NASA Gives Official 'Go' for August 25 Ares I First Stage Motor Test


NASA gave the official “go” for the Ares I first stage Development Motor 1 (DM-1) test targeted for August 25 concluding a two-day test readiness review. Nineteen NASA managers signed off on the official readiness statement. It reads: “Pending satisfactory completion of normal operations flow and open items identified in this review, the Ares I First Stage test hardware is ready to support the static testing of DM-1.”

The review was held at ATK Launch Systems Huntsville, Al. office on July 21-22.  More than 50 solid rocket motor technical experts reviewed every detail of the DM-1 solid rocket motor, now installed in a  test stand at ATK’s Promontory, Utah test facility.  The first stage five-segment development motor has been under development since 2006. It is based on the design of the space shuttle’s four-segment configuration, but includes several modifications.

Max Tavoian, ATK Space Systems manager opened the formal review for ATK. Tavoian noted that most people in the room had been working toward DM-1 for the last three and a half years.

“This review will tell you why DM-1 is ready to go. DM-1 has 46 design objectives and 650 instrumentation channels. This test will prove out a series of technology improvements and design attributes including changes to the propellant grain, nozzle and updated liner and insulation implemented by ATK related to the new five-segment reusable solid rocket motor.”

Over the two days, the team engaged in a healthy and thorough discussion about the motor’s instrumentation, propellant and motor performance, insulation and components, metal case components and seals, and the overall readiness to “go” for test on August 25. The upcoming test is expected to provide valuable data on motor internal pressures, thrust profile, and performance of new designs on the nozzle and the internal motor insulation.  Additional benefits include data on roll-control, acoustics and vibration data. Engineers need all of this data to continue to design the Ares I rocket.
 
No issues emerged from the review that impact test readiness. Final instrumentation will be installed over the next month in preparation for the firing.

Alex Priskos, first stage manager for the Ares Projects Office at NASA’s Marshall Space Flight Center in Huntsville, Ala. chaired NASA’s test readiness review panel. He closed the meeting enthusiastically, acknowledging the hard work of the team which made this successful review possible. “This effort has been a thorough and professional effort. The professionalism of  this team gives me a high level of confidence as we go forward with this test,” he said.

“DM-1 is about taking advantage of all we’ve learned from the Shuttle program — the safety aspects and technology enhancements — and moving forward to the next stage of crewed exploration beyond low-Earth orbit,” explained Priskos. “This test is the first step in a  series of development and qualification tests. The ultimate goal is to design and build a first-stage motor that increases performance, is safe, reliable and will meet or exceed all of our requirements and objectives. The entire Ares team is looking forward to the DM-1firing next month and reviewing the test results.”

Jennifer Morcone, MSFC PAO

Dual-Plane Isolators Emerge as Most Promising Thrust Oscillation Fix


Engineers and rocket scientists love data. So no surprise the NASA thrust oscillation mitigation team has been gathering reams of data to best understand how to design an integrated vehicle that avoids thrust oscillation. This week at Ames Research Center, Moffett Field, Calif.  NASA and industry engineers reviewed the latest progress to qualify and validate our understanding of thrust oscillation problems and solutions. 

For those new to this issue, thrust oscillation is a phenomenon that can appear in all solid rockets where pressure created during launch conditions creates an up-and-down vibration at a frequency that could impact crew situational awareness or health. For Ares I, engineers expect a smooth ride up from liftoff to 115 seconds, but as the first stage nears burnout, thrust oscillations could pose a problem for a few seconds impairing the crew’s ability to read displays and respond to what they see.    

Since the previous technical interchange meeting (https://blogs.nasa.gov/cm/blog/Constellation.blog/posts/post_1239311627391.html) several things have changed. Orion and Ares designs have matured and very helpful measurements have been captured during liftoff of the STS-126, STS-119 and STS-125 space shuttle missions which validate assumptions about how the solid rocket pressure oscillations occur in-flight.  Mathematical modelers have an improved understanding of vehicle responses to candidate hardware designs. And finally, with the conclusion of the crew situational awareness testing, a new requirement has been proposed based on that work.

Constellation engineers have been pouring over new data to pinpoint several important factors that will drive optimal thrust oscillation fixes. 

First, two important numbers to keep in mind: 12.3 Hz and .7g. 

