Форум Новости Космонавтики

ЦитироватьTacSat-4 is a Navy lead Joint project managed by NRL's SED. TacSat-4's mission is to augment current SATCOM capabilities and to advance Operationally Responsive Space systems. TacSat-4 provides 10 Ultra High Frequency (UHF) communications channels that can be used for any combination of communications, data exfiltration, or Friendly Force Tracking (FFT).
 
TacSat-4's HEO (Highly Elliptical Orbit) orbit augments geosynchronous SATCOM by providing near global - but not continuous - coverage, including the high latitudes. TacSat-4 improves on current SATCOM by providing communications-on-the-move (COTM) for existing radios without antenna pointing. TacSat-4 provides flexible up- and down-channel assignments, increasing its ability to operate in some interfered environments. The tasking system, coupled with the orbit, allows dynamic reallocation of communication channels to different theaters worldwide and within 24 hours, enabling rapid SATCOM augmentation to support unexpected operations such as when natural events occur.

Sponsors & Management: The Office of Naval Research is funding the payload, management, and first year of operations. OSD-OFT/DDR&E funded the standardized spacecraft bus. The ORS Office & Air Force are providing the launch on a Minotaur-IV. The Naval Research Lab (NRL) is the program manager.

Spacecraft & Orbit: TacSat-4 is in the Small-Sat class at 450kg with 1000W array and steerable 12-foot payload antenna. The "Low HEO" orbit has a 4 hour period (6 orbits per day), altitude range from 700km to 12,050km, and is inclined at 63.4 degrees with an argument of perigee at 210 degrees[/size]. For a single satellite, a given location on the ground in the Northern Hemisphere is generally in view for about 2 hours per pass and sees three consecutive passes each day.

User Terminals: TacSat-4 enables COTM with existing radios, such as the PRC-117 and 152, and does NOT require user antenna pointing at the typical rates of 16 kbps or less. Advanced capabilities such as converting voice comms to SIPRNET, bridging channels, FFT, or specific buoy data exfiltration collections require a custom terminal for each 2000nm radius area. Given the state of wideband radio development, users are expected to use TacSat-4's 5-MHz channel only for purposes of experimentation. Commercial ODTML transmitters are available to provide a turn-key, IP-based data exfiltration option.

Availability: Launch is scheduled for Fall 2009 on a Minotaur IV from Kodiak, Alaska.

ЦитироватьНа картинке слева параболическая антенна и призматический корпус - ну чисто TecSAR! :wink:

ЦитироватьNRL Positions Unique Elliptic-Orbit TacSat-4 Satellite for Launch
March 11th, 2011 - 10:02 am ET by Business Wire

Naval Research Laboratory spacecraft personnel make final preparations to ready the TacSat-4 spacecraft for a May 2011 launch. Transported March 1, to the Kodiak Alaska airport via an Air Force C-17 and trucked to the Alaska Aerospace Kodiak Launch Complex, the TacSat-4 satellite will be launched aboard an Orbital Sciences Minotaur-IV launch vehicle into a highly elliptical orbit (HEO) with an apogee of 12,050 kilometers.

TacSat-4 is a Navy-led joint mission managed by the NRL Naval Center for Space Technology. The mission of TacSat-4 is to experiment with new satellite communications (SATCOM) techniques, augment current SATCOM capabilities, and advance the development of Operationally Responsive Space (ORS) systems for improved responsiveness of space capabilities.

TacSat-4 augments current SATCOM by providing communications-on-the-move (COTM) for existing radios without requiring antenna pointing and providing 10 Ultra High Frequency (UHF) channels that can be used for any combination of communications, data ex-filtration, or Blue Force Tracking — a system that provides military commanders and forces with location information about friendly military forces.

TacSat-4 provides flexible up and down channel assignments, which increases the ability to operate in busy, and sometimes restrictive, UHF environments. The unique orbit of TacSat-4 also augments geosynchronous SATCOM by providing near global, but not continuous, coverage to include the high latitudes.

"The ability to provide communications on the move without having to stop and point a SATCOM antenna was the most important user requirement and one which drove the design of the system," said Mike Hurley, section head, NRL Spacecraft Development.

The NRL Blossom Point Ground Station provides the command and control for TacSat-4 and maintains its user Virtual Mission Operations Center (VMOC) tasking system, allowing dynamic reallocation to different theaters worldwide and enabling rapid SATCOM augmentation when unexpected operations or natural events occur.

The Office of Naval Research (ONR) sponsored the development of the payload and funded the first year of operations. The Office of the Director of Defense Research and Engineering (DDR&E) funded the standardized spacecraft bus. The Operationally Responsive Space (ORS) Office funded the launch that will be performed by the Air Force Space and Missile Systems Center (SMC).

