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112-501: The program would eventually develop a total of three test prototype flight demonstrators for the proposed Crew Return Vehicle, each having incremental improvements on its predecessor. All three were wingless lifting body vehicles used in drop tests. The X-38 program was canceled in 2002 due to budget cuts. With crew being taken to the ISS by space shuttle, the maximum crew size for the ISS would be dependent on crew rescue capacity. Since it

224-400: A zinc anode, usually in the form of a cylindrical pot, with a carbon cathode in the form of a central rod. The electrolyte is ammonium chloride in the form of a paste next to the zinc anode. The remaining space between the electrolyte and carbon cathode is taken up by a second paste consisting of ammonium chloride and manganese dioxide, the latter acting as a depolariser . In some designs,

336-441: A 7,500-square-foot (700 m) parafoil wing, the largest ever made. Flight control was mostly autonomous, backed up by a ground-based pilot. The X-38 was intended to be semi-permanently docked to the ISS. If the crew became sick or injured during the course of their mission, they would enter the rescue vehicle through a hatched docking mechanism. With execution of a short procedure, the crew return vehicles would automatically fly

448-434: A battery cannot deliver as much power. As such, in cold climates, some car owners install battery warmers, which are small electric heating pads that keep the car battery warm. A battery's capacity is the amount of electric charge it can deliver at a voltage that does not drop below the specified terminal voltage. The more electrode material contained in the cell the greater its capacity. A small cell has less capacity than

560-437: A battery is connected to an external electric load, those negatively charged electrons flow through the circuit and reach to the positive terminal, thus cause a redox reaction by attracting positively charged ions, cations. Thus converts high-energy reactants to lower-energy products, and the free-energy difference is delivered to the external circuit as electrical energy. Historically the term "battery" specifically referred to

672-403: A battery rated at 100 A·h can deliver 5 A over a 20-hour period at room temperature . The fraction of the stored charge that a battery can deliver depends on multiple factors, including battery chemistry, the rate at which the charge is delivered (current), the required terminal voltage, the storage period, ambient temperature and other factors. The higher the discharge rate, the lower

784-421: A battery rated at 2 A·h for a 10- or 20-hour discharge would not sustain a current of 1 A for a full two hours as its stated capacity suggests. The C-rate is a measure of the rate at which a battery is being charged or discharged. It is defined as the current through the battery divided by the theoretical current draw under which the battery would deliver its nominal rated capacity in one hour. It has

896-412: A cell maintained 1.5 volts and produced a charge of one coulomb then on complete discharge it would have performed 1.5 joules of work. In actual cells, the internal resistance increases under discharge and the open-circuit voltage also decreases under discharge. If the voltage and resistance are plotted against time, the resulting graphs typically are a curve; the shape of the curve varies according to

1008-501: A device composed of multiple cells; however, the usage has evolved to include devices composed of a single cell. Primary (single-use or "disposable") batteries are used once and discarded , as the electrode materials are irreversibly changed during discharge; a common example is the alkaline battery used for flashlights and a multitude of portable electronic devices. Secondary (rechargeable) batteries can be discharged and recharged multiple times using an applied electric current;

1120-660: A discharge rate about 100x greater than current batteries, and smart battery packs with state-of-charge monitors and battery protection circuits that prevent damage on over-discharge. Low self-discharge (LSD) allows secondary cells to be charged prior to shipping. Lithium–sulfur batteries were used on the longest and highest solar-powered flight. Batteries of all types are manufactured in consumer and industrial grades. Costlier industrial-grade batteries may use chemistries that provide higher power-to-size ratio, have lower self-discharge and hence longer life when not in use, more resistance to leakage and, for example, ability to handle

1232-625: A first look at structural loads. The vehicle can then proceed with its maiden flight , a major milestone in any aircraft or launch vehicle development program. There are several aspects to a flight test program, among which: Testing that is specific to military aircraft includes: Emergency situations are evaluated as a normal part of all flight test program. Examples are: engine failure during various phases of flight (takeoff, cruise, landing), systems failures, and controls degradation. The overall operations envelope (allowable gross weights, centers-of-gravity, altitude, max/min airspeeds, maneuvers, etc.)

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1344-525: A freshly charged nickel cadmium (NiCd) battery loses 10% of its charge in the first 24 hours, and thereafter discharges at a rate of about 10% a month. However, newer low self-discharge nickel–metal hydride (NiMH) batteries and modern lithium designs display a lower self-discharge rate (but still higher than for primary batteries). The active material on the battery plates changes chemical composition on each charge and discharge cycle; active material may be lost due to physical changes of volume, further limiting

1456-475: A gun. The acceleration breaks a capsule of electrolyte that activates the battery and powers the fuze's circuits. Reserve batteries are usually designed for a short service life (seconds or minutes) after long storage (years). A water-activated battery for oceanographic instruments or military applications becomes activated on immersion in water. On 28 February 2017, the University of Texas at Austin issued

1568-437: A large aircraft are: Specific calibration instruments, whose behavior has been determined from previous tests, may be brought on board to supplement the aircraft's in-built probes. During the flight, these parameters are then used to compute relevant aircraft performance parameters, such as airspeed, altitude, weight, and center of gravity position. During selected phases of flight test, especially during early development of

