Laurent Esmiol for correcting my French.Contents
The Roton is a class of vertical take off and landing (VTOL) interface vehicle. Unlike other interface vehicles it is based upon a helicopter concept rather than an aeroplane or missile form.
The Roton was first developed as a usable interface vehicle by Flame Spiral Industries of New Zealand. The relatively small market for such vehicles has meant that FSI remain the dominant supplier of Rotons to the civilian market. FSI have however licensed their technologies and designs to a wide range of companies of various nationalities.
The VTOL ability of the Roton makes it ideal for military landing operations as it is capable of landing on unprepared ground. In addition the Roton can operate equally well within a vacuum (unlike aeroplane based interface vehicles) making it a very flexible asset.
The aerospace division of Canadian industrial conglomerate Gunner-Long produce the most popular versions of the Roton for military use - the GLR-GA, GLR-MU and the GLR-MT. The GLR-GA, exported as the Ouragan (Fr: Hurricane), is an armed version of the roton equipped with a combined point defence / ground attack dual plasma gun system capable of delivering combat troops or equipment from orbit into a medium to low threat landing zone. The GLR-MU, exported as the Cyclone, is an unarmed version of the GLR-GA while the GLR-MT, exported as the Tourbillon (Fr: Whirlwind), is a dual contra-rotating rotor transport capable of moving 500 tonnes from orbit to a low threat landing zone.Narrative
Enseigne Jeannette Montcalme switched her virtual cockpit over to tactical to watch the progress of "Les Paras" towards the tertiary landing zone. The Roton's EW system queried the troops IFF transponder and updated the position on her plot - about 10 minutes to rendezvous.
The previous evening her Ouragan had delivered the same men and women to a small forest clearing from the troopship orbiting Joi. The autopilot had dropped the Roton into the clearing with so little disturbance that that the roosting flying foxes barely bothered to open their eyes to watch the alien vessel descend. Jeannette had toggled the exit ramp while her gunner monitored the passive sensors for any sign of Elysian rebels ("les grenouille" as the Paras called them). When Rabea reported that there was no rebel activity visible on any of the spectra available to her Jeannette had informed Capitaine Mejdoub that his mission was a go.
Giving her head a quick shake to dismiss her recollections Jeannette scanned the display once more for signs of the Paras' pursuers. Although the landing had gone undetected the Paras' approach to the rebel base had been spotted by a grenouille LTA drone operating beneath the forest canopy. Unfortunately the Paras had not spotted the drone and had walked straight into an ambush. They had managed to break contact but had been cut off from their primary and secondary pickups by a second group of grenouille returning from a patrol. With no enemy icons on her display Jeannette told the autopilot to begin final approach. She often wondered what purpose she served sitting in the Ouragan's control cabin as the Roton had all the manoeuvrability of a flying brick and only two directions of travel - straight up and straight down! Nevertheless MSF regulations required that all passenger carrying interface vehicles should have a human pilot so here she was.
"I've got the
Paras on visual" reported Rabea as the tac display updated itself.
"Tango Delta to
Alpha Uniform we have been acquired, what is your situation? Over."
The encrypted comm meant that Jeannette was unable to tell if it was Mejdoub on the other end of the link, she hadn't had a status update on the Paras casualties as they'd lost their long range comm in the ambush.
Jeannette's tactical display had been updated by the phased array radar activated by Rabea and showed two other grenouille drones (both recon versions fortunately) in detection range. She also felt the thud through her flight seat as the two plasma guns deployed on their pylons. Two seconds later the first recon drone disappeared from the plot incinerated by two plasma bolts.
we have you on visual. Over."
