-
#40 by mfck on 14 Oct, 2016 15:16
-
Why is the addition of the skirt such a problem. Heck, it's not much and is short. I'd call it a mini-skirt myself. They're just making a safe, reliable launch system safer. Wouldn't you feel safer going up on an Atlas than any other rocket?
Sure, mini-skirts are a well established safety measure -
#41 by TrevorMonty on 14 Oct, 2016 16:15
-
As Elon pointed out after lastest mishap, any explosion on liquid fuel stage is fast fire not an explosion. By time Centuar fast fire caused by abort engines is a threat to capsule, the capsule would be well clear and accelerating.In the new configuration, the launch escape thrusters are inside of the skirt, it appears.
How that is going to relieve over-pressure on the Centaur? Seems like it would amplify it.
By the time the launch escape thrusters activate, you would have stopped caring about the performance or survival of the Centaur stage, because the survival of the crew is at stake.
If you crush (detonate) the Centaur when the launch abort thrusters lite off, you could damage the thrusters, nozzles, or the heat shield (as discussed by a former head of engineering at ULA, moments before getting fired). Maybe escape would still be successful; their in-flight demo will confirm... oh wait, they aren't doing an in-flight demo.
For abort to happen, the LV will have detected an problem and signalled capsule. At same time LV would kill thrust, this may involve blowing feed lines to engines. The NS demo was not totally realistic as the booster should've killed its thrust.
As for no inflight LAS test, the term "Test like you fly" comes to mind. I wondered if Boeing bosses would buy a car that's crash safety systems had never be tested. NB the LAS doesn't need a Atlas booster, can be any booster that will give Max Q. -
#42 by Jim on 14 Oct, 2016 16:20
-
Why is the addition of the skirt such a problem. Heck, it's not much and is short. I'd call it a mini-skirt myself. They're just making a safe, reliable launch system safer. Wouldn't you feel safer going up on an Atlas than any other rocket?
Sure, mini-skirts are a well established safety measure
It doesn't doesn't decrease the reliability or safety of the vehicle. -
#43 by Galactic Penguin SST on 14 Oct, 2016 16:35
-
That skirt somehow reminded me of the Delta II with the original 10 feet diameter fairing in the 1990s (ROSAT was launched on one of those). Certainly not elegant but I think that's not quite that ugly actually.
-
#44 by edkyle99 on 14 Oct, 2016 16:58
-
It adds a separation event. If the skirt doesn't separate, the ascent might have to be aborted (I'm supposing).Why is the addition of the skirt such a problem. Heck, it's not much and is short. I'd call it a mini-skirt myself. They're just making a safe, reliable launch system safer. Wouldn't you feel safer going up on an Atlas than any other rocket?
Sure, mini-skirts are a well established safety measure
It doesn't doesn't decrease the reliability or safety of the vehicle.
- Ed Kyle -
#45 by AncientU on 14 Oct, 2016 18:53
-
Why is the addition of the skirt such a problem. Heck, it's not much and is short. I'd call it a mini-skirt myself. They're just making a safe, reliable launch system safer. Wouldn't you feel safer going up on an Atlas than any other rocket?
Sure, mini-skirts are a well established safety measure
It doesn't doesn't decrease the reliability or safety of the vehicle.
It is installed to increase the vehicle safety to an acceptable level for crew flights. -
#46 by Jim on 14 Oct, 2016 20:12
-
Why is the addition of the skirt such a problem. Heck, it's not much and is short. I'd call it a mini-skirt myself. They're just making a safe, reliable launch system safer. Wouldn't you feel safer going up on an Atlas than any other rocket?
Sure, mini-skirts are a well established safety measure
It doesn't doesn't decrease the reliability or safety of the vehicle.
It is installed to increase the vehicle safety to an acceptable level for crew flights.