1680-446: A large current for a sustained period. The Daniell cell , invented in 1836 by British chemist John Frederic Daniell , was the first practical source of electricity , becoming an industry standard and seeing widespread adoption as a power source for electrical telegraph networks. It consisted of a copper pot filled with a copper sulfate solution, in which was immersed an unglazed earthenware container filled with sulfuric acid and

1792-434: A larger cell with the same chemistry, although they develop the same open-circuit voltage. Capacity is usually stated in ampere-hours (A·h) (mAh for small batteries). The rated capacity of a battery is usually expressed as the product of 20 hours multiplied by the current that a new battery can consistently supply for 20 hours at 20 °C (68 °F), while remaining above a specified terminal voltage per cell. For example,

1904-457: A molten salt as electrolyte. They operate at high temperatures and must be well insulated to retain heat. A dry cell uses a paste electrolyte, with only enough moisture to allow current to flow. Unlike a wet cell, a dry cell can operate in any orientation without spilling, as it contains no free liquid, making it suitable for portable equipment. By comparison, the first wet cells were typically fragile glass containers with lead rods hanging from

2016-593: A new aircraft, many parameters are transmitted to the ground during the flight and monitored by flight test and test support engineers, or stored for subsequent data analysis. This provides for safety monitoring and allows for both real-time and full-simulation analysis of the data being acquired. When the aircraft or launch vehicle is completely assembled and instrumented, many hours of ground testing are conducted. This allows exploring multiple aspects: basic aircraft vehicle operation, flight controls , engine performance, dynamic systems stability evaluation, and provides

2128-483: A nickel and a penny ) and a piece of paper towel dipped in salt water . Such a pile generates a very low voltage but, when many are stacked in series , they can replace normal batteries for a short time. Batteries are classified into primary and secondary forms: Some types of primary batteries used, for example, for telegraph circuits, were restored to operation by replacing the electrodes. Secondary batteries are not indefinitely rechargeable due to dissipation of

2240-539: A paste, made portable electrical devices practical. Batteries in vacuum tube devices historically used a wet cell for the "A" battery (to provide power to the filament) and a dry cell for the "B" battery (to provide the plate voltage). Between 2010 and 2018, annual battery demand grew by 30%, reaching a total of 180  GWh in 2018. Conservatively, the growth rate is expected to be maintained at an estimated 25%, culminating in demand reaching 2600 GWh in 2030. In addition, cost reductions are expected to further increase

2352-472: A pilot to predict the takeoff, climb, cruise, and landing performance of an aircraft. These charts, provided by the manufacturer, are included in the AFM /POH. Information the manufacturer provides on these charts has been gathered from test flights conducted in a new aircraft, under normal operating conditions while using average piloting skills, and with the aircraft and engine in good working order. Engineers record

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2464-480: A press release about a new type of solid-state battery , developed by a team led by lithium-ion battery inventor John Goodenough , "that could lead to safer, faster-charging, longer-lasting rechargeable batteries for handheld mobile devices, electric cars and stationary energy storage". The solid-state battery is also said to have "three times the energy density", increasing its useful life in electric vehicles, for example. It should also be more ecologically sound since

2576-640: A single Russian Soyuz TMA vehicle that could be docked to the station at any given time. Later in May 2009 provisions were added for a total of two docked Soyuz vehicles simultaneously and the ISS crew was increased to 6 members. NASA has designed several crew return vehicles over the years with varying levels of detail. A small, in-house development study of the X-38 concept first began at Johnson Space Center (JSC) in early 1995; however, several types of emergency scenarios were recognized by NASA as early as 1992 that drove

2688-502: A single test flight for an aircraft is known as a Test Card. This will consist of a description of the Test Points to be flown. The flight test engineer will try to fly similar Test Points from all test plans on the same flights, where practical. This allows the required data to be acquired in the minimum number of flight hours. The software used to control the flight test process is known as Flight Test Management Software, and supports

2800-586: A specially trained test pilot , the data is gathered by a flight test engineer , and often visually displayed to the test pilot and/or flight test engineer using flight test instrumentation . It includes the analysis of a flight for certification. It analyze the internal and outer part of the flight by checking its all minute parts. Reporting includes the analyzed data result. Introduction Aircraft Performance has various missions such as Takeoff , Climb , Cruise , Acceleration , Deceleration , Descent , Landing and other Basic fighter maneuvers , etc.. After

2912-412: A stake in the commercial success of the aircraft. These civil agencies are concerned with the aircraft's safety and that the pilot's flight manual accurately reports the aircraft's performance. The market will determine the aircraft's suitability to operators. Normally, the civil certification agency does not get involved in flight testing until the manufacturer has found and fixed any development issues and

3024-548: A stop on the ground. Both the shape and size of the X-38 were different from that of the Space Shuttle. The Crew Return Vehicle would have fitted into the payload bay of the shuttle. This does not, however, mean that it would have been small. The X-38 weighed 10,660 kg and was 9.1 meters long. The battery system, lasting nine hours, was to be used for power and life support. If the Crew Return Vehicle

3136-422: A zinc electrode. These wet cells used liquid electrolytes, which were prone to leakage and spillage if not handled correctly. Many used glass jars to hold their components, which made them fragile and potentially dangerous. These characteristics made wet cells unsuitable for portable appliances. Near the end of the nineteenth century, the invention of dry cell batteries , which replaced the liquid electrolyte with