The spacecraft bus was built by NRL and Johns Hopkins University Applied Physics Laboratory (APL) to mature ORS bus standards developed by an Integrated (government and industry) System Engineering Team, the "ISET Team," with active representation from AeroAstro, Air Force Research Laboratory, Johns Hopkins Laboratory APL, ATK Space, Ball Aerospace and Technologies, Boeing, Design Net Engineering, General Dynamics AIS, Microcosm, Microsat Systems Inc., Massachusetts Institute of Technology Lincoln Laboratory, Orbital Sciences, NRL, SMC, Space System Loral, and Raytheon.

The Naval Research Laboratory is the Department of the Navy's corporate laboratory. NRL conducts a broad program of scientific research, technology, and advanced development. The Laboratory, with a total complement of nearly 2,500 personnel, is located in southwest Washington, D.C., with other major sites at the Stennis Space Center, Miss., and Monterey, Calif.

Photos/Multimedia Gallery Available: http://www.businesswire.com/cgi-bin/mmg.cgi?eid=6644080&lang=en

ЦитироватьСолнечные батареи у него прикольные.
http://carbon-free-energy.com/papers/2009/slate_final.pdf

ЦитироватьFri, 18 March, 2011
Taurus XL Failure Investigation Could Delay TacSat-4 Launch[/size]
By Turner Brinton

    WASHINGTON — The U.S. Defense Department this month shipped an experimental satellite communications payload and its spacecraft platform to the Kodiak Launch Complex in Alaska, where they were mated in preparation for launch as early as May 5, a Navy official said March 14.

    However, the launch date for the Naval Research Laboratory (NRL)-developed TacSat-4 satellite could be affected by an investigation into the March 4 launch failure of a Taurus XL rocket, said Mike Hurley, head of spacecraft development at NRL. The Minotaur 4 vehicle that will carry TacSat-4 to orbit shares some hardware in common with the Taurus XL; both vehicles are built by Dulles, Va.-based Orbital Sciences Corp.

    In addition, the military may decide to launch the ORS-1 operational surveillance satellite ahead of TacSat-4 if it is ready in time, the Air Force has said. Although ORS-1 is launching from California's Vandenberg Air Force Base, both launch campaigns share some personnel.

    The Navy started the TacSat-4 program in 2006 to demonstrate an ultra high frequency (UHF) mobile communications capability that would be compatible with many deployed satellite radios. The spacecraft cost $75 million to develop, and the launch cost another $43 million, Hurley said.

    The 450-kilogram spacecraft was built by NRL and the Johns Hopkins University Applied Physics Laboratory of Laurel, Md. TacSat-4 will circle the globe six times a day in a highly elliptical orbit with an apogee — the spacecraft's furthest distance from Earth during each orbit — of 12,050 kilometers. Once on orbit, it will deploy a steerable 4-meter antenna that will provide 10 25- megahertz channels to users inside a coverage area 3,700 kilometers in diameter. TacSat-4's coverage area can be moved within 24 hours to serve users in a different location, Hurley said.

    The Navy currently relies on its fleet of UHF Follow-On geostationary satellites and leased UHF capacity on geostationary commercial satellites for mobile communications links. But geostationary satellites, which operate 36,000 kilometers above the equator, have limitations, and TacSat-4 could offer a unique capability, primarily the ability to reliably cover high latitudes, Hurley said. The satellite could also open up capacity previously unavailable to users with lower priority missions, he said. And because of TacSat-4's lower orbit, many users will be able to link with the satellite while on the move rather than stopping to point their antennas at a geostationary craft.

    The downside of a single satellite in TacSat-4's orbit is that users will be able to link to it for only about two hours at a time, three times a day, Hurley said. But if the mission proves successful, an operational constellation of three or four satellites in this orbit could provide continuous coverage and augment geostationary satellites, he said.

    TacSat-4 will be put through a yearlong military utility assessment led by the Pentagon's Operationally Responsive Space Office. The Navy has a lot riding on TacSat-4's success, because it is one element of a strategy the service has developed to stave off a looming gap in UHF coverage.

    The Navy's UHF Follow-On satellites are aging, and the next-generation Mobile User Objective System spacecraft have been delayed by technical troubles. The Navy has done everything it can do to extend the lives of the satellites on orbit, and also has arranged to use capacity from an Australian UHF payload that will fly on the Intelsat 22 commercial spacecraft set for launch in early 2012. Satellite operator Intelsat has added a UHF payload to another satellite that will launch next year with the expectation that the Navy will need its capacity.

    Meanwhile, the Air Force is processing both TacSat-4 and ORS-1 for May launches, though one will end up launching later. ORS-1 is the higher-priority mission, but has missed several previously scheduled launch dates because of technical troubles. ORS-1 is launching on a Minotaur 1 vehicle, which for the most part has a separate launch crew from the Minotaur 4, allowing them to be processed concurrently and launched within about 30 days of each other, Hurley said. ORS-1 is tentatively scheduled to launch first, and the final launch order should be determined by April, Air Force spokeswoman Valerie Skarupa said March 10.

