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Oct. 28, 2016
NASA Uses Tunnel Approach to Study How Heat Affects SLS Rocket
NASA’s new rocket, the Space Launch System, will hit high temperatures as it reaches speeds of more than 17,000 mph in just 8.5 minutes. So, how does heat affect the world’s most powerful rocket for human missions to deep space, including the journey to Mars? The answer just may be found in a special type of wind tunnel.
9 1/2-foot model of the Block 1 SLS rocket
A 9 1/2-foot (3-percent scale) full model of the Block 1 SLS rocket goes into a shock tunnel for testing at CUBRC Inc. in Buffalo, New York. NASA engineers have teamed with CUBRC to better understand and analyze how the SLS is heated as it ascends into space.
Credits: CUBRC Inc.
NASA engineers have teamed with CUBRC Inc. of Buffalo, New York, to better understand and analyze how the SLS is heated as it ascends into space. A 9 1/2-foot (3-percent scale) full model of the initial configuration of the SLS rocket was designed and built for the first phase of aerodynamic heating tests in CUBRC’s Large Energy National Shock Tunnel (LENS-II). The initial SLS configuration will be used for the first, uncrewed flight of the SLS and Orion spacecraft in 2018, called Exploration Mission-1.
Schlieren imaging
Schlieren imaging — an optical technique for visualizing supersonic flow around objects — is used during the aerodynamic heating tests. This image shows flow over Orion launch abort system at a 15-degree angle of attack.
Credits: CUBRC Inc.
Aerodynamic heating is caused by the friction between the air and the vehicle surface as it accelerates through the atmosphere. Typically, aerodynamic heating is most significant for the SLS vehicle during the second minute of flight, a time period in which the vehicle accelerates from approximately Mach 1 to Mach 4.5. The shock tunnel generates airflow at both supersonic and hypersonic flight conditions, matching what the rocket’s environment will be like during ascent — including temperature, pressure and velocity.
The tests, lasting about 40 milliseconds each, reach speeds of Mach 3.5-5. Test measurements are made in three different ways. First, pressure and aerodynamic heating are measured at nearly 200 individual sensor locations on the test model. Schlieren imaging, which is an optical technique for visualizing supersonic flow around objects, also is used during the tests. Finally, temperature-sensitive paint is applied to critical regions of the test model, and is imaged during the tests to provide additional insight into the heating distribution.
Schlieren image of flow over the SLS solid rocket booster nose cone
This Schlieren image shows flow over the SLS solid rocket booster nose cone and forward attach region to the core stage.
Credits: CUBRC Inc.
The SLS rocket configuration, with boosters attached, is tested at zero and 5 degree angles of attack. In the wind tunnel, the angle of attack is the angle between the model and the oncoming airflow. At a zero degree angle of attack, the airflow is coming exactly parallel to the vehicle. The boosters are removed from the model and the remaining core stage is tested again at higher angles of attack of 15-20 degrees — an orientation observed following booster separation in nominal flight.
“Our primary objective for the test series is to gather conclusive aerodynamic heating model validation data, both before and after booster separation,” said Chris Morris, aerothermodynamics team lead at NASA’s Marshall Space Flight Center in Huntsville, Alabama. The SLS Program is managed by Marshall. “These tests give us a lot of insight into how well our engineering and computer models do at predicting aerodynamic heating on the vehicle. The data is very important for certifying that the thermal protection system on the rocket will be sufficient to protect the rocket’s structure and vital systems inside it.”
A total of 21 tests were completed in early September for the first series. “These are impressive test models, as we have sought to capture geometric details of the vehicle’s external surface – some as small as 0.03 inches in model scale,” said Marshall’s Jason Mishtawy, test engineer on the project. “This level of resolution is necessary to properly simulate aerodynamic heating on many of the smaller features on the rocket.”
A second phase of tests will begin later this fall and use 10 1/2-foot models of the next evolution of the SLS rocket. “Both the crew and cargo configurations of the rocket will be tested, and the results will provide valuable insight into aerodynamic heating on these future versions of SLS,” Mishtawy said.
CUBRC also collaborated with NASA for SLS base heating tests, which used 2 percent scale models of the rocket and propulsion systems to gather data on the heating environments that the base of the rocket will experience upon ascent for both planned and unplanned flight conditions.
The initial SLS configuration will have a minimum 70-metric-ton (77-ton) lift capability and be powered by twin solid rocket boosters and four RS-25 engines. The next planned upgrade of SLS will use a powerful exploration upper stage for more ambitious missions with a 105-metric-ton (115-ton) lift capacity.
Last Updated: Oct. 28, 2016
Editor: Jennifer Harbaugh
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Oct. 4, 2016
 NASA Begins Tests to Qualify Orion Parachutes for Mission with Crew
NASA successfully kicked off a series of tests Sept. 30 to qualify Orion’s parachute system for flights with astronauts, a milestone that will help the agency safely return crew to Earth from deep-space missions.
An Orion test article descends under three main parachutes
An Orion test article descends under three main parachutes during the first evaluation to qualify the spacecraft’s parachute system for flights with astronauts.
In the skies above the Arizona desert, a C-17 aircraft dropped a dart-shaped test article out of its cargo bay from 35,000 feet, or more than 6.5 miles, in altitude over the U.S. Army Yuma Proving Ground in Yuma to examine how the parachute system performed when conditions provided the highest dynamic pressure the parachutes have endured before.
As the test article fell from the sky, three small programmer parachutes initially deployed to reach the desired test conditions and were cut away to begin the Orion parachute deployment sequence. Two forward bay cover parachutes deployed to collect key data, and within seconds those parachutes were cut away and two drogue parachutes were deployed to stabilize and slow down the test article. The sequence continued when three pilot parachutes deployed to pull out the system’s three orange and white main parachutes that are used to slow Orion to a safe landing speed.
The dart-shaped test article was used because it can get to a higher velocity than the capsule-shaped article typically used in testing. When returning from missions in space, the parachute sequence normally begins at an altitude of 24,000 feet with the main parachutes fully deployed at about 4,000 feet.
“The parachute system performed as we expected and getting to this new stage of qualification testing is a real landmark as we prepare for Orion missions with crew,” said CJ Johnson, project manager for Orion’s parachute system at NASA’s Johnson Space Center in Houston. “We’ve had quite a few development tests up to this point to make sure we understand how the parachutes perform in various environments and potential failure scenarios, and this new series will give us confirmation of their performance for when the crew descends under the parachutes as they return from deep space destinations.”
Seventeen engineering development tests have already been completed. To qualify the parachute system for flights with crew, a total of eight tests, including this one, will be conducted over the course of about two and a half years. A capsule-like mockup will be used for six of the remaining tests, while a dart-shaped article will be used for one remaining test. NASA also is providing parachute test performance data to the agency’s Commercial Crew Program partners.
The next test of the parachute system is planned for October, when engineers will evaluate parachute performance when the capsule-shaped test article is dropped from 25,000 feet in altitude.
Orion will next venture into space during Exploration Mission-1 in 2018, an uncrewed mission atop NASA’s Space Launch System rocket, and will travel more than 40,000 miles beyond the moon. The parachute system will be delivered to NASA’s Kennedy Space Center in Florida at the end of this year for integration into the crew module for that test flight and will help the spacecraft slow down to a relatively gentle splashdown speed of about 17 mph in the Pacific Ocean after enduring reentry speeds of up to 25,000 mph as the spacecraft makes its way through Earth’s atmosphere. The first mission with astronauts is currently targeted for as early as 2021.
Last Updated: Oct. 5, 2016
Editor: Mark Garcia
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India delays launch of dedicated South Asia satellite amid tension with Pakistan

