From: Allen Thomson (thomsona@flash.net) Subject: Re: Polaris Chevaline? Newsgroups: sci.military.naval Date: 2003-07-27 15:22:38 PST This thread has inspired me to do something that I've been thinking of for a while: make available the information about Chevaline that came my way back in the '90s. What follows is pretty clearly somebody's extraction of unclassified pages from a larger report or reports, hence the general messiness. I speculate that this material, which came from a US source, may be associated with interest in buying second-hand Chevalines from the UK for use as target dispensers in missile defense tests. Pages are separated by ----- lines. I've made an attempt to preserve the page lay-out and appearance, but there's a limit to what you can do in ASCII. My comments and descriptions are in [square brackets].
All photos with permission from http://www.skomer.u-net.com/projects/chevaline.htm---------------------------------------------------------------------- Unclassified US/UK BALLISTIC PAYLOAD CARRIER SYSTEM This Carrier System is developed from a proven UK Weapon System and consists of a fly-away Bus mounted on a baseframe. It is capable of being flown on a variety of US boost rockets. The Bus is a stable, manoeuvering platform which can be used for the controlled deployment of re-enty payloads or other ejectables exo-atmosphere, in variable sequence depending upon the mission objectives. Post-separation systems on board the Bus control navigation, stabilisation and event sequencing. The System has had full approval for in-service use aboard UK Submarines and is supported by a series of over forty-five fully instrumented flights including from the pad at AFETR, Cape Canaveral. This system and all the necessary supporting equipment is presently housed at Kirtland Air Force Base under the control of Field Command - Defense Special Weapons Agency. Page 1 Unclassified --------------------------------------------------------------------- DGSWS 5820 [stamped] UNCLASSIFIED ISSUE 2 ORIGINAL [Picture of bus looking from above and to the side. Shows two RVs, one fully, one partially. The one that can be seen best appears to have some sort of fabric wrapping, leaving only the hemispherical nose cap uncovered. Lables on the picture are "Attitude Control Thrusters," "Decoy Tubes" and "Bus Propulsion Unit."] 2-46 FIGURE 2-44 RES MATED -Y SIDE [stamped] UNCLASSIFIED DOWNGRADED IN ACCORDANCE TO VAX113/207/ACT(327) D/MOD SY(S&T)/3/4/3/APPENDIX A67 [handwritten]GW NO:1017675 [squiggle, apparently initials] [handwritten date] 25/9/96 --------------------------------------------------------------- Unclassified PHYSICAL CHARACTERISTICS BUS STRUCTURE The Bus structure comprises an aluminum closed torsion box with top and bottom diaphragms, strengthened by vertical divider plates. A steel base plate provides a payload mounting ring, baseframe attachment points, and mountings for separation rocket motors and the Space Reference Unit. Thermal skins protect the Bus components from residual exit heating effects after nose fairing eject. The BUS [sic] has integral lifting points to aid assembly. Approximate Weights and Dimensions: Overall Carrier length: 1.82 meters 72 inches Overall Carrier diameter: 1.37 meters 54 inches Maximum Carrier mass: 735 kg 1620 lb (including all payloads) Overall Bus length: 1.27 meters 50 inches Overall Bus diameter: 1.22 meters 48 inches Empty Bus mass: 318 Kg [sic] 700 lb (including fuels but less payload) Total Payload capacity: 400 Kg [sic] 880 lb BUS SUB-SYSTEMS Electronic Control Assembly (ECA) This electronic unit controls Bus initiation, guidance and event sequencing and has multiple levels of protection against disruption (circumvention). Within its Titanium alloy casing it comprises ; (i) Power Supply Unit providing DC and AC power up to 200V rms., (ii) Guidance Control Computer (hardened with power failure core store recovery and with programmable missions held in EEPROM) and (iii) Interface Control Unit initiating up to seventy-two ordnance or non-ordnance events. Space Reference Unit (SRU) Provides 3-axes attitude, rate and acceleration data to the ECA. The rate gyroscopes and accelerometer are fixed to the SRU body and the attitude gyros are caged with reference to the attitude of the vehicle at Bus separation and all data can be considered incremental from that datum. Bus Propulsion Unit (BPU) Main propulsioin of the Bus is produced by this high thrust hypergolic liquid rocket motor (fuel MAF-1/oxidant IRFNA). It provides 6300 N mean thrust (total impulse 77,500 Ns), which can be expended in multiple manoeuvers. Two nozzles (adjustable) provide different thrust lines to cater for major c.of g. shifts during a mission. The BPU features secondary containment of the liquids and is supplied fully fuelled. Page 3 Unclassified -------------------------------------------------------------------- [Line drawing showing top of booster, mounting unit and main PBV assembly.] [Lables are] [On booster]: "BOOSTER" [On mounting unit]: "BASEFRAME ASSEMBLY" "SEPARATION FIRING UNIT" "EXPLOSIVE BOLTS" "SEPARATION FIRING UNIT" "EXPLOSIVE BOLTS" [On PBV]: "SEPARATION SWITCH" "HYDRAZINE ACTUATION SYSTEM" "DECOY TUBES" "RV" "RV" "BPU TANKS" [There are XYZ coordinate axes in front of the PBV: X is along the line of flight, Z goes though the line of centers of the RVs, and Y is, of course, perpendicular to those two.] ----------------------------------------------------------------- DGSWS 5820 [stamped] UNCLASSIFIED ISSUE 2 ORIGINAL [This is a picture similar to the middle one at the bottom of http://www.skomer.u-net.com/projects/chevaline.htm. Instead of the E.E.E. sign in the dark part of the RV hollow there's one in the shiny part just above that has "1062" in big numbers and some smaller text that I can't make out.]
