Проблемы с Аресами

[SpaceR]

То есть, ещё один камешек на чашу весов в сторону Ареса-1 с жидкостной первой ступенью?
Кстати, вот он (рис. с вышеприведенной ссылки)

[Bell]

Меня все подмывает напомнить про эмпирический закон - каждые 4 года проектирования отдаляют начало полета на 1 год

[Feol]

Арес подтачивает кариес  :lol:

[Александр Геннадьевич Шлядинский]

Меня поражает тут другое. Даже предлагая первую жидкостную ступень они вытягивают всю ракету в высоту. И это при том, что они имеют возможность не связываться с железнодорожным габаритом. Надо пускать побоку Тиокол, делать толстые ступени и тогда все будет отлично.

[DAP]

Надо пускать побоку Тиокол, делать толстые ступени и тогда все будет отлично.

Ярые сторонники Директа писали, что несмотря на относительно небольшой объем контрактов у Тиокола самое сильное лобби в Вашингтоне, что объясняет решения по Аресу.

[Александр Геннадьевич Шлядинский]

Надо пускать побоку Тиокол, делать толстые ступени и тогда все будет отлично.

Ярые сторонники Директа писали, что несмотря на относительно небольшой объем контрактов у Тиокола самое сильное лобби в Вашингтоне, что объясняет решения по Аресу.

Ну дыть, они разорятся вмиг, если перестанут производить свои дымовые трубы такого размера.
Тиокол был, Тиокол есть, Тиокол будет есть... Извиняюсь за боян.  

[DAP]

НАСА провело пресс-конференцию по поводу ситуации с продольными колебаниями (TO). Статья на NSF -
http://www.nasaspaceflight.com/content/?cid=5497

План A - Пассивный изолятор (демпфер) с пружинами  на переходном отсеке между первой и второй ступенями ('Passive SoftRide Isolator Concept') + Пассивный адаптивный абсорбер на юбке первой ступени  (Tuned Mass Absorber , Tuned Oscillating Arrays)  + изоляторы сидений для экипажа (Crew Seat Isolators).

Демпфер аналогичен по идеологии применяемому на EELV (например, для GLAST). Не решены вопросы обеспечения надежности - выход нескольких пружин их строя приводит к разрушению всей связки. Пока имеет "красный" цвет с точки зрения влияние на характеристики ракеты (не приведено пояснений, в какой связи).

Идея использовать парашютный отсек в качестве абсорбера отброшена. Будет ли он активный или пассивный, не решено. Вариант А вроде бы связан с пассивным. Активный будет работать на 600V Li-Poly батарейках. Пассивный построен на 16 приводах (? - actuators) вокруг нижней части первой ступени.

Изоляторы сидений должны снизить нагрузки с 1 G до 0.25 G . Думают, что может вообще не понадобиться, так как используется очень недолго, а массы добавляет прилично (250 кг).

На предварительное рассмотрение результатов проектирования (PDR (Preliminary Design Review), которое будет в следующем месяце, представить окончательные подтвержденные предложения по решению проблемы колебаний не успавают.

В плане Б под первым номером - активные двигатели на юбке первой ступени (Active Pulsing RCS). Вроде бы с импульсом в направлении движения, а не вверх, как раньше говорили. Из плана А убрали, так как разработка потребует, по крайней мере, 4 лет работы.

Б2 - активный абсорбер с электрическим приводом.

Б3 - еще один изолятор между второй ступенью и Орионом.

Основная проблема - нехватка данных о продольных колебаниях. Надеются получить во время запусков шаттла и Ареса I-X (правда их сильно били вроде за то, что данные 4-х сегментного двигателя и 5-ти или 5.5 сегментного в части колебаний мало сопоставимы).

Все относится только к Ориону на МКС. Для решения проблем лунного корабля требуются исследования внутренних физических принципов работы двигателя.

[Feol]

Очень похоже на типичный ход работ в ситуации, когда лично никто не заинтересован в реальном продвижении проекта. Раскачиваем вагоны - для того, чтобы лучше спалось. Объявляем одну и ту же станцию - а какая разница, что никуда не едем, раз не сильно-то и хочется.

