- Joined
- Oct 30, 2009
- Messages
- 14,019
- Reaction score
- 4
- Points
- 0
NASASpaceflight: Endeavour into safing operations – Left gear brake fire investigated:
{...}
“The STS-134 mission was successfully completed with a landing at Kennedy Space Center (KSC), Florida. Both Payload Bay Doors (PLBDs) were closed nominally by 153/02:48:23 GMT [15/13:54:16 Mission Elapsed Time (MET)] in preparation for landing,” noted the documentation.
“The deorbit maneuver for the first landing opportunity at KSC, a dual-engine firing, was performed on orbit 248 at 152/05:29:03 GMT (15/16:32:35 MET). The burn was 158.3 sec in duration with a Differential Velocity of 298.4 ft/sec. The resulting orbit was 23.2 by 188.5 nmi. Entry interface occurred at 152/06:03:06 GMT (15/17:06:38 MET).
“The main landing gear touchdown occurred KSC runway 15 at 152/06:34:50 GMT (15/17:38:12 MET). The drag chute was deployed at 152/06:34:53 GMT. The nose gear touchdown occurred at 152/06:35:00 GMT. Drag chute jettison occurred at 153/06:35:19 GMT. Wheels stop occurred at 152/06:35:33 GMT. The rollout was normal in all respects.”
While the return was – as noted – normal, a later report noted Endeavour’s rollout down the SLF was the second shortest in the history of the Space Shuttle Program (SSP), notable not least because no Detailed Test Objective (DTO) into a “hard braking” test was requested for this landing.
A related investigation is also being carried out on observations of a small fire – lasting around 40 seconds on one of Endeavour’s Left Main Landing Gear – was observed at the end of the braking period as the orbiter came to a stop.
According to Kennedy Space Center (KSC) sources, the teams which greeted the orbiter noticed no indications of the brief fire during the runway inspections, nor did they find any truly discernible indications of a fire after they gave Endeavour a thorough inspection on Wednesday.
It was only during reviews of the landing videos when it was raised to managers, leading to the investigation. Part of the review will be into the braking force applied during rollout, which is believed to have been somewhat “above normal”, given the second shortest roll out in the program.
The incident also impacts on Endeavour’s Transition and Retirement (T&R) processing, given the brakes on the orbiter were set to remain on the vehicle. It is now likely they will be removed to allow for a thorough investigation.
Currently, the two most likely causes are suspected to be excess grease on the wheel/axle or a leaking hydraulic puck, in tandem with the heavier than normal braking. Engineers are expected to recharge the hydraulic pressure and inspect for a puck leakage or any other hydraulic system leakage.
{...}
