Pentagon to Have Dead Satellite Shot Down

[a_lost_packet_]

Interesting note: It was a Pentagon TV broadcast that NASA piggybacked on. I suppose if you're not CNN then you have to take feeds as you can get 'em. <img src="/images/icons/smile.gif" /> <div class="Discussion_UserSignature"> <font size="1">I put on my robe and wizard hat...</font> </div>

 

[a_lost_packet_]

<font color="yellow">shuttle_guy - " ...kinetic..." a very tough shot especially for what they say is a mod they are doing on the fly...</font><br /><br />Yeah, a bit more difficult than hitting a tennis ball with a bb-gun at 2000 yards. <div class="Discussion_UserSignature"> <font size="1">I put on my robe and wizard hat...</font> </div>

 

[yevaud]

T₀ = 2Pi (R_p + H') Sqrt (R₀ + H' / G_p R_p^²)<br /><br />About a 15 hour orbit.<br /><br />T₀ = Orbital period, in seconds.<br />R_p = Planetary Radius, in Km (6380, for Earth).<br />H' = Orbital Altitude, in Km, above the planet's surface.<br />G_p = 0.00981 Km/Sec^², Gravitational acceleration at Earth's surface. <br /><br />[Oops!] <div class="Discussion_UserSignature"> <p><em>Differential Diagnosis:  </em>"<strong><em>I am both amused and annoyed that you think I should be less stubborn than you are</em></strong>."<br /> </p> </div>

 

[MeteorWayne]

Re: Missing<br />That's not good on many levels. I'd say 25% chance of hitting the satellite, and 3% chance of hitting the hydrazine tank, which is the stated goal.<br /><br />They'd better hit it. <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[bobw]

I really enjoyed the way they ignored the reporterette who kept asking if somebody is going to think the anti-satellite missile is a weapon. <div class="Discussion_UserSignature"> </div>

 

[a_lost_packet_]

<font color="yellow">MW - Sorry, I don't buy for a second that this has anything to do with the hydrazine. I guess, having grown up in the Nixon era, I have a bit of skepticism. </font><br /><br />I agree.<br /><br />In the great scheme of things, hydrazine isn't THAT big of a deal. What else on that bird is more serious than that? 1000lbs of hydrazine is like a bit over 100 gallons of water (liquid) for sheer comparison purposes. Keep in mind, that tank is going to be undergoing flash heating and extreme buffeting. In my mind, the structural integrity of that tank is going to be severely reduced fairly quickly. AFAIK, the tank is made to contain the fuel under optimal conditions in space with certain considerations for slight impact.. maybe. Going on a one-way trip dirtside isn't in its design specs. <div class="Discussion_UserSignature"> <font size="1">I put on my robe and wizard hat...</font> </div>

 

[a_lost_packet_]

<font color="yellow">bobw - I really enjoyed the way they ignored the reporterette who kept asking if somebody is going to think the anti-satellite missile is a weapon.</font><br /><br />And, the confrontational jerk that kept harping about how much everything cost. He even wanted to know how much the satellite cost as if, somehow, by shooting down an already non-operational satellite, the satellite's cost had to be figured into the budget for the operation. <div class="Discussion_UserSignature"> <font size="1">I put on my robe and wizard hat...</font> </div>

 

[MeteorWayne]

Sumthin's wrong there Yev, I haven't run the math yet, but why would a lower orbit be longer?<br /><br />Geosync is a 24 hour orbit.<br /><br />Iridiums are faster/shorter<br /><br />LEO orbit is 90 minutes.<br /><br />Why would lower all of a sudden go from 90 minutes to 15 hours??<br /><br />OK, now I'll do the math and see if I'm right <img src="/images/icons/smile.gif" /><br /><br />Wayne <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[yevaud]

Go look. That's the "standard" formulae. <div class="Discussion_UserSignature"> <p><em>Differential Diagnosis:  </em>"<strong><em>I am both amused and annoyed that you think I should be less stubborn than you are</em></strong>."<br /> </p> </div>

 

[bobw]

<font color="yellow">And, the confrontational jerk...</font><br /><br />After seeing the reporters at the pentagon channel it really makes the ones who show up at the NASA briefings look good. <div class="Discussion_UserSignature"> </div>

 

[a_lost_packet_]

This is strange:<br /><br />The standard SM3 uses an heat/infra seeker kinetic hit-to-kill warhead. Basically, it gets up there and looks for it, locks on, fires its third stage and reaches out and touches the target in its no-no spot..<br /><br />But, this is a "cold" bird. It's a dead brick... room temperature. It is an ex-parrot.<br /><br />So, my question is this: Is enough reflected/absorbed radiation from the Sun going to show up against background noise to establish a target solution?<br /><br />They said this was a "modified" SM3. In their words, mostly software to the missile and the Aegis systems. If the warhead is standard, is there going to be enough target radiation to track?<br /><br />*Also -<br /><br />The SM3 standard uses GPS/INS. That's not guidance designed for moving targets. That's where the heat-seeker head for the warhead package comes into play. But, we're dealing with a satellite that isn't designed for aerodynamic flight. Basically, it has severely reduced flight potential... That means it's going to be jerking all over the place as soon as it begins to graze the atmosphere. With a lack of control due to total systems failure, that makes it highly unpredictable. Basically, they're going to have to formulate a window at launch "on the fly" using a best-guess estimate. Then, that window has to be small enough for the warhead to find the target and successfully fire for a hit-to-kill. Given, of course, all of this is standard. There's nothing that says they couldn't have an area effect warhead or directed charge warhead.<br /><br />**Correction: The SM3 standard warhead contains its own attitude controls. So, it is released after a guided second-pulse from the third stage and is self-course correcting using the IR seeker head. <div class="Discussion_UserSignature"> <font size="1">I put on my robe and wizard hat...</font> </div>