[ronatu]

Ares I Moves Forward

Sep 12, 2008
By Frank Morring, Jr./Aerospace Daily & Defense Report
 
After a review by some 1,100 experts from seven NASA field centers, the agency's planned Ares I crew launch vehicle is moving into detailed design with only a few open issues, and is on track to meet the latest revised schedule for its first flight with a crew onboard.


So far, project managers say, it looks like Ares I can support the agency's internal September 2014 target to launch an occupied Orion Crew Exploration Vehicle to the International Space Station (ISS) for the first time. And that may be true even if Congress and the White House decide to keep flying the space shuttle fleet after the end of 2010 to reduce the gap in U.S. human access to space between the two vehicles.

Essentially, it will come down to money, said Jeff Hanley, manager of the Constellation Program that is developing Ares, Orion and the other vehicles that will be needed for a return to the moon. Just how much that is will be covered in the white paper that the shuttle, ISS and Constellation programs hope to complete by the end of the month.

"We are looking at what could be done to keep the shuttle flying and not impact Constellation, and that includes quantifying how much additional resources would be necessary to keep Constellation on plan," Hanley said late Sept. 10 after the Ares I preliminary design review (PDR) concluded at Marshall Space Flight Center. "And that's keeping Constellation on plan to fly on Orion in September 2014 and get us back to the moon by September 2020."

Hanley agreed with shuttle program manager John Shannon, who said Sept. 8 that while the shuttle hasn't "reached the point yet of no return" in shutting down for a 2010 retirement, continuing to fly it probably would have a bigger impact on the heavy-lift Ares V follow-on launcher than on the Ares I itself (Aerospace DAILY, Sept. 9).

"Probably the more driving cases are the Ares V interferences, depending on how long you keep flying the shuttle," Hanley said.

Shuttle and Constellation experts are studying the schedule for modifying a mobile launch platform and other ground infrastructure at Kennedy Space Center to accommodate Ares I. That work already has been delayed by production problems with the new shuttle external tank design, which has pushed the Ares I-X flight-test back from April 15, 2009, into June 2009, Hanley said (Aerospace DAILY, Sept. 11).

Even so, Ares I is ready for detailed design after completing PDR. Fixes to the troublesome thrust oscillation generated across the stack by the solid-fuel first stage will be addressed in a "delta PDR" next summer, but in general the other open issues are well understood and fixable, says Steve Cook, Ares project manager at Marshall.

Among areas needing more study are staging and the shock the pyrotechnics used to separate the two stages will deliver to some avionics boxes, as well as the vehicle's sensitivity to weather conditions. Interface control with the Orion vehicle and ground infrastructure also will need careful attention, he says.

A $20 million increase in the contract with Pratt & Whitney Rocketdyne for the J-2X upper stage engine to provide 65 more ground tests that was announced last week is intended "to give us a more robust approach" with more accurate data and should not affect schedule, Cook says. Critical design review for the engine, which is considered the pacing item for the whole Ares I/Orion stack, got under way this week, Cook said.

"We're ready to proceed into the detailed design onto [critical design review] in March 2011," he said. "It's really a big step in our journey to launch. The last time we did one of these on a human-rated launch system was in 1973 with the space shuttle systems, so it's been over 35 years since we've been here."

[Чебурашка]

В связи с вчерашними успешными испытаниями RS-68A..
Что-то я не могу нигде найти значение удельного импульса для данного движка. Везде пишут только про тягу.
Может кто-нибудь подскажет?

[Дмитрий В.]

В связи с вчерашними успешными испытаниями RS-68A..
Что-то я не могу нигде найти значение удельного импульса для данного движка. Везде пишут только про тягу.
Может кто-нибудь подскажет?

Если он с регенеративным охлаждением, то на NSF назывался УИ в пустоте в районе 414 с.

[frigate]

В связи с вчерашними успешными испытаниями RS-68A..
Что-то я не могу нигде найти значение удельного импульса для данного движка. Везде пишут только про тягу.
Может кто-нибудь подскажет?

