MILNET has created a series of briefs looking at the Department of Defense unmanned systems summarizing the existing, planned and conceptual systems.  Our research has stumbled upon a startling set of commonalties that raise the question of how DoD's joint development practices may have paid off, either intentionally, or through the planned synergy of the jointness doctrine.  Or perhaps it is coincidence or sheer good luck.  Regardless, the  commonality between the programs, if not intentional bear inspection, if for no other purpose to now exploit that synergy for improved time to operation and better overall performance. 

We should note however that of the three MILNET unmanned system briefs,  the MILNET USV brief is based largely on conjecture and perhaps coincidences.   However, years of experience and study of the Department of Defense has also made it clear that while development teams in DoD and the industries that support them are human and mistakes, they can also be quite effective.  Our USV Brief conjecture and speculation may actually have been inspired by tendrils of actual "black budget" projects taking advantage of projects in the public domain.  We would not be surprised to find that many of the suppositions we make are close to actual programs whose existence come to light sometime between 2010 and 2025.

The commonality between the three unmanned systems (UAVs, UUVs, and USVs) center around possible synergies in two major areas, Missions and Technology Challenges.


Missions

The three systems have three different environments, however there are missions that, not coincidentally are quite similar.  This is a natural synergy due to the nature of military missions in general.  For instance, in the Passive Activity area, the three systems all need to conduct real-time, on the moment tactical recon, target acquisition, and target tracking.  Obviously the sensors and specific requirements for the individual environments are quite different.  Recon underwater makes use of totally different sensors and software algorithms than an equivalent recon sub-system aboard a unmanned vehicle in space. 

On the other hand, there may be basics of the sub-missions that are quite similar. At a minimum the processes involved in defining the specifics or the project management task are going to be quite similar.   Another possibility would be in command and control -- perhaps some synergy can be found in common remote control consoles or mission design and download sub-systems.

In terms of system support, the three sub-systems all require on-board intelligence for navigation and communications.  Perhaps not all the necessary intelligence is on-board each system.  For instance, the USV, for many of its missions, may be able to take advantage of national level navigation and communication systems already on orbit, whereas the UUV will probably need to deploy "sister" craft to link up to national level assets -- raise a buoy to connect to GPS, and then act as a navigation node for other UUVs in its local area.  Similar differences occur in communications.  UAVs and USVs most likely can take advantage of direct use of national level communications and navigational assets such as MILSTAR and NAVSTAR (COMs and GPS), however as will be pointed out, there may be circumstances where at least space assets may find themselves in darkness.


Technology Challenges

Technology challenges for the three unmanned missions are similar as well.  Power systems for all three require batteries.  Therefore, at a minimum, battery technology, recharge systems, and low power mode management sub-systems might be shared across all three unmanned systems.


Power

All three unmanned systems are challenged by the need for copious amounts of power.

Space borne systems however are assumed by the layman to always enjoy the energy gift of the Sun. SOL, however, is only magnanimous for those periods where the space borne object is within its direct effects. Sunlight is masked, however, by the planet Earth and if a spacecraft finds itself within the shadow, solar arrays become nothing more than dead weight.

In those circumstances, on-orbit assets must rely on batteries.  In geo-synchronous satellites, the batteries might have smaller capacity, as they act mostly as part of the power stabilization and filtering system, but they are there, never-the-less. 

USVs will not be designed with geo-synchronous orbits in mind, and certainly at least some portion (if not all) of their working life will be spent in darkness.  Therefore, a means for power and yes, even recharging must be taken into account.  It is also reasonable that at least some of  the USVs will require stealthy construction and solar arrays are not stealthy in any way, shape or form, unless perhaps thinks to use them as a disguise of sorts.

The early manned space program discovered the sad facts of solar cell power quite early and the answer was no less quick to become obvious.  The fuel cell was borne, providing electric power from various means. 

The most reliable and longest life was based on the decay of radioactive Strontium, and used by both the U.S. and Soviet spacecraft.  Another is the hydrogen-oxygen fuel cell.  This type of cell is nothing more than a electrochemical energy conversion device that converts hydrogen and oxygen into electricity and heat.  In either case, nuclear or hydrogen-oxygen, the cells were found to be somewhat dangerous and in at least one very public circumstance came near to killing the crew -- Apollo 13 is testament to the fact.

Thus batteries, while not as efficient are thought to be much less dangerous and therefore provide a higher level of overall reliability.  Battery technology challenges are thus shared between all three unmanned systems.