The thrust oscillation frequency of Ares I five-segment solid rocket motor is predicted to be approx. 12.3 Hz. By comparison, the shuttle’s four-segment solid rocket motor thrust oscillation frequency is 15 Hz. Ares I is a bit lower because it is longer. Think of an organ pipe: the longer the pipe, the lower the natural frequency.  The goal of any mitigation is to minimize the effects on the crew due to the first stage thrust oscillation. There are two basic ways to do this: “de-tune” the vehicle stack or increase damping in the system.  “De-tuning” is another way to say frequency separation — moving the natural frequencies of the Ares I vehicle and the Orion spacecraft away from 12.3 hz.  Damping absorbs the extra energy in the system and can be targeted to specific frequencies.  The goal of any mitigation system, or combination of systems, is to de-tune the vehicle approximately 1.5-2 Hz away from the vehicle’s natural resonance and avoid any problematic thrust oscillations with 99% certainty.

Since the Gemini era, NASA spacecraft designers used a limit of .25g peak as a safe threshold against these problematic longitudinal pressure oscillations. Based on increased fidelity gained through the crew situational awareness test series, the Constellation Program expects to set a new threshold, limiting the maximum peak to .7g, with a mean vibration level to not exceed .21g’s rms (root mean square) for any five second period during first stage flight. 

Keeping these figures in mind, the team scrutinized proposed hardware solutions and how well each system, or combination of systems, will impact the integrated vehicle. Each thrust oscillation simulation includes over 10,000 analysis points including variations in forcing function, structural frequency response, and mode shape to provide an accurate assessment of how mitigation solutions will actually work in flight.

Design solutions under active development include passive single and multi-plane C-spring isolators, and mass absorbers called a Tuned Oscillation Array (or TOA).  Work also continues on a LOX damper, which uses the slave mass of the Upper Stage liquid oxygen propellant to dampen out vibrations. Subscale hardware for two LOX damper designs — a bellows and diaphragm — have also been built and tested in the lab. All candidate solutions are being worked full force, and full steam ahead, to meet these updated parameters.

Initially, a dual plane C-spring isolator system was too heavy to incorporate into the overall vehicle design.  The updated designs use titanium, not steel for the isolator springs, improving overall system performance while reducing the weight of the system. The weight reduction made a dual-plane C-spring isolator system much more attractive as a design solution and it is out-performing the other passive systems. The next step is to make a decision about how best to implement a dual plane solution into integrated designs.  Nothing is off the table yet, as the team continues to refine which fix is most robust.

The team’s analysis during this session reemphasized that thrust oscillation is not just a first stage or Ares problem. It’s a technical challenge that impacts the entire vehicle and can be solved by an integrated team of Ares and Orion engineers. Because of this, final decisions about which solution is optimal will be incorporated as an issue into the Constellation Preliminary Design Review scheduled for late this year. The team also looks forward to capturing data from the upcoming five segment development motor test (DM-1) and Ares I-X flight which will further characterize how the in-line vehicle responds.

Reported  by Jennifer Morcone, NASA MSFC public affairs

Welcome to Our New Pad…

Check out the news release:

 

RELEASE: 09-127

 

NASA’S SHUTTLE PROGRAM HANDS OVER LAUNCH PAD TO CONSTELLATION

 

CAPE CANAVERAL, Fla. — The May 31 transfer of Launch Pad 39B at NASA’s Kennedy Space Center in Florida from the Space Shuttle Program to the Constellation Program is the next step in preparing the first flight test of the agency’s next-generation spacecraft and launch system. The Constellation Program is developing new spacecraft — including the Ares I and Ares V launch vehicles, the Orion crew capsule, and the Altair lunar lander — to carry humans to the International Space Station, the moon and beyond.

 

Since the late 1960s, pad B has been instrumental in human spaceflight programs, such as Apollo, Skylab and the space shuttle. The pad originally was built for the Saturn V rockets to launch the Apollo capsules to the moon. In July 1975, the pad was modified to support space shuttle operations. The first space shuttle to lift off from pad B was Challenger in January 1986.

 

The handover took place Sunday after space shuttle Endeavour was moved to Launch Pad 39A. The ground operations team will finish modifying pad B for the Ares I-X rocket launch. Modifications will include removing the orbiter access arm and a section of the gaseous oxygen vent arm and installing access platforms and a vehicle stabilization system.

