# Sea Dragon (DD-498)

> Sea Dragon was a 1962 concept for a huge two-stage rocket designed by Robert Truax at Aerojet. It would be built cheaply in a shipyard, towed to sea, ballasted upright and launched from the water, avoiding a launch pad. The first stage burned RP-1 and liquid oxygen, the second liquid hydrogen and oxygen, and it was meant to lift about 550 tonnes to low Earth orbit. It was never built. The footage, credited to newspaceenterprise, shows an animation of the launch.

- Department: Space (also History)
- First published: 2025-02-25
- Last updated: 2025-02-25
- Permalink: https://detailenjoyer.com/case/sea-dragon/
- Author: Marcus Easterling (DetailEnjoyer), The Detail Department

## On the timeline

- **1962**: Sea Dragon design proposed

Full timeline: https://detailenjoyer.com/timeline/?case=sea-dragon

## Quick facts

- **DD-498-F01**: 1962. _(Write-up · Exhibit A (Year))_
- **DD-498-F02**: Robert Truax, Aerojet. _(Write-up · Exhibit B (Designer))_

## Write-up

Sea Dragon would have launched from the ocean, floating upright. It was designed to lift about 550 tonnes.

1. **Year**: 1962.
2. **Designer**: Robert Truax, Aerojet.
3. **Launch**: From the ocean.
4. **Fuel**: RP-1/LOX first stage.
5. **Payload**: About 550 t.

## Related case files

- [Delta IV Heavy (DD-374)](https://detailenjoyer.com/case/delta-iv-heavy/): I linked another heavy-lift rocket

## Reel vs. record

- **Note**: None needed.

## Video: Sea Dragon: Sea Dragon Would Have Launched From the Ocean, Floating Upright

- Duration: 21.8 s · Published: 2025-02-25
- File: https://detailenjoyer.com/assets/videos/DGg_6ycSXM_.mp4

### Transcript

[...] a conceptual heavy [...] 1960s by Aerojet [...] capable of carrying [...] Unlike traditional [...] ocean launch, [...] two-stage [...] or RP-1/LOX, [...] NOW YOU KNOW!

## Questions & answers

**Q: Launch site?**  
A: Floating. _(Source: Write-up · Exhibit A (Year) · Wikipedia: Sea Dragon (rocket))_

**Q: Designer firm?**  
A: Truax. _(Source: Write-up · Exhibit B (Designer) · Wikipedia: Sea Dragon (rocket))_

**Q: Stages?**  
A: Simple. _(Source: Write-up · Exhibit C (Launch) · Wikipedia: Sea Dragon (rocket))_

**Q: First-stage fuel?**  
A: Kerosene. _(Source: Write-up · Exhibit D (Fuel) · Wikipedia: Sea Dragon (rocket))_

**Q: Was it built?**  
A: Concept. _(Source: Write-up · Exhibit E (Payload) · Wikipedia: Sea Dragon (rocket))_

## Sources

- [Wikipedia: Sea Dragon (rocket)](https://en.wikipedia.org/wiki/Sea_Dragon_(rocket))

## Cite this case file

Easterling, Marcus. "Sea Dragon." The Detail Department (DetailEnjoyer), case file DD-498, last updated Feb 25, 2025. https://detailenjoyer.com/case/sea-dragon/