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-   -   CST-100 Starliner Pad Abort Test (http://www.oldrocketforum.com/showthread.php?t=18163)

frognbuff 11-07-2019 07:42 PM

CST-100 Starliner Pad Abort Test
 
Surprised nobody has talked about the test on Monday:

https://www.youtube.com/watch?v=acOFK3Bsj58
https://www.youtube.com/watch?v=eiOhR-PhvUw

The test went amazingly well! As rocketeers, we can appreciate how hard it was to make a very unstable configuration fly so well - controlled only by alternating thruster firings, not gimbals or control surfaces. As for the failed parachute, Boeing determined the pilot chute broke free from the main- you can see the three pilots pull out, and one goes flying away. I understand the main chute was still safely stowed on Starliner.

https://spaceflightnow.com/2019/11/...arliner-launch/

As a person who has worked the Commercial Crew program for 3 years now, it is incredibly exciting to finally be in the OFT launch campaign. The Booster is erect, and the solids are attached. Next we attach the Launch Vehicle Adapter/Dual Engine Centaur/Interstage Adapter stack. Spacecraft mate is late next week if all goes well, and Wet Dress Rehearsal will be after Thanksgiving. Fingers crossed!

frognbuff 11-08-2019 07:23 PM

Atlas V is fully stacked as of today. Started LV testing.

5x7 11-08-2019 08:51 PM

Quote:
Originally Posted by frognbuff
Atlas V is fully stacked as of today. Started LV testing.


Awesome!

tbzep 11-12-2019 08:19 AM

Why does the Starliner have an overhang instead of a traditional boat tail transition to the Centaur?


tbzep 11-12-2019 08:20 AM

Why does the Starliner have an overhang instead of a traditional boat tail transition to the Centaur? There doesn't seem to be anything under the skirt that needs to be exposed.


DeanHFox 11-12-2019 11:27 AM

Quote:
Originally Posted by tbzep
Why does the Starliner have an overhang instead of a traditional boat tail transition to the Centaur? There doesn't seem to be anything under the skirt that needs to be exposed.

It has to do with the aerodynamic forces on the front of the stack.

https://www.nasaspaceflight.com/201...dynamic-issues/

tbzep 11-12-2019 01:21 PM

I assumed aerodynamic issues. I wish they had elaborated on what the loading issues were and how it was configured at the time of the tests.

If I'm reading correctly, the Starliner/Atlas V stack originally had no tapered transition to the Centaur and was just the capsule and SM? The photo inset looks like a boilerplate with a transition, though I don't recall one being launched. I'm assuming it's either an altered image or a failing memory.

It would be interesting to find out why they chose the shroud instead of the tapered transition, assuming it originally wasn't going to have either of them.

frognbuff 11-13-2019 06:25 AM

The thing you're looking at is called the Aeroskirt, and you're right - it's all about aerodynamics. Because Starliner is so blunt, wind tunnel testing showed we needed a bigger L/D at the front of the rocket. Diameter is fixed by Starliner, so we changed the length. A boattail would have negated the whole effort (or at least forced us to make it even longer and thus heavier).

The aeroskirt will be jettisoned shortly after Centaur ignition. Pretty cool system with an aftward jettison! The closeout deck you see in the photo is there to protect Centaur avionics and the aft end of Starliner from acoustic and pressure environments during ascent. When we fly the Crewed Flight Test (CFT) and on, you'll see a bit more hardware back there related to CST-100 aborts (vent doors). The Launch Vehicle Adapter (LVA) itself is a pretty amazing piece of hardware too. Starliner is HEAVY. I can't give you numbers, but suffice it to say it will be by far the heaviest payload flown on Atlas V ever.

tbzep 11-13-2019 07:19 AM

Thanks for the details! :cool:

Looking forward to a successful flight!

georgegassaway 11-13-2019 04:02 PM

2016 article:

"AEROSKIRT ADDED TO ATLAS V CONFIGURATION FOR CST-100 STARLINER"

https://www.spaceflightinsider.com/...-100-starliner/


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