Так ARES V должен полететь  на RS-68B! :idea:

From Ares V Overview (PDF) - dated 25 Sep 2008 (1.4 Mb)

Ares V конфигурация LV 51.00.48 (June 2008):
Thrust (sea level/vacuum, tonnes) 6XRS68B  1,910.35 t/2,168.71 t
Specific Impulse (sea level/vacuum., seconds) 364.9 s/414.2 s

Информация от Ed Kyle http://www.geocities.com/launchreport/ares5.html

[Дмитрий В.]

"The 6 RS-68 engines powering the Core will fly at 108 percent power levels (6 percent higher than used on Delta-IV currently) and will each produce 702,055 lbs of thrust and have an Isp of 365 seconds at sea level and will have 797,000 lb of thrust and will have an Isp of 414 seconds in a vacuum".
Это отсюда: http://www.nasaspaceflight.com/content/?cid=5451

[Dude]

В связи с вчерашними успешными испытаниями RS-68A..
Что-то я не могу нигде найти значение удельного импульса для данного движка. Везде пишут только про тягу.
Может кто-нибудь подскажет?

Так ARES V должен полететь  на RS-68B! :idea:

На вашей картинке перемешан перечень апгрейдов c RS-68 до А и потом до В .
Апгрейды ведутся последовательно тремя участниками NRO, USAF и NASA. За апгрейд до RS-68А платит NRO, оно платит за 108% тяги и рост УИ до 364/414 для Дельты-4, потом за апгрейд до RS-68B платят USAF и NASA сколько они там получат сказать трудно, но скорее всего несильно больше ибо их работы скорее концентрируются на повышении надежности.

[frigate]

...
На вашей картинке перемешан перечень апгрейдов c RS-68 до А и потом до В.

Картинка увы не моя, а от НАСА; спасибо за комплимент
Подождем новой конфигурации Ares V - там будут и характеристики двигателей  :idea:

[Dude]

Ну дык, я знаю, чья она. Можно и другую более раннюю версию показать. Найдите отличия.

[frigate]

A NEW HEAVY-LIFT CAPABILTIY FOR SPACE EXPLORATION:

Reconnaissance Office (NRO) to partner with the service on the RS-68 engine work, which is already in progress. The NRO plans to develop an upgraded RS-68A variant for a mission. From that variant, NASA would join with the Air Force to develop a common RS-68B version for use on both the Ares V and the Delta IV, featuring upgrades required by NASA for operability and changes planned by the Air Force for their Assured Access To Space program to improve robustness.

Planned modifications to the current RS-68 are:
1. Increased power level to 108 percent from the current 102 percent.
2. Main injector changes to improve Isp to at least 414.2 seconds from the current 407.7.
3. New bearing material to decrease stress corrosion susceptibility.
4. Redesigned turbopump pump inlets to incorporate tip vortex suppression.
5. Redesigned fuel turbopump second stage blisk to decrease susceptibility to cracks.
6. Redesigned gas generator igniter that eliminates squib foreign object debns concern.
7. Higher reliability oxidizer turbopump bearing chill sensor.
8. Higher reliability hot gas sensdr.
9. Redesigned oxidizer turbopump to reduce pre-start and operational helium usage.
10. Modified engine start sequence/configuration to reduce free hydrogen on the pad during engine start.
11. Redesigned ablative nozzle to accommodate the longer-duration Ares V mission profile.
The increased power level and main injector modifications are included in an engine upgrade program that PWR is implementing under a contract with United Launch Alliance for the RS-68A variant. Changes 3 through 8 are currently conducted under the Air Force Assured Access to Space Program. NASA will work with the Air Force to combine the AATS upgrades with changes 9-11 above, required for Ares V, to produce a common RS-68 B engine variant.

К пуговицам претензии есть? (С)  :roll:

[Salo]

http://www.flightglobal.com/articles/2008/10/04/316683/nasa-to-request-ares-v-altair-technology-ideas-in-january.html

NASA to request Ares V, Altair technology ideas in January
By John Croft
NASA in January will ask for industry's help in conquering "key" Ares V heavylift cargo launch vehicle and Altair lunar lander design considerations and trades,

For the Ares V, officials says there will be "multiple awards" for each of five work packages - Earth departure stage, core stage, first stage, avionics and shroud - to be issued next spring. NASA plans to begin detailed development of the booster in 2011, with a first test flight expected in 2018.

