Update on Stratolaunch:http://spacenews.com/stratolaunch-considering-using-multiple-launch-vehicles/
That near-term focus on alternative launch options means Stratolaunch is deferring work on a crewed vehicle that would launch on the Orbital ATK booster. At the International Astronautic Congress in Toronto in October, Stratolaunch and Sierra Nevada Corp. announced they were studying the development of a 75-percent-scale version of Sierra Nevada’s Dream Chaser spacecraft.“What we’ve decided to do is kind of take a pause on further development of that,” he said, as Stratolaunch examines alternative launch options.
Looks like Paul Allen has announced a new arm of his investment fund to develop various concepts which the Stratolaunch system will support, and it's called.......Vulcan Aerospace. (no this is not a co-incidence as Allen is trying stop ULA from using that name, although since I thought Vulcan Inc. is an investment fund the protest will probably come to nothing)
The Stratolaunch aircraft is about 80% fabricated and 40% assembled, and is on track for first flight in 2016.
Quote from: yg1968 on 04/16/2015 12:25 amUpdate on Stratolaunch:http://spacenews.com/stratolaunch-considering-using-multiple-launch-vehicles/From the article:QuoteThat near-term focus on alternative launch options means Stratolaunch is deferring work on a crewed vehicle that would launch on the Orbital ATK booster. At the International Astronautic Congress in Toronto in October, Stratolaunch and Sierra Nevada Corp. announced they were studying the development of a 75-percent-scale version of Sierra Nevada’s Dream Chaser spacecraft.“What we’ve decided to do is kind of take a pause on further development of that,” he said, as Stratolaunch examines alternative launch options.Not a ringing endorsement of OrbitalATK & SnC. (or perhaps their own business model, if they are deferring development)
A smaller vehicle, he said, could be developed more quickly and less expensively. “It takes a more near-term focus on revenue generation,” he said.
Orbital ATK is developing the rocket, which uses solid-fuel lower stages and an upper stage powered by RL-10 engines from Aerojet Rocketdyne.
The most interesting part of that press release is this part:QuoteThe Stratolaunch aircraft is about 80% fabricated and 40% assembled, and is on track for first flight in 2016.
The creation of Vulcan aerospace and the tidbits we know about it makes me thinking. How about Stratolaunch to fill an orbital propellant depot ? 13500 pounds isn't that much, then it is all a matter of frequent flights (or not)Do they plan a second Roc aircraft ? How often could they fly ? once a week ? once a day ?
I wonder how much payload could be orbited by a J-2X S-IVB stage (pretty much an expendable SSTO) air-launched by a Roc...
Well, they discussed it in terms of absolute costs, not relative to something on the ground. A dedicated carrier aircraft--i.e. one that cannot do anything else and where all the costs are charged to the launcher program--is apparently a big chunk of the overall operating costs. So getting that cost down is an important way to reduce the overall program costs.Simply maintaining the certification, license, training and pilots is going to cost money. Think about that L-1011 that Orbital uses--it has three pilots. If it launches only one rocket per year, the salary and training costs of those three pilots have to be charged entirely to that single launch. Now maybe those guys are on retainer and they spend the rest of the year flying 737s for Southwest or something and only show up at Orbital when needed, but Orbital has to pay for their certification and training on the unique L-1011. That cannot be cheap. Same is true for the maintenance guys and everything specific to that aircraft.Stratolaunch is going to have the same issues.
http://arc.aiaa.org/doi/abs/10.2514/6.2013-5422
Quotehttp://arc.aiaa.org/doi/abs/10.2514/6.2013-5422Thank you for that link. I always wondered how much payload to orbit could a 747-400F rocket lift. 747-400F are cheap, they are many, and they can lift 305 000 pounds on their back. The booster described in the paper has three Merlins and three RL-10s - exactly half of a Saturn I :p, not far from an Atlas-Centaur in fact. End result ? 47 000 pounds to orbit, a very respectable number. By replacing the 747F with an An-225 and the Merlin with high performance NK-33s, it must be possible to lift much more than 50 000 pounds to orbit, perhaps the shuttle 65000 pounds, who knows.
Quotehttp://arc.aiaa.org/doi/abs/10.2514/6.2013-5422Thank you for that link. I always wondered how much payload to orbit could a 747-400F rocket lift. 747-400F are cheap, they are many, and they can lift 305 000 pounds on their back.
How to release the rocket from back?You know what happens to SR71/D-21...
Quote from: Katana on 04/25/2015 07:35 pmHow to release the rocket from back?You know what happens to SR71/D-21...They were able to release the Shuttle from the back of the 747 without any mishaps during the ALT tests.Though the ALT test shuttle was about 200,000lbs about a 100,000lbs lighter then the booster.Separation dynamics are a lot easier at subsonic speeds then they are at mach 3.The Stratolaucher design is supposed to be much safer then carrying the payload in the dorsal position.
The booster described in the paper has three Merlins and three RL-10s - exactly half of a Saturn I :p, not far from an Atlas-Centaur in fact. End result ? 47 000 pounds to orbit, a very respectable number. By replacing the 747F with an An-225 and the Merlin with high performance NK-33s, it must be possible to lift much more than 50 000 pounds to orbit, perhaps the shuttle 65000 pounds, who knows.
So the rocket need a wing bigger than shuttle to have similiar aerodynamics.Gliding like shuttle with full fuel...
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.”
