - Empty tanks are dead weight - Dropping them raises the mass ratio of what is left - Each stage can use an engine suited to its job - One stage: 7.9 - Two stages: 10.3 Chapter III · The rocket equation #### Staging US Centennial of Flight Commission: Tsiolkovsky expanded his studies of multistage boosters in the 1920s and 1930s. The comparison on screen applies NASA’s ideal rocket equation to an invented rocket of 100 tonnes with a 2-tonne payload and an exhaust speed of 3.4 km/s: as one stage carrying 90 t of propellant and 8 t of structure it gains about 7.9 km/s; split into a 70-tonne-propellant first stage with 6 t of structure and a 20-tonne-propellant second stage with 2 t of structure, it gains about 4.1 + 6.1 ≈ 10.3 km/s. Try it: switch between one stage and two. The 3D rockets are generic teaching models, not copies of any real vehicle; sizes, flames and exhaust particles are drawn for clarity, not to scale. Sources: [US Centennial of Flight Commission: Konstantin Tsiolkovsky](https://centennialofflight.net/essay/SPACEFLIGHT/tsiolkovskiy/SP1.htm); [NASA Glenn Research Center: the ideal rocket equation](https://www1.grc.nasa.gov/beginners-guide-to-aeronautics/ideal-rocket-equation) ## Chapter IV · Engines and boosters ### Engines and boosters *Chapter IV* Liquids for the long push, solids for the kick. Vulcan, which first flew in January 2024, mixes both kinds of rocket. Its first stage, called the core stage, burns liquid methane with liquid oxygen in two big engines. Its upper stage burns liquid hydrogen and oxygen. For heavier loads, solid boosters are strapped to its sides: none, two, four or six. They add a huge push in the first minutes, then fall away. Which version flies depends on how heavy the cargo is and how high it must go. With six boosters, Vulcan can lift about twenty-seven tonnes to low Earth orbit. Try adding boosters and watch the thrust at liftoff grow. - First stage: 2 BE-4 engines, methane + liquid oxygen - Upper stage, Centaur V: 2 RL10 engines, hydrogen + oxygen - Height: 61.6 m (standard) ![A rocket stage on its transport cradle. AI-generated still.](https://assets.planetpast.com/a/2b/2bc5ae9866ff6d47.jpg) - **0 · 2 · 4 · 6**: GEM 63XL solid boosters - **27,200 kg**: to low Earth orbit, with six Chapter IV · Engines and boosters #### Liquid and solid together Wikipedia (Vulcan Centaur): first launch 8 January 2024 from Cape Canaveral, carrying the Peregrine lunar lander (the lander failed after separation; the rocket performed as expected); first stage with two BE-4 engines burning liquid methane and liquid oxygen; Centaur V upper stage with two RL10 engines burning liquid hydrogen and liquid oxygen; zero, two, four or six Northrop Grumman GEM 63XL solid boosters; 61.6 m tall in the standard configuration; up to 27,200 kg to low Earth orbit with six boosters. Try it: the thrust bar is relative and illustrative; the 3D rocket is a generic model, not Vulcan’s real shape. The 3D rockets are generic teaching models, not copies of any real vehicle; sizes, flames and exhaust particles are drawn for clarity, not to scale. Sources: [Wikipedia: Vulcan Centaur](https://en.wikipedia.org/wiki/Vulcan_Centaur) ### Now picture four boosters pushing together. On Vulcan's second flight, in October 2024, and again on its fourth, in February 2026, the nozzle on one booster failed. Without its nozzle, a booster can no longer speed its gas up, so it loses thrust. One side of the rocket now pushes less than the other. Try failing one yourself. Engineers from ULA, the booster maker Northrop Grumman and the Space Force traced several contributing causes. Both times the core stage compensated, and the rocket still reached its planned orbit. But the Space Force paused its launches on Vulcan and moved four missions to other rockets. The November flight will use a redesigned nozzle while tests continue. ![A scorched nozzle on a test stand. AI-generated still.](https://assets.planetpast.com/a/9e/9eedc10812ec159e.jpg) - **< 30 s**: