Bay Doors Research Articles

A familiar voice in the lab

When voice-activated assistants first appeared on the market, they were perceived as a high-tech frill. Science fiction enthusiasts, reminded of the HAL 9000 computer in the movie 2001: A Space Odyssey, amused their friends by stumping Amazon’s Alexa with commands to open the pod bay doors. Meanwhile, Apple had to prime its Siri iPhone voice assistant with searing comebacks to the question: What are you wearing? But pretty soon, consumers got serious about voice-activated devices, routinely asking the ever-ready, ever-listening vocal presence in their living space for a check on the weather or to cue up the latest from Taylor Swift. Voice activation is now becoming an even more serious technology, completing its journey from science fiction to fact-based science tool with the emergence of voice-activated laboratory assistants. The trick will be upgrading the natural language processing (NLP) programs underpinning home voice systems to recognize chemical names, technical jargon, full

Noise Characterization of a Full-Scale Nose Landing Gear

This paper presents experimental results from a nose landing-gear test campaign. A highly detailed model of the nose section of a 90-seat configuration green regional aircraft concept was built and tested in an aeroacoustic open-jet wind tunnel at full scale. All of the landing-gear components, fixtures, and small details and associated structures such as the complete wheel bay, bay doors, and hydraulic dressings were included at full scale. This paper focuses on one element of the testing: that of component noise assessment. The dressings, wheels, torque link, steering pinion, bay doors, and then the main strut and drag stay were removed in succession, and an acoustic evaluation was performed at a range of velocities from to . In addition, hub caps were installed on the wheels, and their performance as a low-noise treatment is presented and assessed for efficacy. The landing gear, doors, and bay generated most noise in the frequency range between 120 and 400 Hz, but appreciable noise above the baseline was measured up to 10 kHz. The low- to midfrequency aerodynamic noise was found to scale with , as usual; however, the spectra at high frequencies collapsed perfectly when scaled to , confirming the fact that high-frequency noise is radiated from the turbulent flow surrounding small features. The total noise output of the landing-gear assembly differs from that of the sum of the components in isolation due to installation effects. The research in this paper studied these effects and the influence of the components on each other.

Loads and Acoustics Prediction on Deployed Weapons Bay Doors

Unsteady separated flow from deployed weapons bay doors can interact with the highly unsteady flow in the open bay cavity, which is known to exhibit strong acoustic content and could lead to fluid-resonance and high-intensity acoustic noise. The culmination of these unique flow physics can potentially excite structural modes of the doors, aircraft surfaces, or externally carried munitions and fuel tanks and can ultimately lead to aeroelastic instabilities, such as buffet, flutter, limit-cycle oscillations, or fatigue-induced failures. A hybrid Reynolds-averaged Navier–Stokes large eddy simulation (RANS/LES) method with low-dissipation schemes is developed to improve flow and acoustics predictive capabilities for supersonic weapons bays. Computational simulations are conducted for a weapons cavity with different deployed bay doors configurations, including the effect of dynamically moving doors, to assess the tonal content and unsteady aerodynamic loads on the doors. Wind tunnel testing is also carried out to provide unsteady experimental data for use in validating the high-fidelity simulation capability. The simulation results in terms of unsteady pressure, velocity fluctuations, and pressure resonant frequencies are computed and presented. The results suggest that the deployed doors energize the shear layer and cause it to go deeper into the cavity and produce higher unsteady fluctuations on the weapons cavity floor and aft wall. The deployed doors also cause a shift in the dominant resonant modes.

