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21 votes

How do they determine dynamic pressure has hit a max?

At least for some vehicles, "dynamic pressure is closely monitored" is not correct. You need to have an air data probe to actually monitor it, and not all vehicles do. Shuttle: Dynamic ...
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21 votes

Why did a flight controller say "Avionics power nominal" as Antares exploded?

It's eight or ten seconds from the sudden flare at the base of the rocket 'til it hits the ground and actually explodes. I'm not an expert, but I don't see any particular reason why power to the ...
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14 votes
Accepted

What entails "Avionics" on the Antares Rocket?

Avionics is short for "aviation electronics"; on an aircraft it can include computer equipment, communications, guidance and navigation, radar, etc. "Avionics power nominal" implies that the rocket's ...
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13 votes
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Quite some lateral wobble immediately following Antares Orb-2 liftoff. Is that normal?

I asked NASA via Twitter about it hoping they answer it during the Orbital Sciences/Cygnus-2 Post-Launch News Conference, but Stephen Clark from SpaceflightNow.com beat me to it and asked Frank L. ...
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10 votes
Accepted

Progress M-25M launched because of Antares?

They were planned separately. It takes a long time to plan and execute a launch, and both Antares ORB-3 and Progress M-25M had their launch dates set months ago. To see how far ahead some of these ...
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  • 7,089
8 votes

Progress M-25M launched because of Antares?

The ISS is currently supplied (or was) by the following vehicles: Space Shuttle - retired ESA Automated Transfer Vehicle (ATV) - last one has flown - retired JAXA H2 Transfer Vehicle (HTV) - which ...
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8 votes

Advantages of a Solid Fueled Upper Stage

Solid fuel does make sense for a top stage, a so-called kick stage, the most notable example being the Star family. A kick stage has only smaller or similar gross mass as the payload it propels, which ...
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6 votes

Why did a flight controller say "Avionics power nominal" as Antares exploded?

I want to expand on the excellent Russell's answer, which I gladly upvote. I am by far not an expert in spaceflight either, but I happened to take part in a lab operation emergency handling, and used ...
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5 votes

How do they determine dynamic pressure has hit a max?

There are ways to measure dynamic pressure, and in aerodynamically complicated spacecraft (like the shuttle) if measured on its three four "nosecones" it could conceivably occur at (at least ...
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  • 148k
5 votes

How should one analyze the video of the Antares CRS-3 explosion to find the clues to the cause?

I'll just start with some things that came to my mind. Not planning to provide a complete list here. You can look at the craft itself prior to and shortly after launch. Was there any leakage or jets ...
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4 votes

What replacement engine options are there for Antares?

I was looking for possible answers for an US-sourced engine, and was going to float the RS-27A as a possibility (though it's been out of production for over a decade) -- you'd probably need a cluster ...
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4 votes
Accepted

What replacement engine options are there for Antares?

In Dec 2014, Orbital selected the Russian Energomash RD-181, which is basically an export version of the RD-191 used in the Angara booster. This is also a LOX/kerosene engine, derived from the RD-170. ...
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3 votes
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Cygnus on a 3rd party launcher

Cygnus has two main components. The Pressurized cargo compartment is built by Alenia-Thales in Italy. The same folk who built the pressure vehicles for most of the ISS modules and the ATV. The bus ...
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  • 76.7k
2 votes

Did the Cygnus Orb-3 failure disable/destroy both engines?

The second engine definitely stopped at the time of the initial explosion. More accurately, its plume tapers off in 4 frames, or about 0.13 seconds, of the video. The reducing plume is straight and ...
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2 votes
Accepted

What is this long black tube snaking up to the capsule payload of the Antares rocket?

In this closeup, it's pretty obvious this is an air hose. They are routinely used to control the temperature inside the fairing. Here's a similar system on a Vega rocket (for the LISA Pathfinder ...
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  • 122k
2 votes

Quite some lateral wobble immediately following Antares Orb-2 liftoff. Is that normal?

This is speculation - not a complete answer. The smoke blowing off the pad made me take a gander at http://www.wunderground.com/weather-forecast/US/VA/Wallops_Island.html for today July 13th, 2014 ...
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  • 13.6k
2 votes

Would two RD-190's be better or worse than a single RD-180?

Generally speaking, you want as few moving parts as possible, unless the extra parts add a useful redundancy. More moving parts = more things that can go wrong. Some examples: intercontinental ...
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  • 122k
2 votes

Where can I find examples of down-range launch exclusion zones for Falcon-9 and Antares orbital launches?

The marine zones should be in the USCG local notice to mariners http://www.navcen.uscg.gov/pdf/lnms/lnm11012017.pdf (that doesn't have an example, but it should...)
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1 vote

Where can I find examples of down-range launch exclusion zones for Falcon-9 and Antares orbital launches?

Here's an example from a June 2018 (planned) launch of Falcon 9. See page 9. Googling for the two phrases: "Local Notice to Mariners" "Eastern Range" is an effective way to find Florida launches....
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  • 12.3k

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