Orion LAS to be ‘less harrowing’ than Apollo

by Chris Bergin

Marshall Space Flight Center (MSFC) and Langley Research Center (LaRC) engineers are fine-tuning the Orion Launch Abort System (LAS), with an aim of following in the footsteps of Apollo’s system, but without the “high G jolt” that a crew would have endured when fired free of a failing Saturn V.

The refinements include a pintle nozzle that will be able to alter the thrust of the abort motors, and smoothen the abort for those onboard. One of several advanced technologies that are being employed on the new system.
Huge amounts of VSE related insider news and presentations – THE most comprehensive place to follow Ares/Orion development – are available for download on L2. See list at the end of this article.


**ARES V / Mars Transport Vehicle (MTV) LIVE UPDATE PAGES**

**Previous LAS Article**

The LAS consists of a protective cover that fits over the outer shell of the Orion crew module, an adapter cone and a forward mast assembly (tower). The mast assembly contains three solid rocket motors that handle abort and jettison operations and permit attitude control after separation, and control of the module’s orientation.

Advanced technologies include an innovative reverseflow nozzle for the abort motor, ‘a true departure from Apollo era designs,’ noted MSFC’s Stephen Gaddis, deputy manager of the LAS in the Marshall Star. ‘The reverse-flow nozzle receives fuel injection from underneath, but exhaust gases are rotated 155 degrees to reverse their direction.

‘This prevents the abort motor from washing the capsule shield with flame as it fires. The reverse-flow nozzle also will cut the weight compared to the Apollo-era design.

‘We’re working as hard as possible to perfect a state-of-the-art system we hope NASA never needs to use.’

Despite the appearance of the system, the difference between its use on Ares/Orion and Apollo will come via the advances in engineering and lessons learned from the Apollo era – while staying true to the role the old system carried out.

‘(The new LAS) will be less harrowing,’ noted Gaddis. ‘The Apollo (escape system) was a pretty rough ride, capable of pulling up to six G’s in a matter of seconds, or six times standard Earth gravity. The new system will have an active control motor, which provides a much smoother ride and increases crew safety.

‘We want to protect not just our crews’ lives, but their long-term health and physical wellbeing as well.’

Also, the Orion’s LAS, in contrast to Apollo, will be able to cover more of the ascent trajectory, for use during a problematic ascent, as well as on the launch pad abort scenario.

The Marshall team is also developing a pintle nozzle for the attitude control motor. This will allow the LAS to carry out an abort with a much smoother ejection from the failing vehicle, and the alignment for parachute deployment.

Now being tested by Aerojet Corp. of Sacramento, California, the pintle nozzle enables the system to automatically alter the motor’s thrust pressure. This helps steady and align the module, prior to the point where the parachutes are fired out of their holders – minimizing jarring of the crew onboard.

With the first Ares test set to take place in 2009 – although that may be delayed due to serious budget problems being suffered by NASA Constellation – the Ares I-1(R) test flight won’t be the first major test conducted by engineers. That first test will be the live firing of the LAS at White Sands Missile Range in New Mexico in 2008.

The test will be the conclusion of ground tests which are set to start in the spring, with the final element involving the LAS being stacked on top of a Minotaur launch vehicle, and/or a collection of Peacekeeper rockets, before being fired as a launch pad abort, very much in the style of the Little Joe II tests prior to the Apollo missions.

‘The Launch Abort System is scheduled to be the first element of the integrated Orion/Ares I stack to test, and we’ll be the first to fly,’ added Gaddis.

During evaluations, NASA engineers looked at three LAS systems, namely the Multiple External (x4) Service Module (SM) Abort Motor concept, the Crew Module Strap On Motors (x4) concept, and the In-Line Tandem Tractor (Tower) concept – which was baselined into Ares I/Orion design.

The system, once tested and certified, is expected to be the template for all future NASA exploration launches, which could see the system being until the 2030s.

‘I’m confident the Launch Abort System will have a long-term impact on NASA’s exploration mission,’ added Daniel Schumacher, manager of the Exploration Flight Projects Office at MSFC. ‘We’re continuing to develop one of Marshall’s core competencies – development of advanced solid rocket motors – that will support our exploration activities over the next 20 years.

‘The Launch Abort System development effort is critical to the overall Constellation Program, and it’s a privilege to work on it.’

L2 Resources For Ares I, V and Constellation:
DAC-1C Departure points to DAC-2 Upper Stage Graphcs (Many Changes). Orion/CEV Display Layout Presentation (40 pages) – Feb 5. ATK figures on the 5-Seg Booster weight for CLV – Feb 2. Weather Shield (Rain Shield) for Orion on the pad – Feb 1. New Super hi-res images of Ares I – Feb 1. ATK Cutaway graphics of Ares I – perspective and axonometric – Feb 1. Ares I/Orion CxP 72031 Requirements Validation Matrix Information. CEV Paracute Assembly System (CPAS) Presentation.

Orion Launch Abort System (LAS) overview presentation – Jan 16. Major changes to Ares I Upper Stage – expansive details and data. Ares I/Orion CxP 72031 Requirements Validation Matrix Information. Saturn Twang Test Video for use with Ares I-1R. CLV Umbilical Trade Matrix XLS.

Vehicle interfaces for the DAC 1C version of Orion Ares – Jan 3. Ares I-1R Test Flight Plan (full outline) Presentation. Ares I-1 timeline and modification expanded info. Ares I troubleshooting latest. Ares I Reference Trajectory. Boeing’s STS to Ares – Lessons Learned Presentation. Latest Ares I and Ares V baseline Configuration image and data. CLV DAC-1C (Changes to CLV Upper Stage).

Ares I-1: Four Seg+Dummy ‘Tuna Can’ stage. Ascent Developmental Flight Test Presentation. CLV Pad 39B Handover Info and Latest. New images of CLV on top of new MLP and LUT. Lockheed Martin CEV/Orion Updates. Constellation news updates. ATK figures on the 5-Seg Booster weight for CLV.

90 Minute Video of Constellation all hands meeting. CLV TIM Meeting Information. CLV/CaLV Infrastructure, Timelines and Information. Escape System Trade Study Presentation.

CEV-CLV Design Analysis Cycle Review (DAC-2) Presentation. Constellation SRR updates. CLV Stick – Troubleshooting/Alternatives/Updates. New CEV Images (include abort mode). Flight Design and Dynamics Division CEV update. CLV Mono-propellant RCS system. CEV pressurisation system review. CLV/CEV Configuration Images. The 2×3 Seg SRB Crew Launch Vehicle Option Presentation…plus more.

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