Whisper Before You Go

Whisper Before You Go John K Petty David came with a bang.1 A momentary prelude from a dysphonic chorus of pagers announce “Level 1 Pediatric Trauma—MVC ejected” before the abrupt crescendo of the trauma bay doors opening. He is maybe two. Maybe three–years–old. It is hard to tell when a child is strapped in, strapped down, nonverbal, intubated, and alone. The flight team speaks for him, “Four–year–old boy improperly restrained in a single–vehicle crash into a ditch. He was partially ejected. He was unresponsive and pulseless at the scene. He got CPR and code drugs, and they got a pulse back. Emergency medical service (EMS) took him to the nearest hospital where they needled his chest, called for air transport, and scanned him up. He has been shocky for us since we picked him up. Glasgow Coma Scale (GCS) has been three the whole time. They said his head scan showed subarachnoid hemorrhage.” With the words of the flight team as background narrative, we get about doing our thing—hopefully more method and less madness. Bang, bang, bang! Check the tube. Vital signs. IV fluids. Place a chest tube. Hang the blood. Quick X–ray. Neuro exam—nothing. Get him off the board. Warm him up. Place the orogastric (OG) tube. Bang, bang, bang! The neurosurgery resident opens the CT scans from the other hospital. The brain and cervical spine scans show a disaster: some swelling and bleeding in the higher brain, but the worst damage is in the lower brain, brainstem, and top of the spinal cord. I have heard a neurosurgeon describe this pattern before as “internal decapitation.” Such language never makes it into the patient’s chart. For David the last two words of the neurosurgery consult note will eventually read, “Prognosis grim.” He remains unstable in the trauma bay. Inaction is death. We ultrasound his heart, abdomen, and pelvis. He has fluid that shouldn’t be around his heart. He is dying of the neuro injury we cannot control, but the pericardial fluid might be giving him shock, and we can control that. We can’t ignore the fluid. Shouldn’t ignore it. At least, wouldn’t ignore it. So, we bang up to the operating room. Squeezing blood. Spiking fluid. Oxygen tank and crash cart. Up we go. In the operating room, we do much and we do well. We release the fluid around the heart and find it was CPR, not heart injury that put it there. In the pericardial flash we get a view of the cardiac athlete, pounding like the 26th mile of the marathon. We explore the abdomen and find it swollen but innocent of an injury that would take his life. We place our lines and tubes as the neurosurgeons place theirs. If nothing else, we will be able to measure what lies ahead. “Good work, team,” and we bump the door on the way to the pediatric intensive care unit (PICU). The care in the PICU is more Apache brave than Gaelic knight—more bottles, fewer scissors. The curtains and carpets mute the tones. Our efforts continue, but I get a word that David’s father has arrived. He is sitting in a small, private waiting room off of the main PICU waiting room. The PICU staff colloquially refer to this as “the bad news room.” I take a seat next to a solitary man who is having the worst day of his life. His worst day so far. “I am Dr. Petty, and I am one of the doctors who is taking care of your son. I am very sorry about what has happened. Maybe you can tell me a little bit about what you understand is going on, and I’ll tell you what I know.” [End Page 17] He tells me that his wife was driving David back from her sister’s house, just the two of them. He doesn’t know what happened, but he got a call from the other hospital about the crash. His wife was badly hurt. He heard that David had died, but they got him back. Both were transferred up to the...