    But the launch plan could be complicated by the March 4 launch failure of a Taurus XL rocket. In that mission, the rocket's payload fairing failed to separate from the vehicle, resulting in the destruction of NASA's Glory climate monitoring satellite. The fairing separation mechanism was a redesigned version of one that failed two years ago, resulting in the loss of NASA's Orbiting Carbon Observatory satellite.

    The redesigned fairing separation system flew on three successful Minotaur 4 flights last year.

    Orbital's TacSat-4 launch team will review the initial findings of a NASA failure review board by the end of March and decide if there is cause to delay the mission.

    "That's the biggest wildcard for both our launch and the ORS-1 launch," Hurley said.

ЦитироватьMay 14     Minotaur 4  •  TacSat 4
Launch time: TBD
Launch site: LP-1, Kodiak Launch Complex, Alaska

The Air Force Minotaur 4 rocket will launch the experimental TacSat 4 demonstration satellite for the military's Operationally Responsive Space office. TacSat 4 will test new satellite communications systems. Delayed from September, October, November 2010 and May 5. [April 11]

ЦитироватьMinotaur launch schedule in limbo after Taurus mishap[/size]
BY STEPHEN CLARK
SPACEFLIGHT NOW
Posted: April 15, 2011

Two small U.S. military satellites are queued up and waiting to ride into space on Minotaur rockets in May, but managers want to make sure the boosters are immune from the glitch that doomed the launch of a NASA science mission in March.
    
 NASA and Orbital Sciences Corp. are investigating the cause of the March 4 failure of a Taurus XL rocket that destroyed the $424 million Glory mission, a NASA climate research satellite designed to study the atmosphere and the sun's relationship with Earth.

The clamshell-like nose cone responsible for the March 4 Taurus mishap uses similar components as the Minotaur 1 and Minotaur 4 launch vehicles being prepared for a pair of flights in May.

"They are both potentially affected because of similar components," said Lou Amorosi, the Orbital Sciences senior vice president for the Minotaur program. "We are hoping to show separation from Taurus within the next couple of weeks through testing of those components."

Amorosi declined to elaborate on the progress of the Taurus investigation.

A Minotaur 4 rocket is being prepared for liftoff as soon as May 14 from Kodiak, Alaska. Its payload will be the Naval Research Laboratory's TacSat 4 experimental communications satellite.

Workers at Wallops Island, Va., have already stacked a smaller Minotaur 1 rocket on the launch pad. Liftoff from Virginia's Eastern Shore is scheduled for no earlier than May 30 with the U.S. military's ORS 1 spacecraft, a tactical Earth observation satellite for the Pentagon's Operationally Responsive Space office.

TacSat 4 is already at its Alaska launch site, and ORS 1 is awaiting shipment to Virginia.

Orbital Sciences is the prime contractor for the Taurus and Minotaur rocket families.

Amorosi said Thursday there is "no decision yet" on which launch will be allowed to proceed first.

"The satellites are ready, but we are waiting for the Taurus/Glory failure review board to exonerate Minotaur 1 and 4 before we launch," said Peter Wegner, director of the ORS program.

The Taurus rocket's 63-inch-diameter nose shroud failed to separate in the March 4 launch anomaly. The payload fairing, which shields sensitive satellites on the launch pad and through flight in the lower atmosphere, was supposed to fall away a few minutes after blastoff when the Taurus rocket reached the edge of space.

But the two halves of the fairing did not jettison and clung to the rocket as it ascended into space. The extra mass of the nose cone meant the Taurus XL didn't have enough power to propel the Glory satellite into a stable orbit.

Officials say the rocket's upper stage and payload likely splashed down somewhere in the Pacific Ocean.

It was the second payload fairing separation failure in a row for the Taurus rocket. Another NASA science satellite was lost under nearly identical circumstances in February 2009.

Investigators probing the 2009 launch failure did not find a root cause, but officials identified a most probable cause in the hot-gas system that initiates the payload fairing separation.

Orbital Sciences turned to a different cold-gas system successfully demonstrated three times on the Minotaur 4 rocket.

Officials haven't released any preliminary findings on the March 4 anomaly.

ЦитироватьOctober     Minotaur 4  •  TacSat 4
Launch time: TBD
Launch site: LP-1, Kodiak Launch Complex, Alaska

The Air Force Minotaur 4 rocket will launch the experimental TacSat 4 demonstration satellite for the military's Operationally Responsive Space office. TacSat 4 will test new satellite communications systems. Delayed from September, October, November 2010, May 5 and May 14. [May 21]

ЦитироватьSept. 27     Minotaur 4  •  TacSat 4
Launch time: TBD
Launch site: LP-1, Kodiak Launch Complex, Alaska[/size]

ЦитироватьНа картинке слева параболическая антенна и призматический корпус - ну чисто TecSAR!  :wink:

ЦитироватьMinotaur launch campaign begins at Alaska spaceport[/size]
BY STEPHEN CLARK
SPACEFLIGHT NOW
Posted: September 6, 2011

(https://img.novosti-kosmonavtiki.ru/19994.jpg)
Preparations to launch a U.S. Navy communications satellite have kicked off in Alaska three weeks before a souped-up Minotaur rocket will pilot the spacecraft to an orbit 7,500 miles above Earth.

