Fol. 201r, Conrad Haas: the three-stage rocket on the left and a separate design on the right. The date “1529” and initials “C H” are visible above. The folio follows the illustration concordance in the KdiH catalogue.

Sibiu, Romania · Conrad Haas · sixteenth century

A three-stage rocket.
In an armourer’s
notebook.

In the sixteenth century, Conrad Haas drew rockets in stages. Historians explain how they fired in sequence. Look inside, then decide what stays on board.

Open the rocket ↓Try it yourself ↗

↓ Scroll to look inside

In this story

The original drawing
Conrad Haas · 1529
View the document and attribution ↗

A handwritten date

1529. What does this number date? ↗

At the top of the leaf, on one of the separately drawn components, you can see 1529 and the initials C H. These are concrete marks on the page. They must be read alongside the rest of the book, where the dates do not follow chronological order.

The Bavarian Academy catalogue notes late dates on drawings near the beginning of Haas’s section and earlier dates further on. They may refer to designs or preliminary drawings. A dated leaf does not make the whole volume a continuously written diary.

Handschriftencensus uses 1529–1569; KdiH records drawing dates through 1568. KdiH ↗ · Handschriftencensus ↗

Three bodies in one cutaway

One rocket inside another. And another. ↗

In the left-hand drawing, the outer body encloses the green one, which encloses the red one. Their flared mouths appear at different heights. The drawing reveals the exterior and internal arrangement at the same time.

Hans Barth transcribes Haas’s description as “Drey Rackett ineinander geschoben”: three rockets inserted into one another. The colours help the eye follow the parts. We have no original legend that turns them into codes for three different fuels.

The digital cutaway separates the bodies so that you can inspect their relationship. This opening for inspection is not a stage in a historical flight.

The three-stage drawing is figure 2 in Carafoli and Nita’s study, p. 5. Barth ↗ · Carafoli–Nita ↗

Material matters

The cover could be paper. ↗

A rocket in a sixteenth-century notebook should not automatically be imagined as a metal cylinder. Carafoli and Nita describe a treated paper cover that burned with the propellant. Their passage refers explicitly to the two-stage drawing.

For the three-stage drawing, they say the operation was similar. Paper is therefore an interpretation supported by their explanation, with that limit. The model’s fibres, thickness and irregularities are digitally constructed; the drawing does not measure them.

Carafoli and Nita, pp. 4–5. This model does not reproduce a surviving, measured historical object. Carafoli–Nita ↗

Look at the edge

A cover has thickness too. ↗

Move closer to the open edge. The model shows overlapping sheets, short fibres and a rim that is not perfectly regular. These details make a flexible paper material understandable, rather than presenting a smooth surface with no thickness.

In his discussion of rocket-making craft, Barth describes cases formed from several glued layers of paper. That passage does not establish how many sheets were used in this leaf’s rocket. The visible layer count, curvature and opening of the wall belong to the digital interpretation.

The original suggests thickness with outlines and hatching. Compare the model’s edge with the small detail from the drawing: that is where the direct visual evidence ends.

Barth, “Haas und seine Leistung”. Colours and hatching can be inspected in the original scan. Barth ↗ · Commons ↗

A repeated part

Discs with a central mark. ↗

A round component with a small central mark repeats in the drawn bodies. Hatching around its edge suggests thickness. The surrounding letters point to the manuscript’s explanations.

Here you can examine one close up, brought forward from the cutaway. The model preserves its general shape and central mark, without assigning a verified material or a mechanical function established by this project. We do not automatically call it a valve, injector or separation device.

That restraint matters: an old technical drawing can easily become too modern if every familiar-looking part receives the name of a present-day mechanism.

The shape and central mark are visible on fol. 201r; this reproduction does not establish whether the mark represents an opening. Their exact function is not established in this explanation. Commons ↗

A detail at the opening

There is a star inside. ↗

At the mouth of the inner body, the drawing shows a radially divided shape. Dark outlines meet at its centre. The model’s top view follows this detail, which is easy to miss when looking at the entire leaf.

Carafoli and Nita separately discuss a star-shaped charge in some manuscript rockets and compare it with the burning surface of modern solid propellants. That is their technical reading. This reproduction does not establish channel dimensions, a burn profile or a manufacturing recipe.

The geometric resemblance is enough to deserve a closer look. It is not enough to calculate this rocket’s performance.

Carafoli and Nita, p. 6; detail visible in the scan of fol. 201r. Carafoli–Nita ↗ · Commons ↗

At the end of each body

The mouths flare outwards. ↗

At the base of the large body, the shape narrows and then opens like a bell. A similar outline appears at the ends of the smaller bodies inside the cutaway.

Barth draws attention to these bell-shaped outlets. A present-day reader may immediately think of a modern rocket nozzle. The drawn shape alone, however, does not supply a measured profile, gas pressure or expansion efficiency.

The model shows a flared mouth following the page’s outline. Its internal surfaces and lip thickness are interpretive. In the equation you will use below, effective exhaust velocity will be an explicit assumption.

