US Navy Standard Missile Family

[sferrin]

Rocket found off Irish coast shrouded in mystery as Virgin Orbit rules out ownership

It was believed the engine could belong to Virgin Orbit, but the company has ruled out the prospect, prompting further questions

www.irishexaminer.com

 

[NMaude]

Rocket found off Irish coast shrouded in mystery as Virgin Orbit rules out ownership

It was believed the engine could belong to Virgin Orbit, but the company has ruled out the prospect, prompting further questions

www.irishexaminer.com

A very strange catch-of-the-day but judging by the photographs it's the wreckage of a spent Mk-72 rocket-booster, the question is whether or not it's from an SM-2 Block IV, SM-3 or an SM-6?

Edit: Judging by the corrosion on the RM casing it has been in the sea for a while now.

 

[Standard]

View attachment 755710

What is this booster? The mk72 has a single pulse design.

 

[NMaude]

What is this booster? The mk72 has a single pulse design.

I think that it's some sort of proposed design upgrade for greatly increased performance (I suspect for some future very high performance version of the SM-3) launch-booster.

 

[sferrin]

What is this booster? The mk72 has a single pulse design.

That's what I thought too. In fact I saw this picture years before the one above. Was told it was incorrect. Not sure which is true, or if one design replaced the other.

 

[Standard]

That's what I thought too. In fact I saw this picture years before the one above. Was told it was incorrect. Not sure which is true, or if one design replaced the other.

Well, there's also this supposedly official photo from https://www.secretprojects.co.uk/threads/us-navy-standard-missile-family.7671/post-745429

Also, could I ask where and when you found the dual-pulse photo?

 

[sferrin]

https://www.secretprojects.co.uk/threads/amdr-ships.12345/page-3#post-290205

 

[Standard]

https://www.secretprojects.co.uk/threads/amdr-ships.12345/page-3#post-290205

Thanks. Looks like this conversation has happened before. It does seem strange that they would optimize the booster this much. I've seen some DTIC report claiming that single stage all-boost is the "best" thrust profile, at least for ABM missions.

 

[Scott Kenny]

Thanks. Looks like this conversation has happened before. It does seem strange that they would optimize the booster this much. I've seen some DTIC report claiming that single stage all-boost is the "best" thrust profile, at least for ABM missions.

That is how the THAAD works, not that THAAD is a high end ABM...

 

[NMaude]

That is how the THAAD works, not that THAAD is a high end ABM...

There was a proposed THAAD-ER which was a two-stage interceptor that was to use a 21" diameter first-stage.

 

[Standard]

Found the report. It's not really applicable to the mk72, but it might be of interest to this thread.

 

[NMaude]

Found the report. It's not really applicable to the mk72, but it might be of interest to this thread.

I wouldn't surprised at all if figure five in the report is representative of the 21" version of the Mk-104 DTRM used in the SM-3 Block-II interceptor missile.

 

[Standard]

I wouldn't surprised at all if figure five in the report is representative of the 21" version of the Mk-104 DTRM used in the SM-3 Block-II interceptor missile.

I've wondered why they would complicate things further by adding a DTRM to the already boosted ER (SM2IV/SM3/SM6) model. SM-3 has 5 or 6 separate rocket pulses! The report called for "all boost" for the second stage, figure 5 is a single pulse motor.

 

[NMaude]

I've wondered why they would complicate things further by adding a DTRM to the already boosted ER (SM2IV/SM3/SM6) model.

They aren't adding an extra DTRM, the standard Mk-104 DTRM is 13.5" in diameter while the 21" diameter Mk-104 DTRM has the same diameter as the 21" diameter Mk-72 launch-booster, this 21" diameter DTRM has a longer burn-time and more thrust.

SM-3 has 5 or 6 separate rocket pulses!

The SM-3 has three stages - the Mk-72 with a high-thrust, short burn boost only burn-profile, the Mk-104 DTRM has a single-pulse dual thrust burn-profile (A high thrust thrust short burn boost phase followed by a long lower thrust sustain burn-profile) and the Mk-136 TSRM which has two pulses boost only that can be fired once or twice. This makes a total three or four burn pulses.

 

[Standard]

They aren't adding an extra DTRM, the standard Mk-104 DTRM is 13.5" in diameter while the 21" diameter Mk-104 DTRM has the same diameter as the 21" diameter Mk-72 launch-booster, this 21" diameter DTRM has a longer burn-time and more thrust.



The SM-3 has three stages - the Mk-72 with a high-thrust, short burn boost only burn-profile, the Mk-104 DTRM has a single-pulse dual thrust burn-profile (A high thrust thrust short burn boost phase followed by a long lower thrust sustain burn-profile) and the Mk-136 TSRM which has two pulses boost only that can be fired once or twice. This makes a total three or four burn pulses.

Sorry, I mixed up the terminology. By pulses, I was referring to distinct burn profiles. The main thing that I'm wondering is why the original 13.5" SM2IV/SM3/SM6 has a booster (mk72) and then a boost-sustain motor (mk104, designed for MR) on top of that, giving it a boost-boost-sustain profile instead of the usual simple boost-sustain. It might make sense to use an off-the-shelf mk104 as an interim, but you said the new 21" 2nd stage is also dual-thrust? Perhaps the mk72 doesn't provide enough boost?

 

[NMaude]

Perhaps the mk72 doesn't provide enough boost?

The Mk-72 gives plenty of thrust, having a 21" Mk-104 DTRM with boost/sustain burn-profile results in a much higher terminal velocity and the SM-3 Block-II has a sufficiently high burnout speed that it can, IIRC, engage short-range ICBMs.