 Technicians began transferring the three lower stages of the Minotaur 4 rocket to Launch Pad No. 1 at Kodiak Launch Complex on Monday, kicking off assembly of the solid-fueled launcher ahead of its Sept. 27 blastoff.

The Minotaur's first stage, a decommissioned SR118 Peacekeeper missile motor, was placed atop the launch pad's pedestal Monday. The second and third stages of the Minotaur 4 will be stacked Tuesday, according to Alaska Aerospace Corp., which operates the oceanfront launch complex.

The launch site is positioned on the southern shore of Kodiak Island in southern Alaska.

Workers inside a clean room at Kodiak are finishing up work on TacSat 4, a Navy-led satellite designed to offer additional UHF communications channels to U.S. forces in Afghanistan and the Middle East.

Once the satellite is fueled and configured for launch next week, engineers will enclose the 1,000-pound craft inside the Minotaur 4 rocket's 92-inch payload fairing. The Minotaur's fourth stage and nose cone should be moved to the launch pad attached to the rocket around Sept. 14, according to the Air Force, which is providing the launch services for the Defense Department's Operationally Responsive Space office.

After final readiness reviews and a mission dress rehearsal, officials will give a final go-ahead for liftoff Sept. 27 at approximately 1545 GMT (11:45 a.m. EDT), or just before sunrise at the Alaska launch site.

TacSat 4's launch has been held up by rocket delays and a cramped Minotaur flight manifest. The military chose to fly other satellites before TacSat 4, pushing its launch from 2009 until this year, then an investigation into a failure of a similar Taurus XL rocket delayed the mission's start from May until September.

The four-stage Minotaur launcher will boost TacSat 4 into an orbit stretching from an altitude of 435 miles to almost 7,500 miles above Earth. Its targeted orbital inclination is 63.4 degrees.

(https://img.novosti-kosmonavtiki.ru/19995.jpg)
File photo of a previous Minotaur 4 rocket launch from Kodiak, Alaska. Credit: Thom Rogers/T-Minus Productions Inc.

 Orbital Sciences Corp., the Minotaur rocket family's prime contractor, is replacing the launcher's Orion 38 fourth stage with a more powerful Star 48 rocket motor to generate the energy needed to propel TacSat 4 into the high-altitude orbit. The Star 48 motor is produced by ATK Space Systems.

The spacecraft will rapidly sweep near Earth on the low side of its orbit, then slowly rise high in the sky as it reaches its peak altitude, dwelling above battle zones for hours.

Its orbit will place TacSat 4's communications payload in range of polar regions for much of its orbit. Existing communications satellites stationed over the equator have trouble reaching those locations.

"Communication is a critical warfighting requirement," said Larry Schuette, the Office of Naval Research's director of innovation. "TacSat 4 will support forward deployed forces at sea and marines on the ground. We've developed a technology more rapidly and at lower cost that will supplement traditional satellites, giving multiple combatant commanders around the globe another outlet for data transmission and communications on the move."

TacSat 4 is the third in a series of experimental tactical satellites developed under the military's Operationally Responsive Space initiative, which aims to field more focused, less expensive spacecraft to answer the needs of commanders in combat zones.

The ORS office launched its first operational satellite in June on a mission to snap high-resolution images of battlefields and relay them directly to troops on the ground.

TacSat 4 carries a 12-foot communications antenna to relay voice and data messages between military units equipped with small backpack or handheld radios.

"We've got more 10 more UHF channels we can use," said Mike Hurley, director of spacecraft development at the Naval Research Laboratory, which manages the project. "They're very high-gain channels, which means that a marine or a soldier with a man pack or a handheld radio can actually talk to the satellite, which is not really possible now."

The Navy is responsible for the military's UHF satellite communications, and its existing satellites have trouble reaching smaller radios that enable mobile units to communicate with each other.

"That was a big design driver for TacSat 4, to be able to close that link," Hurley said.

(https://img.novosti-kosmonavtiki.ru/19996.jpg)
Sketch of TacSat 4 with solar arrays and antenna deployed. Credit: Naval Research Laboratory

 The ORS program was conceived to link satellites with far-flung military forces, including specialized units, to provide real-time communications, intelligence and reconnaissance data.

