НАСА за неделю:пуск 2 зондов к Луне, испытания нового ракетного двигателя

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NASA запустило в космос измерители лунной гравитации

Леонид Попов, 10 сентября 2011
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Непосредственно на научную фазу миссии GRAIL отведено 82 дня (иллюстрация NASA/JPL-Caltech).
10 сентября в 17:08 по московскому времени два спутника-близнеца GRAIL были отправлены на орбиту. Их миссия – составление карты гравитационного поля Луны. Учёные намерены использовать эту карту для лучшего понимания интерьера естественного спутника Земли и его истории.
Примерно через пять месяцев аппараты GRAIL (Gravity Recovery and Interior Laboratory) должны выйти на почти круговую полярную орбиту вокруг Селены, пролегающую на малой высоте. Два спутника будут двигаться вслед друг за другом.
Пролетая над участками с повышенной или пониженной гравитацией (это могут быть горные районы или впадины, некие массы в глубине Луны), зонды будут немного менять своё взаимное расположение и скорость. А эти тонкие изменения способны почувствовать приборы на борту аппаратов-близняшек.

Запуск спутников-близнецов несколько раз переносили из-за погоды (фотографии NASA/JPL-Caltech).

Основная нагрузка спутников — система измерения лунной гравитации (Lunar Gravity Ranging System — LGRS). Она использует микроволновые антенны для определения расстояния между спутниками с точностью в несколько микрометров. Для достижения такой точности спутники постоянно синхронизируют свои часы, обмениваясь «сигналами времени».
Система питания спутников состоит из солнечных батарей и литиевых аккумуляторов, поставляющих ток бортовым системам во время прохождения лунной тени. Оба аппарата также оснащены аппаратурой для связи с Землёй.

Каждый спутник GRAIL (они обозначены литерами A и B) по размеру сопоставим со стиральной машиной и весит около 200 килограммов. Технически оба лунника почти идентичны, хотя есть небольшие отличия (вроде расположения антенн) того аппарата, что полетит по орбите впереди (это будет GRAIL-B), от его ведомого собрата (NASA/ Jim Grossmann).

После перевода полученных данных в карту гравитации учёные надеются уточнить размер лунного ядра, строение лунных глубин, и, быть может, узнать что-то новое о происхождении земного спутника.
Также стоит добавить, что оба спутника несут набор камер MoonKAM, картинки с которых будут использоваться в образовательных проектах.

Ракета-носитель Delta II стартовала с космодрома ВВС США (Cape Canaveral Air Force Station) во Флориде (фото Thom Baur, United Launch Alliance).

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World's Largest Solid Rocket Motor Ignites in Utah Desert Test

By Rebecca Palmer
Published September 09, 2011
| Space.com

ATK
This still from an ATK webcast shows a side view of the five-segment solid rocket booster DM3 during a Sept. 8, 2011 static test firing at the company's motor proving grounds near Promontory, Utah.

PROMONTORY, Utah – A full-scale test of the world's largest solid rocket motor, which was originally envisioned to power a new [COLOR=blue !important][COLOR=blue !important]NASA[/COLOR][/COLOR] rocket, went off without a hitch in Utah's high desert today (Sept. 8).
Built by Utah-based Alliant Techsystems (ATK), the five-segment solid motor ignited just after 4 p.m. EDT (2000 GMT) in a fiery burst followed by two minutes of a deafening roar. The test, called Development Motor 3 (DM3), shook the desert and surrounding mountains and sent massive columns of smoke billowing into the clear blue sky above.

The ATK rocket motor, billed as the world's largest solid rocket booster by its buildiers, was originally slated to be the first stage of the Ares 1 rocket, a booster designed to launch NASA's Orion crew capsule on [COLOR=blue !important][COLOR=blue !important]moon[/COLOR][/COLOR]-bound trips under the now-cancelled Constellation program. President Barack Obama scrapped Constellation last year in favor of a new space vision aimed at sending astronauts to an asteroid by 2025.
But ATK's giant solid rocket booster, which is similar to the twin rockets used to launch NASA space shuttles for 30 years, could see new life as part of NASA's latest heavy-lift rocket plan, called the Space Launch System, or SLS.
That new [COLOR=blue !important][COLOR=blue !important]launch [COLOR=blue !important]vehicle[/COLOR][/COLOR][/COLOR] is expected to use two huge solid rocket boosters and a central core stage to launch NASA's Multi-Purpose Crew Vehicle on deep space missions.
The rocket booster could also serve as a component of a proposed commercial launch vehicle called Liberty, which ATK has been discussing with the European aerospace firm Astrium.
Thursday's successful test

Hundreds of space enthusiasts and dozens of news agencies watched the test, which was a ground-based static firing rather than a launch.
The large rocket motor lay on its side during today's firing. After countdown and ignition, fire exploded through the center of the rocket case and burned through the solid fuel ignition material. Seconds later, a roar sounded for two full minutes.
The motor carries a thrust capacity of about 3.6 million pounds, or 22 million horsepower. The motor itself is made of five segments that measure 12 feet (3.7 meters) in diameter. Its total length is 154 feet (47 m).
Thursday's test simulated a rocket launch on a hot summer day. Two previous tests simulated winter and springtime conditions.
In today's demonstration, the DM3 motor was heated to about 90 degrees Fahrenheit (32 degrees Celsius) before countdown. During the test, the fire reached a temperature of about 5,000 degrees Fahrenheit (2,760 degrees C), officials said.
[COLOR=blue !important][COLOR=blue !important]New [COLOR=blue !important]technologies[/COLOR][/COLOR][/COLOR] used to gather data worked perfectly during the ground test, ATK Vice President and General Manager Charles Precourt said in a post-test press conference. Early results showed that 10 ultrasonic sensors used to measure the thermal protection in the nozzle of the booster worked perfectly.
"At this point and time it’s a complete success for us and we’re really pleased about that," Precourt said.
The test used nearly 1,000 different instruments to gather data on about 40 different objectives. The rocket motor will be certified to fly at temperatures ranging from 40 to 90 degrees Fahrenheit (4 to 32 degrees C).
Repurposed rocket
The motor is also a key piece of the Liberty rocket ATK is developing in cooperation with Astrium.
ATK and Astrium hope Liberty could be a contender to transport NASA astronauts to low-Earth [COLOR=blue !important][COLOR=blue !important]orbit[/COLOR][/COLOR]. The vehicle could also loft cargo and satellites to orbits around our planet, ATK officials have said.
Liberty could be ready for its first test flight in 2013, with operations perhaps starting two years later, officials have said.



Read more: http://www.foxnews.com/scitech/2011/...#ixzz1XaGNXpQM

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Mars is next
In late November, NASA will launch the sophisticated Mars Science Laboratory (MSL) mission toward the Red Planet. The centerpiece of the ambitious MSL mission is a Mini Cooper-size rover named Curiosity, which will roam the surface of the planet searching for clues of its wet past and potential habitability.
The $2.5 billion Curiosity rover will land in Gale Crater, a 96-mile (154-kilometer) wide scar in the Martian surface that has a central peak which rises higher than Mount Rainer near Seattle. The states of Rhode Island and Connecticut could fit inside it.
The Mars Science Laboratory is expected to land on Mars in August 2012. Once on the surface, Curiosity will explore Gale Crater in hopes of determining if the region could have once supported some form of primitive life on Mars. [Photos: Last Look at Mars Rover Curiosity Before Launch]