3248-573: Is also used as a rating on batteries to indicate the maximum current that a battery can safely deliver in a circuit. Standards for rechargeable batteries generally rate the capacity and charge cycles over a 4-hour (0.25C), 8 hour (0.125C) or longer discharge time. Types intended for special purposes, such as in a computer uninterruptible power supply , may be rated by manufacturers for discharge periods much less than one hour (1C) but may suffer from limited cycle life. In 2009 experimental lithium iron phosphate ( LiFePO 4 ) battery technology provided

3360-536: Is an example of interpolating information from a takeoff distance chart: The make-up of the Flight Test Team will vary with the organization and complexity of the flight test program, however, there are some key players who are generally part of all flight test organizations. The leader of a flight test team is usually a flight test engineer (FTE) or possibly an experimental test pilot . Other FTEs or pilots could also be involved. Other team members would be

3472-510: Is called the open-circuit voltage and equals the emf of the cell. Because of internal resistance, the terminal voltage of a cell that is discharging is smaller in magnitude than the open-circuit voltage and the terminal voltage of a cell that is charging exceeds the open-circuit voltage. An ideal cell has negligible internal resistance, so it would maintain a constant terminal voltage of E {\displaystyle {\mathcal {E}}} until exhausted, then dropping to zero. If such

NASA X-38 - Misplaced Pages Continue

3584-631: Is considered the Father of the Lifting Body Programs. He met with Muratore (1992-93) and shared his design of the X-24A that he used to present the concept of the X-38 to NASA (Wingless Flight, Chapter 9, pages 186-88). The X-38 program used uncrewed mockups to test the CRV design. Flight models were indicated with the letter V for "Vehicle" followed by a number. The X-38 V-131 and V-132 shared

3696-445: Is essentially certain maneuvers to be flown (or systems to be exercised). Each single test is known as a Test Point. A full certification/qualification flight test program for a new aircraft will require testing for many aircraft systems and in-flight regimes; each is typically documented in a separate test plan. Altogether, a certification flight test program will consist of approximately 10,000 Test Points. The document used to prepare

3808-487: Is established and verified during flight testing. Aircraft are always demonstrated to be safe beyond the limits allowed for normal operations in the Flight Manual. Because the primary goal of a flight test program is to gather accurate engineering data, often on a design that is not fully proven, piloting a flight test aircraft requires a high degree of training and skill. As such, such programs are typically flown by

3920-407: Is imperative that the crew members be able to return to Earth in case of an unexpected emergency, a Crew Return Vehicle able to hold up to seven crew members was initially planned by the ISS program leadership. This would have allowed the full complement of seven astronauts to live and work on the ISS. During the early years of ISS on-orbit construction, the crew was limited to three, corresponding to

4032-544: Is important to read every chart and understand how to use it. Read the instructions provided by the manufacturer. For an explanation on how to use the charts, refer to the example provided by the manufacturer for that specific chart. The information manufacturers furnish is not standardized. Information may be contained in a table format, and other information may be contained in a graph format. Sometimes combined graphs incorporate two or more graphs into one chart to compensate for multiple conditions of flight. Combined graphs allow

4144-505: Is known as the "self-discharge" rate, and is due to non-current-producing "side" chemical reactions that occur within the cell even when no load is applied. The rate of side reactions is reduced for batteries stored at lower temperatures, although some can be damaged by freezing and storing in a fridge will not meaningfully prolong shelf life and risks damaging condensation. Old rechargeable batteries self-discharge more rapidly than disposable alkaline batteries, especially nickel-based batteries;

4256-474: Is lacking For this reason, flight testing is carefully planned in three phases: preparation; execution; and analysis and reporting. For both commercial and military aircraft, as well as launch vehicles, flight test preparation begins well before the test vehicle is ready to fly. Initially what needs to be tested must be defined, from which the Flight Test Engineers prepare the test plan, which

4368-539: Is lost and the battery stops producing power. Internal energy losses and limitations on the rate that ions pass through the electrolyte cause battery efficiency to vary. Above a minimum threshold, discharging at a low rate delivers more of the battery's capacity than at a higher rate. Installing batteries with varying A·h ratings changes operating time, but not device operation unless load limits are exceeded. High-drain loads such as digital cameras can reduce total capacity of rechargeable or disposable batteries. For example,

4480-733: Is now sitting outside Building 49 wrapped in construction webbing at Johnson Space Center. As of January 2024, the X-38 V-131R is on loan from NASA to the Evergreen Aviation Museum in McMinnville, Oregon . Data from General characteristics Related development Aircraft of comparable role, configuration, and era Flight testing Flight testing is a branch of aeronautical engineering that develops specialist equipment required for testing behaviour and systems of aircraft or testing

4592-636: Is popular in the automotive industry as a replacement for the lead–acid wet cell. The VRLA battery uses an immobilized sulfuric acid electrolyte, reducing the chance of leakage and extending shelf life . VRLA batteries immobilize the electrolyte. The two types are: Other portable rechargeable batteries include several sealed "dry cell" types, that are useful in applications such as mobile phones and laptop computers . Cells of this type (in order of increasing power density and cost) include nickel–cadmium (NiCd), nickel–zinc (NiZn), nickel–metal hydride (NiMH), and lithium-ion (Li-ion) cells. Li-ion has by far