"The real advantages of the UHF is the equipment can be generally smaller and cheaper, and the nature of that frequency is it will get through trees and rain all that stuff better than the higher frequencies," Hurley said. "From that perspective, it's often a more reliable link."

The Naval Research Laboratory will control the spacecraft for the first year of communications experiments, then the satellite's management will be turned over to U.S. Strategic Command if officials believe there is an operational military utility for the platform.

ЦитироватьFRIDAY, SEPTEMBER 16, 2011

 Technicians attached a 1,000-pound U.S. Navy communications satellite to its launch vehicle this week as preparations continue for liftoff Sept. 27 from the southern coast of Alaska.

The TacSat 4 satellite was moved from its processing facility to Kodiak Launch Complex's primary launch pad Thursday, then workers lifted the fully-fueled spacecraft in place on top of the fourth stage of the Minotaur 4 rocket.

The spacecraft was enclosed inside the rocket's 92-inch payload fairing earlier this month, then the entire nose apparatus was transported to the pad in one piece.

It was the last stop for the U.S. military payload before launching into orbit at approximately 1545 GMT (11:45 a.m. EDT; 7:45 a.m. Alaska time) on Sept. 27.

With the 78-foot-tall launcher now fully assembled, the attention of the launch team will now turn to testing and a series of readiness reviews leading toward the Sept. 27 blastoff from Kodiak Island, Alaska.

TacSat 4 is the third in a series of experimental tactical satellites developed under the military's Operationally Responsive Space initiative, which aims to field more focused, less expensive spacecraft to answer the needs of commanders in combat zones.

Developed by the Naval Research Laboratory, the craft features a 12-foot-wide antenna and 10 UHF communications channels to help reach mobile military units deployed in combat theaters.

The Minotaur 4 rocket will propel the satellite into an orbit stretching from an altitude of 435 miles to almost 7,500 miles above Earth.

The spacecraft will rapidly sweep near Earth on the low side of its orbit, then slowly rise high in the sky as it reaches its peak altitude, dwelling above battle zones for hours.

Its orbit will place TacSat 4's communications payload in range of polar regions for much of its orbit. Existing communications satellites stationed over the equator have trouble reaching those locations.

The launch of TacSat 4 will be the third orbital space mission to originate from the remote Alaska spaceport. Owned and operated by the state of Alaska, Kodiak Launch Complex hosted satellite launchings in 2001 and 2010 with Athena and Minotaur rockets.[/size]

ЦитироватьМинистерство обороны США планирует 27 сентября вывести на орбиту экспериментальный спутник связи "Таксат-4"[/size]

(http://armstass.su/data/Articles/SmallPhoto/110908.JPEG)
МОСКВА, 19 сентября. (АРМС-ТАСС). Министерство обороны США планирует 27 сентября вывести на орбиту экспериментальный спутник связи "Таксат-4" (Tacsat-4). Спутник предназначен для испытания средств связи с войсками в боевых условиях. Об этом сообщили ВВС США.

Запуск спутника с помощью ракеты-носителя "Минотавр-4+" (Minotaur-4+) будет осуществлен с военной базы на острове Кодьяк (шт.Аляска). Спутник принадлежит научно- исследовательской лаборатории ВМС США NRL (Naval Research Laboratory). Масса спутника 460 кг. Он собран на стандартной платформе ORS (operationally responsive space), разработанной Университетом имени Джона Гопкинаса в рамках концепции оперативного выведения в космос по требованию.

Масса полезной нагрузки 190 кг. Она имеет 10-канальный ретранслятор с зонтичной антенной диаметром 3,6 м.

Планируемый запуск будет 100-м запуском спутника лаборатории NRL с момента первого выведения на орбиту ее спутника "Вангуард-1" (Vanguard-1) в марте 1958 года.[/size]

Фото www.onr.navy.mil.

ЦитироватьCrews rehearse Minotaur launch countdown in Alaska[/size]

The launch team gathered on the Alaska coastline Friday for a mission dress rehearsal, a practice countdown in which technicians went through procedures to prepare the Minotaur 4 rocket and TacSat 4 payload for liftoff. The real launch is scheduled for Tuesday morning.[/size]

Цитироватьhttp://www.spaceflightnow.com/minotaur/tacsat4/status.html идет трансляция :)

ЦитироватьMinotaur launch timeline[/size]
SPACEFLIGHT NOW
Posted: September 26, 2011

T-00:00   Liftoff
The first stage's decommissioned Peacekeeper SR118 solid rocket motor ignites to begin the Minotaur 4 rocket's mission. Pitch and roll commands two seconds later will put the rocket on the proper trajectory.

T+00:37   Max Q
Aerodynamic pressure on the vehicle reaches its peak as the Minotaur 4 accelerates through the lower atmosphere.