Navigation

Navigation is another area which creates challenges for all three unmanned systems.  The UAV is perhaps the easiest to navigate.  It is rarely outside the course information capability provided by GPS satellites.  However, there are cases where relying upon that national asset could both be dangerous to the mission, but also deadly to the aircraft.  Military missions require a higher degree of reliability -- that which approaches 100%.  This is due to the possible critical nature and resultant savings in lives of a successful mission, as well as the ripple effect as UAVs become more integrated and a part of the overall operation. 

Thus, it would be foolish to always rely on national level assets such as the GPS constellations.  Fortunately for the UAV mission, there is a fallback in the form of AWACS, which can become the navigation "helper".  Also, larger UAVs can field an on-board inertial guidance platform but smaller aircraft cannot carry sensors AND the inertial guidance platform.

Similarly, it may be found that smaller USVs will not be able to field inertial guidance either.  In this case, both systems will need to rely upon a larger craft to provide the missing navigational information.  But what if the national assets and AWACS (or the space equivalent) are not available?  It seems only prudent for the military to field temporary and localized navigational support. What better way to do that than to have the same craft which is deploying the active force USVs or UAVs to also deploy the local navigation nodes in the from of other unmanned systems.  This is exactly the methodology used by the Navy, the underwater unmanned system almost always requiring local aid in this regard.


Communications

Communications for all unmanned systems is a critical function.  In nearly every case, this is two way communications.  For remotely piloted versions, the very survival of the craft can depend upon a control channel that is reliable (error free), robust (cannot be jammed), and powerful enough to survive interference (jamming and natural).  This is especially the case for space borne assets which are the mercy , much more so than aerial or underwater assets, to solar radiation.

Underwater operations assume poor communications. Both low speed and difficult medium present the worst case communications scenarios. UAVs and USVs enjoy a far easier medium to traverse, however both can be situated where natural topology or position will mean degradation of signal.  A UAV can be on the far side of a mountain thus losing its connection back to the pilot.  The USV might have the entire planet between in and its controller.  In both cases, programming can help by putting the vehicle into a safe hold pattern  Unfortunately that hold pattern is not likely to change the situation in terms of restoring communications. 

In the case of UAVs, the pattern might simply be a "pullup" to a reasonable and safe altitude to avoid terrain intersections (crashing).  The USV might abort a reentry attempt or maneuver away from hostile forces.

Again, as in navigation, communications could be critical.  If this is the case, then the unmanned systems will require inserting a local COMs relay   Over the horizon communications may require multiple legs in that relay and thus more than one such "local" relays may need to be deployed.


Autonomy

Autonomous software systems might be the major area of commonality between the three environments.  Autonomy requires highly advanced software systems, and quite likely may include major reuseable software modules.  Control operator functions for UUV, UAV, and USVs despite controlling vehicles in widely different environments, all will need to employ controls for three dimensional "flight". 

Autonomous operations allow for control operator rest, as well as provide for vehicle safety, allowing the unmanned system to perform tasks that do not require human intervention and indeed eliminate human error.

The high computing requirements add to the power budget since they do require more complex and higher performance computing cores. Thus autonomy will push the computing frontier as well as developing further the on-board power delivery systems.


Control Operation

The military UAV program has created, perhaps, the best integrated hybrid between autonomous and remote control direction of a robotics device.  It is rumored that several UAVs are able to be instructed to enter a hold pattern and the UAV will comply.   Other reports say they can be directed to navigate to a particular GPS position and then enter that hold pattern.  In addition our sources say the higher level UAVs may be instructed to enter a surveillance flight pattern that encompasses areas to avoid, change altitudes, or simply follow a semi-random and therefore unpredictable course while "hitting" all the navigation points that are required to match the intelligence needs for that UAVs sensors.

At the same time, a high bandwidth channel is required to relay real-time flight information to a remote control pilot so that real-time flight control can take place.  Speculation on why a remote control pilot is needed is beyond the scope of this briefing, and in fact might fall into the classified domain. Suffice to say takeoffs and landings seem an obvious critical moment where pilots and aircraft must be seamlessly integrated.

There are three challenges in this area: 1)  Remote control inputs to the aircraft, 2) Telemetry data channel(s) from the UAV sensors, and 3) the video and flight telemetry channels (3) to enable proper flight control by the remote operator.  In addition the transmit/receive functions have the critical function of encryption and necessary RF power in order to insure jam-free operation.


Summary of Commonalties

The following chart indicates some of the commonalties that are obvious, there may be others as well.