NASA X-38 - Misplaced Pages Continue

4704-407: Is ready to seek certification. Military programs differ from commercial in that the government contracts with the aircraft manufacturer to design and build an aircraft to meet specific mission capabilities. These performance requirements are documented to the manufacturer in the aircraft specification and the details of the flight test program (among many other program requirements) are spelled out in

4816-508: Is somewhat offset by the higher efficiency of electric motors in converting electrical energy to mechanical work, compared to combustion engines. Benjamin Franklin first used the term "battery" in 1749 when he was doing experiments with electricity using a set of linked Leyden jar capacitors. Franklin grouped a number of the jars into what he described as a "battery", using the military term for weapons functioning together. By multiplying

4928-455: Is the difference in the cohesive or bond energies of the metals, oxides, or molecules undergoing the electrochemical reaction. For instance, energy can be stored in Zn or Li, which are high-energy metals because they are not stabilized by d-electron bonding, unlike transition metals . Batteries are designed so that the energetically favorable redox reaction can occur only when electrons move through

5040-489: Is the modern car battery , which can, in general, deliver a peak current of 450 amperes . Many types of electrochemical cells have been produced, with varying chemical processes and designs, including galvanic cells , electrolytic cells , fuel cells , flow cells and voltaic piles. A wet cell battery has a liquid electrolyte . Other names are flooded cell , since the liquid covers all internal parts or vented cell , since gases produced during operation can escape to

5152-741: The Daniell cell were built as open-top glass jar wet cells. Other primary wet cells are the Leclanche cell , Grove cell , Bunsen cell , Chromic acid cell , Clark cell , and Weston cell . The Leclanche cell chemistry was adapted to the first dry cells. Wet cells are still used in automobile batteries and in industry for standby power for switchgear , telecommunication or large uninterruptible power supplies , but in many places batteries with gel cells have been used instead. These applications commonly use lead–acid or nickel–cadmium cells. Molten salt batteries are primary or secondary batteries that use

5264-484: The Global Positioning System (a satellite -based coordinate system) to coordinate a safe trip home. Since the Crew Return Vehicle was designed with medical emergencies in mind, it made sense that the vehicle could find its way home automatically in the event that crew members were incapacitated or injured. If there was a need, the crew would have the capability to operate the vehicle by switching to

5376-529: The U.S. Naval Test Pilot School are the programs designed to teach military test personnel. In the UK, most military flight testing is conducted by three organizations, the RAF , BAE Systems and QinetiQ . For minor upgrades the testing may be conducted by one of these three organizations in isolation, but major programs are normally conducted by a joint trials team (JTT), with all three organizations working together under

5488-486: The Zamboni pile , invented in 1812, offers a very long service life without refurbishment or recharge, although it can supply very little current (nanoamps). The Oxford Electric Bell has been ringing almost continuously since 1840 on its original pair of batteries, thought to be Zamboni piles. Disposable batteries typically lose 8–20% of their original charge per year when stored at room temperature (20–30 °C). This

5600-521: The aerodynamic shape of the X-24A . This shape had to be enlarged for the Crew Return Vehicle needs (crew of seven astronauts) and redesigned, especially in the rear part, which became thicker. The X-38 V-131-R was designed at 80 percent of the size of a CRV [24.5 ft long (7.5 m), 11.6 ft wide (3.5 m), 8.4 ft high (2.6 m)], and featured the final redesigned shape (Two later versions, V-133 and V-201, were planned at 100 percent of

5712-420: The atmospheric phase of launch vehicles and reusable spacecraft . Instrumentation systems are developed using proprietary transducers and data acquisition systems. Data is sampled during the flight of an aircraft , or atmospheric testing of launch vehicles and reusable spacecraft . This data is validated for accuracy and analyzed to further modify the vehicle design during development, or to validate

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5824-402: The post-mission phase of a returning booster flight on revenue launches—can be subject to the latter's statistically demonstrated higher risk of accidents or serious incidents. This is mainly due to the unknowns of a new aircraft or launch vehicle's handling characteristics and lack of established operating procedures, and can be exacerbated if test pilot training or experience of the flight crew

5936-506: The CRV size). The 80% scale versions were flown at 15,000 to 24,000 pound weight. The X-38 V-201 orbital prototype was 90 percent complete, but never flown. In drop tests the V-131, V-132 and V-131-R were dropped by a B-52 from altitudes of up to 45,000 ft (13,700 m), gliding at near transonic speeds before deploying a drogue parachute to slow them to 60 miles per hour (97 km/h). The later prototypes had their descent continue under

6048-481: The Flight Test Engineer in planning the test points to be flown as well as generating the required documentation. Once the flight test data requirements are established, the aircraft or launch vehicle is instrumented with a data acquisition system (DAS), or data acquisition unit (DAU) and sensors , to record that data for analysis. Typical instrumentation parameters recorded during a flight test for