Clearing the Board

5 am. We are down to zero. You heard me right. Zero. I cannot believe it. I hit the side of the computer monitor with the palm of my hand. Harder. The system sucks. I assume that the screen has frozen again, that this is some cruel computer mediated joke at my expense. I consider shutting it down, starting it up again. But no. It really is zero. And it is not just in the department, either. I actually get up from my chair, walk out to the waiting room, look for the people who haven’t been registered yet but are still there all the same, the people who are always there, with their dental pain or insomnia or orthopedic complaints, the people who live at the margins of my daily work all the time, these people almost a comfort to me to know they will always be there, that I will always have a job because they will always be there. They are not there. No one is there. The waiting room is cavernous in its emptiness, the giant plasma TV louder than I have ever heard it without the bodies to absorb the sound, the echo of my footsteps across the floor. I open the bathroom doors “Hello, is anybody there?” No one is there. I feel elated. This has never happened to me. I have heard others talk about this moment happening to them, and I always assumed it was tinged with the same hyperbole that colors stories of great trauma saves, that it was at the very least an exaggeration, that there was always a patient already admitted that they were not counting, or some intoxicated individual sleeping it off in the hall. But there isn’t a soul. I half expect some kind of sign to light up, like when I used to play Space Invaders as a child and cleared a screen, Congratulations, you have just completed Level 1! A change in the soundtrack music, a high score listing. Something. But no. My elation fades almost immediately into something uncomfortable. Beyond uncomfortable. It is eerie. It is like the aftermath of some actual alien invasion in a movie (which are the only actual alien invasions I know about) when almost the whole population has been wiped out, except for a couple small hold-out communities which will get driven underground to unite forces, eventually fighting back. I expect that at any second a giant monster created from unadulterated intergalactic irradiation will attempt to break in through the ambulance bay doors. It will be followed by another, another, we will huddle under our counters and try to remember where the panic button is, knowing it does not matter really because no one will know what to do with this kind of panic, how to stave off this kind of disaster. We will be so tired after having worked all night, we will feel our intellects fuzz with the problem of it, trying to find a solution. But we will rally. We will invent weapons out of our paracentesis kits, we will make clubs with casting material, poke needles out to make maces, superheat the saline to make burning water balloons. Oh, we are fighters. Make no mistake. You chose the wrong hospital. Not on my watch. Half-seriously, I peek quickly out the door to look up at the sky. Still dark. Sufficiently creeped out, I go back in to the safe haven of the emergency department. The residents are playing catch with a rolled up ACE bandage and the nurses are shopping on-line, unaware of the impending disaster. And then it happens. Of course it does. The radio starts to beep, there are three traumas coming in 10 minutes, and an entire family has just registered for cold symptoms. If I recall correctly, Level 2 is even harder.

Is closure of entire wards necessary to control norovirus outbreaks in hospital? Comparing the effectiveness of two infection control strategies

The standard approach for norovirus control in hospitals in the UK, as outlined by the Health Protection Agency guidance and implemented previously by Lancashire Teaching Hospitals, involves the early closure of affected wards. However, this has a major impact on bed-days lost and cancelled admissions. In 2008, a new strategy was introduced in the study hospital, key elements of which included closure of affected ward bays (rather than wards), installation of bay doors, enhanced cleaning, a rapid in-house molecular test and an enlarged infection control team. The impact of these changes was assessed by comparing two norovirus seasons (2007-08 and 2009-10) before and after implementation of the new strategy, expressing the contrast between seasons as a ratio (r) of expected counts in the two seasons. There was a significant decrease in the ratio of confirmed hospital outbreaks to community outbreaks (r = 0.317, P = 0.025), the number of days of restricted admissions on hospital wards per outbreak (r = 0.742, P = 0.041), and the number of hospital bed-days lost per outbreak (r = 0.344, P <0.001). However, there was no significant change in the number of patients affected per hospital outbreak (r = 1.080, P = 0.517), or the number of hospital staff affected per outbreak (r = 0.651, P = 0.105). Closure of entire wards during norovirus outbreaks is not always necessary. The changes implemented at the study hospital resulted in a significant reduction in the number of bed-days lost per outbreak, and this, together with a reduction in outbreak frequency, resulted in considerable cost savings.

Shielding Analysis for X-Ray Sources Generated in Target Chamber of the National Ignition Facility

Prompt doses from X-rays generated as result of laser beam interaction with target material are calculated at different locations inside the National Ignition Facility. The maximum dose outside a target chamber diagnostic port is ~10 mSv for a shot utilizing the 192 laser beams and 1.8 MJ of laser energy. The dose during a single bundle shot (eight laser beams) drops to ~0.4 mSv. Doses calculated outside the target bay (TB) doors and inside the switchyards (SYs) [except for the 5.33-m (17-ft 6-in.) floor level] range from a few microsieverts to ~110 μSv for 192 beams and scale down proportionally with a smaller number of beams. At the 5.33-m (17-ft 6-in.) floor level, two diagnostic ports are directly facing two of the TB doors, and the maximum doses outside the doors are 0.5 and 0.16 mSv, respectively. Shielding each of the two TB doors with 6.35-mm-thick Pb (1/4-in.) reduces the dose by a factor of 50. One or two bundle shots (8 to 16 laser beams) present a small hazard to personnel in the SYs.

