ATK conduct DM-2 test – Inline SD HLV gaining NASA support

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Alliant Techsystems (ATK) and NASA have tested the second fully developed “Ares” five-segment solid rocket motor, known as Development Motor-2 (DM-2), at their Utah test facility on Tuesday. The future career prospects for the Solids have increased recently, as they find a central role with the ongoing assessments into a Shuttle Derived Heavy Lift Launch Vehicle (SD HLV).

DM-2 Test:

Tuesday’s test related to the first stage of the Ares I launch vehicle – which remains NASA’s POR (Program Of Record) – although even ATK have recognized the on-going political refinements to NASA’s future, by associating the test of the booster as hardware that has been “identified as a key element of NASA’s future Heavy Lift Launch vehicle.”

Utilizing data from the opening five segment test – with DM-1 back in September of last year – a total of 53 design objectives will be measured through more than 760 instruments.

The motor was cooled to 40 degrees F – resulting in this firing being a DM-2 is a ‘cold motor’ test – in order to measure solid rocket motor performance at low temperature, as well as to verify design requirements of new materials in the motor joints.

“These new materials will allow for the elimination of joint heaters that were necessary in the original 4-segment motor design. This will save significant weight, further reduce system complexity and simplify launch operations, while simultaneously delivering increased operating margins at lower ambient temperatures,” noted ATK.

Other objectives include data gathering on vital motor upgrades, such as the new insulation and motor case liner and the redesigned nozzle which increase the robustness of the design. When fired, the motor produced a maximum thrust 3.6 million pounds, or 22 million horsepower.

“A robust ground and flight test program is a critical part of human-rating to ensure reliability and safety when launching crew into any orbit,” noted Charlie Precourt, VP and GM of ATK Space Launch Systems. “This test is a vital milestone in further growing the performance database for this new five-segment solid rocket motor.

“We designed this motor using a knowledge base gained from over three decades of operations, during which we constantly monitored and improved our design.”

The cases involved with DM-2 have all previously flown on with the space shuttle, collectively launching on 57 missions.

SD HLV Latest:

Following the rollout of President Obama’s FY2011 budget proposal, the role of the solids appeared to have a rather cloudy future, with a call for a “game-changing” HLV to result from a five year study.

While assessments and studies are commonplace for NASA – notably highlighted ahead of the FY2011 budget proposal, when a SD HLV appeared to have large levels of Agency support, prior to vanishing from the President’s vision – the political refinements to the future of NASA continue to focus on a HLV that will draw from the current shuttle technology base and skillsets.

A large 726 page assessment presentation (L2) was completed by the Space Shuttle Program (SSP), mainly focusing on the Sidemount SD HLV, prior to restarting to complete the Inline section of the documentation. However, the original purpose of the study was to finalize the assessments, for the benefit of passing on the knowledge to a potential suitor of a HLV.

Also see:
Part 1: Completed SD HLV assessment highlights low-cost post-shuttle solution
Part 2: SD HLV review outlines ISS Logistics and Transport
Part 3: Lunar/BEO – SD HLV, Commercial and International Architecture Outlined
Part 4: SD HLV: Early SPS Demo Mission Outlined – Risk Assessments Findings

With large support from the US Senate’s FY2011 refinements, the central role of a SD HLV has been returned to the forefront.

Signs of an Agency position, via a refined roadmap, is also showing signs of maturing, as a body known as the Human Exploration Framework Team (HEFT) work through evaluations into providing a viable path that reaches out as far as 2028.

“EA/Engineering: We briefed Charlie (Bolden) and Lori (Garver) on HEFT in mid July and they accepted our recommendations will talk to the Senate about those,” noted the latest Staff Senior Meeting notes (L2).

“The HEFT team talked to the steering council. The team will continue through August 31st and then turn it over to a long term HEFT team.”

Documentation on the HEFT effort was acquired by L2, which provided key overviews on their findings and recommendations – several articles to follow, covering interesting elements, such as the In-Space Exploration vehicle.

On the HLV, the HEFT noted the key role such a vehicle would have in the exploration architecture, while dismissing the need for a five year study

“Launch Vehicle Findings: An HLV is central to any robust human exploration program. Delaying a decision on HLV configuration and requirements to 2015 limits NASA’s options and hampers planning. There is no benefit to delaying work on the HLV, no technology needed for capability development,” noted the HEFT presentation (L2).

“NASA will lose an opportunity to build from the existing flight-proven systems. Losing the capability to build an SSP-derived HLV will require the development of new manufacturing, processing, and launch infrastructure at additional cost and schedule risk.

Three vehicles were assessed/outlined by HEFT, with a Saturn V heritage 33′ diameter RP-1 HLV, sporting 1.25 m lbf RP engines/boosters, 1.25 m lbf thrust class LOX/RP-1 core stage, and a J-2X-285 Upper Stage, was noted as problematic.

“An RP-based HLV (100-120 t) and a replacement for the (Russian) RD-180 is higher cost to NASA and therefore requires supplemental funding from DoD (Department of Defense) to offset increased costs,” noted the HEFT.

“RP-Based Vehicle Advantages: Vehicle architecture provides more capability and flexibility (114-157 t with and without boosters). Eliminates reliance on RD-180 Atlas V. Expands US liquid propulsion industry capabilities. Shared production infrastructure with the Air Force.”

The SD HLV equivalent was also listed, based on a 33′ diameter core, driven by RS-68Bs, evolvable to RS-68B E/O, and five segment PBAN boosters, evolvable to HTPB – with an Upper Stage powered by J-2X.

Yet it was the recommendation in HEFT’s conclusions to “Accelerate Shuttle-derived, in-line Medium Heavy Lift Implementation” that pointed to the configuration of choice, one which mirrors – but does not cite by name – the notional Jupiter-246 SD HLV.

“Shuttle-Derived Advantages: Lower DDT&E – fits within Agency budget for HSF (Human Space Flight) development. Schedule benefits – evolves current hardware (2-3 years faster). Utilizes experienced workforce. Based on hardware with demonstrated reliability and performance (101-118 t),” the HEFT noted.

Working off the current Shuttle ET Diameter core, the 27.5′ diameter core vehicle would be driven by Space Shuttle Main Engines (SSMEs) – utilizing existing RS-25D stock, prior to evolving to the less expensive (non-reusable) RS-25Es. The Upper Stage would be driven by RL10A4-3 engines.

Options to use 4 or 5 segment PBAN boosters, evolvable to HTPB, are also listed, likely referencing to a fast turnaround of a Block I configuration – whilst also showing how Tuesday’s test could technically be seen as highly valuable to a SD HLV.

“Recommendation: Accelerate the HLV decision – moderate HLV. Initiate a Shuttle-derived inline HLV Program beginning in FY2011. Initial 90 – 100 t range,” added the HEFT presentation. “Defer human rating and upper stage to Block II.”

Several major updates are expected over the coming months, although sources are noting that the focus is on the aforementioned Inline SD HLV, as opposed to an RP-1 or Sidemount SD HLV.

This can also be seen via work being conduced at the Marshall Space Flight Center (MSFC) – who have already been told they will lead the HLV project, along with splinter work into hardware evaluations, such as assessments into the use of spare Light Weight Tank (LWT) ET-94 at the Michoud Assembly Facility (MAF), which is leading the way to become the SD HLV Main Propulsion Test Article (MPTA).

As with the addition of STS-135, the conclusion and approval of political refinements into NASA’s future will be the key driver.

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