[stamped UNCLASSIFIED] FIGURE 2-14 +Z 'C' CONE 2-16 VAX113/20/ACT(327) DOWNGRADED IN ACCORDANCE TO D/MOD SY(S&T)/3/4/3/APPENDIX A67 [Initials] -------------------------------------------------------------------- [seems to be cropped a little at the top] [stamped UNCLASSIFIED] ISSUE 2 ORIGINAL [Picture somewhat similar to the left-hand one in http://www.skomer.u-net.com/projects/chevaline.htm but taken from further to the left and closer. The red tank is labled "Hydrazine Tank" and the things under it are labled "Thermal Batteries." The box to the right of the tank that's labled DL/CT in the Web picture is labled DB/C on in the version I have.]
FIGURE 2-32 -Y +Z THERMAL BATTERIES CONNECTED [STAMPED] UNCLASSIFIED 2-34 VAX113/20/ACT(327) DOWNGRADED IN ACCORDANCE TO D/MOD SY(S&T)/3/4/3/APPENDIX A67 [Initials] [handwritten] 25/9/96 ---------------------------------------------------------------------- DGSWS 5820 UK/US/EYES ONLY ISSUE 2 UK SECRET ORIGINAL UNCLASSIFIED [stamped over above two lines] [Picture giving booster-eye view of bottom of PBV. Labels are]: "Attitude Control Thrusters" "Bus Eject Motor" "Decoy Tubes" "Bus Eject Motor" "Electronic Unit" "Safety/Arming Plugs" FIGURE 2-16 -X BOTTOM DIAPHRAGM, ERMs [?] AND DECOYS INSTALLED UK SECRET UK/US EYES ONLY UNCLASSIFIED [stamped over above two lines] 2-28 DOWNGRADED IN ACCORDANCE TO VAX113/207/ACT D/MOD SY(S&T)/3/4/3/APPENDIX A67 [initials] ----------------------------------------------------------------- Unclassified PERFORMANCE The Bus is a manoeuverable, stabilized vehicle capable of carrying and ejecting (along pre-planned trajectories) up to 400 kg of payload during flight. It was designed for the accurate targeting of RVs and exo-atmospheric placement of pen-aids. It undergoes major displacements and turns during a mission and is navigated by continuous velocity monitoring with respect to an inertial reference established just prior to separation. Utilising the Bus's accuate positioning capability, the dispersal of objects can be in single or delayed burst modes to produce constellations, trails, etc, during the exo-atmospheric portion of Bus flight. FLIGHT TIME The Bus has onboard thermal batteries which are normally initiated immediately prior to separation from the booster. These batteries give the Bus a typical powered flight time of 9 minutes. Events may be operated later in flight by the use of self powered firing circuits initiated by a trigger from the ECA. By the use of additional battery power Bus operations can be extended up to 20 minutes (governed by hydrazine fuel utilisation). SEPARATION FROM BOOSTER The Bus is normally separated from the booster using two solid eject rocket motors which have a thrust of 24000 N each, imparting a velocity of 30 m/s with respect to the booster. Use of soft separation by means of hydraulic rams can give a typical separation velocity of 5 m/s. IN-FLIGHT VELOCITY CONTROL, STABILITY AND ACCURACY During free flight, changes in the velocity of the Bus are achieved by use of the liquid fuelled BPU. This motor has a mean thrust of 6300 N and a total impulse of 77,500 Ns, and can change the Bus velocity by up to 0.2 km/s. The BPU is capable of multiple operations and can be used to control the velocity of the Bus to within 0.1 m/s The Bus is stabilised in flight by a 3-axis attitude control system utilising dual level hot gas thrusters. This provides 360 deg steering in pitch, +/-30 deg steering in yaw and can be controlled +/-70 deg in roll. The mean steady state attitude error is typically 0.1 deg under no load conditions, 0.2 deg during ejection of lightweight object groups and 0.3 deg during a main engine burn. Following major asymmetric transient loads, such as RV ejection, the attitude recovers to nominal within 2 seconds. The Bus is mass balanced such that the c.of g. always lies within its stabilisation control box. The gross changes in the c. of g. which occur during flight are adequately catered for through corresponding changes to the control system parameters. Page 5 Unclassified ----------------------------------------------------------------- Bus Propulsion Unit [Very poor-quality picture] A bi-propellant engine providing thrust for gross manoeuvring of the vehicle in flight. Driven by hot has from the hydrazine actuation system, it comprises two thrust