Jeannette hit the landing site icon on her display and told the autopilot "Max descent rate." Her stomach lurched towards her throat as the Roton dropped out of the sky and moments later reversed direction as the rotor tip rockets fired to lower the Ouragan gently to the ground as the landing feet deployed. Leaving Rabea to monitor the tac display she cycled through the external camera views watching the Paras running for the loading ramp carrying their wounded with them while the rear guard deployed at the edge of the clearing.
to Tango Delta, we're taking ground fire here preparing to withdraw in
The external cameras showed Jeannette the port plasma gun rapid firing towards the tree line. The plasma bolts splashed into the edge of the forest over the heads of the retreating Paras. Red glowing plaser cartridges cascaded onto the ground below the gun causing the mat of grass-vine to smoulder. Splitting her view to bring up flight ops. Jeannette instructed the autopilot to spin up the rotor ready for a quick liftoff.
rounds!" Rabea announced, the pitch of her voice rising with the tension.
From the tip of
the Roton's nose the laser mirror tracked round towards the approaching
bombs, invisible beams stabbed out.
The roton rocked as the final mortar bomb exploded 30 metres away. Jeannette switched to the status display - no red lights, a couple of ambers on the primary APU.
"We're all aboard." came Mejdoub's voice on the internal comm. Jeannette grinned and hit the commit button on her ops display. The angle of attack of the roton's rotor blades tilted up and bit the air throwing the Ouragan into the air and away from the Elysian forest and the grenouilles. The roton climbed into the cloudy sky but just as Jeannette began to relax the SAM launch alarm began to chime and her display automatically switched to tac mode.
"Rabea make sure the guns are back in PD mode." Jeannette called up the counter-measures program and watched the display as the EW focussed on the incoming missiles and the dispensers began to release flares and decoys. Despite the best efforts of the system only two of the SAMs were distracted and the two others continued to bore in - the roton was a big target and not capable of evasive manoeuvres.
Feeling useless, and very vulnerable, she watched as the Ouragan's radar's locked on to the missiles and, as they came into range, engaged them with the two plasma guns.
"Splash two vampires." breathed Rabea as the icons for the final two missiles disappeared from the display.
The roton continued it's climb to orbit, otherwise unmolested, leaving the forest below to the attentions of the orbital KE strikes. The grenouilles however had quickly dispersed once they had failed to prevent the Ouragan's rescue mission and most of them evaded the retaliation.Development
Gunner-Long have produced Rotons, under license from FSI, for several decades and the GLR-GA, MU and MT models represent the second generation to find service with various militaries. The first generation of vehicles were simply militarisation of existing FSI models. Typically FSI would supply the airframe and rotors to which Gunner-Long would fit military standard avionics and comms. Depending upon the customer's requirements various countermeasures were also fitted.
GLR-GA Ouragan and GLR-MU Cyclone
The GLR-GA (Ground Assault) and MU (Military Utility) models were developed as part of a joint programme with FSI. The aim of the programme (known as Sycamore) was to produce a common core design which could be adapted to both military and civilian uses while allowing a far greater degree of adaptability than the previous military conversions of civilian models.
Sycamore Project Airframe and Rotor
Above Sycamore Project Schematic showing location of common systems.
The Sycamore programme commenced in 2278 and by 2281 the core design (which was based on the evolution of the FSI HL-67D roton) had been finalised and tested in software.
With the completion of the Sycamore design the two companies continued separate development of the military and civilian versions. FSI launched their Sycamore variant as the HL-90 in 2289.
Gunner-Long also continued to develop the Sycamore design however the unique nature of rotons meant that the process had a number of novel constraints.
In addition the small anticipated production run required that, where possible, components and systems had to be off-the-shelf to minimise development costs.
Weapon and Sensor Systems
The Gunner-Long engineers' and designers' answer to the design conundrum was the combination of three existing weapons systems with the roton airframe.
The Hoplite system was mounted in the roton's nose with the phased array panels incorporated in the nose cone. The PD laser was therefore able to engage any targets threatening the roton from above the plane of the rotors with virtually no additional modifications.
Two Scythian plasma gun systems were mounted on retractable pylons on opposite sides of the the main body, below the rotors, to give the roton a ground attack capability in all aspects below the plane of the rotor blades. It was impossible to mount the systems externally (as is the case on the X-Wing) due to the very high air speeds and temperatures experienced during reentry. Two weapons were required to cover all possible angles of attack. Each weapon was supplied by a 1000 round capacity cassette of plaser cells.
