Palapa-D1 - CZ-3B - 31.08.09 09:28 UTC - Сичан

[fagot]

Для упрощения 3-й ступени они не делают апогейный импульс, т.к. широта космодрома позволяет выводить спутники на стандартную американскую ГПО в два включения, а при недогрузе просто выводят их на суперсинхронные орбиты и немного уменьшают наклонение. А для увеличения ПН опорную орбиту и перигей приходится делать пониже, но в принципе время существования на такой орбите вполне достаточное для принятия решения в случае нештатного выведения. У старых Атласов и Ариан-4 еще ниже перигей был.

[Dude]

Спасибо, это понятно. Но так они отрезают себе возможность исправить на КА устранимый со временем сбой, например, с ориентацией или СУ ДУ.

[fagot]

Очевидно они считают более выгодным меньше терять каждый раз в ПН, чем пытаться выиграть на устранении редко возникающих сбоев. Много за всю историю было на ГПО спутников с устранимыми сбоями, утонувших из-за слишком низкого перигея?

[Старый]

Джентльмены, а разве такая орбита называется "суперсинхронная"? Я почемуто всю жизнь думал что "суперпереходная"...

[Dude]

думаю исходный термин идет с Атласов "СуперСинхронная Переходная Орбита" - SuperSynchronous Transfer Orbit (SSTO)

[Старый]

думаю исходный термин идет с Атласов "СуперСинхронная Переходная Орбита" - SuperSynchronous Transfer Orbit (SSTO)

Хорошо хоть не "Сингл Стейдж Ту Орбит". При чём тут Атласы то?

[Dude]

Двойная аббревиатура, бывает, хотя известный Orion F1 официально летел именно на сей термин (SSTO) и на Атласе, а не куда-то еще, но есть еще и термин Super-GTO, всмысле выше чем High-GTO.  



Спасение утопающих, дело рук самих утопающих (с)

[Старый]

Я всю жизнь считал что эта орбита называется STO - Супер Трансфер Орбит. - Суперпереходная орбита.

[Dude]

Старый, хотите научу трюку, которым современные дети проверяют   орфографию и главное - корректность семантики? Введите в поиск Гугля фразу "Super Transfer Orbit", а потом "SuperSynchronous Transfer Orbit" (кавычки " " обязательны) и не читая результаты просто сравниваете у кого больше счетчик попаданий.  Закон больших чисел. :wink:

[Dude]

Норад его опять потерял, а владелец утверждает, что КА уже на ГСО.

http://www.thalesgroup.com/Press_Releases/space_090909_Palapa-D_communications_satellite_now_in_geostationary_orbit/?pid=1575

[Гуманоид]

Добрался все-таки до точки стояния. Несмотря на весь шум.

[Новый]

Добрался. Не смотря на тот же шум потерял более 30% САСа.

[Dude]

Как Liss уже говорил выше - предварительная причина - один из двигателей верхней ступени не смог обеспечить штаный режим тяги.

9/17/09 09:55 AM ET
Long March Operator Announces Board of Inquiry Members
By Peter B. de Selding

    LONDON — The operator of China's Long March rockets on Sept. 17 issued a statement on the composition of the board of inquiry investigating the underperformance of the Long March 3B vehicle, saying current plans are to complete the inquiry by mid-November.

    Operating under quality-control guidelines set by the China Aerospace Science & Technology Corp., the Chinese Academy of Launch Vehicle Technology (CALT) is coordinating the investigation as manufacturer of the Long March series. CALT selected the members of the two groups — a working team and an investigation committee — that are conducting simultaneous reviews of the first serious failure of a Long March rocket in a decade. The Aug. 31 incident placed Indonesia's Palapa-D telecommunications satellite in a too-low orbit.

    China Aerospace Science and Technology Corp. has set up its own committee to review the results of the investigation.

    "The Investigation Working Team, headed by Mr. Cen Zheng, General Director of LM-3A series of launch vehicles, consists of system engineering, propulsion subsystem and telemetry subsystem specialist groups. The findings made by the Investigation Working Team are to be reviewed and approved by the Investigation Committee, headed by Mr. Yang Shuangjin, Vice President of CALT for quality control," China Long March Industry Corp. said in its statement. "The investigation results from the Investigation Committee are to be reviewed and approved independently by the Oversight Commission, which is chaired by Mr. Bai Jingwu, Deputy Director of Science and Technology Commission of CASC."

    Preliminary results indicate that one of two identical engines on the rocket's upper stage failed to deliver the required thrust to put the Palapa-D satellite into its intended orbit. The satellite's builder, Europe's Thales Alenia Space, announced Sept. 9 that Palapa-D had been placed into final geostationary position using its own thrusters. Thales Alenia Space Chief Executive Reynald Seznek said at the time that the satellite has enough onboard fuel remaining to provide 10 years of full service, or two thirds of its 15-year contractual lifetime.

[anik]

http://www.spacenews.com/civil/091119-burn-through-blamed-long-march-mishap.html

"The investigation into the underperformance of one of two upper-stage engines during the flight, which placed Indonesia's Palapa-D satellite into a useless orbit, concluded that failure was caused by a burn-through of the engine's gas generator.

The board of inquiry into the vehicle's first failure in 13 years concluded that the most likely cause of the burn-through was foreign matter or humidity-caused icing in the engine's liquid-hydrogen injectors. To prevent a recurrence of the problem, the liquid hydrogen gas-feed system on future rockets will be fitted with a filter to prevent the passage of ice or other foreign objects.

In addition, the gas generator in the third-stage engine's liquid hydrogen cavity in the future will be purged before launch to prevent ice buildup."

"Long March launch services provider China Great Wall Industry Corp. of Beijing said in a Nov. 19 statement that the board of inquiry has reproduced the failure on the ground and concluded that the Aug. 31 failure "was solely caused by the underperformance" of one of the two identical third-stage engines"

"The affected engine was found to have delivered 38 percent less thrust than it should have for 43 percent of its total working time, China Great Wall said in the Nov. 19 statement.

China Great Wall said the new upper-stage engine filter has been qualified for flight and will be flight-tested before this year using otherwise identical engines.

Responding to Space News inquiries, China Great Wall General Manager Fu Zhiheng on Nov. 19 said the demonstration launch will feature the Long March 3C, fitted with two strap-on boosters. The mission is intended to carry a domestic Chinese satellite into geostationary-transfer orbit, the destination of most telecommunications satellites.

Meanwhile, Palapa-D prime contractor Thales Alenia Space of France and Italy announced Nov. 16 that the satellite, which was guided into its intended orbit by a series of firings of its on-board engines, has completed its in-orbit acceptance review and is now ready for use at 113 degrees east longitude by its owner, PT Indosat Tbk of Jakarta.

The satellite's in-orbit service life is now estimated at more than 10.5 years, instead of 15-16 years if it had not used fuel to correct the defective orbit, Thales Alenia Space said."

[Liss]

Прогар газогенератора из-за посторонней частицы... Положительно, все космические державы любят посторонние частица.
Интересно, почему тяга двигателя упала только на 38%...