after liftoff, the nozzle fails - **3 + 1**: three boosters at full thrust, one weakened - **orbit**: still reached, as planned - Investigation by ULA, Northrop Grumman and the Space Force - Four military missions moved to SpaceX - Next flight: 40 Amazon Leo satellites Chapter IV · Engines and boosters #### When a nozzle fails Spaceflight Now: on Vulcan’s second flight a nozzle disintegrated on one of two GEM 63XL motors; on the fourth (USSF-87, 12 February 2026) a nozzle failed on one of four boosters less than 30 seconds after liftoff, and the rocket reached its intended orbits despite reduced, asymmetric thrust. An investigation by ULA, Northrop Grumman and the US Space Force identified several contributors; the next flight uses an improved nozzle design while testing continues. Wikipedia: on flight 2 (4 October 2024) the booster lost its nozzle; after flight 4 the Space Force paused national security launches on Vulcan. Air & Space Forces Magazine: four missions moved from Vulcan to SpaceX. Try it: fail a nozzle. In this model the core engines swivel to keep the rocket straight, one common way of steering; the angles are exaggerated for clarity. The 3D rockets are generic teaching models, not copies of any real vehicle; sizes, flames and exhaust particles are drawn for clarity, not to scale. Sources: [Spaceflight Now (28 Oct 2026): United Launch Alliance announces mid-November return to flight for Vulcan](https://spaceflightnow.com/2026/10/28/untied-launch-alliance-announces-mid-november-return-to-flight-for-vulcan-rocket/); [Wikipedia: Vulcan Centaur](https://en.wikipedia.org/wiki/Vulcan_Centaur); [Air & Space Forces Magazine (Oct 2026): ULA says Vulcan will launch again in November after a months-long pause](https://www.airandspaceforces.com/united-launch-alliance-vulcan-rocket-launch-again-november/) ## Chapter V · To orbit ### To orbit *Chapter V* Sideways, very fast. Reaching orbit is less about going up than going sideways fast. A launcher climbs out of the thick air, then tips over and spends most of its fuel building horizontal speed. At orbital speed it keeps falling around the Earth instead of back down to it. The first to get there was Sputnik 1, launched by the Soviet Union on the fourth of October 1957: a sphere fifty-eight centimetres across, weighing eighty-three point six kilograms, circling Earth every ninety-eight minutes. Today rockets carry whole batches. Thailand's THEOS-2 Earth-observation satellite rode a European Vega rocket from French Guiana in October 2023, and Vulcan's next flight carries forty internet satellites at once. ![A long-exposure night launch. AI-generated still.](https://assets.planetpast.com/a/6f/6f100cb309c5c9b0.jpg) ![A museum-style model of a small sphere with four antennas: 58 cm, 83.6 kg (NASA). AI-generated still.](https://assets.planetpast.com/a/15/152974b3e181e69c.jpg) - **58 cm**: across, about a beach ball - **83.6 kg**: mass - **98 min**: per orbit ![Flat satellites stacked inside a payload fairing. AI-generated still.](https://assets.planetpast.com/a/a7/a7cddaffbc14946d.jpg) Chapter V · To orbit #### Getting to orbit ESA: orbit at 300 km needs about 7.8 km/s. NASA History: Sputnik 1, launched by the Soviet Union on 4 October 1957, was about 58 cm across, weighed 83.6 kg and took about 98 minutes per orbit. Airbus (October 2023): THEOS-2, built by Airbus for Thailand, was launched on a Vega rocket from Kourou in French Guiana. Spaceflight Now: Vulcan’s fifth flight is to carry 40 Amazon Leo satellites. The climb-then-turn path on screen is a simplified illustration of a typical ascent, not a real trajectory. Try it: launch again and follow the path from the pad to orbit. The 3D rockets are generic teaching models, not copies of any real vehicle; sizes, flames and exhaust particles are drawn for clarity, not to scale. Sources: [ESA Kids: space velocity](https://kids.esa.int/space_velocity/); [NASA History: Sputnik and the dawn of the space