by Staff Writers
New Delhi (Sputnik) Oct 26, 2016

Islamabad was already against the launch of the satellite, as it wanted it to be brought under the purview of the SAARC, while India wanted to reserve certain rights. Afghanistan also has reservations regarding the satellite. All other member countries of SAARC have ratified the proposal to launch the satellite.

India’s launch of a satellite on behalf of the South Asian Association for Regional Cooperation (SAARC) was announced two years ago by Prime Minister Narendra Modi during the SAARC summit in Kathmandu. However, the launch date has been postponed indefinitely due to disagreements between India and its neighbor over ongoing violence in Kashmir.

The Indian Space Research Organization (ISRO) says it won’t be possible for it to carry out the much-anticipated launch of the SAARC satellite as scheduled in December. Instead, it plans to launch its ambitious Geosynchronous Satellite Launch Vehicle (GSLV) Mark – III.

An ISRO official told Sputnik that it is certain that the launch of the South Asian satellite will be delayed by more than a month, although the exact date for the launch of GLSV Mark-III remains to be finalized.

The dedicated satellite was designed by India and will serve the needs of the eight SAARC countries, providing a range of public services. The two metric ton satellite has 12 Ku band transponders; each is dedicated to providing communication, education, telemedicine, disaster monitoring and other need-based services to one country in the region, according to ISRO.

Prime Minister Narendra Modi had proposed offering the use of the exclusive satellite to other countries in the region; India is the only one among them which possesses the ability to build and launch satellites for communications, earth observations and space research.

Meanwhile, the postponement of the satellite launch also coincides with heightened tension between India and Pakistan, necessitating the cancellation of the group’s annual summit, which was to be hosted by Islamabad.

Islamabad was already against the launch of the satellite, as it wanted it to be brought under the purview of the SAARC, while India wanted to reserve certain rights. Afghanistan also has reservations regarding the satellite. All other member countries of SAARC have ratified the proposal to launch the satellite.

SAARC was formed in 1985: Bangladesh, Bhutan, India, Maldives Nepal, Pakistan and Sri Lanka were its seven original members but it was subsequently expanded to include Afghanistan.

Source: Sputnik News

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