Rockets and Spaceflight: From Fireworks to Reusable Boosters

Follows: Orbits: Why the Moon Doesn't Fall (or Rather, Keeps Falling), and the space-race chapters of The 1950s and The 1960s in Decades of Leadership

On 16 March 1926, in a farm field at Auburn, Massachusetts, a physics professor lit a contraption of pipes and tanks fuelled by gasoline and liquid oxygen. It rose 12.5 metres, flew for about two and a half seconds, and landed 56 metres away in a cabbage patch. Forty-three years later, a descendant of that machine, 111 metres tall, sent three men to the Moon. By 2025 the world was launching rockets into orbit more than 300 times a year, and many of their first stages were flying home to land.

In this deep dive

1. Fire arrows, three dreamers and one equation
2. Why reaching orbit is so hard
3. From the V-2 to the Moon
4. The Space Shuttle, its two disasters, and the station it built
5. Rockets that land, and a crowded sky
6. The state of affairs in late 2026
7. Open questions and trade-offs

Part 1 — Fire arrows, three dreamers and one equation

The principle of the rocket is older than the rocket. In the ancient world, Hero of Alexandria described the aeolipile, a sphere mounted over a boiling kettle that spun as steam escaped from two bent pipes. It was a curiosity, but it showed that a jet of gas pushes back on whatever releases it.

The first true rockets came from China, where gunpowder was invented. A tube closed at one end and packed with gunpowder, tied to a long stick for stability, would shoot forward when lit, pushed by the hot gas rushing out of the open end. In 1232, during the battle of Kai-Keng, Chinese defenders fired what were recorded as "arrows of flying fire" at Mongol invaders. NASA's own history notes that we don't know how much damage they did, though the psychological effect was probably large.

There is also the legend of Wan Hu, a Chinese official said to have tied 47 rockets to a chair, lit them all at once and vanished in a cloud of smoke. It is a legend: there is no evidence it happened, and if it did, as NASA's history page dryly puts it, he was probably blown to pieces. Treat it as folklore, not history.

Rockets spread west as weapons. Rocket barrages fired by Indian forces against the British in 1792 and 1799 impressed the British enough that Colonel William Congreve designed rockets for Britain's own forces. During the War of 1812, British ships fired Congreve rockets at Fort McHenry in Baltimore, the scene that gave the US national anthem its "rockets' red glare".

For centuries, though, rockets stayed inaccurate and weak. They burned solid powder, which once lit can't be throttled or stopped. The leap came when someone thought of burning liquids.

That was Robert Goddard, a physics professor at Clark University in Massachusetts. Liquid fuels pack more energy and can be pumped, throttled and shut off. His first liquid-fuelled rocket, nicknamed "Nell", made that short flight into the cabbage patch at Auburn on 16 March 1926. It was not impressive to look at. It was the Wright Flyer of rocketry.

A rocket isn't pushed by the air behind it. It is pushed by its own exhaust, which is why it works best where there is no air at all.

Spaceflight had three founding thinkers, who worked mostly in isolation from each other in Russia, the United States and Germany.

Konstantin Tsiolkovsky (1857–1935) lost most of his hearing to scarlet fever at nine, was turned away by schools and taught himself mathematics and physics from books. Working as a provincial schoolteacher, he wrote out the basic equation of rocket motion and dated it 10 May 1897. In May 1903 he published Exploration of Outer Space by Means of Rocket Devices, which argued for liquid propellants and showed that what limits a rocket's final speed is the speed of its exhaust. He is credited with the line, from a letter of 1911, that "Earth is the cradle of humanity, but one cannot live in a cradle forever." (The wording varies between translations.)

Robert Goddard derived the same mathematics independently around 1912 and held 214 patents, including two from 1914 for multi-stage and liquid-fuelled rockets. In 1919 the Smithsonian published his paper A Method of Reaching Extreme Altitudes. On 13 January 1920 a New York Times editorial, "A Severe Strain on Credulity", mocked him, claiming that a rocket couldn't work in a vacuum because it would have nothing to push against. On 17 July 1969, the day after Apollo 11 left for the Moon, the Times printed a correction: "it is now definitely established that a rocket can function in a vacuum as well as in an atmosphere. The Times regrets the error." Goddard had died in 1945.

