NASA and contractor engineers have developed multiple options for "de-tuning" the Ares I rocket to prevent any problematic thrust oscillations from originating in its solid-rocket main stage to sync up with the natural resonance of the rest of the vehicle. 

The Constellation Program Control Board set a formal baseline for thrust oscillation mitigation during a meeting Dec. 17.  Moving forward, the Ares I vehicle design will be updated to include the addition of upper plane C-Spring isolator module and the upper stage fuel tank LOX damper.

While evaluations of data from the DM-1 motor test and Ares I-X test flight to date show no problematic thrust oscillation vibrations occurred, the Constellation team concluded incorporating the upper plane C-Spring isolators and LOX damper at this phase of design is a sensible addition.

"When we discover an engineering risk, like thrust oscillation, we tackle it with full rigor," said Jeff Hanley, Constellation Program manager. "That's what this team has done with thrust oscillation. We assumed the worst when the problem was first discovered. The good news is there is no empirical evidence of problematic oscillations from our ground test of the first stage development motor or during the Ares I-X first test flight."

"The isolators work like shock absorbers to de-tune the vehicle and the LOX damper will counter the vehicle acoustic response by absorbing and disrupting the oscillation. Together these options will give us added confidence in the tuning of the vehicle as we mature the Ares and Orion designs," added Hanley.

The NASA team, along with the prime contractors, has worked this issue carefully, understanding and minimizing any effects of the integrated vehicle response by introducing new thrust oscillation hardware into the design. The team will "scar," or prepare, the upper stage design to accommodate the addition of this mitigation hardware at a later time, if desirable.

"The options approved today puts us on a robust foundation as we move forward," said Hanley. "Finalizing the thrust oscillation design now allows us to keep to our schedule and provides contractors specific requirements about what we need them to build."

At NASA's Kennedy Space Center in Florida, a crane positions a sixth tower segment onto five segments already secured to a new mobile launcher, or ML, being constructed to support the Constellation Program. When completed, the tower will be approximately 345 feet tall and have multiple platforms for personnel access. The construction is under way at the mobile launcher park site area north of Kennedy's Vehicle Assembly Building. The launcher will provide a base to launch the Ares I rocket, designed to transport the Orion crew exploration vehicle, its crew and cargo to low Earth orbit. Its base is being made lighter than space shuttle mobile launcher platforms so the crawler-transporter can pick up the heavier load of the tower and taller rocket. For information on the Ares I, visit http://www.nasa.gov/ares

Check out the photos of the new Constellation Program mobile launcher being built at the Kennedy Space Center. 

The photos can be found under the HOT PICS listings on the Kennedy Space Center Media Gallery.

 At NASA's Kennedy Space Center in Florida, the tower on a new mobile launcher, or ML, for the Constellation Program grows as the fourth section is lowered into position. The tower will be approximately 345 feet tall when completed and have multiple platforms for personnel access. The ML is being built at the mobile launcher park site area north of Kennedy's Vehicle Assembly Building. The launcher will provide a base to launch the Ares I, designed to transport the Orion crew exploration vehicle, its crew and cargo to low Earth orbit. The base is being made lighter than space shuttle mobile launcher platforms so the crawler-transporter can pick up the heavier load of the tower and taller rocket. For information on the Ares I, visit http://www.nasa.gov/ares.

Constellation program managers agreed to reevaluate the proposed Ares I-Y flight test during an Oct. 30 Control Board and plan to take the decision up the ladder to management at NASA Headquarters soon. The decision could result in the removal of the Ares I-Y flight from the manifest in order to better align test flights with evolving program objectives.

As part of the program’s ongoing review of its ground and flight test strategy, managers evaluated the flight test plan and decided that the Ares I-Y flight fell too late in the vehicle development phase to provide useful information and lacks key elements to make it a true validation of the flight vehicle’s systems.

Originally, the I-Y test was defined as an incremental “placeholder” and planned for 2012.  It was to be a suborbital flight to test a five-segment booster, a flight production upper stage -- without a J-2X engine -- a functional command module and launch abort system and a simulated encapsulated service module.

