Water based rocket launches

[kerbiloid]

1. With a water-launch Sea Dragon they would never repair the launchpad after every launch. Just wait a little until water rushes back.
2. Every launch would bring hundreds tons of floating fish, already boiled and ready for lunch.

Edited September 18, 2016 by kerbiloid

[AlexisBV]

On 18/09/2016 at 9:36 AM, kerbiloid said:

2. Every lunch would bring hundreds tons of floating fish, already boiled and ready for launch.

That's what I read.

[passinglurker]

while the promotional pieces make this look and sound like a viking sea dragon reading further shows that thier goals are a little more sensible...

Quote

COST

• Projected cost $18 Million USD. $4090/lb. $9000/Kilogram
• Possible to split payloads
• Example configuration: 8 cylindrical payload spacing. 550lbs each (249kg). $2,249,500/ 249kg payload space.
• O/F = 5.5

OTHER

• Thrust (vac) 1111 kN
• Thrust (SL) 916.3 kN
• LH2/LO2
• O/F = 5.5

At a light ~3 ton to LEO payload and a $/kg ratio in the same realistic ball park as industry standards paints this less as sea dragon reborn and more as trading a higher cost per unit for lower infrastructure costs.

If this comes to fruition I'd expect much of the fantastical claims and investor bait to slowly be cut leaving just the core sea born launching technology. The resulting launch vehicle would probably look very different from the promotional "seadragon with an aerospike" concept we saw, but launching from the ocean isn't necessarily impractical its been demonstrated on a sub-scale in the past with seabee and seahorse just like how DC-X and grasshopper demonstrated landing rocket stages on a sub-scale before spaceX was landing real firsts stages on barges in the middle of the ocean. whats killed this idea in the past is the damn sea dragon legacy of trying to make it a big dumb corner cutting booster made out of steel and pressure fed boosters, powered by almost magical economies of scale.

If they keep this quality over quantity focus on minimizing infrastructure and personnel costs while making the rocket sturdy and self sufficient enough to compensate then maybe they can make sea launch practical and competitive. 

 

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Edited September 20, 2016 by passinglurker

[wumpus]

I guess the other question is "why SSTO"?  Much of the reason for being 2,700 tons is that you don't care at all about mass and are willing to just keep scaling up.  But what happens if you split it into two big dumb boosters?  Since the engine shouldn't be a weight factor, I'm assuming that you wind up throwing away "leftover" fuel/oxidizer that isn't pressured (and has to be tossed to regain TWR).  I've yet to see a reason to use SSTO with current Isp values, and would be shocked if this was any different.