 

[a_lost_packet_]

<font color="yellow">bobw - After seeing the reporters at the pentagon channel it really makes the ones who show up at the NASA briefings look good. </font><br /><br />LOL true.<br /><br />NASA Channel Broadcast Reporter: "So, Mr. Griffin. Can you explain to us this whole "space" thing and what it's all about? I mean, that's a pretty wild concept - someplace with no air. I think our readers would like to hear more about it..." <div class="Discussion_UserSignature"> <font size="1">I put on my robe and wizard hat...</font> </div>

 

[MeteorWayne]

NP, just haven't had a chance yet <img src="/images/icons/smile.gif" /><br />It seems couterintuitive, but much in the land of physics does... <img src="/images/icons/laugh.gif" /> <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[yevaud]

<i>It seems couterintuitive, but much in the land of physics does...</i><br /><br />Isn't that the truth! <div class="Discussion_UserSignature"> <p><em>Differential Diagnosis:  </em>"<strong><em>I am both amused and annoyed that you think I should be less stubborn than you are</em></strong>."<br /> </p> </div>

 

[rybanis]

I'm glad MW pointed me here.<br /><br />Thats a good point, ALP. Perhaps they can arrange it so the missiles seeker is looking at the target when the target is reflecting sunlight or something? <div class="Discussion_UserSignature"> </div>

 

[rybanis]

Simple guys, the military is also going to be testing a new time-dilation warhead. Two birds, one stone. Co'mon people! <div class="Discussion_UserSignature"> </div>

 

[yevaud]

Yes, because you have to match the rotational velocity of the Earth. I was waiting for someone to pick up on that. <div class="Discussion_UserSignature"> <p><em>Differential Diagnosis:  </em>"<strong><em>I am both amused and annoyed that you think I should be less stubborn than you are</em></strong>."<br /> </p> </div>

 

[MeteorWayne]

That's what I think. You have to be moving faster relative to the surface in order to stay in orbit.<br /><br /> <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[MeteorWayne]

huh? That's not realated to the orbital period.<br />We must not be talking about the same thing.<br /><br />The orbital period is only affected by the altitude (earths rotation is irrelevent). And of course, the atmosphere, the lower you go.<br /><br />We must be talking about different things.<br /> <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[yevaud]

Btw, Wayne, I never said a lower orbit would be longer. I merely posted the approximate orbital period for this satellite, followed by the proper equation. <img src="/images/icons/smile.gif" /> <div class="Discussion_UserSignature"> <p><em>Differential Diagnosis:  </em>"<strong><em>I am both amused and annoyed that you think I should be less stubborn than you are</em></strong>."<br /> </p> </div>

 

[a_lost_packet_]

Meh..<br /><br />There you guys go again. Gettin' all "mathy" an' stuff..<br /><br /><img src="/images/icons/wink.gif" /> <div class="Discussion_UserSignature"> <font size="1">I put on my robe and wizard hat...</font> </div>

 

[Testing]

Even though dead, the sat will still be warmer than the background and the seaker is IR. But it also has other guidance not IR alone. They don't have to hit the tank just hit the sat. At the energy level involved some piece will take out the tank. <div class="Discussion_UserSignature"> </div>

 

[yevaud]

Look at the math. To descend, you have to increase your velocity and match Earth's rotational velocity. Bless me if that's not so. When the Shuttle does a "De-orbit burn," they are <i>increasing</i> their velocity, not lowering it (sorry, that's what I thought you'd meant by "counter-intuitive."<br /><br />At any rate, the point being is that the comment about a 15-16 hour orbit is approximately correct. <div class="Discussion_UserSignature"> <p><em>Differential Diagnosis:  </em>"<strong><em>I am both amused and annoyed that you think I should be less stubborn than you are</em></strong>."<br /> </p> </div>

 

[a_lost_packet_]

Unless it has some additional modifications, the warhead is self-guiding AFAIK. (The standard SM3.) I suppose it could have some linkage which allows for ground-based course corrections.<br /><br />Right now, according to released information, the standard seeker is "Block IA" with more advanced systems not due to be integrated until, at least, later this year with the beginnings of Block IB and more up to 2012. This doesn't include any special mission-specific modifications.<br /><br />Ground Based Launch/High Alt intercept vid SMS3-BIA: http://www.youtube.com/watch?v=U99cRebGmWU<br /><br />Could this be an early test of one of the more advanced seeker systems?<br /><br />Warhead Guidance systems (SDACS) mfr - http://www.atk.com/customer_solutions_missionsystems/cs_ms_w_mdi_sm3.asp <br /><br /><br />*Also, not included in the above, the new Anti-ICBM (AKA "Star Wars - Reloaded" )testing done with ATK et al is designed around a kinetic intercept/kill warhead and the second phase of testing calls for launch from a mobile platform. <div class="Discussion_UserSignature"> <font size="1">I put on my robe and wizard hat...</font> </div>

 

[yevaud]

<i>In doing so it accelerates in the Earths gravity so that atmospheric interface the the velocity is almost back up to where it was when the burn was performed.</i><br /><br />I suppose in my imperfect way of posting, that's rather what I meant. <div class="Discussion_UserSignature"> <p><em>Differential Diagnosis:  </em>"<strong><em>I am both amused and annoyed that you think I should be less stubborn than you are</em></strong>."<br /> </p> </div>