T+00:57   Stage 1 Sep./Stage 2 Ignition
At an altitude of 15 miles, the rocket's ATK-built solid-fueled first stage exhausts its supply of propellant and is jettisoned. The second stage's SR119 motor ignites to continue the flight toward space.

T+01:55   Stage 2 Burnout
The second stage SR119 motor, built by Aerojet, burns out at an altitude of 58 miles.

T+02:05   Stage 2 Sep./Stage 3 Ignition
After a 10-second coast, the Hercules SR120 third stage motor fires for a 72-second burn.

T+02:17   Fairing Jettison
The 92-inch graphite-epoxy aluminum honeycomb payload fairing that protected the satellites during the ride through the lower atmosphere is jettisoned as the rocket ascends into space at an altitude of 78 miles.

T+03:18   Stage 3 Burnout
The Hercules SR120 motor completes its burn and the Minotaur 4 enters a coast period lasting almost 20 minutes, during which the vehicle's altitude will soar to more than 400 miles.

T+22:55   Stage 3 Separation
The Minotaur's third stage is released to re-enter Earth's atmosphere.

T+23:06   Stage 4 Ignition
The Star 48 solid rocket motor is ignited to complete the job of placing the payload into orbit. This is the first flight of a Minotaur 4 rocket with the Star 48 fourth stage motor. This version of the rocket is called the Minotaur 4+ configuration.

T+24:28   Stage 4 Burnout
The fourth stage uses up its propellant and burns out as it enters the targeted elliptical orbit with a perigee altitude of about 115 miles, an apogee altitude of 7,487 miles, and an orbital inclination of 63.435 degrees.

T+27:48   TacSat 4 Separation
The Navy's TacSat 4 satellite is deployed from the Minotaur 4 rocket's fourth stage.

Data source: Orbital Sciences Corp.[/size]

Цитировать1319 GMT (9:19 a.m. EDT; 5:19 a.m. Alaska time)
 T-minus 2 hours, 30 minutes. The latest weather briefing indicates all criteria are now green and expected to remain that way for the rest of the countdown.

Meteorologists now expect partly cloudy skies with a widely scattered deck of clouds at 5,000 feet, winds from the west between 5 mph and 15 mph, and a 10 percent chance an elevated proton flux from solar activity could violate launch rules.

Otherwise, forecasters don't believe there will be any weather that could threaten launch today.

Цитировать1625 GMT (12:25 p.m. EDT; 8:25 a.m. Alaska time)
SPACECRAFT SEPARATION CONFIRMED. The rocket's telemetry being radioed through a ground station in Chile confirms the payload separated. The vehicle's orbital parameters are as expected.

Цитировать1650 GMT (12:50 p.m. EDT; 8:50 a.m. Alaska time)
The REEF tracking station in the Indian Ocean has acquired the first signal from TacSat 4, confirming it's alive following launch.

ЦитироватьЦирк...
...
То есть в прошлый раз они запустили на Минотавре с Кодьяка кучу мелюзги (в большинстве своем - гражданской) - и все параметры орбит позасекретили. А сейчас пустили вполне себе нормальный военный (хоть и экспериментальный) спутник связи - и элементы выдаются открыто...

ЦитироватьСпокойно. По-первости в ST иногда проскакивает то, что потом убирают. Посмотрим на развитие гласности.

ЦитироватьКартинка из серии "а мне пофиг ваш NOTAM"?

Цитировать03:28 28/09/2011
США вывели на орбиту экспериментальный военный спутник связи[/size]

ВАШИНГТОН, 28 сентября. /Корр.ИТАР-ТАСС Владимир Калинин/. Американская ракета-носитель "Минотавр-4", запущенная во вторник с космодрома на острове Кадьяк /штат Аляска/, вывела на околоземную орбиту экспериментальный военный спутник связи.

По словам сотрудника минобороны США Питера Вегнера, новый аппарат будет обеспечивать лучшую и более безопасную для военнослужащих радиосвязь непосредственно в боевых условиях. "Данная система избавит американских солдат от необходимости устанавливать антенны в опасных местах, - рассказал Вегнер. - Теперь пользоваться рацией можно будет прямо из укрытия, не подвергая риску жизни людей, которые должны обеспечивать устойчивую радиосвязь".

Орбита экспериментального спутника рассчитана таким образом, чтобы он мог обеспечивать максимально продолжительные сеансы связи в зонах боевых операций с участием военнослужащих США, таких как Ближний Восток. "Сейчас, если группа спецназа выполняет боевую задачу в горных районах Афганистана, она может рассчитывать лишь на 15 минут использования рации в день, - сообщил Вегнер. - После запуска нового космического аппарата продолжительность сеансов радиосвязи в этих зонах вырастет до семи-восьми часов в сутки".

Общая стоимость экспериментального спутника составляет 190 млн долларов, включая 45 млн долларов, которые были потрачены непосредственно на его запуск. Ожидается, что аппарат пробудет на околоземной орбите год, после чего минобороны США примет решение об успешности новой программы.[/size]

ЦитироватьКакто вот чувствую что орбита особенная но не могу понять в чём особенность такой орбиты.