The detection and countermeasures suites from the Longview AEW drone were also installed in the main fuselage, below the rotor, incorporating detector arrays in the skin giving the roton excellent detection capabilities below the plane of the rotor.
Above Ouragan GLR-GA Schemtic showing location of primary weapon and sensor systems. Courtesy of Gunner-Long Public Relations.
Control and Communications Systems
Triply redundant fly-by-light control systems and hardened optical data buses were installed. A range of encrypted comms equipment was also included giving the roton the ability to maintain contact over orbital distances and to integrate with space, atmospheric and ground forces data nets. The precise nature of the comms equipment was obviously dependent upon the customer however the roton's comms infrastructure was designed to operate with a wide variety of systems. Standard navigation packages (GPS, Inertial, Dead Reckoning) were also fitted to the flight computers.
While neither crew member normally had very high task loadings simulations indicated that a single pilot would be unable to manage both flight and weapons control in the event of battle damage. The roton was therefore configured for dual control - pilot/commander and co-pilot/gunner. The standard physical roton controls were combined with two copies of the Scythian X-Wing (a single seat vehicle) virtual cockpit to provide access to the roton's flight information, equipment status, sensor information and tactical data .
Two small MHD Turbines were fitted as redundant auxiliary power units (APU) for the weapons and sensor systems while power for the roton's flight systems was supplied by dual fuel cells as part of the core sycamore design.
Self-healing fuel tankage and pipe work were also provided for the four systems requiring it.
Independent life support systems were provided for the crew and passengers giving a shirt sleeve environment in both the cockpit and cargo hold. The crew system was rated at 350 man hours continuous usage (7 days for two crew) while the cargo system was rated for 2000 man hours. Both systems included attachment points in the hold for the provision of addition life support consumables if extended duration operation was required.
The crew cabin was fitted with a single person airlock and standard docking port. The cargo bay's docking hatch had no airlock but was fitted with attachment points for an airlock both internally and externally. The cargo hatch also had an extendible ramp to allow foot and vehicle access to the cargo bay without the need for any external facilities. The cargo hold itself included attachment points for various items of cargo handling equipment.
Above Close up image of an Ouragan GLR-GA roton during live fire exercises. Image shows the relative positions of the deployed plasma gun and cockpit and the cockpit recess in the roton's hull. Courtesy of MSIF Media Ops.
The plasma gun ammunition cassettes are exchanged via a loading mechanism in the cargo hold. The empty cassette is removed from the weapon bay by the automatic loader, the cassette is then manually replaced with a full one and the loader returns it to the weapon bay. Replacement cassettes, if available, can be fitted during flight if additional crew are present to do so. Alternatively an automatic loader (with 10 additional cassettes) can be fitted capable of reloading both weapons.
Once all the component systems had been assembled the difficulty was in integrating them into a working whole. The elements taken from the Scythian proved reasonably straight forward to incorporate, as did the Hoplite air defence which was effectively unchanged from its intended purpose. What proved to be most problematic was linking the Longview AEW sensors with the two plasma guns to provide point defence below the plane of the rotor. After several abortive attempts at modifying the Scythian fire control systems the problem was partially solved by adding the Guardian air defence coordination software. The Guardian software was originally intended to coordinate the local air defences of a small wet naval task force by combining data from a variety of sensor platforms and assigning targets to the available defensive weaponry. The Guardian software was able to integrate the roton's Longview and Hoplite systems with only minimal modifications and passing targeting instructions to the Scythian fire control proved fairly straightforward. The only remaining problem was determining which targeting information the plasma guns should be responding to - the Guardian anti-air or the Scythian ground attack? After a number of attempts at incorporating threat assessment software a simple switch was fitted to allow the crew to control the allocation manually.
The final virtual design completed testing in late 2283, only two years after the completion of the Sycamore project, due to the mature nature of the components and parallel early development with the Sycamore project. By 2284 the first prototype was undergoing trials with Canadian and French Republican Space Forces and the first production units entered Canadian service in early 2286 and French service in 2287.