Introduction: Dreaming of Infrastructure

Baghdad, Banda Aceh, Beirut, Detroit, Dhaka, Harare, New Orleans. In these times chronicling the devastation and annihilation of cities—through capital flight, natural disaster, slum eviction, and war—I gravitate to stories about restoring ruined cities. Halfway through Slaughterhouse Five, Kurt Vonnegut's novel about the firebombing of Dresden, we find an eccentric scene. After surviving Dresden's conflagration, Billy Pilgrim, optician and ex-GI, escapes traumatic memories by becoming “unstuck in time” (93). He journeys with the Tralfamadorians, creatures from outer space who teach him to time-switch so that he can move fluidly through his own private and public histories. Finding a war movie intolerable, Pilgrim imagines it in reverse: “American planes, full of holes and wounded men and corpses took off backwards from an airfield in England. Over France, a few German fighter planes flew at them backwards, sucked bullets and shell fragments from some of the planes and crewmen.” Pilgrim changes space by changing time. German guns suck bomb fragments from wounded American airmen as “the formation flew backwards over a German city that was in flames. The bombers opened their bomb bay doors, exerted a miraculous magnetism which shrunk the fires, gathered them into cylindrical steel containers, and lifted the containers into the bellies of the planes” (93–94). How can we shelter or care for, how can we nurture, the ruined city in the belly of the text?

Low Speed Wind Tunnel Buffet Testing on the F/A-22

Buffet results from the F/A-22 V-9 model test conducted in the Lockheed Martin Aeronautics Marietta Low Speed Wind Tunnel (LSWT) between 515-02 and 5-18-02 are presented. The purpose of the test was to determine the effect on stability and control parameters of CFD derived potential aerodynamic solutions for attenuating vertical tail buffet. Instrumentation was added to permit assessment of the effects of these potential configurations on buffet loads. The data from the test show buffet attenuation benefit from several of the configurations tested, with two fence configurations showing significant reductions in the buffet response up to approximately 32 degrees angle-of attack. CFD analysis predicted significant effects of Mach number, engine inlet mass flow, and scaling on buffet onset. Therefore, any consideration of incorporating such configurations as determined by wind tunnel test should be verified by model testing with these effects present and by full-scale evaluation. Significant buffet attenuation is also shown with side weapons bay doors open. (Note: The configuration showing most promise for buffet attenuation resulted in a loss in lateral stability at 32 degrees)

RANS and DES Turbulence Model Predictions of Noise on the M219 Cavity at M=0.85

Two rectangular cavity configurations, with and without bay doors, at Mach 0.85 are investigated with the objective of assessing the ability of 3D CFD with advanced turbulence modelling to predict narrowband and broadband flow noise. A non-linear, two-equation, eddy-viscosity model run in unsteady mode (URANS) is compared with Detached Eddy Simulation (DES) on a cavity with a L/D ratio of 5. In a thorough evaluation, comparisons are made between DES variants published in the literature, namely Spalart-Allmaras, k-ε and k-ω-SST. We also assess the effect on the noise spectra of using different CFD prediction time-samples of approximately 100 flow passes compared with 250 flow passes. Detailed experimental data for both cavity configurations provide a valuable opportunity to compare the predicted spectra at many points along the cavity ceiling and band-limited amplitude along the cavity length. We conclude that for such cavity flows, all DES models perform similarly well and are superior to unsteady RANS due to their inherent ability to resolve broadband structures.