Hermann Oberth (1894–1989) had his doctoral dissertation on rockets rejected in 1922 as "utopian", and published it privately in 1923 as Die Rakete zu den Planetenräumen (The Rocket into Planetary Space). The book helped inspire small rocket societies around the world. Oberth advised Fritz Lang's 1929 film Woman in the Moon and mentored the members of the German Society for Space Travel, among them a young enthusiast named Wernher von Braun.

The equation all three found is now called the Tsiolkovsky rocket equation, though an English mathematician, William Moore, had outlined it as early as 1810. It is short, and it explains almost everything about why spaceflight is hard.

Part 2 — Why reaching orbit is so hard

As Orbits explains, to stay up you must move sideways fast enough that the Earth curves away beneath you as fast as you fall: about 7.8 kilometres per second, or 28,000 km/h, in low orbit. On the way up a rocket also loses speed to gravity (it spends minutes fighting its own weight) and to air resistance. Engineers add those losses up as a "change of velocity", Δv (delta-v). Getting from the ground to low Earth orbit takes about 9.3 to 10 km/s.

The rocket equation says how much propellant that needs:

Δv = v_e × ln(m₀ ÷ m_f)

Here v_e is the exhaust speed, m₀ is the rocket's mass full of propellant and m_f its mass when the propellant is gone; "ln" is the natural logarithm. Flip it round and the full-to-empty mass ratio is e^{Δv ÷ v_e}: an exponential (see Why Exponential Growth Rules Everything). Each extra km/s you want multiplies, rather than adds to, the propellant you need.

Put numbers in. A kerosene and liquid oxygen engine like SpaceX's Merlin has an exhaust speed of about 3 km/s in vacuum; the hydrogen-burning RS-25 that powered the Space Shuttle reaches about 4.4 km/s. Take Δv = 9.4 km/s:

Ninety-six per cent. Everything else (engines, tanks, pumps, computers, the payload) has to fit in the remaining 4%. A loaded petrol car, for comparison, is a few per cent fuel. A rocket is a flying fuel tank with a very small amount of anything else.

The problem isn't energy. Each kilogram in low orbit carries about 30 megajoules of motion energy, less than the chemical energy in a kilogram of kerosene. The problem is that the propellant has to lift itself.

This is why rockets are built in stages. Once the first stage has burned its propellant, its empty tanks and heavy engines are dead weight, so you throw them away and carry on with a smaller rocket. Splitting 9.4 km/s into two equal halves, each kerosene stage needs only a mass ratio of about 4.8, so "only" about 79% of each stage is propellant, which engineers can actually build.

Real rockets match the arithmetic. A Falcon 9 weighs about 549 tonnes at lift-off and can put 22.8 tonnes into low orbit if nothing is recovered: about 4% of its launch mass. If the first stage keeps back fuel to fly home and land on a ship, the payload drops to 17.5 tonnes, about 3%. The Saturn V that launched Apollo weighed nearly 3,000 tonnes and could put 140 tonnes in low orbit, about 5%.

Going further is harder still. To head for the Moon a spacecraft must reach about 11 km/s, close to the escape speed in Orbits, so the same Saturn V that could put 140 tonnes in low orbit could send only 43.5 tonnes towards the Moon, less than a third as much. Every extra km/s is paid for exponentially.

This is sometimes called "the tyranny of the rocket equation", and it has a consequence that shaped sixty years of spaceflight. If almost all of a rocket is fuel and tanks, and you throw the tanks and engines away after a single use, each launch costs roughly the price of building a large aircraft and then crashing it into the sea.

Part 3 — From the V-2 to the Moon

The V-2: the first rocket into space, built by prisoners

The first rockets big enough to reach space were built in Nazi Germany, and they were built by slaves.

In the 1930s the German army recruited von Braun and other rocket enthusiasts to develop long-range missiles. The result was the A-4, renamed by propaganda the Vergeltungswaffe 2, "Vengeance Weapon 2": the V-2. It burned alcohol and liquid oxygen, consuming about a tonne of propellant every seven seconds, could carry roughly a tonne of explosive about 320 kilometres, and fell on its target faster than sound, so there was no warning. On 20 June 1944, a V-2 test rocket launched straight up reached about 174.6 km, well above the conventional 100 km edge of space: the first human-made object to get there. Combat use began in September 1944, against Paris and then London. Between 3,200 and 3,600 were fired at Allied targets.