The GLR-MU Cyclone is essentially the GLR-GA Ouragan minus the sensor systems, weaponry and auxiliary power units. The Cyclone retains the radar absorbent fuselage, redundant controls and comms systems and the GLA-EW 002G countermeasures suite. The removal of the various offensive systems increases the cargo capacity of the Cyclone relative to the Ouragan and substantially decreases the cost.GLR-MT Tourbillon
Following the unexpected popularity of the Ouragan and the Cyclone, and wishing to capitalise on the expertise built up during the development process, Gunner-Long commenced development of a scaled up version of the Cyclone at the request of the French Republican Navy (MSF) in 2285.
The size of the Cyclone was increased by 20% effectively doubling both the mass and cargo capacity of the roton. The much increased mass meant that a single rotor was insufficient to power the roton's take-off so two, five bladed, contra-rotating rotors were used.
Although the Tourbillon was meant to be a simple stretched version of the Cyclone, reusing the majority of components, the double rotor required a complete overhaul of the flight control systems. The first virtual design was completed in 2287 but another five years were required to perfect the controls in reality with the first three prototypes completing acceptance trials with MSF in 2292. The first production batch of Tourbillon entered service in 2293.
All three Gunner-Long rotons were based upon the Sycamore Project's core design and as such they have their main features in common.
Above Ouragan GLR-GA (left) and Tourbillon GLR-MT (right) rotons hovering in close formation. The rotons are equidistant from the camera so the image gives a good indication of the relative size of two models. The image was taken at the 2301 Mirambeau Air Show during the MSIF EdI display. Note that both vehicles have cargo bay doors and cockpit shields open following an earlier demonstration of RPV launches. Courtesy of MSIF Media Ops.
The main body is cylindrical in form with an aerodynamic nose cone and a slightly flared base. The body had to contain all the Roton's equipment as external stores (weapons, fuel, sensors etc.) would be damaged by the high airspeeds and temperatures of reentry. The fuselage is a monocoque design (that is to say the strength is provided by the fuselage shell rather than by an internal framework) optimised for a vertical load path and constructed of low radar visibility materials (the civilian version of course used standard aerospace composites).
Propulsion is provided by a horizontal rotor (or rotors), each blade tipped with a rocket motor. The blades are mounted on a magnetic bearing at the base of the nose cone. The main body of the Roton is prevented from rotating by redundant radial rocket motors. The tendency for counter-rotation is much less on the roton than a helicopter as there is no transfer of rotational motion between the rotor and the main body as this is provided by the blade tip rockets. In theory only vertical motion is transferred via the bearing, although in practice there is some transfer of rotation that has to be compensated for.
Above Roton landed on the Tiranean moon Europos. Image was taken during a MSIF training exercise and shows a Cyclone roton with the cargo bay door open and ramp deployed. Note that the rotor blades are highly piched (actually only 20 degrees from vertical). This allows the roton to direct the bulk of its rocket thrust vertically. Picture Courtesy of MSIF Media Ops.
During takeoff and atmospheric flight the blade tip rockets power the rotation of the rotor and the blades provide lift, in the same manner as the blades on a helicopter. In vacuum the blades are tilted so that the rockets are almost vertical to provide a thrust along the axis of the Roton. The slight angle is required to maintain the rotation of the rotor as this provides the means (centripetal force) to pump the propellant from the tanks in the main fuselage, through the body of the blades, to the blade tip rockets. This arrangement means that the roton does not require the expensive, heavy and difficult to maintain turbo pumps and pressurised fuel tanks found on other forms of interface vehicle. The roton's ability to operate in a vacuum and to land vertically also means that it is capable of landing and taking off from airless worlds (unlike equivalent space planes).
Above A Tourbillon in re-entry configuration (foreground) following de-orbit injection burn. Note the rotor blades in the swept back orientation so that they remain within the wake of the roton's heatshield during aerobraking. A second Tourbillon can be seen in the backgound in its storage configuration with folded blades. Courtesy of MSIF Media Ops.
