Accident Report, Fatality

[GarrisonChisholm]

Above, the Quartermaster 4-bal Capsule, extended range 'High' resource pod off-set in image.

Being an accident report discussing the loss of Bob Kerman, Scientist, and 3 TOURIST (Transient Objective University Researching Interdisciplinary ScientisT) kerbalnauts on High Quarterlander 2, what would have been the 4th kerballed landing on Minmus.

Background, Equipment.

The Quartermaster 4-Person Capsule had been flown 5 times previously, three times balled, and had proven quite capable of safely conducting its crew's passage on missions lasting up to 79 days, though never flown past ~ 30.  It was constructed early in the space-program so-as to possess a multi-kerbal capsule capability that was stable and safe for hands-free re-entry.  The vessel can return from Minmus with a direct-entry periapsis of 20km, though typically the Kerbin return orbit is circularized to spare the crew unnecessary stresses.  The Agency had suffered no notable failures, and was actively working through a small handful of minor issues to perfect the design.

The Flight.

Launch was nominal if low, though orbit was achieved at ~79k/km with no undue concern.  On service-fairing deployment however it was observed that a fairing panel became hung up on one of the service module's 4 landing 'piers', and while it soon broke free it took away 2 of the 4 deployable solar panels.  On panel deployment, it was found that the 2 adjacent panels adequately powered the vessel as well as covering complimentary azimuths, so no mission threat was observed.

The crew then endured a ~ 5 day stay in orbit while they waited for their injection window to Minmus.  As the 3 crewed flights previously, orbit was maintained with no warnings or concerns.  On day 3 of the mission however during a routine arming and power check it was found that one of the 4 Ant reentry engines was unresponsive, and after troubleshooting Mission Control declared it dead for future mission use.  Should the re-entry engines be needed, the opposite engine to the fail would be simply deactivated, and so no mission threat was observed.

When the transfer injection window opened a particularly precise burn was achieved, with an acceptable 179k Minmus periapsis found with 14 days of transit.  The crew settled into normal transit routine.

Approximately 2 hours later the capsule reported that power was dangerously low and life support had been disabled.  Mission Control looked into the matter and found that the solar panels had positive sun angle and the batteries were charging, and so advised the crew to disable their alarms and expect the batteries to be fully charged in less than an hour.  Orbital geometry saw no reason for this power loss-  it was well beyond Kerbin's shadow, and Mun was on the opposite side of the planet.

Approximately 3 days later the crew reported lightheadedness.  Upon investigation it was found that there was a CO2 level of 98%.  All scrubbers were running and functional, and were observed to be actively lowering the CO2 levels.  No action was taken by Crew or Control to re-activate the systems, they appeared to be functioning when observed.  Little could be done, and the crew asphyxiated before the atmosphere could be returned to safe levels.  The mission was scrubbed, and the capsule safely returned to Kerbin for recovery of the remains.

Analysis.

The craft had weathered many orbital shadow periods during her wait with no battery warnings, and the primary solar panel arrays were correctly aligned for use, in addition to the fact that the undamaged secondary capsule panels were deployed normally.  The burn for Minmus was conducted on the night side of Kerbin, so the batteries before engine ignition were in Discharge.  On engine ignition, the alternators began charging the batteries.  During the 150 second burn the batteries should have been topped off at 2200 units.

Control supposes that the alternator flow triggered a fault in the computer subsystems, such that the battery regulator was stuck looking for charge from the alternator, thus not charging once the engine burn concluded and the craft was in solar lux.  The batteries then drained, and the energy crisis began.

Control's conclusion that with the restoration of solar charging all would be corrected resulted in poor instructions being given to the crew and the dire situation developing in the capsule overlooked until remedy was not possible-  though it is questionable there was any remedy at all.  The scrubbers were working when examined, and seen to be lowering CO2.

Procedure Updates & Resolutions.

1)   The Capsule should have a Manual Purge feature, to flush the atmosphere in the cabin and allow complete replacement by on-board O2.  EVEN by EVA the atmosphere cannot be vented, thanks to the high degree of fail-safe engineering in the auto-airlock doors.  Had the craft had this feature, the crew would have survived.

2)   Additional solar panels should be installed and the fairing separation issues corrected, or the soon-to-be developed RTG units should be installed in every crewed vessel to prevent this loss again.

3)   A Kerbin orbital test of all ship systems should be conducted, attempting to reproduce failure modes observed, before the craft is again used beyond LKO.

4)   While a timely EVA by Bob would have given him 2 extra hours for the capsule atmosphere to restore, it should be noted however that he declined to do so out of fairness to his 3 crew-mates who could not.

The KSA hopes this analysis will bring some closure to the 4 families and many Agency employees affected, and as well serve to caution other space agencies of potential opportunities for failure.

Edited July 2, 2017 by GarrisonChisholm
typos