chambers fed from a pair of tandem oxidant (nitric acid) and fuel (MAF-1) piston tanks. It provides velocity increments for the BUS [sic] up to 0.2km/sec. - 6300 N axial thrust (77,500 NS total impulse) - Velocity control achieved to within 0.1m/sec. - Fuel flow rate whan firing 2.5kg/sec. ------------------------------------------------------------------ Unclassified ENVIRONMENTAL CHARACTERISTICS The Carrier is a rugged system - designed to meet operational requirements over a long service life. Total through-life support with re-buy and refurbishment has maintained the equipment at the bottom of the failure-rate "bathtub" curve for an extended period. The shock and vibration qualification test severities imposed for the A3 motors included substantial margins which have proved adequate to encompass the enviroments imposed by alternative boosters. SHOCK The Carrier has been approved to a shock requirement which equates to a 1- in -500 probability of occurrence in-service. LOW LEVEL FLIGHT SHOCK Half-sine shock levels covering low level flight shock events such as booster ignition 33g for 35 ms along the X axis 10g for 35 ms along the Y and Z axis HIGH LEVEL FLIGHT SHOCK The most severe shocks for items mounted on the Bus and Baseframe are those arising from the operation of the Bus Separation System. The Carrier has been approved using the following levels of high level shock: [Begin table] Structural Zone "g" Duration (ms) Units mounted on the baseframe, 1000 0.25 base structure and lower half 300 0.75 of the base structure BPU and units mounted on the 300 0.25 Bus lower diaphragm and the ribs 125 1.00 above the lower diaphragm Equipments mounted on the top 125.00 1.00 diaphragm [End table] VIBRATION The vibration levels utilised in the design and test of the Carrier equate to a 1-in- 44 probability of the occurrence. The complete Carrier was designed to be subjected to random vibration of 0.005 g^2/Hz +/- 3 dB at 20Hz increasingly linearly to 0.03 g^2/Hz at 500Hz, and 003g^2/Hz over 500Hz to 2kHz, for 40 secs in each of the 3 missile axes in turn, the levels being controlled at the baseframe. The majority of carrier components and equipment have been tested to a "Component" requirement of 0.15 g^2/Hz +/- 3 dB over 20 Hz to 2 kHz for 30 secs in all axes. Equipment not tested to this "Component" requirement was separately reviewed and found to have substantial margins. Page 7 Unclassified -------------------------------------------------------------------- Unclassified SAFETY General The Carrier is equipped with a series of mechanical and electrical safety breaks. The assembly has been designed so that it will fail safe should a component failure occur. Safety Features The bus is fitted with Safety Plugs for ground handling and processing which isolate both the pre- and Post-separation power supplies and must be replaced by Arming Plugs before the mission. Pre-separation power supply produced in the ECA is safeguarded by pairs of open contacts on 2 gravity/time sensor switches, each switch using a different mechanical damping system. Protection against inadvertent operation of the ordnance is provided by the use of distribution boxes employing opto- electronic isolation modules which give complete electrical and physical isolation between the trigger inputs and outputs. Radio Frequency Attenuation Connectors (RFACs) transfer the trigger energy to Type E fuseheads whilst isolating them from other possible sources of energy. The liquid systems incorporate primary and secondary containment plus many other safety features, such that at least three unlikely events would need to occur before the system can be pressurized. Safe Monitoring It is possible, subject to operational requirements, to establish the state of each substantive safety break by visual examination or safe electrical testing. APPROVALS Eastern Space and Missile Center has granted range safety approval against ESMC Regulation 127-1 for operations at the Eastern Test Range (ETR) during three phases of the UK In-Service programme: (a) Flat Pad launches of developmental hardware (1978 - 1980) (b) Submarne launches of Acceptance standard hardware (1980 - 1982) (c) Submarine launches of Procuction standard hardware (1982 - 1987) These approvals include all operations from assembly to launch of the Carrier. Outline approval for use of an adaptation of the In-Service system for launch from NASA, Goddard Space Flight Centre, Wallops Flight Facility, Va has been granted under GSFC/WFF Range Safety Manual RSM-93. This approval covers the use of a rail pad launch. All explosive items have special to type containers with UN clearance for transport by road and air. Page 9 Unclassified ----------------------------------------------------------------------