The point is that even if the skirt was not needed for aeroloads, it is benign and passive and doesn't detract the vehicle operation. -
#47 by Rocket Science on 14 Oct, 2016 20:25
-
That skirt somehow reminded me of the Delta II with the original 10 feet diameter fairing in the 1990s (ROSAT was launched on one of those). Certainly not elegant but I think that's not quite that ugly actually.
I remember that!
http://www.b14643.de/Spacerockets_2/United_States_5/Delta_II/Gallery/DeltaII_1.htm
-
#48 by AncientU on 14 Oct, 2016 20:55
-
Why is the addition of the skirt such a problem. Heck, it's not much and is short. I'd call it a mini-skirt myself. They're just making a safe, reliable launch system safer. Wouldn't you feel safer going up on an Atlas than any other rocket?
Sure, mini-skirts are a well established safety measure
It doesn't doesn't decrease the reliability or safety of the vehicle.
It is installed to increase the vehicle safety to an acceptable level for crew flights.
The point is that even if the skirt was not needed for aeroloads, it is benign and passive and doesn't detract the vehicle operation.
The point is that it is needed to allow the vehicle to meet minimum safety standards.
It therefore is an active, safety-related component that the vehicle cannot fly without.
It is not 'making a safe, reliable launch system safer.' -
#49 by Khadgars on 14 Oct, 2016 21:04
-
Why is the addition of the skirt such a problem. Heck, it's not much and is short. I'd call it a mini-skirt myself. They're just making a safe, reliable launch system safer. Wouldn't you feel safer going up on an Atlas than any other rocket?
Sure, mini-skirts are a well established safety measure
It doesn't doesn't decrease the reliability or safety of the vehicle.
It is installed to increase the vehicle safety to an acceptable level for crew flights.
The point is that even if the skirt was not needed for aeroloads, it is benign and passive and doesn't detract the vehicle operation.
The point is that it is needed to allow the vehicle to meet minimum safety standards.
It therefore is an active, safety-related component that the vehicle cannot fly without.
It is not 'making a safe, reliable launch system safer.'
You are splicing phrases to make your point. The Atlas V stack is and has been demonstrated to be one of the (if not the most) reliable and safe vehicle flying today. Because they added a unique payload on top of said stack doesn't change that fact, even if it requires some tweaks to adapt to the payload. -
#50 by Jim on 14 Oct, 2016 22:02
-
The point is that it is needed to allow the vehicle to meet minimum safety standards.
It therefore is an active, safety-related component that the vehicle cannot fly without.
It is not 'making a safe, reliable launch system safer.'
So what. Again, what is your point in this whole discussion.
It is not active and it does not reduce the reliability of the vehicle. It is a the addition of simple structure.
Much like the differences in aerodynamics of the SR-71 vs YF-12 which required ventral fins to be mounted under the fuselage and engine nacelles to maintain stability.
If they added the skirt at the beginning like the 2nd RL10, we wouldn't be having this discussion -
#51 by mfck on 14 Oct, 2016 22:24
-
The point is, it does not improve safty, it restores it. Maybe.
-
#52 by king1999 on 14 Oct, 2016 22:45
-
At the minimum, with the skirt on, Starliner now no doubt will be referred as a "She" or "Her". Of course unless you are from Scotland.
-
#53 by Unobscured Vision on 14 Oct, 2016 22:56
-
I think that as time goes on and more data is released we'll get more of an idea of how the changes will benefit the CST-Atlas configuration. ULA has probably made the right call in solving this problem, but it shouldn't have come to this ...
I'd like to see performance and aerodynamic data before giving the changes a Go/No-Go. I've gone on record elsewhere as being quite critical of this whole design, for a lot of reasons, but I'll keep it above-board and remain neutral for now. -
#54 by Lar on 15 Oct, 2016 02:13
-
Seems to be a bit more testiness here than I favor. No need for sparring or scoring points. BETEO.
-
#55 by Johnnyhinbos on 15 Oct, 2016 02:16
-
I'd just like to point out that this delay is an honest admission that what Boeing/ULA and SpaceX alike are trying to accomplish is amazingly difficult. We, as sideline spectators, tend to get worked up a bit strongly about our team (and come down hard on same said team when they don't meet our expectations).