Space Shuttle debris and meteoroid impacts

This paper describes observations and analyses of meteoroid and debris impact damage to the Space Shuttle Orbiter over the past decade. Since 1992, NASA Space Shuttle Orbiter post-flight inspection procedures have been altered to allow systematic identification and sampling of meteoroid/debris impacts in selected areas of the vehicle. These areas include the crew module windows and radiator panels that line the interior of the payload bay doors. In addition, other significant impact damage is identified and sampled on other critical surfaces or exposed structures such as wing leading-edge panels, external thermal-protection materials, radiator interconnect lines, and Ku-band antenna components. Samples of the impact damage are obtained and subjected to scanning electron microscope energy dispersive X-ray analysis to determine elemental composition of impactor materials recovered from the impact site. Based on these results, the source of the impact damage is categorized as meteoroid or debris, and debris particle types are identified. Historical trends indicate a large variability in debris impact rates from mission-to-mission with higher impact rates than average occurring more regularly since 1998. Predictions of post-flight damage are compared to observed damage using BUMPER code and as-flown attitude timelines.

Pioneer Rocketplane Conceptual Design Study

The Pioneer Rocketplane is a two-seat, F-111-sized aircraft powered by turbofan engines and a kerosene/oxygen-burning RD-120 rocket engine that, using an expendable upper stage, boosts a 3000-lb satellite to a circular low Earth orbit. The Rocketplane takes off with its turbofan engines and climbs to approximately 20,000 ft, where it meets a tanker aircraft, taking on about 48,000 lb of kerosene jet fuel. The Rocketplane then moves to a second tanker aircraft, where it takes on about 130,000 lb of liquid oxygen. After disconnecting from the tanker, the vehicle ignites its rocket engine and climbs to an altitude of 70 miles. Although never reaching orbit itself, the Rocketplane is outside the sensible atmosphere. It opens its payload bay doors and releases the upper stage, which ignites and delivers the satellite payload to its intended low Earth orbit. The doors are then closed, and the aircraft reenters the atmosphere and lands. The second phase conceptual design study is described in which prior configuration design and optimization studies have been integrated into a viable baseline air vehicle concept on which performance analysis is conducted

Shape memory wire improves sealing of aircraft doors

In aviation safety, providing maximum security for door seals is a crucial part of the specification. Other factors include ease of passenger entry and egress. Such doors require opening and closing only whilst on the ground. Other types of doors are required which can be opened in flight such as weapons bay doors on military aircraft not to mention doors for the undercarriage. But present generation aircraft seals have many deficiencies. To try to overcome these shortcomings Northrop Grumman has patented a new seal based on the special characteristics of a material new to the sealing industry, that of ‘shape memory alloys’.

