NK missile did better than thought....

[docm]

Oopsie....

The first stage fired normally

The second stage fired normally (previously not thought to have)

The third stage didn't separate and fire, which ended the mission

It exhibited attitude control thrusters (the puffs of 'smoke' on the pad) and advanced steering

Link...

North Korean rocket flew further than earlier thought

BY CRAIG COVAULT
SPACEFLIGHT NOW
Posted: April 10, 2009

New details emerging from the analysis of data from North Korea's April 5 Taepo-Dong-2 test indicate the vehicle flew successfully several hundred miles further than previously believed and used more advanced steering than has been demonstrated by the North Korean's before.

The rocket impacted as far as 2,390 miles from the launch site as opposed to about 1,900 miles as earlier announced by the U. S. and Japan.

Smoke puffs from the side of the vehicle at the moment of liftoff and after, indicate the rocket could have been equipped with attitude control thrusters.

It also temporarily flew in space before failing and dropping back into the atmosphere at relatively slow speed that enabled debris to survive till impact rather than burning up.

The updated analysis indicates the failure occurred when the solid propellant third stage of the vehicle failed to separate properly after the second stage fired normally. After burnout the second stage coasted upward into space where the third stage was supposed to separate and fire, but did not.

Earlier it was believed that the second stage had failed early in its burn.

The rocket also demonstrated more advanced steering and other advances that could enhance its deployment as a silo-based ballistic missile.

The Japanese Ministry of Defense and U.S. Defense Dept. now believe that the second stage of the rocket performed as planned rather than failing early in its flight phase.

The new information comes from updated radar tracking calculations and possibly also U.S. Air Force Defense Support Program (DSP) missile warning satellite data.

The bottom line is that the North Korean vehicle flew as much as 500 miles further over the Pacific toward Hawaii than U.S. and Japanese forces had announced initially.

The new data now indicates that the second stage fell in the impact zone the North Koreans had earlier warned shipping and aircraft away from, instead of falling short of that zone as earlier indicated by the U.S. and Japan.

The vehicle's second stage uses a Scud-ER (extended range) rocket engine that employs "step-throttling" in its propulsion to stretch the second stage burn duration to gain range and velocity.

For the April 5 space launch mission the second stage was to use the same step-throttling technique, according to Charles Vick of Global Security.org. In years past Vick has provided accurate and detailed rocket analysis data to varied users, including the Congressional Research Service.

The rocket performance data indicate that during the April 5 flight, the second stage did ignite after separation from the first stage, says Vick.

The vehicle was flying in space at this time above 50 miles altitude, just above the outer fringes of Earth's atmosphere.

Earlier data indicated that the failure occurred during this throttle-down sequence to as low as 65 percent thrust.

But the new data shows the second stage performed this critical activity as planned, Vick told Spaceflight Now.

The updated impact point was calculated from U.S. sensor data as the vehicle flew out of range of Japanese radars about 1,000 miles east of Japan.

Details visible in the North Korean state television video of launch have also been analyzed further, turning up at least two major news issues on vehicle guidance and design.

Smoke puffs from the side of the vehicle at the moment of liftoff and after, indicate the rocket could have been equipped with attitude control thrusters.

This was not observed during the first Taepo-Dong-2 launch in 1998 and could indicate much more advanced steering capability than the rocket nozzle steering vane system used in the much more crude Scud launcher.

The puffs jet from the side of the vehicle at where the second and third stages meet. The most visible puffs occur a split second before ignition (see picture above) and then again at liftoff. A Japanese enhancement of the video indicates that the puffs continue as the vehicle climbs out and pitches over to accelerate, says Vick.

There are also indications in the video that the North Koreans added a structural covering over the entire third stage of the rocket once it was on the pad to form a constant volume outer diameter between the upper stage and the payload shroud.

Earlier DigitalGlobe WorldView 1 commercial satellite imagery of the vehicle when it first arrived on the pad showed a more narrow upper stage with a bulbous payload shroud. The liftoff views of the vehicle show a constant outer diameter. Japanese enhancement of the imagery show the same changes, Vick said.

Why the North Koreans would want to place an extra fuselage covering over the third stage could relate to vehicle aerodynamics or flight temperature extremes the upper stage may experience.

But it would be much easier to install such a fairing before erection on the pad unless there were access ports to the satellite payload or upper stage used during pad processing that needed to remain open for access during early processing.

 

[newsartist]

Oopsie....

The first stage fired normally

The second stage fired normally (previously not thought to have)

quote]

The fact that it didn't splash at the first stage impact zone showed that it gained additional velocity from something.