After British bombers hit the Peenemünde research centre in August 1943, production moved to the Mittelwerk, a factory dug into a mountain in central Germany. According to the Smithsonian National Air and Space Museum, which displays a V-2, the rockets were built by about 2,000 civilian technicians and roughly 10,000 prisoners from the Mittelbau-Dora concentration camp, many of them forced at first to live underground in terrible conditions. The museum's figures make the weapon's history plain:

Other estimates differ (some put deaths from the attacks nearer 9,000 and among the workers nearer 12,000), but every serious account agrees on the grim headline: more people died building the V-2 than were killed by it.

The first machine to reach space was a weapon of terror, built by prisoners who were worked to death.

Von Braun joined the Nazi party in 1937 and the SS in 1940, rising to the rank of major. He admitted visiting the Mittelwerk factory 12 to 15 times and called conditions there "repulsive"; he denied seeing deaths himself. In May 1945 he surrendered to the Americans and was taken to the United States with about 1,600 other German specialists under Operation Paperclip. His team built the rocket that launched America's first satellite, and later, as director of NASA's Marshall Space Flight Center, he was chief architect of the Saturn V. Both the United States and the Soviet Union built their first large rockets using captured V-2s and V-2 knowledge. How to weigh von Braun's achievements against his past is still argued over, and an honest account of the space age has to include both.

Sputnik, Gagarin and Apollo

On 4 October 1957, the Soviet Union launched Sputnik 1 from Tyuratam in Kazakhstan (now the Baikonur Cosmodrome). It was a polished metal sphere 58 cm across, weighing 83.6 kg, with four long radio antennas, and it circled the Earth every 96.2 minutes. Its radio signal lasted 22 days, until the batteries died; it burned up on 4 January 1958 after 1,440 orbits. It was launched on a modified R-7, the intercontinental missile designed under the Soviet chief designer Sergei Korolev.

The political shock in the United States was enormous. Within months Washington had created the Advanced Research Projects Agency and passed the National Defense Education Act, which funded science and maths students, and Congress passed the act that created NASA. Sputnik 2 had already carried the dog Laika into orbit on 3 November 1957; she died of overheating within hours, a fact the Soviet government hid until 2002. America's first satellite, Explorer 1, followed on 31 January 1958.

On 12 April 1961, Yuri Gagarin flew one orbit of the Earth in Vostok 1, about 108 minutes from launch to landing according to the official figure (a later analysis puts it at 106). "Poyekhali!" ("Let's go!"), he said at lift-off. What the Soviet Union hid for ten years was that he ejected about 7 km up and came down by parachute separately from his capsule, a detail that, under the rules then in force, could have disqualified the flight as a record; it was not admitted until 1971. Alan Shepard became the first American in space on 5 May 1961, with a 15-minute flight that went up and came down without orbiting.

Three weeks later, on 25 May 1961, President John F. Kennedy asked Congress to commit the United States to landing a man on the Moon and returning him safely to Earth before the decade was out.

The programme that followed, Apollo, became one of the largest engineering projects in history. At its peak about 400,000 people worked on it. It had a terrible start: on 27 January 1967, a fire during a ground test killed Gus Grissom, Ed White and Roger Chaffee inside their capsule, filled with pure oxygen and fitted with a hatch that opened inward and could not be opened in time. Crewed flights stopped for about 20 months while the spacecraft was redesigned. In December 1968, Apollo 8 became the first crewed mission to leave Earth orbit and circle the Moon.

Apollo 11 launched on 16 July 1969. On 20 July, Neil Armstrong stepped onto the Moon: "That's one small step for a man, one giant leap for mankind." He and Buzz Aldrin spent 21 hours and 36 minutes on the surface while Michael Collins orbited above. They splashed down in the Pacific on 24 July.

The Soviet Union ran its own crewed lunar programme. Its giant N1 rocket was launched four times between February 1969 and November 1972, and all four launches failed; the second exploded on the pad. Korolev had died in January 1966. The programme was halted in 1974. The race was over.