6160-503: The Flight Test Instrumentation Engineer, Instrumentation System Technicians, the aircraft maintenance department (mechanics, electrical techs, avionics technicians, etc.), Quality/Product Assurance Inspectors, the ground-based computing/data center personnel, plus logistics and administrative support. Engineers from various other disciplines would support the testing of their particular systems and analyze

6272-549: The ISS design without any negotiations with international partners. NASA Administrator, Sean O'Keefe , appointed by President George W. Bush , stated in December 2001 that he intended to adhere to the recommendations of the IMCE, including the implementation of Core Complete. The X-38 project cancellation was announced on April 29, 2002 as a cost-cutting measure in accordance with the IMCE's recommendations. The Core Complete concept

6384-481: The active materials, loss of electrolyte and internal corrosion. Primary batteries, or primary cells , can produce current immediately on assembly. These are most commonly used in portable devices that have low current drain, are used only intermittently, or are used well away from an alternative power source, such as in alarm and communication circuits where other electric power is only intermittently available. Disposable primary cells cannot be reliably recharged, since

6496-483: The air. Wet cells were a precursor to dry cells and are commonly used as a learning tool for electrochemistry . They can be built with common laboratory supplies, such as beakers , for demonstrations of how electrochemical cells work. A particular type of wet cell known as a concentration cell is important in understanding corrosion . Wet cells may be primary cells (non-rechargeable) or secondary cells (rechargeable). Originally, all practical primary batteries such as

6608-414: The ammonium chloride is replaced by zinc chloride . A reserve battery can be stored unassembled (unactivated and supplying no power) for a long period (perhaps years). When the battery is needed, then it is assembled (e.g., by adding electrolyte); once assembled, the battery is charged and ready to work. For example, a battery for an electronic artillery fuze might be activated by the impact of firing

6720-656: The backup systems. In addition, seven high-altitude low-opening ( HALO ) parachute packs were included in the crew cabin, a measure designed to provide for the ability to bail out of the craft. An Advanced Docking Berthing System (ADBS) was designed for the X-38 and the work on it led to the Low Impact Docking System the Johnson Space Center later created for the planned vehicles in Project Constellation . The X-38 vehicle

6832-463: The batteries within are charged and discharged evenly. Primary batteries readily available to consumers range from tiny button cells used for electric watches, to the No. 6 cell used for signal circuits or other long duration applications. Secondary cells are made in very large sizes; very large batteries can power a submarine or stabilize an electrical grid and help level out peak loads. As of 2017 ,

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6944-428: The battery be kept upright and the area be well ventilated to ensure safe dispersal of the hydrogen gas it produces during overcharging . The lead–acid battery is relatively heavy for the amount of electrical energy it can supply. Its low manufacturing cost and its high surge current levels make it common where its capacity (over approximately 10 Ah) is more important than weight and handling issues. A common application

7056-703: The capacity. The relationship between current, discharge time and capacity for a lead acid battery is approximated (over a typical range of current values) by Peukert's law : where Charged batteries (rechargeable or disposable) lose charge by internal self-discharge over time although not discharged, due to the presence of generally irreversible side reactions that consume charge carriers without producing current. The rate of self-discharge depends upon battery chemistry and construction, typically from months to years for significant loss. When batteries are recharged, additional side reactions reduce capacity for subsequent discharges. After enough recharges, in essence all capacity

7168-400: The cathode, while metal atoms are oxidized (electrons are removed) at the anode. Some cells use different electrolytes for each half-cell; then a separator is used to prevent mixing of the electrolytes while allowing ions to flow between half-cells to complete the electrical circuit. Each half-cell has an electromotive force ( emf , measured in volts) relative to a standard . The net emf of

7280-449: The cell is the difference between the emfs of its half-cells. Thus, if the electrodes have emfs E 1 {\displaystyle {\mathcal {E}}_{1}} and E 2 {\displaystyle {\mathcal {E}}_{2}} , then the net emf is E 2 − E 1 {\displaystyle {\mathcal {E}}_{2}-{\mathcal {E}}_{1}} ; in other words,

7392-421: The charts contain and how to extract information from the charts by direct reading and interpolation methods. Every chart contains a wealth of information that should be used when flight planning. Examples of the table, graph, and combined graph formats for all aspects of flight will be discussed. Interpolation Not all of the information on the charts is easily extracted. Some charts require interpolation to find

7504-644: The chemical reactions are not easily reversible and active materials may not return to their original forms. Battery manufacturers recommend against attempting to recharge primary cells. In general, these have higher energy densities than rechargeable batteries, but disposable batteries do not fare well under high-drain applications with loads under 75 ohms (75 Ω). Common types of disposable batteries include zinc–carbon batteries and alkaline batteries . Secondary batteries, also known as secondary cells , or rechargeable batteries , must be charged before first use; they are usually assembled with active materials in

7616-452: The chemistry and internal arrangement employed. The voltage developed across a cell's terminals depends on the energy release of the chemical reactions of its electrodes and electrolyte. Alkaline and zinc–carbon cells have different chemistries, but approximately the same emf of 1.5 volts; likewise NiCd and NiMH cells have different chemistries, but approximately the same emf of 1.2 volts. The high electrochemical potential changes in