By fall 2008, program managers were already looking at changing direction for the Ares I-Y test to improve the overall program’s chances of flying a full test vehicle by 2014. Now, with the Constellation Program nearing its preliminary design review and with maturing vehicles and systems, managers agree the I-Y test objectives can be achieved through other tests already in the manifest.

For example, the ascent abort test for Orion’s Launch Abort System can be incorporated into abort tests planned at White Sands Missile Range in 2012 and 2013 and on the first Orion flight in 2014. The ascent test will document the performance of the LAS in the event control of the launch vehicle is lost after first stage separation.

Removing the Ares I-Y flight test eliminates a unique vehicle configuration that must be designed and managed separately from the objective designs of Ares and Orion. It allows the team to focus on achieving a first launch of a thoroughly verified system and represents a tightening of the program as a function of its maturation that will ultimately save money needed for other tests.

“It simply does not fit where we are headed,” said Jeff Hanley, Constellation Program manager and chairman of the Control Board. “The test vehicle was intended to meet evolving needs but the current configuration is too different from what the program requires to certify the Ares/Orion vehicle systems.”

The current Constellation manifest shows the Ares I-Y flight test scheduled in March 2014, just a year out from the proposed first crewed flight Orion 2, planned in 2015.

Managers are also considering other options including a flight test that would fly in 2012 or 2013 that would have revised flight test objectives to better support vehicle development.

How do you stop a 200,000-pound solid rocket motor from ending up at the bottom on the Atlantic Ocean? With the biggest, strongest rocket parachutes ever built of course!  And they are snuggly packed in the forward section of the Ares I-X rocket, awaiting their debut performance.  The Ares I-X flight will be the first full flight test of the Ares I first stage parachute system.

NASA and ATK have successfully conducted nine development tests of the parachute
system including the main cluster parachute test on May 20, 2009. Credit: U.S. Army
 Yuma Proving Ground  (Watch the test, Windows, streaming)

NASA, ATK and other partners have successfully tested each element of the parachute system. In fact, over the last three years, the team has conducted three pilot, two drogue, three single main, and one main cluster parachute drop tests at Yuma Proving Ground in Yuma, Az.

But Ares I-X will be the best test of the whole kit and caboodle because of the unique flight profile.

"You simply can't drop 200,000 pounds out of a plane. The only way we can do drop testing is from a C-17 aircraft and there is a 90,000 pound load limit. The Ares booster weighs more than double that," said Ron King, Ares first stage deceleration subsystem manager at NASA's Marshall Space Flight Center in Huntsville, Al. "And Ares I-X is the only test of the entire flight sequence from start to finish, or separation to splashdown as it will be."

On October 9, 2009 NASA and industry engineers dropped a 72,000 pound test payload
from the back of a U.S. Air Force C-17 aircraft from an altitude of 25,000 feet, tying the
record for the heaviest load ever extracted from the aircraft during flight. This drop test
was designed to push the main parachute's canopy to its  limit -- supporting a
250,000-pound dynamic load. The payload included the main parachute for the Ares I
rocket. Credit: U.S. Army Yuma Proving Ground

The Ares deceleration system consists of three types of parachutes: (1) a small pilot chute which pulls out the drogue chute; (2) a 68-foot diameter drogue chute and (3) three 150-foot diameter main parachutes. Here's how the sequence goes:

The Ares I-X first stage separates from the upper stage at 124 seconds into the test flight, at an altitude of 130,000 feet. The vehicle's four tumble motors then fire to slow the first stage for its return trip to Earth and eventual recovery. At an altitude of about 15,000-feet the nose cone is jettisoned, immediately deploying the pilot parachute. The pilot chute will in turn deploy the 68-foot drogue parachute, which is the workhorse of the system and will re-orient the booster to vertical and slow it to acceptable conditions for main parachute deployment. At about 4,000 feet, the separation at the base of the forward skirt extension occurs, pulling out the three 150-foot diameter main chutes packed within. These majestic red, white and blue canopies slow the booster even more, carrying it gently to splashdown.

