J-2X Firing:

There will be two major roles for SLS, one is to launch cargo and one to launch the Orion (MPCV) on Beyond Earth Orbit (BEO) missions.

The core stage is an 8.4m diameter “External Tank” heritage system, with the top converted to host the Upper Stage structure, and the aft restructured to house the Main Propulsion System (MPS) – which will drive what will initially be three – or four, based on ongoing trades – Space Shuttle Main Engines (RS-25Ds), before existing stocks are exhausted, allowing for the transition to the expendable version of the SSME, known as the RS-25E.

The core will also support two boosters, initially hosting two five segment Solid Rocket Boosters (SRBs) from ATK, with an industry competition determining the the long term design, which may result in a transition to liquid (RP-1) based boosters.

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The vehicle will initially be able to fly without the Upper Stage, and in some cases would fly with a smaller replacement in the form of a Delta IV “Kick Start” Upper Stage system.

For the massive 130mt, fully evolved, Block II SLS – which will be a natural advancement on the opening Block I and Block IA configurations – an extra 80 feet in length will provide room for the main Upper Stage, which will – as currently baselined – utilize three J-2Xs as the Earth Departure Stage (EDS).

Development of the engines – which Wednesday’s test is a major part of – and the Upper Stage stage hardware will continue alongside the SLS work, prior to being held back until the Block II is ready to fly. As NASA documentation (L2) noted: “Complete J-2X and put ‘on the shelf’ for later use with SLS Block II. Move Integrated Stack avionics to this stage. This Upper Stage burns out prior to orbit insertion (ala Saturn V).”

The J-2X engine is being developed for the Marshall Space Flight Center (MSFC) SLS Program by Pratt & Whitney Rocketdyne of Canoga Park, California – who are also the manufacturer for the RS-25s.

Initially starting life for a role as a single engine on the Ares I Upper Stage, work began on the engine in 2006, based on engineering which reached back as far as the 1960s with the original J-2 engine – five of which powered the SII Second Stage of the Saturn V.

This latest variant is capable of generating 294,000 lbf (1,310 kN) of thrust, and is being tested at the new A2 test stand at Stennis Space Center. Testing began with P&W Rocketdyne successfully evaluating the initial J-2X gas generator design in 2008, followed by the completion of a second round of successful gas generator tests in 2010.

On June 11, the J-2X Development Engine E10001 was lifted into position using the Vertical Engine Installer (VEI) and successfully installed into the A-2 test stand at Stennis Space Center. This installation followed a close call that occurred on June 1, when the extended hydraulic cylinder on the VEI retracted unexpectedly, causing a sudden one-foot descent of the engine and its VEI mounting plate.

After the hardware was checked, a July 14 “burp” test – as it was called – of engine E10001 briefly produced 30,000 pounds of thrust, during a combined chill test and 1.9-second ignition test.

The second test firing of J-2X development engine E10001 occurred on July 26. The planned duration of the firing was to be seven seconds. However, the test was shutdown after 3.72 seconds due to a high pressure measurements in the main combustion chamber.

On August 17, the J-2X team conducted test A2J005. The test was terminated early (32.2 seconds of a planned 50-second run) for high thrust because the gas generator oxidizer orifice discharge coefficient was slightly larger than predicted. Valuable thrust balance data was obtained which allowed the team to make the necessary modifications. However, the outcome was a decision to remove the engine from the test stand.

“The decision was made by the J2X Project to pull engine 10001 from the test stand at Stennis Space Center after the engine hotfire on August 17th due to cracks noted in the Main Oxidizer Valve (MOV) seal in several places,” noted an update from the L2 J-2X Status Updates.

“There was also a piece of seal estimated at 0.75” to 1” long that was missing. Additional borescope inspections revealed a single piece of FOD (Foreign Object Debris) inside the ball shaft. MOV and MOV actuator removal is now complete.  Failure investigation and anomaly resolution continues.”

With a new MOV assembled and acceptance tested, the J-2X engine was returned to the A-2 test stand, ahead of another hot-fire test on September 28, which conducted the pre-planned 40 second firing.

On October 25, a full 500 second test was planned, known as Hotfire Test 7. However, this test was halted after 140 seconds into the firing.