Apollo 13, in April 1970, showed how close to the edge it all ran: an oxygen tank exploded on the way to the Moon, and the crew survived by using their lunar lander as a lifeboat. Apollo 17 in December 1972 was the last. No one has walked on the Moon since.

Part 4 — The Space Shuttle, its two disasters, and the station it built

After Apollo, NASA built a spacecraft meant to be reusable. The Space Shuttle was a winged orbiter that launched like a rocket, with two solid rocket boosters and a huge external fuel tank, and landed like a glider. The boosters were recovered from the ocean and refurbished; the tank was thrown away. Each orbiter was designed for about 100 flights.

It first flew on 12 April 1981, twenty years to the day after Gagarin. Over 30 years it flew 135 missions, could carry 27.5 tonnes to low orbit at a time, and helped build the International Space Station. It was a superb machine in many ways. It was not cheap. NASA's own analysis, by Harry Jones of NASA Ames Research Center in 2018, put a Shuttle launch at about $1.5 billion averaged over the programme, or about $54,500 per kilogram to low orbit. Refurbishing the orbiter and boosters between flights turned out to be slow, painstaking and expensive.

It also killed fourteen people.

Challenger, 28 January 1986. Seventy-three seconds after launch, Challenger broke apart, killing its seven crew, including the schoolteacher Christa McAuliffe. The presidential commission traced the cause to rubber O-rings sealing a joint in the right solid rocket booster. On that unusually cold morning they failed to seal, and hot gas burned through to the external tank. Before the launch, engineers at the booster's maker, Morton Thiokol, had recommended against launching below 53 °F (about 12 °C); NASA managers pushed back, and Thiokol's senior managers overruled their own engineers. The commission called it "an accident rooted in history": the O-ring problem had been known for years. During a televised hearing, the physicist Richard Feynman dropped a piece of O-ring material, squeezed in a clamp, into a glass of iced water and showed that it lost its springiness when cold. His appendix to the report ended with a line every engineer should know:

"For a successful technology, reality must take precedence over public relations, for nature cannot be fooled." Richard Feynman, 1986

Columbia, 1 February 2003. Eighty-two seconds after Columbia's launch on mission STS-107, a large piece of foam insulation broke off the external tank and struck the left wing, damaging the carbon heat shielding on its front edge. On re-entry at the end of the mission, superheated gas entered the wing and destroyed it, and all seven crew died. The investigation board found the deeper cause in the organisation: foam had hit orbiters on earlier flights, and managers had come to treat it as an acceptable risk. It recommended, among 29 recommendations, that the Shuttle be retired. The last Shuttle flight landed in July 2011.

Two disasters, two different physical causes, one shared pattern: a known warning sign became normal because nothing bad had happened yet. Feynman had seen the same thing in the numbers: his appendix criticised NASA's wildly optimistic estimates of how reliable the Shuttle was.

The International Space Station is the Shuttle's most lasting legacy. Its first module, Zarya, launched on 20 November 1998, and people have lived on board continuously since 2 November 2000, nearly 26 years by the end of October 2026. It weighs about 450 tonnes, and five space agencies run it: NASA, Roscosmos, the European Space Agency, Japan's JAXA and the Canadian Space Agency, with fifteen countries involved. It is planned to operate until the end of 2030; in June 2024 NASA chose SpaceX, in a contract worth up to $843 million, to build a vehicle that will steer it into a controlled re-entry away from populated areas. Commercial stations are being developed to follow it.

Part 5 — Rockets that land, and a crowded sky

The obvious fix for "build an airliner, crash it into the sea" is to land the rocket and fly it again. It took a long time to make that work, because of the rocket equation: every kilogram of landing legs, fins and fuel saved for the landing is a kilogram of payload you can't carry.

SpaceX's Falcon 9 first flew on 4 June 2010. In December 2015, a Falcon 9 first stage, after sending satellites on their way, flipped round, fired its engines to fly back, and landed upright on a landing pad: the first time the main stage of an orbital rocket had come back for a controlled landing. On 30 March 2017 a booster that had already flown launched again. By 2025 individual boosters had flown 30 times, and SpaceX's certified limit had risen to 40 flights each. As of 31 October 2026, according to the running record kept on Wikipedia, Falcon 9 had flown 700 times, with 697 fully successful missions.

