"If we could come up with a structural system for ganging them in clusters of nine—just a three-by-three grid, with shared propellant feeds—and make nine of those clusters, and integrate them into Izzy’s structure somehow—that being the hard part—then we’d have an array of eighty-one engines. If those things all come on at full power when we pass through perigee, it’ll give us enough combined thrust to make a difference. I think we can make the Big Ride work with that level of power."