SEA DRAGON,mito da sfatare o occasione perduta?

Nei forum Americani si parla spesso del SEA DRAGON,un gigantesco (veramente GIGANTESCO) razzo vettore che avrebbe potuto mettere in orbita bassa 550 tonnellate (!!) ed essere impiegato per le missioni Apollo sulla luna.Oltre a costare molto meno rispetto ad un Saturno V,il Sea Dragon era anche parzialmente recuperabile.Questo “monstrum” avrebbe dovuto essere lanciato dal mare (da quì il nome).Ora,visto che se ne parla molto (l’ultimo Thread è su NASA forum),e addirittura si parla anche di riprendere il progetto in chiave privata, vorrei chiedere agli esperti del nostro forum:bufala o ennesima occasione perduta?

The biggest rocket ever

In the early 1960ies and before the MCD criteria were formalized “in writing”, Aerojet anticipated a low-cost and truely big dumb rocket: the Sea Dragon. It seems their gut feeling told them the way to go. To date, this is the biggest rocket ever seriously postulated. Sea Dragon was a two-stage reusable vehicle, the first stage using LOX and Kerosine, the second LOX and Hydrogen. The first stage would have made a parachute ocean landing. Both stages were single engine pressure fed (Aerojet’s studies suggested that development of a single large engine would be simpler and reliably higher than that of a cluster of smaller engines). Sea Dragon was truely colossal. The mere numbers speak for themselfs: The Sea Dragon was to have had a payload capacity of 550 tons to LEO with a take-off weight in the range of 20.000 tons! The vehicle would have stood 168 m with 23 m in diameter. Twice those numbers and you have the TITANIC. No doubt these are ocean vessle dimensions rather than those of a flying machine (stressing my point that in rocketry we talk about ship building rather than airplane manufacturing techniques). Indeed, the Sea Dragon was to be built on the ocean front in a ship yard and then towed to the launch site. Launch site is actually saying too much, because the Sea Dragon would have launched, partially submerged, directly out of the ocean (this concept had evloved out of Navy experiments with submarine based missles). Ballast tanks would have positioned and trimmed the rocket properly before ignition.

Aerojet calculated the cost to 59 to 620 per kg. NASA had an interest in the Sea Dragon largely because of its large payload capacity. It had the cost calculations independently reassessed and they were largely confirmed. Immagine a 100 kg ticket price! In other words, we could fly into space for 10.000. Perhaps not cheap but well within range of affordability.

Too bad it didn’t come true. As NASA’s planetary ambitions shrank (to practically zero), the Sea Dragon was moth-balled and eventually forgotten.