7728-413: The complete development and certification of a new aircraft, launch vehicle, or reusable spacecraft. Therefore, the duration of a particular flight test program can vary from a few weeks to years. There are typically two categories of flight test programs – commercial and military. Commercial flight testing is conducted to certify that the aircraft meets all applicable safety and performance requirements of

7840-403: The crew members safely to Earth. Once undocked, the vehicle would be deorbited using a deorbital propulsion system (DPS). The eight-thruster DPS would adjust the spacecraft's attitude and retrofire to slow the X-38 down, allowing gravitational attraction to pull it back into Earth's atmosphere. A DPS module was developed by Aerojet and delivered to Johnson Space Center in 2002 for V-201. Following

7952-418: The data acquired for their specialty area. Since many aircraft development programs are sponsored by government military services, military or government-employed civilian pilots and engineers are often integrated into the flight test team. The government representatives provide program oversight and review and approve data. Government test pilots may also participate in the actual test flights, possibly even on

8064-607: The demand to as much as 3562 GWh. Important reasons for this high rate of growth of the electric battery industry include the electrification of transport, and large-scale deployment in electricity grids, supported by decarbonization initiatives. Distributed electric batteries, such as those used in battery electric vehicles ( vehicle-to-grid ), and in home energy storage , with smart metering and that are connected to smart grids for demand response , are active participants in smart power supply grids. New methods of reuse, such as echelon use of partly-used batteries, add to

8176-407: The design of the vehicle. The flight test phase accomplishes two major tasks: 1) finding and fixing design problems and then 2) verifying and documenting the vehicle capabilities when the vehicle design is complete, or to provide a final specification for government certification or customer acceptance. The flight test phase can range from the test of a single new system for an existing vehicle to

8288-443: The discharged state. Rechargeable batteries are (re)charged by applying electric current, which reverses the chemical reactions that occur during discharge/use. Devices to supply the appropriate current are called chargers. The oldest form of rechargeable battery is the lead–acid battery , which are widely used in automotive and boating applications. This technology contains liquid electrolyte in an unsealed container, requiring that

8400-416: The electrodes. Low-capacity NiMH batteries (1,700–2,000 mA·h) can be charged some 1,000 times, whereas high-capacity NiMH batteries (above 2,500 mA·h) last about 500 cycles. NiCd batteries tend to be rated for 1,000 cycles before their internal resistance permanently increases beyond usable values. Fast charging increases component changes, shortening battery lifespan. If a charger cannot detect when

8512-506: The external part of the circuit. A battery consists of some number of voltaic cells . Each cell consists of two half-cells connected in series by a conductive electrolyte containing metal cations . One half-cell includes electrolyte and the negative electrode, the electrode to which anions (negatively charged ions) migrate; the other half-cell includes electrolyte and the positive electrode, to which cations (positively charged ions ) migrate. Cations are reduced (electrons are added) at

8624-535: The fastest charging and energy delivery, discharging all its energy into a load in 10 to 20 seconds. In 2024 a prototype battery for electric cars that could charge from 10% to 80% in five minutes was demonstrated, and a Chinese company claimed that car batteries it had introduced charged 10% to 80% in 10.5 minutes—the fastest batteries available—compared to Tesla's 15 minutes to half-charge. Battery life (or lifetime) has two meanings for rechargeable batteries but only one for non-chargeables. It can be used to describe

8736-407: The first/ maiden flight . Battery (electricity) An electric battery is a source of electric power consisting of one or more electrochemical cells with external connections for powering electrical devices. When a battery is supplying power, its positive terminal is the cathode and its negative terminal is the anode . The terminal marked negative is the source of electrons. When

8848-460: The flight data and create performance charts based on the behavior of the aircraft during the test flights. By using these performance charts, a pilot can determine the runway length needed to take off and land, the amount of fuel to be used during flight, and the time required to arrive at the destination. The data from the charts will not be accurate if the aircraft is not in good working order or when operating under adverse conditions. Always consider

8960-431: The flight testing, the aircraft has to be certified according to their regulations like FAA 's FAR , EASA 's Certification Specifications (CS) and India 's Air Staff Compliance and Requirements. 1. Flight Performance Evaluation and documentation 2. Reduction of Flight performance to standard conditions 3. Preparation and Validation of Performance Charts for Operating Data Manual (ODM) Performance charts allow

9072-516: The full envelope expansion paradigm of traditional aircraft testing. Previous and current test programs include the early drop tests of the Space Shuttle , the X-24B , SpaceShipTwo , Dream Chaser , Falcon 9 prototypes , OK-GLI , and SpaceX Starship prototypes . Flight testing—typically as a class of non-revenue producing flight, although SpaceX has also done extensive flight tests on

9184-922: The government certifying agency. In the United States, this is the Federal Aviation Administration ( FAA ); in Canada, Transport Canada (TC); in the United Kingdom (UK), the Civil Aviation Authority ; and in the European Union , the European Aviation Safety Agency (EASA). Since commercial aircraft development is normally funded by the aircraft manufacturer and/or private investors, the certifying agency does not have

9296-422: The high temperature and humidity associated with medical autoclave sterilization. Standard-format batteries are inserted into battery holder in the device that uses them. When a device does not uses standard-format batteries, they are typically combined into a custom battery pack which holds multiple batteries in addition to features such as a battery management system and battery isolator which ensure that