During reentry, once injection maneouvers are completed, the rotor blades are raised up so that they trail behind the Roton as it enters the atmosphere base first. The heat shield produces a sufficiently large wake that the blades can freely rotate in a feathered configuration (i.e. edge on to the flow of air generating no lift). Once the Roton's speed has been reduced by aerobraking the angle of the rotor blades is gradually changed to provide braking. This operation requires no rocket power as the rotor is merely acting as a brake. Once the landing zone is reached the rockets are fired to provide additional control during final approach and landing. In actual fact no power is required to effect a soft landing as the Roton can land using the energy stored in the rotor to halt its decent as it touches down by flaring the blades to increase lift (this is the manoeuvre known as auto rotation in helicopters).
The flared base of the main body has an actively cooled heat shield for reentry. The landing gear is recessed into the sides of the main body and, when deployed, project over and below the base.
When not in operation the roton's blades are normally folded down the side of the main body thereby greatly reducing the hanger requirements. When carried aboard interstellar or in-system vessels Rotons can either be stored in an internal hanger or an external cradle.
The cockpit, with the crew airlock hatch to one side, is situated immediately below the rotor bearing. The front face of the cockpit is a transparent bubble giving both crew 180 degrees of horizontal visibility and 120 degrees of vertical visibility. The bubble itself is set back into the body of the roton in a recess so that it does not protrude into the roton's slipstream. The external cockpit (the civilian version of the sycamore has an internal cockpit) is provided to allow the crew sufficient visibility to land the roton in the event of complete failure of sensor systems. In high threat situations, where sensor systems remain operational, the cockpit is protected by blast doors. Access to the cockpit is via the crew airlock which has exits to both an external docking port and the cargo bay.
The cargo hatch is on the same side of the craft just above the flared base. The hatch comprises an external fairing that opens by moving out from the roton's body and then up above the hatch which consists of a pressure tight door with a standard docking fitting. The pressure door itself opens horizontally to give access to the cargo bay via an automatic deployable internal ramp that protrudes over the heat shield. The cargo bay can be opened in flight (at air speeds less than 200 kph) to allow air drops (of paratroops or cargo) or the deployment of drone aircraft.
GLR-GA Ouragan and GLR-MU Cyclone
The Ouragan and Cyclone models have a single, six bladed rotor and externally there is little difference between the two when the Ouragan has its plasma guns retracted. The only visible difference are the bay doors for the plasma guns and the slightly more bulbous nose housing the Hoplite laser mirror.
On the Ouragan the plasma gun bays are placed just below the rotor at 90 degrees around the circumference of the roton from the cockpit and cargo hatch (thus if the cockpit and cargo hatch face north and the plasma guns face east and west).
Above Ouragan of the MSIF EdI during live fire exercises. Note the spent plaser cells being ejected below the left-hand plasma gun. Courtesy of MSIF Media Ops.
Both models have six landing legs - each of which has a four toed foot. As the leg deploys outwards and downwards from the roton's body, over the flared heat shield, the toes of the foot fold out to take the weight the vehicle. The six feet are capable of supporting the roton on any hard, reasonably flat (a slope of less than 10%) surface. In soft ground however a fully loaded Ouragan or Cyclone will also rest on the base heat shield.GLR-MT Tourbillon
The much heavier Tourbillon has a dual, counter rotating rotor system in which each rotor has five blades giving ten in all. Otherwise the Tourbillon reuses as many components as possible from the Cyclone as possible. Aside from double rotors and the larger fuselage the only other obvious differences are the eight sets of landing gear.
The basic purpose of the three Gunner-Long rotons is to move troops and equipment between a planetary surface and orbit. The design of the roton means that atmospheric flight is essentially limited to vertical motion, some horizontal travel is possible but only at very low speeds. This limitation imposes severe restrictions on the type of missions that can be undertaken.
