Constellation battle numerous Top Risks – Orion loses unmanned capability
The Orion Crew Exploration Vehicle (CEV) is undergoing further reductions in its capability – including the elimination of the vehicle’s unmanned ability – as Constellation managers attempt to resolve numerous issues ahead of the Orion Project PDR (Preliminary Design Review). Issues noted in the recent “Top Risks” review list 10 serious issues with the Ares and Orion vehicles, ranging from Ares I-X, through to Orion itself.
A large amount of uncertainty surrounds the future of the Ares I Crew Launch Vehicle, uncertainty that even led to the high ranking MOD (Mission Operations Directorate) director, Paul Hill, to speak only of his confidence that there will at least be a “follow on program” – whatever that may be – after shuttle is retired, during the end of June All Hands address to MOD staff. (Article to be published in the coming days).
However, it is unlikely any fallout from the Augustine Commission – which Mr Hill was referencing – will result in the Ares I-X test flight being cancelled, as the four segment test vehicle attempts to keep to its mid-September launch date.
See all of NASASpaceflight.com’s Constellation related articles:
Ares I-X Processing Latest:
Although public schedules continue to class Ares I-X as launching at the end of August, internal manifests show Ares I-X as launching NET (No Earlier Than) September 18, with threats of day-to-day slips based on processing milestones.
“Accomplishments include the transfer of the Aft Skirt to Rotational Processing Surge Facility (RPSF) and the Forward Assembly to the VAB (Vehicle Assembly Building), the completion of the Forward Assembly Review, and the mating of the Aft Skirt to Aft Motor Segment,” noted an 8th Floor (MOD) overview of status (L2).
However, the opening stacking operations on the handed-over Mobile Launch Platform (MLP) – one of the key processing milestones – have been delayed by over a week, due to what appeared to be issues repairing a broken crane that is being tasked with transferring the assembled Aft Booster for its stacking in the VAB. While that is related, tests on the stack’s “integrity” are being called as per mate review for I-X.
“Ares I-X (VAB HB-3/4) (RPSF) (Pad-B): Aft Booster transfer to pallet on hold for crane repair. Transfer to VAB and stacking moved to next Wednesday, July 8th,” noted the latest daily processing flow information (L2).
Based on the realigned flow timeline, Monday will involve work in High Bay 3, relating to MLP Flame trench closeouts. Over in High Bay 4, the forward assembly will be prepared for 5SS Lift/Mate operations, ahead of Aft Booster stacking on Wednesday.
So far, no alteration to the launch date has been noted on the internal milestones, though it may be expected – due to the tight flow ahead of rollout to Pad 39B, scheduled for just three days ahead of launch.
“AB Camera & Bracket Installations/DFI (Development Flight Instrumentation) Cable Bracket Installation complete-to-date. Remaining work will be completed in the VAB,” added other processing notes.
“VAB HB-4 (High Bay 4): Interstage/Forward Assembly match drilling complete. Stack-1 Modal testing setups are in work. Re-pining pressure transducers in work. US-7 Harness and connector mates continue.
“VAB HB-3: HDP alignment optics in work. Stacking preps continue. No Weekend/Holiday work planned.”
Ares I-X Major Risks:
As noted on the June 22, 09 “Top Risks” review notes, acquired by L2, Ares I-X has four major issues – one of which relates to the continually slipping launch date, and three related to technical issues. Levels of ‘risk’ range from the smallest on the 25 box risk matrix, noted as 1×1 (GREEN), to the highest, seen as 5×5 (RED) – which list the ‘Likelihood’ the issue would occur x severity of ‘Consequence’ such an issue would have on the vehicle.
Interestingly, Thrust Oscillation (TO), even on the Ares I-X four segment – as opposed to the well know issues with the Ares I five segment – first stage dominates Ares I-X’s Top Risks findings.
This is despite warnings from the Ares I-X Chief Engineer over a year ago – as reported by this site – that TO and vibro-acoustic effects on the vehicle’s Flight Termination System (FTS) required mitigation.
“Requirement: FTS Range frequency – using current Air Force waiver. FTS Components environments exceeded at T+110 seconds – end of burn (Thrust Oscillation condition),” wrote the Chief Engineer on his expansive presentation (available on L2) to the Ares I-X System Critical Design Review (CDR) Phase II meeting in June, 2008.