9408-402: The highest share of the dry cell rechargeable market. NiMH has replaced NiCd in most applications due to its higher capacity, but NiCd remains in use in power tools , two-way radios , and medical equipment . In the 2000s, developments include batteries with embedded electronics such as USBCELL , which allows charging an AA battery through a USB connector, nanoball batteries that allow for

9520-430: The information for specific flight conditions. Interpolating information means that by taking the known information, a pilot can compute intermediate information. However, pilots sometimes round off values from charts to a more conservative figure. Using values that reflect slightly more adverse conditions provides a reasonable estimate of performance information and gives a slight margin of safety. The following illustration

9632-463: The jettison of the DPS, the X-38 would have glided from orbit and used a steerable parafoil for its final descent and landing. The high speeds at which lifting body aircraft operate can make them challenging to land. The parafoil would have been used to slow the vehicle and make landing easier. The landing gear consisted of skids rather than wheels: the skids worked like sleds so the vehicle would have slid to

9744-429: The large-scale use of batteries to collect and store energy from the grid or a power plant and then discharge that energy at a later time to provide electricity or other grid services when needed. Grid scale energy storage (either turnkey or distributed) are important components of smart power supply grids. Batteries convert chemical energy directly to electrical energy . In many cases, the electrical energy released

9856-520: The length of time a device can run on a fully charged battery—this is also unambiguously termed "endurance". For a rechargeable battery it may also be used for the number of charge/discharge cycles possible before the cells fail to operate satisfactorily—this is also termed "lifespan". The term shelf life is used to describe how long a battery will retain its performance between manufacture and use. Available capacity of all batteries drops with decreasing temperature. In contrast to most of today's batteries,

9968-598: The military aircraft flight test is the Operational Test (OT). OT is conducted by a government-only test team with the dictate to certify that the aircraft is suitable and effective to carry out the intended mission. Flight testing of military aircraft is often conducted at military flight test facilities. The US Navy tests aircraft at Naval Air Station Patuxent River and the US Air Force at Edwards Air Force Base . The U.S. Air Force Test Pilot School and

10080-439: The necessity to compensate for the performance numbers if the aircraft is not in good working order or piloting skills are below average. Each aircraft performs differently and, therefore, has different performance numbers. Compute the performance of the aircraft prior to every flight, as every flight is different. Every chart is based on certain conditions and contains notes on how to adapt the information for flight conditions. It

10192-705: The need for crew return from the International Space Station: In early 1996, a contract was awarded to Scaled Composites , Inc., of Mojave, Calif., for the construction of three full-scale atmospheric test airframes. The first vehicle airframe was delivered to JSC in September 1996. In an unusual move for an X-plane , the program involved the European Space Agency and the German Space Agency DLR . It

10304-425: The net emf is the difference between the reduction potentials of the half-reactions . The electrical driving force or Δ V b a t {\displaystyle \displaystyle {\Delta V_{bat}}} across the terminals of a cell is known as the terminal voltage (difference) and is measured in volts . The terminal voltage of a cell that is neither charging nor discharging

10416-422: The number of holding vessels, a stronger charge could be stored, and more power would be available on discharge. Italian physicist Alessandro Volta built and described the first electrochemical battery, the voltaic pile , in 1800. This was a stack of copper and zinc plates, separated by brine-soaked paper disks, that could produce a steady current for a considerable length of time. Volta did not understand that

10528-437: The number of times the battery can be recharged. Most nickel-based batteries are partially discharged when purchased, and must be charged before first use. Newer NiMH batteries are ready to be used when purchased, and have only 15% discharge in a year. Some deterioration occurs on each charge–discharge cycle. Degradation usually occurs because electrolyte migrates away from the electrodes or because active material detaches from

10640-443: The open top and needed careful handling to avoid spillage. Lead–acid batteries did not achieve the safety and portability of the dry cell until the development of the gel battery . A common dry cell is the zinc–carbon battery , sometimes called the dry Leclanché cell , with a nominal voltage of 1.5 volts , the same as the alkaline battery (since both use the same zinc – manganese dioxide combination). A standard dry cell comprises

10752-631: The original composition of the electrodes can be restored by reverse current. Examples include the lead–acid batteries used in vehicles and lithium-ion batteries used for portable electronics such as laptops and mobile phones . Batteries come in many shapes and sizes, from miniature cells used to power hearing aids and wristwatches to, at the largest extreme, huge battery banks the size of rooms that provide standby or emergency power for telephone exchanges and computer data centers . Batteries have much lower specific energy (energy per unit mass) than common fuels such as gasoline. In automobiles, this

10864-408: The overall utility of electric batteries, reduce energy storage costs, and also reduce pollution/emission impacts due to longer lives. In echelon use of batteries, vehicle electric batteries that have their battery capacity reduced to less than 80%, usually after service of 5–8 years, are repurposed for use as backup supply or for renewable energy storage systems. Grid scale energy storage envisages

10976-447: The pilot to predict aircraft performance for variations in density altitude, weight, and winds all on one chart. Because of the vast amount of information that can be extracted from this type of chart, it is important to be very accurate in reading the chart. A small error in the beginning can lead to a large error at the end. The remainder of this section covers performance information for aircraft in general and discusses what information

