SUBMARINE-BASED ASAT SYSTEM
I would like to congratulate D. Nahrstedt on his proposal (Jan 91 SUBMARINE REVIEW, pp. 50-55) that submarines would make ideal platforms for an ASAT system based at the antipodes of the known Soviet launch sites, a proposal fll’St made in the open literature by A Karemaa of General Dynamics in the April 1988 USNI Proceedin&S. While the thrust of Nahrstedt’s proposal is valid and important, there are some important details which must be considered.
First, even the extended range version of the Standard missile is probably incapable of boosting a suitable kinetic kiD vehicle (KKV) of approximately 20 kg mass to the necessary velocities. With its conventional warhead the SM-2 ER is cited in the open literature as having an effective ceiling of only 80,000 feet; for this missile to accelerate a roughly four-fold smaller mass (the KKV) to velocities of several thousand knots and altitudes over 100 miles would seem unlikely. While it may be possible to boost a very small KKV to near orbital velocity using this system, there are three reasons for not using the SM2. There is substantial technical risk in this approach, in that a newer, smaller KKV would have to be developed (the ones used in the Army and Air Force ASAT systems would be too large). A truly useful system would require substantial altitude capability (perhaps 1500 km) to assure successful intercept of satellites launched in elliptical orbits with their apogee (high point) over the antipode to avoid interception. The SM-2 ER (RIM-67B) is not configured for submerged launch, is currently semi-actively radar guided, and at 26 ft. is rather long for most torpedo tubes.
A better choice might be to configure the KKV to be mounted on a POSEIDON or lRIDENT C-4 missile as booster, and launch the vehicle from a dedicated SSBN, perhaps a late model SSBN-640 class. This approach would have several advantages. First, it would use an existing platform instead of adding another mission to an already overbooked attack submarine force. An ICBM-type booster clearly would be able to boost an existing KKV to whatever velocity and altitude was necessary, perhaps even to synchronous orbit. The KKV need not be ultraminiaturized, reducing technical risk and enhancing kill probability. The TRIDENT and POSEIDON missiles are of course configured for submerged operation, and would not require lengthy development before introduction into the Fleet. The SSBNs are designed for launching missiles with high accuracy using inertial guidance for the submarine and the missile, a prerequisite for this scenario where no external guidance of the vehicle is possible during its flight. Finally, the longer range of the SLBM-boosted vehicle enables the submarine to attack the satellite from points in the ocean more distant than the exact antipode of the launch point (corrected for the earth’s rotation). A smaller booster would oblige the submarine to be almost directly under the path of the satellite, limiting the area of ocean it can operate in, and putting it at greater risk.
A second important point is that the antipodes of the American launch centers at Cape Canaveral, Vanderberg AFB, and Wallops Island are all in the Indian Ocean, and the Soviets may find basing ASATs on submarines to be effective as well. H the Soviets are believed to possess such a capability, it will be necessary to station some number of SSNs in the Indian Ocean to counter this threat. At llresent this is not an issue, inasmuch as the U.S. currently does not plan a surge in satellite launchings during a crisis. However, the wlnerability of our current satellite systems may change this position. It is of interest, however, that the antipodes to the launch sites of many other nations are also in ocean areas and therefore may be held at risk by U.S. submarines. Thus the U.S. may blockade spaceborne commerce in precisely the same fashion it can for seaborne commerce. Thus the antipode to the Chinese launch site at Xi Chang is off the north Chilean coast, that to sites in the Middle East (such as Iraq) is in the South Pacific, and the antipode to the Indian launch site at Srihari-Kota is also in the South Pacific.
A final issue in this scenario is tracking of the target and guidance of the missile to intercept it. It will be necessary to not only see the launch of the satellite, but to track it long enough to determine its orbital elements with some precision, then pass this information along to the submarine in time for it to program its missile(s) for launch and intercept. In the absence of other cues, this process must occur in the time period of half an orbit; i.e., 45 minutes. Note that while the terminal guidance of the .KKV can be passive IR or visible, the KKV must first be guided to the vicinity of the intercept by other means (probably inertial) before the KKV sensor is in range and can take over. A feasible system might entail an ELF alarm to announce a launch and summon the submarine to a depth where it can receive the orbital elements as they become available, perhaps by blue-green laser from the American satellite tracking the launch. The submarine would require substantial onboard computational power to calculate and program its missiles for a high velocity intercept trajectory (or two) in only a few minutes. aearly a responsive positive control system would be required for weapons release given the political sensitivity of destroying another nation’s satellite(s). While these tasks may be technically demanding, they are clearly within the state of the art.
Ricluud Thompson
NAMES OF SUBMARINES
Dear Sir,
I feel that the SEA WOLF (SSN-21) Class should be named SKIPJACK, SEADRAGON, SKATE, SHARK, SCAMP, SNOO~ SCULPIN, SWORDFISH and SARGO.
They have the Burke aass to name after Congressmen.
Yours truly
Ted E. Minter
APPROACH OFFICER RANGING
I enjoyed LCDR Peppe’s article on mental ranging techniques in the January 1991 issue of the SUBMARINE REVIEW and thought it was important enough to warrant special attention during wardroom training. An OOD needs quick target range estimates to verify the validity of other solutions and to determine effective approach and attack courses. The article provided a means to obtain those quick estimates.
I believe that there are a few errors in the triangulation range section; two are typographical, and one was the choice of a range reference poinL However, the final result was correcl The equation on page 81 should equate the range to
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Finally, by convention, sonar ranges based on spherical array outputs are referenced to the spherical array. Peppe’s range is based on the intersection of the towed array axis with a line perpendicular to the towed array axis which passes through the intersection of the spherical bearing and the towed array bearing. The difference between the two ranges can be significant for targets not within 20′ of the spherical array beam, but his simplification corrected this problem. I have included an enclosure which illustrates the difference between his range reference and the conventional range reference and which validates his simplification.
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THE FIRST SOVIET NUCLEAR SUBMARINES
Dear Sir,
I’ve read “The First Soviet Nuclear Submarines” by Norman Polmar (The SUBMARINE REVIEW, January 1991) with great interest.
Research work on and development of nuclear submarines had been kept secret even from us “conventional” submariners, but when I came across the name of Eng.-Capt. 1st Rank PEREGUDOV, I immediately recalled that particular name.
Back in 1954, I served in a WHISKEY -class sub with Peregudov’s son. He was Executive Officer and I was a Department Head. I knew that his father, Rear Admiral Peregudov, held an important position in the Navy in Leningrad, but that was all I knew about him. Unlike his father, the son had no special talents. Thanks to his father he was promoted to Executive OffiCer and later on to Captain and that last assignment proved fatal. His maiden voyage became also the last one: his submarine ran aground in shallow waters and he was promptly relieved of his duties. Again, because of well placed connections in the Navy, he got a sinecure in the office of the Main Naval Staff in his hometown of Leningrad which was, incidentally, the most favourite city for Soviet naval officers.
From that time on I never met or heard of him again.
Cordially yours,
J, Roitman
LCDR, Sovit Navy (Ret.)
Haifa, Israel