 

[docm]

It didn't splash where we expected it to. No telling if it met the NK's expectations, but something tells me at least the first stage did.

 

[jimglenn]

That seems like a weird way to steer a rocket these days, jets shooting from the side, especially at takeoff.

Most normal people use tilting nozzles, or vernier rockets. I can see gas jets once you are above the atmosphere,
because fins don't work there. Kim if you are listening, you are a dork. Hire me and get better results than
the cheapo fake internet scientists you have. Probably from china. Get some real US talent.

I saw the nozzle end of a C4 missile once, I remember that the hole was big enough to crawl into. Don't
remember seeing any verniers, but that was a long time ago. The Titan I think had a weird way of bleeding
fuel asymetrically that burned reddish. Pretty strange, but effected steering. Where's DR. Rocket when we
need him?

 

[vladdrac]

Every time I hear the missiles name I think of primitive tribesmen lifting their loincloths at each other...from a safe distance. :lol:

 

[silylene]

That seems like a weird way to steer a rocket these days, jets shooting from the side, especially at takeoff.

Most normal people use tilting nozzles, or vernier rockets. I can see gas jets once you are above the atmosphere,
because fins don't work there. Kim if you are listening, you are a dork. Hire me and get better results than
the cheapo fake internet scientists you have. Probably from china. Get some real US talent.

I saw the nozzle end of a C4 missile once, I remember that the hole was big enough to crawl into. Don't
remember seeing any verniers, but that was a long time ago. The Titan I think had a weird way of bleeding
fuel asymetrically that burned reddish. Pretty strange, but effected steering. Where's DR. Rocket when we
need him?

I didn't see any attitude control nozzles. I saw an initial burn through at the joint. It nearly blew up on liftoff.

 

[MeteorWayne]

There's a thread on this in M&L

 

[silylene]

There's a thread on this in M&L

Yep, and I linked the launch video to it (watch it here, then comment a reply in the M&L thread).

no evidence of attitude control thrusters, IMHO. http://www.youtube.com/watch?v=GwxXedvvDpQ

 

[jimglenn]

I read the M&L thread. The first stages are liquid, so that leaves out leaky o-rings.

Thrusters does sound dumb. How about a turbo pump exhaust? The Atlas had that,
a separate nozzle. Or it could be some kind of APU, powering up an evil experiment.

The NoDongBong was not that impressive. I say we smoke their launch site for fun.

 

[silylene]

The smoke clearly came out when the engines first started, before any motion. There are many seals near the turbine, engine and nozzle. Any of these could've leaked, allowing a burst of hot gases to move rapidly upwards between the fuel tanks and the skin, and escape the joint between stage1 and stage 2.

 

[jimglenn]

The problem of smoke coming from joints has been a major difficulty in rocketry from the beginning.

How you pack the propellant can influence the burn rate. O-rings are not a good idea. Kim probably
hired some temp engineers from the wrong country. You need those SS von braun types, blues eyes.

 

[docm]

NK missile: now we know......

Now we know specifically why our post-launch intelligence was lacking....

Link.....

EXCLUSIVE: U.S. failed to use best radar for N. Korea missile

Gates refused area commander's request

By Bill Gertz (Contact) | Wednesday, April 15, 2009

EXCLUSIVE:

Defense Secretary Robert M. Gates denied permission for the U.S. Northern Command to use the Pentagon's most powerful sea-based radar to monitor North Korea's recent missile launch, precluding officials from collecting finely detailed launch data or testing the radar in a real-time crisis, current and former defense officials said.

Jamie Graybeal, Northcom public affairs director, confirmed to The Washington Times that Air Force Gen. Gene Renuart, the Northcom commander, requested the radar's use but referred all other questions to the Pentagon.

Pentagon spokesman Bryan Whitman said Mr. Gates' decision not to use the $900 million radar, known as SBX, was "based on the fact that there were numerous ground- and sea-based radars and sensors in the region to support the operational requirements for this launch."

SBX, deployed in 2005, can track and identify warheads, decoys and debris in space with very high precision. Officials said the radar is so powerful it could detect a baseball hit out of a ballpark from more than 3,000 miles away, and that other radars used by the U.S. would not be able to provide the same level of detail about North Korea's missile capabilities.

 

[jimglenn]

Re: NK missile: now we know......

Radars are all the same, like toothpastes, peanut butter, doctors, etc. It costs too much
money to operate such a giant radar needlessly. Way more than a microwave oven. We
have to watch expenses these days.

 

[MeteorWayne]

Re: NK missile: now we know......

I have to ask, why did you feel the need to create a new thread? There's another here in FS, and the weeks old thread in M&L. I will merge this into one of the others....