Quote from: tobi453 on 01/01/2018 10:38 amOrbital made so many strategic mistakes during the COTS/CRS program with Antares and Cygnus that my faith in the people in charge is highly limited. Just look where SpaceX is today with F9/Dragon and compare it to Antares/Cygnus.Dragon is up to 12 missions not including a failure, Cygnus has flown seven, not including the failure. I was impressed when Orbital ATK quickly adapted to the Antares failure by moving Cygnus to Atlas 5 for three launches, gaining payload in the bargain. Cygnus has been carrying more payload mass than Dragon. The Antares engine change to RD-181 after the failure - during the Ukrainian situation no less - was also pretty impressive. If Orbital made a mistake, it was in trusting the reliability of NK-33/AJ-26, but that is only obvious after the fact.
Orbital made so many strategic mistakes during the COTS/CRS program with Antares and Cygnus that my faith in the people in charge is highly limited. Just look where SpaceX is today with F9/Dragon and compare it to Antares/Cygnus.
No, sorry for not being clearer...There was a USAF/DoD study which essentially argued that fly-back was better than boost-back, and which appeared to represent the conventional wisdom at that time. (Circia 2005-2010? I am sure there is a link to in one of my old posts, but cannot find it.)
Quote from: meekGee on 12/31/2017 07:43 pmhttps://en.wikipedia.org/wiki/Next_Generation_LauncherYou believe Wikipedia? That article is riddled with errors.
https://en.wikipedia.org/wiki/Next_Generation_Launcher
NGL uses solid motor first and second stages, augmented as needed by solid boosters. These are "state of the art" solids, with better mass fractions and specific impulse numbers than earlier motors.
They offer more thrust per dollar and higher reliability than equivalent liquid boosters.
Castor 600 produces almost as much thrust as a Falcon 9 v1.2 first stage, but with far fewer moving parts. The reliability appeals to me. So do the simplier launch countdowns.
Composite solid propellant motors are actually more "state of the art" than kerosene/LOX liquid rockets, in terms of the sequence of developments. Redstone, Atlas, Titan 1, Thor, and Jupiter predated Pershing, Minuteman and Polaris.
People here tend to dis SMART, but at a basic level it's no different than SpaceX's fairing recovery. What seems more damning to me is that ULA itself is not taking it seriously. If they were out there blowing test boosters apart to see if they could get clean separation with acceptable shock levels, trying out aerodynamic decelerators, and testing big parachutes and recovery helicoptors/boats, then I'd feel they could still be in the mix in the 2020s. But if they wait and add it on later, it will be a few years later yet due to the later start, plus extra engineering to add recovery in, and the inevitable necessary changes could compromise certification. 3 years to a competitive system would be OK. 6 years, as I'd guess if they retrofit SMART later, seems like too much.
The implications are less than clear to me. Falcon Heavy, if successfully developed, gives up an awful lot to recover its boosters. That big rocket can only boost 8 tonnes to GTO in that mode. Vulcan can do that with basically one-third as much rocket.
Getting payloads to LEO on RLVs is only half picture, to really open up space especially BLEO. Reusable OTVs are needed along with fuel depots, ideally supplied from ISRU. ULA are addressing the OTV with ACES. ULA future may be as pure space transport company, leaving others to handle earth-LEO leg.
~1/3 by mass, but ~2x by cost. Which is more relevant here?
Quote from: envy887 on 01/02/2018 01:47 amQuote from: edkyle99 on 12/31/2017 08:09 pmThe implications are less than clear to me. Falcon Heavy, if successfully developed, gives up an awful lot to recover its boosters. That big rocket can only boost 8 tonnes to GTO in that mode. Vulcan can do that with basically one-third as much rocket.~1/3 by mass, but ~2x by cost. Which is more relevant here?Cost and reliability and performance.
Quote from: edkyle99 on 12/31/2017 08:09 pmThe implications are less than clear to me. Falcon Heavy, if successfully developed, gives up an awful lot to recover its boosters. That big rocket can only boost 8 tonnes to GTO in that mode. Vulcan can do that with basically one-third as much rocket.~1/3 by mass, but ~2x by cost. Which is more relevant here?
Cost is determined in large part by reliability.
Falcon Heavy intends to compete by flying a much larger rocket that requires low cost recovery and reuse of the first stages to make it pay, sacrificing much potential performance in the trade.
It is a more complex machine than Vulcan.
Vulcan sacrifices no performance, is single core even for Heavy missions, offers vertical integration, etc.
In all likelihood, both will win missions, find niches, etc., but it isn't clear to me which will cost less in the end.
When I say "liquid booster" I'm using the original, early Space-Age description of a boost stage, which can be a first stage. The Falcon 9 first stage is a "booster" by this definition.
Shutting down a rocket stage after lift off is a very bad idea, regardless of propellant type.
Thrust oscillation can be mitigated by design on a newly-designed solid motor launch vehicle, which is NGL.
Vulcan uses Castor GEM-63XL solid rocket motors.
Quote from: butters on 01/01/2018 07:21 pmCan ULA come up with a more effective way to use BO's engines than BO can?Here is a key question. Let's think about that. In order for Vulcan to use BE-4 more efficiently than New Glenn, New Glenn will have to fall short of recovering and re-flying each first stage four times or more, just based on the number of engines needed per flight. That is a capability that has yet to be demonstrated by anyone. The necessity of such turn-around numbers is apparent to Blue Origin, of course, because the company is planning on pulling off such achievements. Plans do not guarantee success. Approaching eight years into Falcon 9 service, SpaceX has not yet reached that goal. - Ed Kyle
Can ULA come up with a more effective way to use BO's engines than BO can?
Where have ULA stated Vulcan price of $99M. Only price I've heard is less than $100M. They are not same thing.
Quote from: TrevorMonty on 01/02/2018 07:45 amWhere have ULA stated Vulcan price of $99M. Only price I've heard is less than $100M. They are not same thing.Whatever. Advertised price for something six or more years into the future is not the same as billed price today either.The quoted price is for basic Vulcan core plus Centaur III, no solids. When comparing to FH, need to add six solids and Centaur V... which will basically doubles the price, whether that's 2x $99M or 2x <$100M.This price also assumed ten launches* per year, half of them commercial. * I seriously doubt that ULA/Boeing/LockMart would stay in the business with 10x $100M (or less) revenue per year. This is basically what they were getting from ELC -- for launching nothing. At these discounted prices, their margin will be quite thin, to say the least.
ULA is working on a next-generation rocket called Vulcan that will be less expensive to manufacture and fly than its current Atlas booster.
Our prices are coming down every day, we now talk about a $99 million launch service.
It is a more complex machine than Vulcan. Vulcan sacrifices no performance, is single core even for Heavy missions, offers vertical integration, etc. In all likelihood, both will win missions, find niches, etc., but it isn't clear to me which will cost less in the end. - Ed Kyle