What did that do to prices? Jones's 2018 NASA analysis compared the Shuttle's $54,500 per kilogram with SpaceX's advertised Falcon 9 price at the time, $62 million for up to 22,800 kg, which works out to about $2,720 per kilogram. "Commercial launch," he concluded, "has reduced the cost to LEO by a factor of 20."

Three honest caveats. First, these are list prices for a whole rocket at its full capacity, not what a typical customer pays for each kilogram it actually sends. Second, the list price has risen since 2018. Third, outside estimates put SpaceX's internal cost per launch well below its price, which matters because about three-quarters of Falcon 9 launches in 2025 (122 of 162) carried SpaceX's own Starlink satellites. Still, the fall in cost is real and large, and it changed what is worth launching.

Starship, SpaceX's much larger fully reusable system, has had a mixed and fast-moving test campaign. On 13 October 2024 its giant first stage was caught by mechanical arms on the launch tower on its return. In 2025 several flights failed, others succeeded. The third version of the rocket first flew on 22 May 2026, and on 28 September 2026 Starship reached orbit for the first time, releasing 26 Starlink satellites. As of late October 2026 it had not yet caught its upper stage, or demonstrated the ship-to-ship transfer of propellant in orbit that SpaceX's Moon-lander plan relies on. SpaceX says full reuse will cut costs far further; that has not been shown yet.

Other countries are following. In 2026, Chinese rockets were reported to have recovered first stages too, including the privately built Zhuque-3 in August.

A crowded sky: mega-constellations and debris

Cheap launches changed what goes up. Here is the number of orbital launch attempts worldwide, from the catalogue maintained by the astrophysicist Jonathan McDowell:

In 2025, SpaceX alone launched roughly half of all the world's orbital rockets.

Most of that cargo is communications satellites flying in huge swarms, or mega-constellations, in low orbit, from a few hundred to about 1,200 kilometres up, beaming internet to users on the ground. As of 29 October 2026, McDowell's count showed SpaceX had launched 13,069 Starlink satellites, of which 11,190 were still in orbit and 1,879 had come back down and burned up. Amazon's system, launched as Project Kuiper and renamed Amazon Leo in November 2025, had launched just under 400 satellites; it missed a US licensing deadline to have about half of its 3,236 planned satellites up by July 2026, and the regulator granted a waiver. China's state-backed Guowang network plans more than 13,000 satellites and had about 200 operating by September 2026; a second Chinese network, Qianfan, had about 250 launched. OneWeb has launched about 650.

Boosters say these networks bring fast internet to ships, aircraft, remote villages and disaster zones that cables will never reach. Critics worry about one company, or one government, controlling so much infrastructure, about the satellites' military uses, and about crowding.

That last worry has a name: the Kessler syndrome. In June 1978 the scientists Donald Kessler and Burton Cour-Palais warned that once enough objects are in orbit, collisions create fragments that cause more collisions, a chain reaction that could make some orbits unusable for generations. Some events since have made it worse: in January 2007 China destroyed one of its own old weather satellites, about 865 km up, with a missile; in February 2009 two satellites collided by accident; in November 2021 a Russian anti-satellite test destroyed an old Soviet satellite, creating about 1,500 tracked fragments that crossed the orbits of both the ISS and China's Tiangong station.

ESA's report states the problem bluntly: even if no more launches happened, the amount of debris would keep growing through collisions, so actively removing old objects will be needed. The saving grace of very low orbits is drag: the thin upper atmosphere pulls satellites down within years, which is why so many dead Starlinks have already burned up. Higher orbits have no such cleaner.

Low orbit cleans itself, slowly. Higher up, every piece of junk stays for decades or centuries.

Part 6 — The state of affairs in late 2026

The United States and Artemis. NASA's Artemis programme aims to return people to the Moon. Artemis I flew an uncrewed Orion capsule around the Moon in 2022. On 1 April 2026, Artemis II launched four astronauts (NASA's Reid Wiseman, Victor Glover and Christina Koch, and Canada's Jeremy Hansen) on a nine-day flight around the Moon, splashing down in the Pacific on 10 April. Koch became the first woman and Glover the first person of colour to travel beyond low Earth orbit, Hansen the first non-American to fly around the Moon, and the crew travelled about 406,771 km from Earth, beyond Apollo 13's record. In early 2026 NASA restructured the next steps: according to NASA's Artemis pages (updated in October 2026), Artemis III, planned for 2027, will now stay in low Earth orbit to test docking between Orion and test versions of the SpaceX and Blue Origin landers, and Artemis IV, planned for 2028, is to be the first crewed landing since 1972. Both landers still have major tests ahead, and NASA's schedules have slipped repeatedly before.

