http://www.seattletimes.com/business/boeing-aerospace/space-wa2/QuoteBut now that human spaceflight plan is shelved, along with Orbital’s planned rocket.[Vulcan Aerospace president Chuck Beames] said Orbital’s rocket “was not hitting the economic sweet spot to generate revenue,” so Vulcan has reopened the design plan and is “evaluating over 70 different launch vehicle variants.”
But now that human spaceflight plan is shelved, along with Orbital’s planned rocket.[Vulcan Aerospace president Chuck Beames] said Orbital’s rocket “was not hitting the economic sweet spot to generate revenue,” so Vulcan has reopened the design plan and is “evaluating over 70 different launch vehicle variants.”
Quote from: arachnitect on 06/01/2015 05:30 amhttp://www.seattletimes.com/business/boeing-aerospace/space-wa2/QuoteBut now that human spaceflight plan is shelved, along with Orbital’s planned rocket.[Vulcan Aerospace president Chuck Beames] said Orbital’s rocket “was not hitting the economic sweet spot to generate revenue,” so Vulcan has reopened the design plan and is “evaluating over 70 different launch vehicle variants.”Didn't they just ribbon-cut the factory in LA?And I can't see the problem being the specifics of the rocket. They already went through a number of pretty extreme iterations with it. "was not hitting the economic sweet spot " is such corporate BS talk. As if there is an optimal "sweet spot" for generating revenue, beyond which it's just too much money and who whats THAT. Instead: "was too expensive". Less syllables, too!
Turning it into a conventional super-lift aircraft for cargo is probably a better idea and a better current market than a rocket carrier. Though the risk is it would not be optimized for either, and too many engineering issues crop up. Sunk cost fallacy at play.
Oh dear, I fear all 70 variants may come back with the same answer - air launch isn't economic, especially given both the cost of developing the huge aircraft & new/modified rocket and the increasing innovation - leading to cost reductions - in other parts of the market (SpaceX, Blue Origin, ULA's Vulcan rocket, potential small-sat launchers etc).
The structural requirements of a fully-fuelled rocket hanging horizontally (and addressing the impact of even small amounts of G while being carried), in addition to the vertical loads during launch, will make the rocket's design heavier and less structurally efficient. It will reduce the payload. Air-launch may not be economically viable.
And I can't see the problem being the specifics of the rocket. They already went through a number of pretty extreme iterations with it.
"was not hitting the economic sweet spot " is such corporate BS talk. As if there is an optimal "sweet spot" for generating revenue, beyond which it's just too much money and who whats THAT. Instead: "was too expensive". Less syllables, too!
I suspect Paul Allen was enamored with SS1 and didn't (as noted) do a full due-diligence analysis of the factors for air-launch. The key "economic" factor has always been the requirement for a high operations/launch tempo to make it work and StratoLaunch is marginal in that regard.
Wouldn't an air launch have less air drag? Then you could make the rocket much shorter and fatter. Not only do you reduce bending moment, the whole structure becomes lighter and more rigid. Turn a problem into an advantage.John
http://www.seattletimes.com/business/boeing-aerospace/space-wa2/
Meanwhile, said Beames, Vulcan has decided to diversify beyond the Stratolaunch project by investing in other space companies. It put money into Seattle-based Spaceflight this spring and is actively searching for more candidates.
Does anyone know if the stratolaunch carrier would be capable of a high alpha launch that might reduce the bending moments and enable a scaled up version of the late Len Cormier's spacevan concept?This, if I inferred correctly, by releasing the winged orbiter at a really high angle of attack in a climb, meant the wing was only scaled for landing weight and the were no pitch up bending moments on the tank/fuselage to crap out your mass fraction. [Is the spacevan concept somewhat like a cross between an altitude-optimised hybrid between a ramp-launch and a VTHL (vertical take-off horizontal landing) system?]And are we sure there are no inspired systems engineering combinations that couldn't make air-launch feasible, I feel we are throwing in the towel far too easily, and soon, without fully exploring the huge '(possible?) solution space'.What about Gary Hudson's VALS concept?http://forum.nasaspaceflight.com/index.php?topic=36709.msg1344145#msg1344145
Air launch has always seemed like a terrible idea. The first issue is that while you get a bit of starting height, you are working with a negative vertical velocity that you have to overcome right from the get go after being dropped. Sure wings can help with that but at some point you get diminishing returns and if you throw that weight of wings and extra structure towards fuel instead, you might as well just go from the ground and have one less "stage". In my mind, the other obvious cons like no hold down testing and safety of carrying what equates to a giant pressure vessel quickly outweigh any pros.
If the LV suffers a RUD on pad or just above the pad, it tends not to be hugely catastrophic. Any damaged/contaminated/incinerated ground infrastructure is comparatively simplistic (and cheaper) to fix up.If the LV blows itself to pieces attached to the Roc or in the immediate area of the Roc post separation, you are going to lose the plane, along with the crew. The potential for people to die goes up significantly.
So the North American X-15 series of spaceplanes should not have been flown from the B-52 carrier aircraft according to your reasoning?