We do not identify this as a calculated, tested modern nozzle. Barth ↗ · NASA ↗

The same leaf, a different design

The bindings belong to the adjacent rocket. ↗

The right-hand drawing has a red element, a smaller tube and crossed green bindings. It also has its own inscription. These parts should not be transferred, for convenience, to the three-stage rocket on the left.

Barth identifies this as a rocket intended to travel out and return. In his reading, two chambers exhaust in opposite directions, with the second igniting for the return. That is an intention described by a historian, without a measured trajectory here.

The adjacent object is now a separate interpretation of this second drawing. Its bindings follow the visible crossings. The red element’s function remains unspecified; we do not present it as a proven ignition path for the three-stage rocket.

Barth, “Haas und seine Leistung”, discussion of fols. 201 and 205, figs. 18–19. Barth ↗ · Commons ↗

Choose a motor

One motor begins. The next carries on. ↗

Carafoli and Nita explain successive ignition through the two-stage drawing: the first motor sets the assembly in motion, then flame reaches the second motor’s propellant.

On the next page they describe the three-stage rocket’s operation as similar. Select the motors in turn to follow this reading. In a working object, the construction would determine the sequence; in this explanation, you choose when the view changes.

The flame is illustrative. It does not indicate a historical temperature, jet length or burn duration.

Carafoli and Nita, pp. 4–5. We have no recording here of the actual ignition sequence. Carafoli–Nita ↗

Scroll to consume the cover

What remains after the burn? ↗

Paper changes how the first stage should be imagined. In Carafoli and Nita’s explanation, the cover burned with the propellant. Once the first stage was exhausted, the next motor continued as an independent body.

Their passage concerns the two-stage rocket; extending it to three relies on their statement that it worked similarly. The disappearing cover is an illustration of that interpretation, controlled by scrolling.

Below, you will do something different: in a modern experiment, decide whether to release an empty casing that has remained intact. This isolates the problem of mass and does not claim to reconstruct Haas’s separation system.

Neither the disappearance rate nor the shape of the charred edge is a historical measurement. Carafoli–Nita ↗

Why does a rocket move?

Gas goes one way. The body goes the other. ↗

A rocket does not need to push against air to propel itself. It expels gas and changes its motion in the opposite direction. The arrows show those directions only; their lengths are not a scale of velocities or forces.

As propellant is consumed, the remaining mass changes. If a motor also has to accelerate empty covers, the same amount of propellant produces a different result from leaving those covers behind.

The ideal rocket equation expresses that relationship through a mass ratio and effective exhaust velocity. It is a modern explanation used here to understand the principle.

NASA Glenn, “Ideal Rocket Equation”. Effective exhaust velocity includes pressure’s contribution to thrust. NASA ↗

A drawing and a trial are different evidence

What was tested in 1555? ↗

In his 1969 article, Doru Todericiu argued that the principles of the three-stage rocket were tested in Sibiu in 1555. Carafoli and Nita mention successful experiments with the preceding, two-stage type, without dating them in that passage. These are not two confirmations of a single flight by the rocket drawn here.

Among the documents checked for this page, we have not identified a contemporary test log, an independent flight account or performance measurements. We cannot infer an altitude from them or claim that this digital model reproduces that flight.

Our failure to identify such evidence does not prove the trial never happened. It establishes the limit of this explanation: we can examine the drawing and historians’ readings, then test a physical principle separately.

Todericiu, 1969, pp. 475–479; Carafoli and Nita, p. 5. Image: two-stage drawing, figure 1, p. 4. Todericiu ↗ · Carafoli–Nita ↗

Your turn · a modern experiment

What is worth leaving behind? ↗

The rocket, fuel and payload stay the same. After each of the first two burns, decide whether to keep the empty casing. The next motor must accelerate everything you keep.

An ideal model, without air or gravity. It shows a change in velocity, not the altitude or performance of the historical rocket.

You decide what the next motor carries.

Compare all four choices

Casings left behind	Δv	Mass still on board
Neither	347 m/s	7.8 kg
First	460 m/s	4.5 kg
Second	373 m/s	5.6 kg
Both	557 m/s	2.3 kg

Δv = vₑ ln(m₀ / m₁)

This example uses 6 kg of propellant, 6.6 kg of structure, a 1.2 kg payload and a specific impulse of 62 s. These are demonstration values. The final casing stays on board.

Back to the evidence

One notebook. Four contributions. ↗

The volume now called the Sibiu Manuscript brings together texts from different periods. Haas worked in a book begun before him. Haas had worked at the city’s arsenal since 1551. The manuscript was discovered in Sibiu’s State Archives in 1961.

1–36
Hans Haasenwein
Fireworks text; the copy was completed in 1458.
37–68
Anonymous author
An artillery manual from the late fifteenth century.
69–111
Johannes Formschneider?
Military picture collection; the attribution is uncertain.
112–392
Conrad Haas
Artillery and pyrotechnics. Catalogues differ slightly on the section’s boundaries.

A volume bringing several separately written texts together is a composite codex. Its 392 leaves are not 392 pages: each leaf has two sides. The catalogue describes a format of approximately 21 × 16 cm. The book containing this history is physically much smaller than its image on your screen.