Engineer Memoirs by E. L. Rouny

TECHNOLOGY AND CULTURE Book Reviews 263 were set for 25 feet. But there was no low-level bombsight, the B-24s bomb bay doors were fitted with elastic safety latches that would not allow the bombs to be dropped unless the doors were fully opened, the bomb-release gear frequently malfunctioned, and even if all went well the charges might not explode after they entered the wa­ ter. On top of this, the special cameras also failed to function on occasion so that damage assessment had to be based on eye-witness reports. In the great hunting season ofJuly and August 1943, when U-boats stayed on the surface to fight, aircraft began to be lost. More followed when Luftwaffe patrols roamed the Bay of Biscay. The Lib­ erator was well enough armed that it could beat a singleJu-88 or a single FW-200, but usually not more than one. As Max Schoenfeld, earlier a student of Winston Churchill, re­ lates, this was an offensive war against submarines which neither the army nor the navy understood until, in the fall of 1943, they switched viewpoints. The army saw antisubmarine warfare as an offensive op­ eration in which mobile squadrons would be shifted from one place to another as opportunity dictated. The practical problem was that support personnel were not so easily trained and transferred. More­ over, the army convinced itself that the real place to attack U-boats was in the construction yards as part of the grand strategic offensive. The navy, on the other hand, could only see close escort of convoys and not hunter-killer groups and long-range patrols, a stance dic­ tated by available resources. Schoenfeld has made sound use of British and American archives to tell his story, detailing each combat, and assessing the results of this technological segment of the war. Robin Higham Dr. Higham was editor of Aerospace Historian from 1970 through 1988 and is cur­ rently writing a book on the Royal Air Force and preparation for war, 1931-1941. Engineer Memoirs. By E. L. Rouny. Alexandria, Va.: U.S. Army Corps of Engineers, 1995. Pp xvi+214; glossary, index. No price given. This paperback memoir consists of edited selections from a series of tape-recorded interviews conducted by Dr. Barry W. Fowle of the Engineer School. General Rouny had a fascinating and varied career, which merits close study. His father, a Polish farmer, came to the United States in 1912; that he studied in night school for 14 years may be a significant clue to the capabilities which led this immigrant’s son to become a lieutenant general in the U.S. Army, an ambassador, and an adviser to presidents. After obtaining a de­ gree in civil engineering atJohns Hopkins, Rouny breezed through the U.S. Military Academy, where he became a protégé of Professor 264 Book Reviews TECHNOLOGY AND CULTURE Abe Lincoln and thus a member of the “Lincoln Brigade” of out­ standing officers, which virtually assured him a fast track to promo­ tion. For this review in Technology and Culture, I shall address Rouny’s role in relation to military technology and leave his services as an arms control negotiator and ambassador to other more appropriate journals. This volume is filled with insights on the practical problems of leadership that alone would make it well worth reading, but so does its account ofhow one imaginative individual helped to exploit available material effectively. For example, Rouny describes the at­ tempts to eliminate minefields by various technical means that he made while serving with an engineer battalion in the 92nd Division in Italy as a young officer, such as explosive snakes of primacord or rotating flails attached to tanks, only to return to the old reliable method: an engineer soldier probing the ground with a bayonet. After VE day Rouny, already recognized as an imaginative thinker, was ordered back to Washington to OPD, the Operations Division, where he joined the dream team charged with preparing for future wars with “mind-boggling and mind-stretching ideas.” To generate them he “worked hard at preparing for these dream sessions, read­ ing history, being briefed by scientists, and talking to global strate...

Stalking the U-Boat: USAAF Offensive Antisubmarine Operations in World War II by Max Schoenfeld

262 Book Reviews TECHNOLOGY AND CULTURE Stalking the U-Boat: USAAF Offensive Antisubmarine Operations in World War II. By Max Schoenfeld. Washington, D.C.: Smithsonian Insti­ tution Press, 1994. Pp. xi+231; illustrations, maps, tables, appendi­ ces, notes, bibliography, index. $37.50 (cloth). The organization of the United States Army Air Force Antisubma­ rine Command (AAFAC) in October 1942 revived the old struggle between the army and the navy over who should control land-based aircraft operating over the sea. Also at issue was the way to conduct anti-U-boat operations. The Battle of the Atlantic was rising to a crescendo in March and April 1943, after which the tide would turn in favor of the Allies. The two groups created to be the AAFAC, the 479th and the 480th, represented the ultimate development of equipment of the day. Their B-24D Liberators with 10-centimetric radar were on the cutting edge of technology as well as being the longest-ranged landplanes available. They were based first in New­ foundland, then in the United Kingdom under the Royal Air Force’s Coastal Command, and finally at Craw Field, Port Lyuatey, North Africa, under the United States Navy. At first the aircraft and crews suffered from their inexperience. Once in Britain, they learned under the expert tutelage of Coastal Command, which was launching its offensive to make crossing the Bay of Biscay hazardous for U-boats. Coastal Command welcomed the B-24s because the Germans hadjust developed Metox, a receiver that could detect the probing waves of the new Leigh-Light Welling­ ton’s radar but which would not be able to detect the 10-centimetric radar carried by the B-24Ds for another year. The USAAF SCR-515, later supplanted by the SCR-717, had a range of from 10 to 20 miles against U-boats and about 40 miles for coastlines. The problem was sea clutter, especially as the aircraft came down to attack heights of 50 to 200 feet above the sea, when the U-boat target would disappear from the radar. Usually by then the submarine was in sight. The problem was to drop depth charges in a line at 100-foot intervals starting ahead of the swirl left by the boat’s conning tower. In order to be lethal, the depth charges had to land very close to the pressure hull within ten seconds of the disap­ pearance of the U-boat. This degree of precision required excellent performance from the crew members concerned to spot, stalk, and attack the rarely sighted boats (the number of hours of patrolling per sighting varied from roughly eighty-seven when Grand-Admiral Karl Doenitz ordered his craft to stay on the surface and fight with their 20-millimeter cannon to over sixteen hundred when he at last ordered them to transit submerged). The problems for the airmen were manifold. They had to home in undetected on a U-boat (a task aided by the sounds of the diesels, which made it impossible for lookouts to hear aircraft) so as to catch it on the surface or onlyjust submerged, as the depth charge fuses TECHNOLOGY AND CULTURE Book Reviews 263 were set for 25 feet. But there was no low-level bombsight, the B-24s bomb bay doors were fitted with elastic safety latches that would not allow the bombs to be dropped unless the doors were fully opened, the bomb-release gear frequently malfunctioned, and even if all went well the charges might not explode after they entered the wa­ ter. On top of this, the special cameras also failed to function on occasion so that damage assessment had to be based on eye-witness reports. In the great hunting season ofJuly and August 1943, when U-boats stayed on the surface to fight, aircraft began to be lost. More followed when Luftwaffe patrols roamed the Bay of Biscay. The Lib­ erator was well enough armed that it could beat a singleJu-88 or a single FW-200, but usually not more than one. As Max Schoenfeld, earlier a student of Winston Churchill, re­ lates, this was an offensive war against submarines which neither the army nor the...