ЦитироватьВысокоапогейная для частого пролета радиационных поясов, что улучшает работу аппаратуры и СБ.

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ЦитироватьВысокоапогейная для частого пролета радиационных поясов, что улучшает работу аппаратуры и СБ.

:)

ЦитироватьObjectives:
 Demo High Dwell ORS Capability via a HEO Orbit

TacSat-4 Example of HEO Orbital Coverage:
Minimizes Number of Spacecraft & Launches

ЦитироватьЭта же орбита использовалась и СЛДКомами.
Очевидно в ней есть какаято специфика но непонятно какая.
 Она часом не кратная?

Цитировать4 часа на 6 = 24 часа.
6 пролетов в сутки

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Цитировать4 часа на 6 = 24 часа.
6 пролетов в сутки

Чтото у меня нацело не делится. Или там надо учитывать прецессию плоскости?

ЦитироватьSierra Nevada Corporation's (SNC) Space Systems has revealed its role in the recently-launched TacSat-4 mission. The Universal Interface Electronics (UIE) unit developed by SNC and launched as part of the TacSat-4 mission on September 27th. The UIE unit is a prototype of SNC's distributed, modular avionics architecture developed as part of the DoD plug and play responsive satellite initiative. The primary purpose of the UIE device is to enable rapid interfacing of various devices with differing interface protocols via firmware reprogramming with the intent of eliminating expensive and time consuming hardware modifications and requalification. TacSat-4, sponsored by the Office of Naval Research, is the latest in a series of satellites intended to demonstrate an ability to rapidly deploy small, low-cost spacecraft that can meet the needs of military commanders at the theater level. It is part of a larger DoD initiative known as Operationally Responsive Space (ORS). SNC's Space Systems group provided the satellite for the Air Force Research Laboratory's (AFRL) TacSat-2 ISR satellite, which launched in December of 2006, and the SPA Avionics Experiment (SAE) payload on TACSat-3 that launched in May of 2009. With regards to the significance of the TacSat-4 experiment, Jeff Summers, SNC's Space System's VP of Technology, said, "The development and subsequent flight of the UIE on the TacSat-4 mission is important to SNC as it represents validation of the on-board processor base lined in all 18 of SNC's commercial ORBCOMM Generation 2 satellites."

ЦитироватьЦирк...
...
 А сейчас пустили вполне себе нормальный военный (хоть и экспериментальный) спутник связи - и элементы выдаются открыто...

Цитировать0,6719

ЦитироватьLow-cost UHF antenna deployed on Navy satellite[/size]
BY STEPHEN CLARK
SPACEFLIGHT NOW
Posted: October 8, 2011

The umbrella-like antenna on the U.S. Navy's experimental TacSat 4 communications satellite has popped open and begun relaying voice messages a week after launching from southern Alaska, according to mission officials.

(https://img.novosti-kosmonavtiki.ru/20543.jpg)
Photo of the TacSat 4 UHF communications antenna during ground testing. Credit: Naval Research Laboratory
 
The 12-foot-diameter antenna opened three days after the craft's Sept. 27 launch aboard a Minotaur 4 rocket from Kodiak Launch Complex in Alaska.

TacSat 4 was developed by the Naval Research Laboratory, marking that organizations 100th satellite since the dawn of the space age. Its objective is to demonstrate advanced communications capabilities for U.S. forces deployed in war zones like Afghanistan.

Mike Hurley, the lab's head of spacecraft development, said the TacSat 4 "antenna has deployed and is working well," adding the satellite has already started processing voice data to and from user radios on the ground.

Designed and built in-house by the Navy Research Laboratory for approximately $2 million, the 60-pound antenna was folded up like an umbrella for launch. A strap connected with a breakable joint held the antenna in the launch position until the command was issued to deploy, then 20 springs pushed out the antenna in a few seconds.

Commercial satellite antenna-builders have approached the Navy for details on the TacSat 4 design, according to Hurley. Many satellite antennas are much more costly, and industrial proposals to build TacSat 4's antenna were too expensive for the mission's limited budget.

TacSat 4's payload includes 10 UHF communications channels. According to military officials, UHF communications make up for a lack of bandwidth with high reliability.

From its unique orbit between 465 miles and 7,457 miles above Earth, TacSat 4's communications signals can reach existing handheld radios with deployed military units.

Legacy military communications satellites are stationed three times further from Earth, meaning its signals aren't as strong and troops need a larger radio to transmit and receive messages.

Although TacSat 4 can only cover part of the Earth at one time, a fleet of four or five similar satellites could provide global coverage and facilitate "communications on the move" for U.S. forces. Military personnel now must stop and point a large antenna toward a satellite to receive communications.