 

 

Space Shuttle Program Hands over Launch Platform to Constellation


The handover of Mobile Launcher Platform-1 from NASA’s Space Shuttle Program to the Constellation Program at a Kennedy Space Center ceremony on March 25 is the next step in returning people to the moon and exploring beyond.

The 4,625-ton, two-story steel structure will be modified for the first test flight of NASA’s next-generation spacecraft and launch vehicle system. The Ares I-X rocket test, which is targeted for launch this summer, will provide important data for developing Ares I and support a critical design review next year.

“It truly is a historic day to be turning over a major piece of hardware from one manned spaceflight program to another,” Shuttle Launch Director Mike Leinbach said. “It really doesn’t happen very often.”

MLP-1 holds special memories for Leinbach, considering it has taken part in 51 shuttle launches — more than NASA’s other two launch platforms. Its rich history also includes three Apollo launches, including Apollo 11 that put humans on the moon; and three Skylab missions, making it the first mobile launcher platform to support space station, Apollo, space shuttle and Constellation programs.

The launch platform had just been used on March 15 to launch space shuttle Discovery on its STS-119 mission to the International Space Station.

After Leinbach shared some history of the launcher, the banner that read “Go Discovery” was changed to “Go Ares I-X” to reflect its new mission with the Constellation Program.

 “We are excited to have this mobile launcher platform turned over to us,” said Pepper Phillips, director of the Constellation Project office. “This is a real enabler for us.”

Constructed in 1964, Mobile Launcher-1, or ML-1, originally was used for transporting and launching the Saturn V rocket for Apollo lunar landing missions. For Skylab and Apollo-Soyuz, ML-1 was modified with a “milkstool” pedestal that allowed the shorter Saturn IB rocket to use the Saturn V tower and service arms. ML-1 was modified in 1975 for use in shuttle operations and was renamed Mobile Launcher Platform-1, or MLP-1.

  In support of the transition, United Space Alliance, Lockheed Martin and NASA collaborated to simplify design plans and capitalize on previous shuttle upgrades and existing infrastructure. 

The first modifications for MLP-1 began in May 2008, with the installation of 20 water bag cleats to the platform’s right-hand solid rocket booster hole, which will prevent any possible acoustic damage to the rocket during liftoff.

In December 2008, the ground control system hardware, which controls the ground equipment for checkout and launch, was installed onto MLP-1.

Next, MLP-1 will undergo ground control hardware testing at Kennedy’s Launch Pad 39B. Upon completion, the platform will move to the Vehicle Assembly Building’s High Bay 3 to begin its stacking with Ares I-X.

During the handover ceremony, Brett Raulerson, United Space Alliance manager for MLP operations, received a commemorative plaque that will be hung in the MLP shop. An identical plaque also will hang in Kennedy’s Launch Control Center.           

   “This MLP is the workhorse of the fleet,” Raulerson said. “It’s exciting to know it’s going to support three (space) programs before it is finished.” 

    Following the Ares I-X flight test, MLP-1 will be disassembled.

 

By Frank Ochoa-Gonzales

Small Steps to a Great Adventure


If the greatest adventures begin with small steps, the Constellation Program took giant strides in 2008 and has more planned for 2009. Here is an excerpt from the year’s-end note, dated December 2008, Constellation Program Manager Jeff Hanley sent to his team.


All, as I type this I’m coming to the end of nearly a full week in our nation’s capitol, and here at the end of our third year as a team I owe you an update from 50,000 feet (sorry, 15 km). I think it’s important that our entire team have this context, so that we can together take on the challenges that 2009 will surely bring.

First, as I review the events of 2008, and the progress that we together have made across this agency team, I am truly proud of what you have accomplished — and you should be too. Today we have projects and hardware and software in nearly every phase of the lifecycle, from pre-formulation of our lunar surface strategy and the international partnerships that are already beginning to form, to formal formulation of the Ares V and Altair requirements, to completion of the program definition phase for Ares I, Orion, and their sister projects, to the testing of engine components and fabrication of flight test hardware for Pad Abort 1 and Ares I-X.

The program has built considerable momentum in the past 12 months and indeed over the last three years since we stood up as a team. We’ve done it for a fraction of the cost in people and resources compared to Apollo, shuttle and station through this phase. We’ve done it while the same supporting institutions execute our other two human spaceflight programs. We’ve done it with focus and resolve to transition shuttle workforce and assets to the new program in the smartest way possible. We’ve done it — done it all — with the Moon as our goal. “Design for lunar” has guided our every move, our every decision, within the bounds of what we can fiscally afford through these lean years until shuttle is retired.