age](https://www.nasa.gov/wp-content/uploads/static/history/sputnik.html); [GeoConnexion, Airbus release (Oct 2023): THEOS-2, Airbus-built satellite for Thailand, successfully launched](https://geoconnexion.com/news/theos-2-airbus-built-satellite-for-thailand-successfully-launched); [Spaceflight Now (28 Oct 2026): United Launch Alliance announces mid-November return to flight for Vulcan](https://spaceflightnow.com/2026/10/28/untied-launch-alliance-announces-mid-november-return-to-flight-for-vulcan-rocket/) ## Epilogue ### Every rocket, from a bamboo-ramp festival rocket to Vulcan, runs on the same idea: throw mass backwards, fast, and you move forwards. From the rice fields of Yasothon to Cape Canaveral, the physics is the same. The rocket equation makes orbit expensive: most of a rocket is fuel, and every small part, down to a booster nozzle, has to work perfectly. Will the redesigned nozzle hold on the thirteenth of November? Watch the launch, and now you will know what to look for. - 1903: Tsiolkovsky publishes the physics of rocket flight - 1926: Goddard’s liquid-fuel rocket - 1957: Sputnik 1 reaches orbit - 2023: Thailand’s THEOS-2 launched - 2024: Vulcan’s first flight - 13 Nov 2026: Vulcan’s planned return - Stills are AI-generated - 3D rockets are generic models - Calculators use the ideal rocket equation - Liftoff: six boosters light together - The first two minutes: boosters burn out and drop - Staging: the upper stage lights Epilogue · Sources #### Sources Every fact in this film comes from the sources below. The chapter stills and pictures are AI-generated illustrations; the sphere with antennas is a generic museum-style model. The 3D rockets, plumes and trajectories are generic teaching models; the calculators apply NASA’s ideal rocket equation to invented masses where stated, and the Earth uses NASA Blue Marble imagery. Sources: [Spaceflight Now (28 Oct 2026): United Launch Alliance announces mid-November return to flight for Vulcan](https://spaceflightnow.com/2026/10/28/untied-launch-alliance-announces-mid-november-return-to-flight-for-vulcan-rocket/); [Air & Space Forces Magazine (Oct 2026): ULA says Vulcan will launch again in November after a months-long pause](https://www.airandspaceforces.com/united-launch-alliance-vulcan-rocket-launch-again-november/); [Wikipedia: Vulcan Centaur](https://en.wikipedia.org/wiki/Vulcan_Centaur); [NASA Glenn Research Center: rocket thrust](https://www.grc.nasa.gov/WWW/K-12/airplane/rockth); [NASA Glenn Research Center: nozzle design](https://www1.grc.nasa.gov/beginners-guide-to-aeronautics/nozzle-design); [NASA Glenn Research Center: specific impulse](https://www.grc.nasa.gov/www/BGH/specimp.html); [NASA Glenn Research Center: the ideal rocket equation](https://www1.grc.nasa.gov/beginners-guide-to-aeronautics/ideal-rocket-equation); [Bangkok Post: rocket festival in Yasothon](https://www.bangkokpost.com/life/social-and-lifestyle/941813/rocket-festival-in-yasothon); [Vice Creators: shooting rockets into the heavens to please the rain god in Thailand](https://creators.vice.com/en/article/mba39b/shooting-rockets-into-the-heavens-to-please-the-rain-god-in-thailand); [NASA History: 95 years ago, Goddard’s first liquid-fueled rocket](https://www.nasa.gov/history/95-years-ago-goddards-first-liquid-fueled-rocket/); [NASA (2026): from cabbages to craters, NASA marks one century of modern rocketry](https://www.nasa.gov/centers-and-facilities/goddard/from-cabbages-to-craters-nasa-marks-one-century-of-modern-rocketry); [US Centennial of Flight Commission: Konstantin Tsiolkovsky](https://centennialofflight.net/essay/SPACEFLIGHT/tsiolkovskiy/SP1.htm); [ESA Kids: space velocity](https://kids.esa.int/space_velocity/); [NASA History: Sputnik and the dawn of the space age](https://www.nasa.gov/wp-content/uploads/static/history/sputnik.html); [GeoConnexion, Airbus release (Oct 2023): THEOS-2, Airbus-built satellite for Thailand, successfully launched](https://geoconnexion.com/news/theos-2-airbus-built-satellite-for-thailand-successfully-launched)