Haas records his origin in Dornbach, near Vienna. In Sibiu, the catalogue identifies him as arsenal master from 1551. His section covers powders, military fires and recreational fires, with a particular interest in rockets. Weapons and fireworks belong to the same technical culture.

The 203 drawings attributed to Haas’s part are partly coloured. The catalogue lists green, yellow, violet, red, brown, blue and ochre. Colour is one of the tools used to make components and cutaways easier to follow.

Handschriftencensus dates Haas’s part to 1529–1569; the Bavarian catalogue records dates on drawings up to 1568. The Bavarian Academy catalogue counts 392 leaves and attributes 203 drawings to Haas’s part. The original is at Romania’s National Archives in Bucharest, Ms. 2286. A facsimile is registered in Sibiu as Varia II 374. KdiH ↗

Sibiu · 1961

The manuscript was known. Its significance emerged later. ↗

Writing in 1969, Doru Todericiu recalled encountering the manuscript eight years earlier during research in Sibiu. Archive catalogues already listed it as an old work on ballistics and pyrotechnics. Recognising its significance for rocket history changed the way it was read.

That is why “discovered in 1961” needs care. The volume did not emerge then from an unknown place. Research drew attention to the technical contents of a book that had already been preserved and catalogued.

Its shelf mark also needs attention. Current descriptions locate the original at Romania’s National Archives in Bucharest, Ms. 2286. Varia II 374, the number long associated with the Sibiu story, is listed by Handschriftencensus for the facsimile. These are different objects with different roles.

Todericiu, 1969, p. 475; KdiH and Handschriftencensus for the physical description and current shelf marks. Todericiu ↗

From one page to another

An idea in a manuscript. Other rockets in print. ↗

Haas worked in a world where technical knowledge circulated through drawings, manuscripts, workshops and printed books. The Bavarian catalogue compares him with Johann Schmidlap and Leonhart Fronsperger. It conditionally suggests that some texts or drawings may have served as models for printed works.

The chronology below preserves that caution. Schmidlap’s 1561 and 1564 editions are those named by KdiH; we do not declare them the work’s first editions. In 1650, Kazimierz Siemienowicz’s Artis Magnae Artilleriae Pars Prima appeared in Amsterdam.

The plate from that treatise shows rockets mounted to sticks. The engraving uses numbers and regular outlines; Haas’s leaf uses letters, colour and handwritten notes. You can compare ways of communicating a construction. Chronological order and visual similarity do not by themselves establish direct copying.

1529Haas · the date visible in the drawing on fol. 201r
1561 · 1564Schmidlap · editions named by KdiH
1568 / 1569Haas · late drawing dates (1568, KdiH); end of the catalogue date range (1569, Handschriftencensus)
1650Siemienowicz · book printed in Amsterdam

Drawing and catalogue dates, named editions and a printed treatise. The sequence is not a demonstrated chain of transmission.

Plate G, “Rockets mounted to sticks”, from Artis Magnae Artilleriae, Amsterdam, 1650. Engraving by Jacob van Meurs; treatise author: Kazimierz Siemienowicz. Courtesy of Science History Institute. Public domain. Science History Institute ↗

Conrad Haas · Sibiu

And a little house, above the rockets. ↗

Haas also drew this structure carried by rockets. The image shows the reach of the notebook’s technical imagination. It does not establish that a flying house was built or carried people.

Barth reads the “flying little house” in the context of fireworks. He cites Haas’s explanation of a tower-like form covered with paper and painted, and rejects a hasty interpretation as a craft for space travel.

Seen this way, the house becomes easier to understand within the notebook’s world: a spectacular shape for recreational fire. Its resemblance to a capsule in a modern reader’s eyes also reveals something about that reader’s expectations.

1894 → 1923

Sibiu appears again in rocket history.

Hermann Oberth was born in Sibiu in 1894. His 1923 book on rockets into interplanetary space became an important work in astronautics. We have no evidence here of a direct transmission of ideas from Haas’s notebook to Oberth’s book. ROSA ↗

The “flying house”, attributed to Conrad Haas. A design illustrated in the manuscript; flight performance unknown.
Conrad Haas · Wikimedia Commons · Public domain

At the end of the notebook

The armourer who recommended peace. ↗

In the advice transcribed by Hans Barth, Haas recommends peace: the guns stay under cover, the shot is not fired, the ruler keeps his money and the armourer his life.

Paraphrased from Barth, who identifies fol. 377. Carafoli and Nita record the peace advice on p. 7. The passage has not been checked directly in a facsimile of that leaf. Barth ↗ · Carafoli & Nita ↗

What we know. What we interpreted. ↗

The drawings are historical documents. The 3D cutaway is a visual interpretation of them. Fibres, thicknesses, layers and surface curvature are digitally constructed, without measurements of a surviving object. The right-hand drawing’s bindings appear in a separate model. The experiment uses the ideal rocket equation and chosen masses to isolate the effect of empty casings. Neither its velocities nor its animation durations are measurements of a Haas flight.