I know you all have seen the public discourse regarding Ares and Orion and shuttle, and understandably such discourse can temper our resolve to push forward — if we let it. But, let’s review the bidding. First, we should remind ourselves, as we saw in intimate detail at last summer’s Lunar Capability Concept Review (arguably the finest such review the team has yet executed), that the Ares I/Ares V/Orion/Altair transportation system is highly integrated and keenly designed to open the lunar frontier to us in the years to come. Our driving requirements of going anywhere on the Moon, staying twice as long as Apollo in a sortie mode, sending twice as many crew members, and enabling their return at any time, must remain at the forefront of any consideration to alter the nation’s exploration launch architecture. I assure each of you that we are doing all we can to communicate this key aspect of our baseline plan — it is about much more than launching Orion to LEO (Low Earth Orbit).

The shuttle team, as you know, has performed a study of projected cost and decision points for extending the life of shuttle. I have not seen the report in its final form so I won’t comment on the interim version. But I will say — will reassure you — that Constellation’s needs, interests, and requirements were central to their deliberations, and we were partnered closely with the study team to provide the Constellation implications of any extension. It was a good effort and I am quite satisfied that any impacts to Constellation are well accounted for.

Somewhat in tandem, in October we kicked off our own special study led by Ralph Roe out of NESC (NASA Engineering and Safety Center) to look at options to accelerate Constellation to allow the first human flight to occur prior to our March 2015 commitment date. All of the deputy managers of our program and project offices participated, along with a substantial number of experienced contributors from outside the program. It took our most recent baseline plan — including budgets, schedules, technical content, risks and threats, and assessed achievability of three different acceleration cases to improve upon the March of 2015 commitment date, assuming of course that resources were added to do so. Ralph briefed the draft report to leadership at HQ (NASA Headquarters), and while it is still being finalized, the findings are not new — the upshot being, if you want to accelerate Ares I and Orion then significant new money must be added to the Constellation budget in FY09 and FY10. This is the same answer that we provided more than a year ago when asked what it would take to keep our September 2013 baseline with an adequate level of confidence.

And no wonder – if you look at a “traditional” funding profile for an aerospace program and compare it to the Constellation budget profile, the deficit in these early years is obvious. What it compels us to do, therefore, is defer some key work to later that would buy down considerable risk — flight and ground tests, manufacturing demos, test articles to investigate structural margins, engineering development units, buys of long lead parts, etc. This is where we are at today with our internal target of September 2014, compounded by very lean reserves in these same two years to deal with surprises.

We’re at where we’re at. In the weeks ahead we will proceed assuming no new money will be forthcoming to accelerate and we will instead move forward to adjust our plan to meet our March 2015 commitment. If a decision comes forward to accelerate by the April timeframe, an earlier date is still possible, but that gets less and less likely with each passing month.

Again, none of this should be a surprise — though some will feign shock and accuse us of overselling. But we have been very careful these three years to avoid that. We have consistently pointed out that our internal ‘work to’ dates were aggressive with this fiscal profile and what additional funding it would take to increase our confidence and ability to execute. These same realities have been reinforced by those who independently review us. Throughout we have applied common government and industry practices and methods for how projects and programs are funded and managed. We kept the option open to enable a more aggressive date as long as we reasonably could before last summer’s re-baselining. Two years of continuing resolutions haven’t helped, but we’ve worked around them to the best of our ability to keep moving forward.

Look at all you’ve accomplished in spite of that!!

All this is offered as context to further amplify what an amazing result — in spite of it all — that 2008 has produced. Constellation is not a paper program anymore. It is a full-fledged assault on the frontier, and if we keep the mission at the forefront of our sights then we can persevere. As the year draws to a close, we enjoy broad support in Congress, we have a vision that we’ve not only embraced but have strategically over the last three years codified in an exploration architecture with a broad range of capability to allow us to unlock first cis-lunar space and then the inner solar system in the years to come… and who knows what other missions these new tools might be employed for?

In the coming year, let’s continue to make history — one milestone at a time — as we celebrate those whose shoulders we stand upon more than a generation ago.