European retrievable carrier Eureca servicing by Hermes

It has been demonstrated that HERMES with a cargo bay configuration as depicted in figure 1 (5 m length, 3 m diam.) with Handling and Positioning Aid (HPA) and HERMES Robotic Arm (HERA) is capable to service a small platform like EURECA, which is an NSTS quarter payload. Only 1 3 of the HERMES cargo bay volume and payload mass is required for the accommodation of the payload Orbital Replaceable Units. By implementing two additional hydrazine tanks refuelling can be avoided for a two-years EURECA mission. The overall servicing configuration is described as follows: The European Retrievable Carrier EURECA-B is mechanically attached through its -y-side sill trunnion to the HERMES berthing port. The HERMES cargo bay doors with radiators are opened and oriented to earth. The HERMES Robotic Arm is equipped with a Module Service Tool (MST) ready for Orbital Replaceable Unit (ORU) exchange. The HERMES berthing port is located at the rear side of the cargo bay in order to achieve best visibility, clearance and accessibility of the HERMES Robotic Arm operation within the cargo bay and the EURECA payload area. The EURECA solar arrays and antennas remain deployed. During the servicing operation, power will be provided by the fully deployed solar arrays. In order to minimize the plume impingement effect, the solar array edge is directed to the HERMES wing.

British Patent Abridgments

A fixed wing aircraft which can take‐off and land vertically, or at a speed below stalling speed, lift being obtained by substantially downwardly directed jets, has longitudinally arranged strakes on the under‐surfacc of the fuselage or other nozzle carrying part to intercept the gases deflected upwardly off the ground and prevent their upward flow over the sides of the fuselage or part by deflecting the gases downwardly. In the aircraft shown partially in side elevation and front elevation here, gases arc discharged downwardly from nozzles 2, 3, on cither side of the fuselage to provide direct lift. The nozzles arc adjustable to provide forward thrust also. In such an aircraft, circulation of the discharged gases beneath the fuselage and upwardly over its sides, reduces the lifting effect when the aircraft is close to the ground. Fore and aft extending strakes 5 intercept this circulation, and direct the gases outwardly and downwardly away from the fuselage to reduce the lift loss. The strakes may be adjustable and retractable and may also act as bomb bay or undercarriage bay doors. A lateral fence 7 retractable by jack 10, extends between the forward ends of the strakes, and an undercarriage bay door 6, retractable by jack 11, extends between the rearward ends, and may also be usable as an airbrake. Recirculation of hot gases into the engine intakes (not shown) is also prevented by this means.