“The test, scheduled for 500 seconds duration, was prematurely stopped at 140 seconds due to a TCON (test controller) redline limit violation. Initial investigation indicated that the early termination was caused by a pump discharge pressure redline violation,” added the J-2X Updates. 

“Additional evaluation revealed that the minimum redline limit, which was activated specifically for this test at engine start plus 140 seconds to guard against pump cavitations, was inadvertently set in the TCON software as a maximum (instead of a minimum).  No hardware damage was noted.  Preliminary results indicate that the primary objectives (i.e. flow meter and engine calibration at mainstage power level) of the test were achieved.

“A corrective action team has been formed and will work to determine root cause and corrective action prior to the next hotfire that is tentatively scheduled for November 9th.”

Once again, the experienced teams of Stennis showed their value, successfully working the data in readiness for Wednesday’s live firing, which lasted for the full duration of 499.7 seconds, followed by managers noting the quick look data appears to be good.

“The J-2X engine team and the SLS program as a whole are extremely happy that we accomplished a good, safe and successful test today,” said Mike Kynard, Space Launch System Engines Element Manager at MSFC. “This engine test firing gives us critical data to move forward in the engine’s development.”

“The J-2X engine is critical to the development of the Space Launch System,” added Dan Dumbacher, NASA’s deputy associate administrator for exploration systems development, said after the test at NASA’s Stennis Space Center in Mississippi. “Today’s test means NASA is moving closer to developing the rocket it needs if humans are to explore beyond low-Earth orbit.”

E10001 is one of five development engines, which will provide the data for two certification engines, prior to the move to actual flight engines which will ride with SLS. Managers noted that – for this class of engine – this is the least number of units used to test and develop towards the flight-ready engine.

“Today we made smoke and fire with a rocket engine yet again. The Stennis Space Center in Mississippi, long the front line in testing NASA’s propulsion systems from the Apollo to the shuttle era, is now helping us understand the J-2X engine. The J-2X will power the upper stage of our new Space Launch System (SLS), which will carry the Orion spacecraft, its crew, cargo, equipment and science experiments beyond Earth orbit,” added NASA Administrator Charlie Bolden.

“Today’s engine test fire -  at nearly 500 seconds, the longest one to date – is one in a series of tests that will provide critical data to help fine tune the engine to maximize performance and provide the SLS with the capability to take humans to new destinations. And it’s not the only activity that NASA has going on around the nation as we open the next great chapter of space exploration.”

(Images: Via L2 content, driven by L2′s new SLS specific L2 section, which includes, presentations, videos, graphics and internal updates on the SLS and HLV, available on no other site. Other images via NASA TV and PWR.)

(L2 is – as it has been for the past several years – providing full exclusive SLS coverage, available no where else on the internet. To join L2, click here: http://www.nasaspaceflight.com/l2/)

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SLS Studies:

Months – if not years – of studies and reviews have surrounded the selection of NASA’s new Heavy Lift Launch Vehicle (HLV), only for the aforementioned studies to consistently provide a “winning configuration” known as the Shuttle Derived (SD) Heavy Lift Launch Vehicle (HLV).

While the very nature of a SD HLV being the “best choice” for NASA is a point of conjecture in numerous arenas, the studies never led to any firm decisions being taken at the NASA leadership, or more importantly at the political level.

With the President’s FY2011 budget proposal proving to be highly unpopular, the Senate’s Authorization Act changed NASA’s course and put its weight behind a Space Launch System (SLS) which utilized both Constellation (Ares) and Shuttle hardware.

This Act was based on consultations between lawmakers, space industry heads and NASA managers on the best approach for both supporting the International Space Station (ISS) in the second half of this decade, prior to evolving into the required HLV for Beyond Earth Orbit (BEO) missions.

However, the Act’s requirements appeared to be met by a level of disapproval from NASA leadership, as yet more studies were ordered, resulting in the Marshall Space Flight Center (MSFC) led review of potential launch vehicle configurations via three RAC (Requirements Analysis Cycle) teams.

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As the RAC studies were continuing, a preliminary report into the SLS from NASA also highlighted budget and schedule concerns – much to the surprise of some RAC team members – although the report was embedded with caveats in finalizing their costings and evaluations on its own claims.

