Extending the Search for the Holy Grail
The Submarine Force is fortunate that it has more than four decades of a common culture among operators of both attack (SSN) and strategic deterrent (SSBN) submarines. Since the very inception of SSBN patrols in 1960, assignment of most officer and enlisted personnel to each type has been need-based, and not a function of an individual’s specialty. It has been unusual for an individual completing a full career in submarines not to have served on both. In fact, for many years into the program, all SSBN COs had first been successful SSN COs. Even today, many exceptional officers get to command both. Unlike Air Force F 117 and 82 pilots, where the fighter versus bomber mentality still prevails, submariners have a uniform concept of what stealth is and how to best employ it. The reason that the Submarine Force is so fortunate is that many of the post Cold War missions that have evolved require that the SSN operate in a manner very reminiscent of how the SSBN has always operated-as a mobile, covert fire base constantly ready to strike unseen strategic targets ashore as directed.
What the SSBN mission clearly required was the establishing of a stance, as soon as the target set began coming within weapon range, where a continuous 24/7 passive (listening) connectivity assured that launch orders would begin coming aboard the ship as soon as they had begun being transmitted. Whereas some Cold War SSN missions made a similar continuous passive connectivity desirable (for ship’s safety and timely intelligence updates), others such as Anti-Submarine Warfare (ASW) precluded such a stance, and operational and tactical needs were adequately satisfied by the ship passively checking for traffic once or twice a day. However, better connectivity was always desirable, and comms from speed and depth was the Holy Grail of SSN communications for years. Many schemes were tried and employed with some limited success, such as tape-recorded messages to nearby aircraft in sonobuoysized devices launched from a deep submarine or employing short and agonizingly slow Extremely Low Frequency (ELF) bell-ringer cueing which directed a submarine to come to periscope depth for traffic. Such schemes marginally met the SSNs’ Cold War needs.
Comms at speed and depth remained an issue when post Cold War missions found on station SSNs waiting direction to quickly launch weapons against emergent targets ashore, but some key parameters had changed. No longer was the implementing and authorizing order for launch like an SSBN’s. Their’s was a brief set of alphanumerics that took several minutes to receive at very low data rates. This was acceptable since it took even longer to make other final shipboard preparations, so message receipt and verification still qualified as happening in near real time, i.e., it didn’t slow down the total process). Instead, the SSN/SSGN traffic to be received could be voluminous retargeting data with Air Tasking Order (A TO) implications concerning airspace decontliction issues. Furthermore, it is conceivable that the entire process from message transmission to weapon release be completed in a few minutes to permit engagement of a briefly vulnerable mobile target.
The apparent (provisional?) answer to this problem appeared to be the assumption that since the missions involved would be conducted in littoral waters, and since all littoral waters are shallow (?),the ship would be at periscope depth (and at slow speeds) and high data rate mast-mounted antennas would meet the need (which in fact they admirably do under these assumed conditions). Therefore, comms at speed and depth was a less important issue than it had been. However, conclusions drawn from assumptions are not facts, and the assumption-breaking consideration occurs when the new SSBN to SSN operational analogue is further analyzed.
As previously stated, SSBNs went on alert, to include establishing a 24/7 passive connectivity, as soon as weapons came in range of their targets. Some targets begin being in weapon range of SSNs (and soon SSGNs) as much as a thousand miles from the shoreline off which the ships’ patrol station lies. It is likely that the ships have proceeded to that point at reasonably high speeds, but now in the absence of high data rate comms at speed and depth, the weapons they carry are either only sporadically targetable for the next few days or, if near real time connectivity is established at periscope depth, actual on-station arrival will be delayed by more than a week. In theory, an ELF bell-ringer can call the submarine to periscope depth to copy updated intelligence and targeting data at high data rates, but the process of getting there often takes a half-hour or so, during which the ship’s speed of advance (SOA) is close to zero. It is unlikely that either the latency between bell-ringer and connectivity or the adverse impact on overall SOA would be acceptable, given the fast-paced nature of littoral warfare.
A similar situation occurs when the platform departs upon mission completion. It was very serendipitous that USS PROVIDENCE (SSN 719), having left station to head home after a long and successful deployment, chose to come shallow and copy traffic shortly after the 9/11 attack. Unilaterally deciding that its Toma-hawks might be of some use, PROVIDENCE did a 180 and headed back to the northern Arabian Gulf while informing the chain of command it was ready to engage and requested water space assignments. Back in range in a timely manner, she and sister ship KEY WEST (SSN 722) were the first U.S. platforms to fire into Afghanistan. Had PROVIDENCE copied message traffic many hours later, her timely return might have been precluded. Clearly, it is just as critical that an SSN or SSGN theater asset have continuous passive connectivity for the first thousand miles leaving station as it has been discussed for the last thousand miles enroute station. If these in and out connectivities were to be established at slow periscope depth speeds, than actual on-station time would be reduced by as much as three weeks, with all the attendant opportunity costs to other missions such as Intelligence, Surveillance and Reconnaissance (ISR), Mine Warfare (MIW) and Special Operating Forces (SOF) operations.
To fully exploit the warfighting and deterrent capabilities of SSNs and SSBNs, they both need to approach and leave their assigned littoral patrol areas with full passive connectivity established while at operational speeds and depths. For intuitive reasons, the hardware and methodology employed should simultaneously provide the platform with total local optical, radio frequency (RF) and acoustic situational awareness. While actually on station, and if the waters are shallow and the counter detection threat manageable, mast-mounted antenna suites would continue to satisfactorily meet connectivity requirements. In addition, although no longer number one on a rank-ordered mission list, the ASW mission still exists, and comms at speed and depth would significantly answer its connectivity shortfalls. All in all, it is conceivable that two complementary technical approaches might be required to make much more employable what are already highly deployable platforms.