Composite technologies will play a dominant role in the request for proposals, including solutions for how to manufacture 10m (33ft) diameter composite barrels for the core stage and other components, among the largest composite structures ever to be assembled, says NASA.

Other composite-related technologies being sought include damage tolerance and detection, solid rocket motor composite metals, composites joining techniques, non-autoclave construction, composite dry structure development and composite damage failure detection for launch aborts. In addition to composites, Ares V technology needs also include long-term cryogenic fluid management and nozzle sensitivity to pocketing.

For Altair, technology requirements include designs for composite primary structures and crew compartment pressure vessels, cryogenic fluid management and a "highly reliable" LOX/LH2 throttling engine. NASA plans to hold an industry day in November in advance of the RFP release.

[Salo]

На Аресе-5 и Альтаире композитные баки и конструкция?
Я пропустил момент, когда на Альтаире перешли на LOX-LH2.

[ronatu]

....Unreasonable Rocket - Were Done for the Year
October 16th, 2008
 
Paul Breed posts:

Keven met us at FAR and we tried a 90 second hover. We just did not have enough thrust to lift the vehicle with the fuel necessary for a 90 second flight. We had margin in the system design, but not enough.

We never did get the mixing to work well enough to get proper decomposition. This lowered ISP meant more fuel to carry, higher liftoff pressures and higher flow rates on the flow orfices, we had some margin in each area, but the low ISP and poor mixing ovewelmed the margin. We can fly for 60 seconds, maybe even 75, but not 90 seconds with 25Kg of payload. We will try again in 2009 if there are prizes remaining.

I assume that at least the 180 second the 2nd place prize will be unwon.

I'm going to take some time off and relax, I want to thank all the people that have wished us well and folowed our journey. I also want to wish the Armadillo and truezero teams good luck.
Read the rest of this entry »

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NASA Reinstalls Main Mirror In SOFIA Airborne Observatory
October 16th, 2008
PALMDALE, Calif., (NASA) - Engineers and technicians from NASA, the German Space Agency and the Deutsches SOFIA Institut recently reinstalled the German-built primary mirror assembly into NASA's Stratospheric Observatory for Infrared Astronomy, or SOFIA, airborne observatory.

Technicians removed the glass mirror from the modified 747SP observatory in April 2008 and transported it to NASA's Ames Research Center, Moffett Field, Calif., where it received its reflective aluminum coating in a vacuum chamber in June 2008. The coating, five one-millionths of an inch thick, will be reapplied as necessary during the 20-year life of the program.. Read the rest of this entry »

Posted in Space Race News, NASA | No Comments »

Colliding galaxies reveal colossal black holes were common in early Universe
October 16th, 2008
 
New observations made with the Submillimeter Array of telescopes in Hawaii suggest that black holes – thought to exist in many, if not all, galaxies – were common even in the early Universe, when galaxies were just beginning to form. Astronomers have found two very different galaxies in the distant Universe, both with colossal black holes at their heart, involved in a spectacular collision.

4C60.07 – the first of the galaxies to be discovered – came to astronomers' attention because of its bright radio emission. This radio signature is one telltale sign of a quasar – a black hole, spinning rapidly, feeding on its parent galaxy. A new image captures the moment, approximately 12 billion years ago, when this galaxy ripped a stream of dusty gas from a neighbour. Read the rest of this entry »

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NASA Spacecraft Hardware Begins Journey Down Ohio River
October 16th, 2008

Cleveland , (NASA) – Full-scale components of the Ares I-X test rocket designed and manufactured at NASA's Glenn Research Center will be showcased during a briefing for media on October 22 at 3:30 p.m. EDT at the Wellsville Intermodal Facility in Wellsville, Ohio, prior to their journey down the Ohio River.

As part of the briefing, media representatives will be able to view one of the components being offloaded from a flatbed truck onto the Delta Mariner vessel docked on the Ohio River. Eleven of these components make up the upper stage simulator of the Ares I-X test rocket and represent the size, outer shape and mass of the second stage of the Ares I rocket being developed by NASA as the first vehicle of its new launch system.
....