Internal Program-level Frustrations:

A final report to lawmakers is now well overdue, leading to frustrations surfacing from within NASA at even the management level. One of the more impassioned speeches came from Launch Director Mike Leinbach, who addressed his Firing Room workforce after the S0044 Launch Countdown Sim was completed.

Paraphrased highlights from the speech quickly became the subject of high praise from those who had worked the sim. However, a recording of what was actually said has since been acquired by this site, after the audio file spread throughout several NASA centers – again gaining nothing but praise for the highly respected manager - as it provided one of what is believed to be many examples of frustration from within NASA.

“For the final S0044 folks, what I’m about to say would not be appropriate on launch day, and this is our last chance to talk together,” noted Mr Leinbach over the recorded Launch Director loop (transcribed from an audio recording via L2).

“The end of the shuttle program is a tough thing to swallow and we’re all victims of poor policy out of Washington D.C., both at the NASA level and the executive branch of the government and it affects all of us – it affects most of you – severely.

“I’m embarrassed that we don’t have better guidance out of Washington DC. Throughout the history of the manned space flight program we’ve always had another program to transition into – from Mercury to Gemini, and to Apollo to the Apollo-Soyuz test program, to Skylab and then to the shuttle – we’ve always had something to transition into.

“And we had that, and it got cancelled and now we don’t have anything, and I’m embarrassed that we don’t. Frankly, as a senior NASA manager, I’d like to apologize to you all that we don’t have that – so there you are. I love you all, I wish you all the best.

“We will press on through this flow and this launch in the way we always do. We’re going to play this game to the final out and then we’ll be done. I just wish you all the best, and again Godspeed to you all. Thank you.”

As the loop was opened, rapturous applause could be heard ringing around the Firing Room.

SLS Decision:

However, a follow-on vehicle is close to being officially announced, following an increased amount of activity at the executive level this week, resulting in a top level meeting between the SLS leadership and NASA administrator Charlie Bolden, which finally picked the configuration.

“SLS and GO briefed Bolden on a proposed SLS architecture with the following decisions made (finally),” noted one memo (L2). “8.4m core and Upper stage. RS-25s (Space Shuttle Main Engines) on core stage. J-2X on Upper Stage. 4 or 5 segment solid boosters for initial flights.”

While the boosters are highly likely to be five segment motors, the “initially” reference was explained, noting the evolved BEO SLS is yet to know if it will ride with SRBs or Liquid boosters.

“Competed boosters for evolved vehicle (between solid boosters and LOX/RP-1 (Kerolox) boosters),” added the memo. “RFP (Request For Proposals) to be quickly developed to provide data on competed boosters.”

However, ATK have been quick off the mark in informing NASA’s leadership they are ready to support, not just with the initial SLS, but also into the future, via the 130mt class vehicle.

According to source information, the Utah-based company – and home of the RSRM (Reusable Solid Rocket Motor) – have proposed a Firm Fixed Price (FFP) contract for 10 boosters, available between 2012-2015, whilst noting available assets that can support up to 11 SLS missions prior to asset depletion in 2020.

This is notable, given ATK are proposing the initial use of boosters in their expendable mode, thus eliminating several hundred million dollars worth of recovery and refurbishment costs. Sources also add that ATK’s approach from a “cost and schedule” standpoint has been highly impressive.

As far as ATK’s approach for the fully evolved SLS vehicle, source notes claim a future static test could be provided as a pathfinder test for an upgraded booster.

Such an upgraded booster may include recently proposed change to a HTPB (Hydroxyl-terminated polybutadiene) fueled solid in “composite over wrapped steel cases” thus allowing higher MEOP (Maximum Expected Operating Pressure) – to as much as 1500 psi.

As previously reported, there are also proposals to use lighter weight nozzles with expansion ratios up to 12:1, although such a large scale change would require study at least at a Ground Support Equipment (GSE) level, given its relation to Launch Platform design.

KSC information has also noted that preliminary assessments will be used to find a use for the Ares I Mobile Launcher (ML), currently sat near the Vehicle Assembly Building (VAB) with no future role to play, following the cancellation of the Constellation Program (CxP) and thus its main customer, the Ares I.