From: Allen Thomson (thomsona@flash.net) Subject: Polaris Chevaline? Newsgroups: sci.military.naval Date: 2003-12-30 16:50:47 PST From the Google-cached version of http://www.insys-ltd.co.uk/space/capabilities/capabilities.htm Strategic Systems Involvement in the UK's strategic and tactical nuclear weapons over several decades culminated in INSYS's appointment to the role of Design Authority for the complex Chevaline Penetration Aid Carrier (PAC), during the 1970's UK Polaris Improvement Programme. The PAC was a sophisticated autonomous spacecraft with guidance, 3-axis stabilisation and propulsion. Following a successful series of development and acceptance flights, this entered service with the Royal Navy in the early 1980's. In addition to full development and production responsibilities for the PAC, INSYS exercised major responsibilities for systems aspects associated with the Chevaline project, concerned with mass monitoring and control, rocket plume modelling, sub-system alignment, structural modelling and separation/trajectory modelling. INSYS personnel were members of the analysis teams sent to the US in support of all the development and in-service flight tests. From our background and expertise on the Chevaline, INSYS was in an excellent position to work on behalf of the UK MOD in many aspects of the successor ballistic missile system, Trident. Wide-ranging research and more specific studies were conducted into Trident re-entry performance. Of particular interest is the assessment of re-entry behaviour taking into account the effects of asymmetric aerodynamics caused by ablation and erosion. A legacy from this work was the capability in hypersonic aerodynamics and the state-of-the-art modelling tools for re-entry behaviour. A complete suite of software is available associated with the re-entry performance prediction methodology developed by INSYS. Exo-atmospheric Flight Testing INSYS is the only UK company which regularly designs, develops and flies payloads for the US missile defence programme, currently the responsibility of the US Missile Defence Agency (MDA). This results from US recognition of the INSYS extensive database, and innovative concepts which complement the US activities. Combining the expertise developed in strategic systems with its engineering and maunufacturing capability INSYS became the UK Principal Contractor for the provision of a sophisticated payload on a major UK/US collaborative re-entry vehicle flight experiment, flown on the US STARS booster from Barking Sands launch facility on Kauai. The Contract carried out for DERA (now Dstl), Farnborough involved the design, manufacture, development and qualification of the flight payload which included an instrumentation and telemetry package which provided exceptional flight dynamics data to analysts. INSYS Trials and Safety engineering disciplines were fundamental to the successful flight preparation activities during assembly, integration and test (AIT) and the flight campaign. During the same time period 1990 to 1993, INSYS were design authority for the provision of a number of experimental payloads to other US MDA exoatmospheric flight tests. Re-Entry Vehicles More recently INSYS has been awarded contract by Dstl, Farnborough as UK PC for the development of re-entry vehicles for the US missile defence community. INSYS work closely with US Space and Missile Defense Command who are the launch facilitators and other US sub contractors including Lockheed Martin, Coleman Aerospace/ Orbital Sciences, Ball Aerospace and ITT Industries. Key to INSYS involvement in these programmes was its composite materials and precision manufacturing capability discussed later. The most recent flight test to include an INSYS designed and manufactured re-entry vehicle was in May 2002 when an RV target was provided for a US Patriot PAC3 intercept experiment.