Yet on the June 22, 2009 “Top Risk” review, “Thrust Oscillation and its affects on the Flight Termination System (Range Safety),” is classed as a 4×5 risk, showing it’s actually increased as a concern.
That increase is related to the time of ascent where TO’s effects on the vehicle’s FTS exceeds rated vibrational input levels, now deemed as starting around T+70 seconds – not T+110 seconds – into flight.
This in turn has placed pressure on obtaining the required Air Force waiver for the range, without which, Ares I-X would not be allowed to launch.
Another waiver will be required on the second “Top Risk” – related to Thrust Oscillation effects on the first stage TVC (Thrust Vector Control) electronics, used to gimble the solid rocket motor’s nozzle during steering commands. This risk, which is listed as 3×5, makes its debut on the Top Risk list.
However, a waiver on this issue is understood to be less of a problem to acquire, due to the knowledge of the “stock shuttle legacy SRB TVC system”, which Ares I-X will be using.
The biggest risk, a 5×5 risk, relates to the “vibro-acoustic environment input to Upper Stage Simulator (USS) exceeding structural margins.”
Very little is noted on this problem, although a recommendation that the USS should receive additional bracing to carry the higher than anticipated loads is noted as an avenue of mitigation. It is not known if that work has already been added to Ares I-X’s processing flow, although no reference has been made on the daily processing notes.
Ares I-Y Status Update:
The second test flight for Ares – prior to the ‘full up’ Ares I unmanned test flight in 2014 – remains in flux, as managers discuss either the deletion of Ares I-Y, or changes to the vehicle’s configuration and test requirements.
Ares I-Y’s future is embedded into the drive to solve “schedule disconnect” issues that were raised at the start of this year’s PMR (Program Milestone Review or Program Manager’s Recommend) cycle, which showed threats to the entire Constellation schedule, and the possibility that the gap between shuttle retirement and Orion’s FOC (Full Operational Capability) debut on Orion 4 (ISS crew rotation) could be as large as seven years.
With such a gap deemed as unacceptable by Constellation management, Ares I manager Jeff Hanley built his own point-by-point plan to return the schedule back into the March, 2015 IOC (Initial Operating Capability – or Orion 2) timeframe.
Mr Hanley’s plans included the deletion of the Ares I-Y test flight – which has now slipped to 2014 – to be possibly replaced by an Ares I-X hybrid known as Ares I-X Prime, capable of carrying out high abort testing earlier in the Constellation schedule.
These plans remain under discussion, with the latest information – noted on the latest MOD 8th Floor News – pointing towards evaluations into flying a reconfigured Ares I-Y vehicle, earlier in the schedule. However, as per evaluation notes, advancing this stage of testing may not be possible.
“Ares I-Y flight definition: The Ares Project presented their assessment to determine the earliest possible date to fly I-Y as a powered second stage configuration,” noted the 8th Floor memo (L2).
“The earliest available Upper Stage is June 2014 (3 month slip to current I-Y date), this is driven by facilities. The earliest available J-2X engine is February 2013 for upper stage integration, this does not support Upper Stage need dates or all testing.
“Currently Ares I-Y is scheduled for March 2014 with no powered second stage. Many believe that the program needs to demonstrate two unmanned flights prior to the first manned flight, today’s manifest has only one.
“The board decided not to change the manifest at this time, but a detailed CR (Change Request) with all the proposed changes, including Orion and Ground Operations impacts and test needs, will come to the board in October.”
Ares I itself has three top risks, with First Stage nose first re-entry, now classed as a 4×4 risk and increasing. Range Safety System certification is classed as a 4×5 risk and increasing, while TVC certification is now a noted as a 3×5 risk.
Interestingly, Thrust Oscillation is not listed for Ares I.
Orion Status Update:
Orion is likely to survive any fallout from potential changes to the forward plan for NASA’s return to the moon. However, the manned vehicle is suffering from its own technical challenges, in part due to the continued stripping of its capabilities based on mass growth versus Ares I performance.