Perhaps it might be a good time to reflect on the incredible challenges faced by these private entities and marvel at how they are developing solutions to overcome these hurtles.
Personally, I am amazed, impatient, infatuated, enamored, devastated, speechless, irate, and above all, star struck by what is happening in my adult lifetime and absolutely can't wait to see what happens next.
So, I wish Boeing, ULA, SpaceX, BlueOrigin, Bigelow, Rocket Lab, NASA with SLS, the Chinese space agency, and the Russians all the best with your endeavors. What you're doing is amazing... -
#56 by Ronsmytheiii on 15 Oct, 2016 11:46
-
I think people here are overreacting, its just a simple answer to an engineering issue. No underlying technical issues, aesthetics aren't really that different.The only negative I can see is the schedule slip, but Boeing isn't alone in engineering issues slowing down first flight. This is just good old engineering at its finest.
-
#57 by Jim on 15 Oct, 2016 12:21
-
The point is, it does not improve safty, it restores it. Maybe.
There is no maybe -
#58 by Jim on 15 Oct, 2016 12:24
-
I've gone on record elsewhere as being quite critical of this whole design, for a lot of reasons,
What are those reasons and what are they based on?
Please share because I doubt they would stand up -
#59 by muomega0 on 15 Oct, 2016 14:11
-
I think people here are overreacting, its just a simple answer to an engineering issue. No underlying technical issues,
Why did the US adopt a space policy to prevent Atlas/Delta from launching crew? Besides being a convenient way to maintain excess, expensive launch capacity, did anyone think that solids and crew would not be mixed in the future rockets? Since Earth departure is a very small part of LOC....perhaps yes.
Links are added to reduce length. Apologies ahead time...
On the positive side, it's his shortest post ever.1) Solids and non common configurations
Just stop, this is not a place to preach your crusade. Those have nothing to do with the addition of the skirt.
2) economics "10 flights to achieve 100M/ea"
3) multiple configurations and testing (expendable and why certify a LV (Atlas with Solids) that will be retired and the new LV with solids (Vulcan V0) will eventually replace the solids, but cannot be reused to reduce costs?)
--
The thread title does not contain the word 'skirt'...is there a location that narrowly focusses on this topic?
There are are some who think that LH2 would be the ideal fuel for BEO/abort while others support methane while others support solids from Earth...but it seems counterintuitive to Stifle Dissent, no?The Atlas V stack is and has been demonstrated to be one of the (if not the most) reliable and safe vehicle flying today.
When was the last time a Centaur second stage with two RL10 engines with two SRBs flew, 5x2, 4x2?
Will a 422 fly cargo in the future and will the skirt remain for cargo as the SRBs burn for 88 seconds?
Atlas Launches 2010-2019
Atlas Launches 1990-1999
Atlas Launches 2000-2009
USAF 45th Space Wing Study released in 2009 concluded that the Ares I capsule will not survive an abort between MET's of ~30 and 60 seconds. Another conclusion is that it re-affirmed the predictive codes of the 1980s, where, to increase performance, solids were added to Titan. Days after ESAS, and confirmed here, for example, about a year later Ares could not do the job because of LAS mass. What are the range of times being studied for the destruct button in this 422 configuration?
That is why when Musk revisted Titan I with only one engine type, those who, even serendipitously, knew history, understood its merits.I've gone on record elsewhere as being quite critical of this whole design, for a lot of reasons, but I'll keep it above-board and remain neutral for now.
Many many reasons to be both critical and supportive...
What this comes down to is how the short term certification rules are being met and the implications for long term.
Is the risk guaranteed to be under Y%, or just probably under Y% and what probability?--Note the former costs are humbling at best. The only real answer is demonstrated reliability which is why cargo (dirt cheap propellant)/test flights really would help or just take the risk without all the costs until the LV is retired. Will even one flight give any more confidence?