All models of roton are extremely vulnerable to air attack and their low manoeuvrability makes them easy targets. Consequently they are only used where complete local air superiority is available.
The roton's greatest advantage is its ability to operate from unprepared fields and on vacuum worlds. As a consequence roton's are the favoured lander for detached patrol missions where adaptability is at a premium. For similar reasons they are also regularly found as the main military interface transport on colony worlds.
The Ouragan's heavy point defence armament, VTOL capability and good stealth characteristics makes it ideal for special forces operations from orbit. Typically these types of operations can be split into two categories - the large raid and the small raid.
A large raid would normally take place in six stages.
During its initial development the Ouragan was briefly considered by the MSF for use as the main lander for the Verdun class of Assault Landing Ships. The high vulnerability to air attack meant that the Ouragan was dropped in favour of the Zenith VSTOL space plane. Ironically the Zenith later proved too unreliable and was itself dropped in favour of the Tornade II STOL space plane. By the time the Zenith's shortcomings were discovered construction of the Verdun was too far advanced to reconfigure the hangar deck for rotons.
The Ouragan first saw combat in 2290 during the Elysian rebellion on Joi, 61 Ursae Majoris. A Division de Debarquement had been dispatched by the MSF to reinforce the failing French colonial government. Ouragans were assigned to a number of the warships and fleet auxiliaries accompanying the Verdun Assault Landing Ship that formed the core of the Division. The Ouragans were used to deploy special forces troops and equipment directly from orbit to secure the runways of the two main cities (Esperance and Bonne Chance) to allow the Tornade II landers from the Verdun to bring down the main force. The Ouragans were also used extensively in search and destroy missions against rebel guerrilla units to deploy, supply and recover long range patrol groups.
Although the Elysian campaign was relatively short the Ouragans acquitted themselves well against the well, albeit lightly, equipped rebels. The point defence capabilities proved themselves on several occasions preventing the destruction of several aircraft. Indeed during one surprise mortar attack, following the sabotage of ground based PD units, against the Esperance spaceport the PD systems of two parked Ouragans prevented the destruction of not only themselves but also five Tornade II landers.
The extreme usefulness of the Ouragan in colonial operations, where long runways were few and far between, resulted in the MSF deploying the Ouragan as the primary interface vehicle for the naval liaison unit based at each colony's orbital terminal.
Above Ouragan GLR-GA roton in Low Earth Orbit. The cockpit shield is open which is unusual during orbital operations and it is likely that the picture was staged for the benefit of the camera. Courtesy of MSIF Media Ops.
The introduction of the Cyclone and Tourbillon in the late 2290s significantly improved the MSIF's VTOL interface capability. The increased load capacity of the two unarmed rotons allowed the MSIF to mount (land, supply and recover) substantial raids without the need to secure a planet side runway.
The Kafer War has seen the MSIF's rotons in action along the length of the French Arm. The VTOL interface capability has proved invaluable in numerous operations and has been the saviour of thousands of troops cut off from other means of supply or evacuation.
Gunner-Long Military Rotons
The Roton is a real world reusable launch vehicle. The Rotary Rocket Company flew a non-orbital test version in 2000. They intended to use a conventional rocket engine to attain orbit but to land on the rotor. Development has unfortunately ceased due to the recent economic downturn.
The original concept for the Roton was proposed by HMX and also used the rotors for lift off as per my 2300 version.
My 2300AD version of the Roton is an adaptation of the real world designs and is probably less efficient in that it uses liquid hydrogen as fuel (as per the 2300AD standard). One of the real world advantages of the Roton is its use of kerosene. This obviates the need for cryogenic cooling of the fuel and improves the efficiency of the centrifugal pumping.
The statistics of the three roton's were calculated by factoring quoted real world values for the Rotary Rocket designs for the dry weight of the vehicle. The fuel requirements and cargo capacities however were calculated using GDW's Star Cruiser Naval Architect's Manual (NAM) rule of requiring a fuel mass of one sixth the GLOW. Signatures were also calculated using the NAM
Copyright J.M. Pearson, 2003