11088-440: The reactions of lithium compounds give lithium cells emfs of 3 volts or more. Almost any liquid or moist object that has enough ions to be electrically conductive can serve as the electrolyte for a cell. As a novelty or science demonstration, it is possible to insert two electrodes made of different metals into a lemon , potato, etc. and generate small amounts of electricity. A voltaic pile can be made from two coins (such as

11200-404: The statement of work. In this case, the government is the customer and has a direct stake in the aircraft's ability to perform the mission. Since the government is funding the program, it is more involved in the aircraft design and testing from early-on. Often military test pilots and engineers are integrated as part of the manufacturer's flight test team, even before first flight. The final phase of

11312-447: The technology uses less expensive, earth-friendly materials such as sodium extracted from seawater. They also have much longer life. Sony has developed a biological battery that generates electricity from sugar in a way that is similar to the processes observed in living organisms. The battery generates electricity through the use of enzymes that break down carbohydrates. The sealed valve regulated lead–acid battery (VRLA battery)

11424-493: The umbrella of an integrated project team (IPT) airspace. All launch vehicles , as well as a few reusable spacecraft, must necessarily be designed to deal with aerodynamic flight loads while moving through the atmosphere. Many launch vehicles are flight tested, with rather more extensive data collection and analysis on the early orbital launches of a particular launch vehicle design. Reusable spacecraft or reusable booster test programs are much more involved and typically follow

11536-414: The units h . Because of internal resistance loss and the chemical processes inside the cells, a battery rarely delivers nameplate rated capacity in only one hour. Typically, maximum capacity is found at a low C-rate, and charging or discharging at a higher C-rate reduces the usable life and capacity of a battery. Manufacturers often publish datasheets with graphs showing capacity versus C-rate curves. C-rate

11648-428: The voltage was due to chemical reactions. He thought that his cells were an inexhaustible source of energy, and that the associated corrosion effects at the electrodes were a mere nuisance, rather than an unavoidable consequence of their operation, as Michael Faraday showed in 1834. Although early batteries were of great value for experimental purposes, in practice their voltages fluctuated and they could not provide

11760-600: The world's largest battery was built in South Australia by Tesla . It can store 129 MWh. A battery in Hebei Province , China, which can store 36 MWh of electricity was built in 2013 at a cost of $ 500 million. Another large battery, composed of Ni–Cd cells, was in Fairbanks, Alaska . It covered 2,000 square metres (22,000 sq ft)—bigger than a football pitch—and weighed 1,300 tonnes. It

11872-769: Was also known as the X-35 (but that designation was already allocated by the USAF to Lockheed Martin's entry in the Joint Strike Fighter Program ) and the X-CRV (experimental - Crew Return Vehicle). Severe cost overruns plagued the ISS program during its development and construction during the late 1990s and early 2000s. To bring costs under control the International Space Station Management and Cost Evaluation (IMCE) Task Force

11984-623: Was created. The task force introduced a new concept known as "American Core Complete", whereby the U.S. would unilaterally reduce the previously agreed-upon American contributions to the ISS while retaining its role as the controlling member of the International partners. Core Complete (as opposed to the originally planned "Station Complete") deleted the American Habitation Module, the American CRV, and Node-3 from

12096-840: Was manufactured by ABB to provide backup power in the event of a blackout. The battery can provide 40 MW of power for up to seven minutes. Sodium–sulfur batteries have been used to store wind power . A 4.4 MWh battery system that can deliver 11 MW for 25 minutes stabilizes the output of the Auwahi wind farm in Hawaii. Many important cell properties, such as voltage, energy density, flammability, available cell constructions, operating temperature range and shelf life, are dictated by battery chemistry. A battery's characteristics may vary over load cycle, over charge cycle , and over lifetime due to many factors including internal chemistry, current drain, and temperature. At low temperatures,

12208-432: Was needed, it would only take two to three hours for it to reach Earth. The parafoil parachute, employed for landing , was derived from technology developed by the U.S. Army . This massive parafoil deploys in 5 stages for optimum performance. A drag chute would have been released from the rear of the X-38. This drag chute would have been used to stabilize and slow the vehicle down. The parafoil (area of 687 square meters)

12320-497: Was originally called X-35 . The program manager was John Muratore , while the Flight Test Engineer was future NASA astronaut Michael E. Fossum . Rob Meyerson , who later went on to become President of Blue Origin , was an early member of the team. The X-38 design used a wingless lifting body concept originally developed by the U.S. Air Force in the mid-1960s during the X-24 program. R. Dale Reed worked for NASA from 1955-2000 and

12432-502: Was roundly criticized by many experts at the time since a majority of development work on the X-38 had been completed. The prototype space vehicle was approximately 90% complete at the time it was cancelled. The X-38 V-132 is now on permanent loan from NASA to the Strategic Air and Space Museum at Ashland, Nebraska. As of October 2015 the 90% complete X-38 V-201, having been moved out of Building 220 at Johnson Space Center,

12544-420: Was then released. It would open in five steps (a process called staging). While the staging process only takes 45 seconds, it is important for a successful chute deployment. Staging prevents high-speed winds from tearing the parafoil. The spacecraft's landing was to be completely automated. Mission Control would have sent coordinates to the onboard computer system. This system would also have used wind sensors and

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