Presentations on the 21st Century Launch Complex proposals (L2) – a stunning set of documents which include the “Point Of Departure” Architecture overviews (and will be the focus of upcoming articles) – also mirror the comments which point to the SLS joining forces with the Ares ML, as much evaluations are continuing into a need for the ML to play a role until the evolved SLS.

“Allocate ML for SLS. Modifications to support SLS architectures, with scarring for extensibility. Incorporate standardized interfaces, using mobile launcher to adapt to  vehicle requirement,” noted the Architectures Refinement Cycle 5.0 section of the latest presentation (in June) via L2.

It is also understood that Boeing will be the main contractor for the SLS vehicle, likely explaining their work at the Michoud Assembly Facility (MAF) on a small scale strongback core, as much as it is likely the first SLS test flight will utilize the stored Light Weight Tank (LWT) ET-94.

The role of Pratt & Whitney Rocketdyne (PWR) appears to be secure for at least the opening gambit of the SLS growth towards its 2016 IOC (Initial Operating Capability), with 12 RS-25Ds available for one-off roles with SLS flights, following their transition from the Space Shuttle Program (SSP).

It is not yet known if a transition to the expendable RS-25E will be made after the four sets of RS-25Ds have been used.

After being the long lead item for Ares I, the Upper Stage J-2X is continuing to make progress, after recently becoming housed in the A-2 Test Stand at the Stennis Space Center (SSC). Beginning in mid-June, the engine will undergo a series of 10 test firings that will last several months.

“An upper stage engine is essential to making space exploration outside low-Earth orbit a reality,” said Mike Kynard, manager of the J-2X upper stage engine project at NASA’s MSFC in a recent public statement.

“The J-2X goes beyond the limits of its historic predecessor and achieves higher thrust, performance, and reliability than the J2. We are thrilled to have the engine in the test stand to validate our assumptions about engine performance and reliability.”

It’s role with the SLS was one of the initial key requirements ordered by General Bolden, after he rejected the two-phase SLS approach.

(The progress on the SLS status will continue to be followed up over the coming weeks. L2 members, follow our exclusive SLS update coverage via the SLS and HLV tags. Images used:  Via L2 content and NASA.gov – plus Mr Leinbach photo via Brian Papke, MaxQ Entertainment/NASASpaceflight.com).

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Constellation Turmoil:

Constellation’s schedules have been slipping at an alarming rate over the past few years, with the last PMR (Program Milestone Review) confirming a 12 month slip in the IOC (Initial Operational Capability) to March, 2015. This date relates to Orion 2, with Orion 4 – currently classed as the first crew rotation for the International Space Station (ISS), otherwise known as FOC (Full Operational Capability) – launching one year later in March, 2016.

While these dates continue to be the official timeline, internal reviews have found those schedules to be “broken”, with CxP departments across the program reporting they are at “zero percent confidence” for keeping to the March, 2015 (IOC) timeline.

While continued changes to the designs of Ares and Orion are part of the natural development cycle, issues such as Thrust Oscillation and vehicle performance have come at a price for both schedule and costings, despite fine work from the engineering teams tasked with mitigating the issues.

CxP attempted to protect the schedule and budgetary pressures by offsetting these additional strains by deleting test items – notably on the Upper Stage. However, this only proved to cause further disconnects throughout the program.

Issues with the Ares I Upper Stage engine, J-2X, have also been noted, although no specific information has been made available due to the classified nature of certain vehicle elements.

“Disconnects” have been previously noted on various stages of the vehicle, such as with a key Launch Abort System (LAS) test, cancelled with just 24 hours notice due to additional testing requirements being cited by the Orion program, adding months to the realigned test schedule, which in turn added further strain to the already heavily-delayed Orion PDR (Preliminary Design Review).

Orion contractor Lockheed Martin were already complaining last year about continued changes to the requirements of vehicle, which is likely to undergo another major change during the upcoming summit meeting, after it was noted the switch from a crew of six to four will be a lead item for discussion.

Several vehicle systems have been progressing through their development cycle to plan, but have subsequently suffered via waiting for related systems to catch up due to technical challenges, or return to a steady funding cycle, in turn causing a schedule mismatch “ripple effect” through the master timeline.