More than fifty years after Apollo 17, people have flown around the Moon again. Nobody has yet walked on it again.

China. China has built and runs its own space station, Tiangong, completed in 2022 and usually crewed by three astronauts; China was effectively kept out of the ISS after a 2011 US law barred NASA from direct cooperation with Chinese space agencies. In June 2024 its Chang'e 6 mission brought back about 1.9 kg of rock from the far side of the Moon, the first samples ever returned from there. China's human spaceflight agency announced in 2023 a plan to land two astronauts on the Moon before 2030, using a new Long March 10 rocket, a Mengzhou crew capsule and a Lanyue lander. Its 2025 tally of 92 orbital launch attempts was second only to the United States.

India. On 23 August 2023, India's Chandrayaan-3 made the first soft landing near the Moon's south pole, making India the fourth country to land on the Moon, at a reported cost of around 615 crore rupees (under $100 million). Its Gaganyaan programme is preparing India's first crewed spacecraft; the first uncrewed test flight had not flown as of late October 2026. In July 2026 Vikram-1, built by the private company Skyroot, reached orbit.

Japan and Europe. On 19 October 2026 (UTC), Japan launched MMX on its new H3 rocket, a mission to bring back samples from Phobos, one of the moons of Mars. Europe's new heavy rocket, Ariane 6, first flew in its most powerful four-booster form on 12 February 2026, and on 5 September 2026 Isar Aerospace's Spectrum rocket, launched from Andøya in Norway, made what is reported as the first successful orbital launch from Western European soil.

Russia. Russia continues to fly cosmonauts and cargo to the ISS on Soyuz and Progress spacecraft. Its launch rate has fallen sharply from the Soviet era: 17 attempts in 2025, compared with 108 by the Soviet Union in 1982.

Rules. The 1967 Outer Space Treaty, with 118 parties as of October 2025, forbids any nation from claiming the Moon or other bodies, bans nuclear weapons in orbit, and makes states responsible for their companies' activities in space. The US-led Artemis Accords, first signed in October 2020 and joined by 78 countries as of 28 October 2026, set out principles for lunar exploration, including the use of resources mined in space. Russia has called them an attempt to write space law in America's favour, and China and Russia are developing a separate International Lunar Research Station with their own partners. Supporters see the Accords as practical rules for a busier Moon; critics see them as stretching the treaty's ban on appropriation.

Part 7 — Open questions and trade-offs

People or robots? Robotic missions are far cheaper and take no human risk. Chang'e 6 brought back far-side samples without a crew. Supporters of human spaceflight answer that people do science in the field that robots can't, that crewed missions inspire public support and students, and that a species confined to one planet takes a long-term risk. The ISS has at least shown that people can live and work in orbit without a break for more than a quarter of a century; whether that justifies its cost compared with dozens of robotic missions is exactly the disagreement. These are judgements about value, not just engineering, and reasonable people weigh them differently.

Who pays, and who benefits? Launch prices fell because a private company built reusable rockets, helped by NASA contracts. Supporters see the best of public-private partnership; critics see one company becoming hard to do without, for launches, internet service and even astronaut transport. Both describe the same facts.

Can low orbit be kept usable? Mega-constellations, anti-satellite tests and dead rocket bodies all add risk. To see how fast things have changed: at the end of 2024, ESA counted about 11,000 active satellites of all kinds; by late October 2026, SpaceX alone had about 11,000 working Starlinks. Very low orbits and planned de-orbiting limit the risk from each satellite, but ESA warns that debris would keep growing even if launches stopped. Debris removal is still at the demonstration stage, and there is no global traffic-control system for space.