Artist concept of the Ares I-X first stage recovery sequence. Credit: ATK

"The velocity and re-entry environments we'll see on Ares I-X are a bit less than Ares I, but we will get a great deal of data to help us refine the final flight hardware designs," said King. "We can't wait to see our giant parachutes off the coast of Florida."

Jennifer Morcone, NASA Marshall Space Flight Center public affairs office

The answer is yes if you consider that three NASA astronauts are practicing future off-planet spacewalks undersea this week off the Florida coast.

The three astronauts, joined by a Constellation Program engineer and a team of diving “buddies,” are performing engineering evaluations for next spring’s NEEMO 14 mission.

The NASA Extreme Environment Mission Operations 14 (NEEMO 14) was slipped from October to allow the National Oceanic and Atmospheric Administration (NOAA) to complete a safety review of its Aquarius underwater laboratory.

Aquarius, located three miles off Key Largo in the Florida Keys National Marine Sanctuary, is the world's only permanent underwater habitat and laboratory

The team of NASA divers and astronauts spent last week doing preliminary work at a Key Largo, Fla., base.  This week the team will perform some engineering evaluations on a low-fidelity, full scale mock-up of the Altair lunar lander positioned next to NOAA’s lab. 

The engineering tests include 1/6 g operational evaluations of unloading a mock-up of the Lunar Electric Rover off the lander platform, rover hatch size evaluations, and incapacitated crew rescue operations.

Veteran space shuttle pilot Eric Boe is leading the NASA team. Joining Boe are veteran astronauts and aquanauts Mike Gernhardt and Richard Arnold, along with Lunar Electric Rover deputy project manager Andrew Abercromby.

The rover and lander mockups rival the size of the vehicles NASA is designing for future planetary exploration. The lander mockup is wider than a school bus is long and almost three times as high, measuring 45 feet wide and 28 feet high, including a six-foot high crane. The rover mockup is slightly larger than a full-size SUV, standing eight feet tall and 14 feet long.

Boe completed his first space flight as pilot on STS-126 in November 2008 and is assigned to pilot the STS-133 mission targeted for September 2010. Gernhardt is a veteran of four space shuttle flights, four spacewalks and two NEEMO missions. Arnold completed two spacewalks during his first spaceflight, the STS-119 mission in March and he was part of the NEEMO 13 mission in August 2007.

Andrew Abercromby serves as the deputy project manager and a biomedical engineer for the Lunar Electric Rover project and deputy lead for the Exploration Analogs and Mission Development project. As part of the Human Research Program, he is a project engineer for the Extravehicular Activity Physiology, Systems and Performance project for Wyle Integrated Science and Engineering Group in Houston.  He has extensive experience in planning and executing field test operations including NEEMO and NASA’s Haughton Mars Project, Desert RATS, and the Pavilion Lake Research Project.

NEEMO missions are a cooperative project among NASA, NOAA and University of North Carolina at Wilmington the university.

How long does it take humans to travel to the moon? Currently, Constellation is planning for the trans-lunar coast to take no longer than 4 days, or 96 hours. Apollo’s design requirement was for the coast time to range between 60 hours and 100 hours. The actual missions (Apollo 10-17) varied from 72 hours to 83 hours.

So why would it take longer on the future missions? It may not actually. At this point, Constellation is in the requirements definition and preliminary design phase for the lunar exploration portion of the program therefore requirements are set for the most stressing - maximum and minimum - types of conditions.

The trans-lunar cruise duration is a function of the energy or change in velocity (delta-V) applied at the trans-lunar injection, or TLI, burn. The energy requirements for the TLI burn will vary depending on where the planned landing site is located on the moon and when the mission is launched, among other factors. So, if a mission is launched on a more favorable opportunity, less energy will be required for the TLI burn and the trip would be quicker.

Since Constellation is planning for worst-case conditions at this point, the transfer time in the current plan minimizes the amount of propellant, and therefore the mass, required for trans-lunar injection. When Constellation flies actual missions to the moon, there will likely be the same flexibility as Apollo to shorten the duration of the flight toward the moon if it is desirable to do so.

Artist’s concept of NASA’s Orion crew exploration vehicle and Altair Lunar Lander while the Earth departure stage performs the trans-lunar injection burn (JSC2009-E-031248).