The summit will attempt to realign all the individual schedules, find potential funding ‘get-wells’, and create a viable timeline to try and bring Ares and Orion back into the March 2015 IOC target. However, confidence this can be achieved without a major boost to Constellation funding is classed as low.

Gap Reduction:

The serious nature of the “broken” schedules have been known for a few months, with an immediate slip of six months added internally to the master schedule, during a period when CxP were evaluating acceleration options. This occurred prior to the latest estimate of a slip of between 12 to 18 months – in total – on top of the current schedule.

Those acceleration options have since fallen by the wayside, with the worst case cost estimate coming in at around $7 billion just to bring the program back to the 2007 tatget of a 2014 launch of Orion 2. The priority now is to attempt to find a “magic solution” of bringing Ares/Orion in with a shot of making the March, 2015 IOC date. Avoiding further slips to the right is the goal, as opposed to acceleration of the schedule.

The situation with Ares is known in key areas of the Agency, with a “9th Floor” NASA HQ effort already taking place to evaluate the viability of cancelling Ares I, and replacing the launch vehicle with an EELV (Evolved Expendable Launch Vehicle) – such as an Atlas V Heavy or a Delta IV Heavy – whilst moving the Marshall Space Flight Center (MSFC) effort towards concentrating on Ares V.

NASA managers have alternative options, including COTS-D, which would initiate SpaceX into bringing their Dragon manned vehicle on line as a bufferzone during the gap. However, while NASA are supportive of SpaceX’s efforts, sources claim it would take a major leap of faith to hand the task of buffering the gap to such a ‘new’ space flight company.

Shuttle Extension:

Building up a head of steam is shuttle extension, with wide-scale support at both the program and political level. Initially curtailed by former NASA administrator Mike Griffin – who was firmly in the Ares camp – the strongest wording in favour of extension, at a program level, was seen this week on the Shuttle Stand-Up/Integration report, on L2.

“Last week, around 200 prime contractors and suppliers went to Washington D.C. and got briefs from the Hill and key NASA people,” noted the report. “They went over to the Hill and talked to over 100 Congress representatives or their staffers.

“The message was that the Shuttle is operating well and is safe to fly.”

That “message” directly counters Mr Griffin’s efforts to warn against extending the shuttle, after citing safety numbers that intimated a disaster was on the cards if the vehicles flew past 2010. It also makes the point the shuttle is an operating vehicle, whereas the alternatives remain out of sight.

The report goes on to note the need to avoid CxP from falling yet further behind its originally schedule – whereas previous statements have alluded to the possibility of acceleration – which is no longer viable without additional billions being pumped into the program, potentially the same amount it would take to extend the shuttle by two years.

“To close the gap it would be necessary to hold the funding to make sure the CxP does not move any further to the right, and to add additional funding if Congress deems it necessary to fly into 2011 and 2012,” added the report. “It was well received but these are tough budget times.”

There are conflicting numbers on how much it would cost to extend the shuttle program, with various options available. Most of the options opt for two orbiters flying though the extension, with one grounded as a ‘near flight ready’ orbiter that can supply spares to her two sisters.

Program milestone charts acquired just this week by L2 confirm that the Michoud Assembly Facility (MAF) ‘additional’ tanks have been set up the purpose of pre-empting extension, with opening work completed on at least two brand new tanks past the yet-to-be-approved STS-134.

A refurbished ET-122 is also available for STS-135 – currently the Launch On Need (LON) tank for STS-134.

Should extension receive the required funding, MAF would be able to build new tanks, as all the shuttle related tooling has been protected via the outlines in the recent Senate Bill. However, a decision will need to be made soon, with layoffs of key skill set workers already taking place in New Orleans, and a systematic shutdown of shuttle related contractors soon to head past the point of no return.

The end of April has been deemed as D-Day for the shuttle program’s potential to extend. However, the in-built protection from the Senate Bill is understood to have gained enough time for the cut-off to be as late as the summer.

A lot will depend on what the next NASA administrator prefers, and more so the political will to find the best solution to ensure the United States does not suffer from a lack of domestic manned launch capability for over half a decade.

L2 members: Documentation – from which the above article has quoted snippets – is available in full in the related L2 sections, now over 4000 gbs in size.

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