"TacSat-4 supports a critical warfighting requirement: communication," said Rear Adm. Nevin Carr, the chief of naval research. "We've developed a technology that will supplement traditional satellites, giving military personnel on the ground another outlet for data transmission and facilitating 'comms on the move.'"

Hurley said testing of the TacSat 4 spacecraft should be complete next week, and there's another four-to-five weeks of testing of ground terminals and user equipment before the real mission begins.

The $118 million TacSat 4 mission is designed for a one-year test campaign to show the utility of the added UHF communications capacity, then the satellite could be transitioned to normal military operations.

TacSat 4 is part of the Defense Department's Operationally Responsive Space office, which was established to develop niche satellites with less funding than traditional military programs.[/size]

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Цитировать0,6719

Маловато. Похоже, антенну еще не раскрыл.

ЦитироватьПо одному измерению мало, но ход мысли правильный.

Цитироватькучу мелюзги они засекретили, а этого нет. Гласность настала что-ли временная...  :roll:

Цитировать239 мин х 6 = 1434 мин. Без двух минут звёздные сутки - кратность налицо.

Цитироватьthe Operationally Responsive Space Office and the Defense satellite acquisition community will evaluate the performance and user feedback from TacSat-4 to determine if follow-on birds will be procured.

ЦитироватьКстати, а когда у него орбита стала 239 минут?

ЦитироватьА что, коллеги, все-таки нотифицированная негеостационарная заявка USTRO-1 прокатит для 10 UHF-каналов на 25 кГц каждый на нашей птичке?
К сожалению, слышали от него пока только S-диапазон :-(

ЦитироватьЗапеленгованные радиолюбителями УКВ-сигналы 251.700 и 256.375 МГЦ с КА на ОТМ и на ГСО в р-не 10 з.д. заявлены в сети USTRO. Возможно, на ГСО источником этих сигналов является 90014 (он же 90043).

ЦитироватьА что, коллеги, все-таки нотифицированная негеостационарная заявка USTRO-1 прокатит для 10 UHF-каналов на 25 кГц каждый на нашей птичке?
К сожалению, слышали от него пока только S-диапазон :-(

Цитировать

ЦитироватьА что, коллеги, все-таки нотифицированная негеостационарная заявка USTRO-1 прокатит для 10 UHF-каналов на 25 кГц каждый на нашей птичке?
К сожалению, слышали от него пока только S-диапазон :-(

Всегда считал, что эта заявка - под УКВшные пищалки на ОТМ-овских SDS'ах. Но может и под сабж сгодится.  :roll:

Цитировать"Что-то мне подсказывает" [(с)Старый], что заявка USTRO-1 появилась  в те времена, когда TacSat'a-4 еще не изобрели.

Цитировать.... Если исключить известные радиолюбительские спутники, научные, метео и пилотируемые, остается-то всего ничего: LEOTELCOM нескольких сортов, RINCON1, SACRED, USASAT-30A и -30С, USPOJOAQUE и USTRO-1.

ЦитироватьА какой буквой обзывается согласованные заявки?

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ЦитироватьА какой буквой обзывается согласованные заявки?

"C"

ЦитироватьА там нет такой устры  :oops:, есть "A" , "N", "U", a "C" нету   :(

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ЦитироватьА там нет такой устры  :oops:, есть "A" , "N", "U", a "C" нету   :(

Есть там "C". Их там полно.

ЦитироватьCurrent TacSat-4 UHF downlinks have been found on 249.600, 252.950, 253.000 and 254.125 - ODTML transponder should also reveal something.

ЦитироватьМарш в своем твиттере:

ЦитироватьCurrent TacSat-4 UHF downlinks have been found on 249.600, 252.950, 253.000 and 254.125 - ODTML transponder should also reveal something.

https://twitter.com/#!/uhf_satcom

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ЦитироватьМарш в своем твиттере:

ЦитироватьCurrent TacSat-4 UHF downlinks have been found on 249.600, 252.950, 253.000 and 254.125 - ODTML transponder should also reveal something.

https://twitter.com/#!/uhf_satcom

Я не смог найти частотной заявки под эти частоты.

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ЦитироватьCurrent TacSat-4 UHF downlinks have been found on 249.600, 252.950, 253.000 and 254.125 - ODTML transponder should also reveal something.

Я не смог найти частотной заявки под эти частоты.

ЦитироватьХм. А если все-таки USTRO-1?

Код Выделить Развернуть

BEAM NAME EMISS/REC FREQ.(MHz) BDWDTH(kHz) FR.MIN(MHz) FR.MAX(MHz) CLASS
RS49 E 260 20000 250 270

Правда, 249.600 чуть-чуть не влезает, но это можно обдумать.

ЦитироватьВ первую очередь проверил. Там в нотификации частоты прописаны от и до. Ни одна не бьется.