Ares I can launch the ISS version of Orion, thanks to a series of mass stripping exercises – notably the ZBV (Zero Based Vehicle) effort. However, the Lunar Orion’s mass properties – again based on Ares I’s performance capability – is a major challenge, seeing its “score card” mass properties between Orion 606-E (December 2008) and Orion 606-G (May 2009) grow into a RED risk for the program.
Solutions will need to be sought throughout all of the major components on Orion; with the LAS (Launch Abort System), CM (Crew Module), SM (Service Module) and Jettisoned Spacecraft Adapter (SAJ) all trending up in mass – which includes the breaching of the “managers reserves”, set aside for mass growth margins.
Orion is also suffering from problems with its electric power generation and storage margins, which is threatening a redesign of the vehicle’s Solar Arrays/Panels.
According to documentation, the required margins on the ability for the solar panels to generate enough power for storage in the vehicle’s batteries – for use during the Lunar Orion’s flight out of sunlight – is short by 22 percent.
The solutions to this problem would require either an increase in the size of Orion’s solar wings and/or additional battery storage capacity – with both options adding yet more mass to the vehicle. The ISS Orion’s electric power generation and storage margins are understood to be within requirements.
Engineering challenges with new flight hardware are commonplace, yet solutions to those problems should also be expected, thanks to the talented engineering workforce Constellation has at its disposal. In Orion’s case, NASA and Lockheed Martin engineers have been meeting at Lockheed’s Denver base to aid that mitigation process.
“Many MOD personnel have been in Denver the last two weeks supporting the Orion Project Subsystem Design Review (SSDR). The purpose of the design review is to resolve issues and close details on the subsystems prior to the Orion Project PDR, which is scheduled for August this year, followed by a software review in November,” noted the 8th Floor.
“MOD folks are heavily engaged at the subsystem level and are providing valuable input to the project. The coordination and integration of the MOD review has been lead by our CEV Operations Manager.”
As previously reported, Orion’s crew capability has been reduced from carrying six crewmembers to four – with the possibility of adding six person crews after Orion’s design has matured. This drive is part of Mr Hanley’s suggestions for finding get-wells in the vehicle’s development cycle by simplifying the “Apollo on Steroids” spacecraft with the aim to increase margin in the overall schedule.
However, Constellation’s management are taking the crew reduction a stage further, by changing Orion’s capability from 0-6 crew (unmanned capability) to 2-4 crew – with a contingency of no less than one crewmember being able to fly the vehicle. Such a change eliminates Orion’s ability to fly unmanned, which could have been utilized in a number of scenarios.
“Orion Crew Size Requirement: There were a couple of key topics of interest to MOD this week at the CxCB (Constellation Control Board),” noted a memo outlining discussions (L2). “First, a change to the requirements for Orion to be capable to fly 0-6 crew to 2-4 crew.
“Four is the requirement for Lunar and flights to ISS do not require 6, thus reducing the maximum crew by 2 will simplify design and build margin in the schedule.”
Orion will be designed with the intent that two crew members will fly the vehicle, but can be operational if only one crew member is available during a contingency event.
“There was a concern raised that unless 1 crew (one person) is specified, the design will not be driven to make it actually operational by 1 crew,” added the CxCB memo.
“The Orion Project interpreted the 1 crew requirement to be only contingency, with the focus being on 1 crew being able to control the vehicle and to ingress and egress (hatch operation).
“The board decision was that the intent is to get one crew back safely, not provide a nominal one crew capability. The design will be for 2-4, with 1 crew contingency. An action given to rewrite the single crew requirement to clearly reflect the intent vs. leaving the contingency words it in the rationale.”
It is not clarified in the CxCB notes as to whether the loss of unmanned capability relates to both ISS and Lunar Orion’s full mission capability, such as Lunar landings – which currently involve Orion being left unmanned on orbit. If that specific capability is lost, only two crewmembers would be able to undock with Altair and land on the lunar surface, while two crewmembers stay with Orion.
Such a loss of capability is unlikely, due to the massive impact such a decision would have on moon missions. Sources also claim an autonomous capability is likely to remain for leaving Orion in a Lunar orbit, and that the change relates to eliminating Orion’s ability to return to Earth without the aid of the crew.
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.