What is it worth? Apollo cost about $257 billion in 2020 dollars; India's Chandrayaan-3 landed near the Moon's south pole for a reported 615 crore rupees, under $100 million, roughly three thousand times less (Apollo carried people and returned rock, so this is not a like-for-like comparison). Falling costs mean the question is shifting from "can we afford to go?" to "what is worth doing once we are there?", and that is a question about science, money and values, not just rockets.

How safe can crewed spaceflight be? The Shuttle lost two of its 135 missions, about one flight in 68, and the Apollo 1 fire killed three more astronauts on the ground. No airliner would be allowed to fly with odds anything like that. Riding on top of hundreds of tonnes of burning propellant remains far riskier than any form of everyday travel. How much risk is acceptable, for professionals, for paying tourists, for a Moon landing, is a question each programme answers differently.

Cheaper rockets turned "can we afford to go?" into "what is worth doing once we're there?"

Will space stay peaceful? The 1967 Outer Space Treaty bans nuclear weapons and other weapons of mass destruction in orbit. The anti-satellite tests of 2007 and 2021 used ordinary missiles, and both left long-lived debris that every other operator now has to dodge. Satellites now matter to navigation, communications, finance and armies alike, which makes them both more valuable to protect and more tempting to attack, and the rules on conventional weapons in space are far thinner than the rules on nuclear ones.

Is there a new race? The United States plans a crewed landing in 2028, China before 2030. Some see a rivalry like the 1960s; others point out that the two programmes have different partners, legal frameworks and goals, and that the US-led Artemis Accords and the China-Russia lunar station project are building two different clubs rather than one finish line.

And the oldest lesson in this story still holds. Challenger and Columbia were not lost to unknown physics. They were lost to warnings that had become routine. Feynman's line applies to every rocket that flies now: nature cannot be fooled.

The takeaway

Rockets began as Chinese fire arrows; the science of spaceflight came from three isolated dreamers, Tsiolkovsky, Goddard and Oberth, and one equation. Because the propellant has to lift itself, the rocket equation forces a kerosene rocket to be about 96% propellant to reach orbit, which is why rockets have stages and why throwing them away made spaceflight so expensive. The first rocket into space, the V-2, was built by concentration-camp prisoners, and more of them died making it than were killed by it. Sputnik, Gagarin and Apollo were driven by Cold War rivalry; the Shuttle was reusable but cost about $54,500 per kilogram, and its two disasters came from normalised warnings. Rockets that land cut costs to roughly a twentieth, and launch rates hit a record 329 attempts in 2025. In late 2026 the sky is filling with constellations and debris, Artemis II has flown around the Moon, and both the US and China aim to land people there before 2030.

Try this: test the rocket equation yourself with a calculator. Pick an exhaust speed of 3 km/s and work out e^(Δv ÷ 3) for Δv = 3, 6 and 9.4 km/s. Notice how the mass ratio goes from about 2.7 to 7.4 to 23: tripling the speed you need multiplies the propellant, it doesn't triple it. Then find the next launch on a public launch schedule and watch the first stage come home.

