By Geoff Fein
In the ongoing debate over whether to keep DDG-1000 alive beyond the first two ships or to build more of the venerable Arleigh Burke-class destroyers, Raytheon [RTN] says it has demonstrated to the Navy a case for turning future Zumwalt ships into light cruisers.
Earlier this year, the Navy tasked Raytheon with looking at how quickly the company could implement a ballistic missile defense (BMD) capability onto DDG-1000. Of interest to the Navy was the time frame for adding BMD, which hull would get the capability, what exactly is the capability the ship would get, as well as what were the risks and challenges in pursuing this concept, Mike Moe, director of seapower capability systems for Raytheon integrated defense systems, told Defense Daily in a recent interview.
“Their time frame they were looking at in this tasking was 2015. We did our analysis, and came back in 30 days. We found we could do it one year later…2016…[that] was the earliest we could provide credible capability,” he said.
As it stand now, in the current operational requirements document (ORD) for Zumwalt, there is no call for BMD, Moe noted.
Raytheon came up with three options for bringing BMD capability to Zumwalt. The options looked at radar, software and missiles, Moe said.
The ship would need to have enough capability to radiate enough energy to be able to discern a target when it was in space and then to put weapons on that target, he added. “So the radar had to change.”
In Zumwalt’s case, the Dual Band Radar (DBR) would have to be modified, Moe said.
DBR is designed to go across a wide spectrum of the family of ships in the Navy, Moe said, including the CVN-78 Ford-class of aircraft carriers. DBR has two pieces–the SPY-3 which is X-band and the Volume Search Radar (VSR), which is S-band, Moe explained.
Raytheon is the prime for the back end for both radars, and Lockheed Martin [LMT] provides the VSR base on the S-band side, Moe said.
“The VSR was the radar that needed to be adjusted. In the development of VSR, from day one on Zumwalt, there was space allocated for growth…for other missions or more pressing threats that might require more volume search even in the air defense spectrum,” he said. “We had room in there to add additional modules, additional TR (transmitter receiver) pieces.”
VSR is partially populated, Moe said. It has about 2,600 modules in the current radar, the one in development right now.
To make it BMD capable, Moe said the radar would have to be fully populated…fill in the rest of the blanks that were left for growth in the original design.
One idea was to leave the VLS the way it is and see what that could provide in the way of BMD if the BMD software were added and the missile changed.
A second idea was to fully populate the VLS to its fullest extent. A third idea was to fully populate the VLS but also change the duty cycle…that would change the frequency of how much energy would be put a target, he added.
“Each one of those…the baseline…the term we use is sensitivity…so the sensitivity of the baseline radar is a zero dB sensitivity. So when we did the fully populated we got to a 11 dB of sensitivity which means more power on target,” Moe explained. “And then with the change in the duty cycle, we got to 15 dB. So 15 dB of sensitivity was the maximum we could get out of fully populating [the radar], putting all the modules in all the holes that weren’t used initially and bring that kind of capability to bear for this capability we are looking for.”
The Navy, Moe noted, went right away for the 15 dB. “So that’s where our focus was at, but we also [priced] the 11 dB capability. So there were really two options off the baseline, which was zero dB as a reference point.”
So Raytheon grew the radar to be all it could be, against the BMD threat, and they did the corresponding analysis with their radar folks to see if the solution would give them a credible capability. “The answer was yes,” Moe said.
In Zumwalt‘s combat system, there is no software for a BMD mission, Moe said, although there was software to integrate the Stand Missile for area air defense.
“The actual missile defense algorithms for discrimination and those kind of things to work with a threat in the exo-atmosphere required different algorithms and different software,” he said. “Because we build that software for all of our radars, the BMD system radars, that was something we felt would be easy to bring in and leverage into our command and control system on Zumwalt.”
Moe said Raytheon also looked, from purely a cost point of view, at the Aegis BMD capability and what could be leveraged from that to save money. But to do that, Moe added, would require some provisions within the government and some kind of national team approach because of the proprietary nature of Aegis BMD effort underneath Lockheed Martin and with the Missile Defense Agency.
“But we saw that as something that certainly should be considered. So we put that into our assessment of other ways you could go at this requirement to leverage some additional capability that’s already in play [in] Aegis BMD,” he said.
For the software, Raytheon is going to take that from existing software they use in various radars for missile defense. Moe said the company would leverage that software into the additional code they had to change, and bring in the discrimination algorithms to be able to discriminate the object of interest particularly in the exo-atmospheric threat.
The third option looked at the missiles.
Allowances had to be made for using the SM-3 missile because it is an exo-atmospheric platform, Moe said. “That was probably the easiest of the pieces.”
Moe added that the Raytheon team looked at a marinized PAC-3 for use on a shipboard environment or a SM-6 variant that would be competed somewhere downstream.
The missile people were concerned whether or not the missile would fit in the MK 57 launcher, Moe said. And when the Navy moves in 2015 to a 21-inch full up more robust SM-3, would that missile fit?
“First off, the missile does fit. Every missile that fits in the MK 41 launcher on the current Aegis fleet will fit in the 57,” Moe said. “In fact we have about 15 to 20 more inches of vertical room and we have about three more inches of diameter relative to the size of the modules.”
So everything that can be shot out of an Aegis 41 launcher can be shot out of a 57 launcher with a lot of margin left, Moe noted.
“The difference is, for SM-3, because it goes exo-atmospheric, it needed a second cable that references the missile to its ship platform upon launch,” he said. “So it has a zero reference from where it is launching from as it goes out into space, and that cable provides GPS, inertial [navigation] uplink…[a] reference point upon launch. So [there is] a little difference for that missile because of how it works.”
After all the analysis, Raytheon told the Navy the company could provide a very credible capability in the short term…2016, Moe said.
One the cost side, non-recurring cost came out to be $389 million for the 11 dB and approximately $400 million for the 15 dB radar. For recurring costs is was $117 million for the 11dB solution and $110 million for the 15 dB solution, Moe said.
“So all in all we could provide capability [in] 2016. We would meet the third hull realizing Zumwalt‘s first hull comes out in 2014 and is on schedule right now in the May-June time frame. A year later, hull two comes out in 2015, and hull three became our ship of choice to meet the requirement the Navy had given us.”