Sources & Further Reading

Sources
- Early rockets (Hero's aeolipile, Chinese fire-arrows, 1232 Kai-Keng, the Wan Hu legend, Indian rocket barrages of 1792 and 1799, Congreve, Fort McHenry), Tsiolkovsky's 1898/1903 work, Goddard's 16 March 1926 flight (2.5 s, 12.5 m, 56 m), Oberth's 1923 book, V-2 propellant use: NASA Glenn Research Center, "Brief History of Rockets".
- Goddard ("Nell", 1919 paper, 1920 New York Times editorial and 1969 correction, 214 patents); Tsiolkovsky (1857–1935, equation dated 10 May 1897, May 1903 paper, 1911 letter); Oberth (rejected dissertation, 1923 book, Woman in the Moon, VfR); the rocket equation's history (Moore 1810): Wikipedia articles on each, used for leads and cross-checked.
- V-2 production, prisoner labour and deaths, deaths from attacks, numbers fired, and its role as ancestor of launch vehicles: Smithsonian National Air and Space Museum, V-2 (A-4) object record. V-2 altitude record (174.6 km, 20 June 1944), first combat use, range: Wikipedia, "V-2 rocket". Von Braun's party and SS membership, Mittelwerk visits, Paperclip: Wikipedia, "Wernher von Braun".
- Sputnik 1, Sputnik 2, Explorer 1, ARPA and NDEA: Wikipedia, "Sputnik 1". Vostok 1: Wikipedia, "Vostok 1". Freedom 7: Wikipedia. Apollo 11 timeline and quote: NASA, "Apollo 11 Mission Overview". Apollo programme figures: Wikipedia, "Apollo program"; Apollo 1: Wikipedia, "Apollo 1"; N1: Wikipedia, "N1 (rocket)"; Saturn V: Wikipedia.
- Shuttle: Wikipedia, "Space Shuttle"; Challenger: Rogers Commission findings and Feynman's appendix (via Wikipedia, "Rogers Commission Report"); Columbia: Wikipedia, "Columbia Accident Investigation Board". Shuttle and Falcon 9 cost per kilogram and the factor of 20: Harry W. Jones, "The Recent Large Reduction in Space Launch Cost", NASA Ames Research Center, ICES 2018 (NASA Technical Reports Server).
- ISS: Wikipedia, "International Space Station"; US Deorbit Vehicle: NASA news release, 26 June 2024.
- Delta-v to orbit (9.3–10 km/s): Wikipedia, "Delta-v budget"; exhaust speeds (Merlin 1D 310 s, RS-25 453 s): Wikipedia, "Specific impulse". Falcon 9 mass, payload, first flight, 700 launches as of 31 October 2026, 2026 list price: Wikipedia, "Falcon 9"; booster reuse milestones: Wikipedia, Falcon 9 booster list.
- Starship flight history: Wikipedia, "SpaceX Starship flight tests", with the 28 September 2026 orbital flight and its 26 Starlink payloads cross-checked in Jonathan McDowell's launch log.
- Orbital launch attempts by year and country: Jonathan McDowell, General Catalog of Artificial Space Objects, table updated 26 October 2026; SpaceX share computed from his launch log (updated 29 October 2026). Starlink totals: McDowell, Starlink statistics page (29 October 2026). Amazon Leo: Wikipedia, "Amazon Leo"; Guowang: Wikipedia, "Guowang".
- Debris: ESA, "ESA Space Environment Report 2025"; Kessler and Cour-Palais (1978), ASAT tests and the 2009 collision: Wikipedia, "Kessler syndrome".
- Artemis II: NASA, Artemis II mission page; record distance and crew firsts: Wikipedia, "Artemis II". Artemis III and IV plans: NASA, Artemis III mission page (updated 19 October 2026) and Artemis programme page (updated 21 October 2026).
- China: Wikipedia, "Tiangong space station", "Chang'e 6", "Lanyue". India: Wikipedia, "Chandrayaan-3", "Gaganyaan". 2026 launches (Ariane 64, Spectrum, Vikram-1, Zhuque-3, H3/MMX): Wikipedia, "2026 in spaceflight", cross-checked in McDowell's launch log. Outer Space Treaty and Artemis Accords: Wikipedia articles of those names.
- Computed in Python: mass ratios and propellant fractions (e^(9.4/3.0) = 23.0, 95.6%; e^(9.4/4.4) = 8.5, 88.2%; two-stage e^(4.7/3.0) = 4.8, 79%), payload fractions (Falcon 9 4.2% and 3.2%; Saturn V about 5%), kinetic energy per kilogram at 7.8 km/s (30.4 MJ, against 43 MJ/kg for kerosene), 2026 Falcon 9 price per kilogram.

Go deeper
- 🌐 NASA Glenn: Brief History of Rockets — a short, clear history from Hero to the V-2, written for students
- 🌐 Jonathan McDowell's space statistics — the independent, constantly updated count of every launch, used by journalists and researchers
- 🌐 ESA Space Environment Report 2025 — the authoritative yearly picture of space debris
- 🌐 NASA: Artemis — the current Moon plans, from the source (check the "updated" date)
- 📘 A Man on the Moon — Andrew Chaikin (the definitive narrative of Apollo, built on interviews with the astronauts)
- 📘 Von Braun: Dreamer of Space, Engineer of War — Michael J. Neufeld (a Smithsonian historian's balanced biography, honest about Mittelwerk)
- 📘 "What Do You Care What Other People Think?" — Richard Feynman (includes his own account of the Challenger investigation)