Six years after the tragic loss of Columbia and her crew, the efforts to improve the safety of the space shuttle continue to honor their memory. With the shuttle arguably the safest it’s ever been, the safety modifications to vehicle hardware and procedures are only half the story.
A liberated piece of External Tank’s insulating foam impacted and breached a RCC (Reinforced Carbon Carbon) panel on Columbia’s left wing during the January 16th launch, Columbia had no chance of surviving the unforgiving environment of re-entry.
Despite some voices – mostly those opposed to extending the shuttle program due to their Ares-based interests – citing scary loss of vehicle probability numbers for the remaining flights, the space shuttle is far safer than before STS-107.
Extensive modifications to the External Tanks have seen a huge reduction in foam liberation, with the 2008 missions recording four of the cleanest flights in the shuttle programs history, resulting in no damage to the orbiter’s Thermal Protection System (TPS).
Since Return To Flight (RTF), no orbiter has suffered TPS damage that has even come close to calling up the additional backup of LON (Launch On Need) – which utilizes a plan to call up the next scheduled shuttle on a rescue mission.
Knowing an orbiter hasn’t suffered any damage has proved to be one of the key RTF improvements, thanks to multiple checks throughout the mission.
Those methods involve hardware and process improvements, such as the WLEIDS (Wing Leading Edge Impact Detection System), used to ‘feel’ for any impact threats to the orbiter RCC/TPS that may have been missed by the multitude of imagery and radar tracking techniques that follow the shuttle during her ride uphill.
Flight Day 2 now involves the use of another RTF capability, the Orbiter Boom Sensor System (OBSS), used to check critical areas of the orbiter TPS, prior to Flight Day 3’s RPM (Rbar Pitch Maneuver) photography – resulting in thousands of images of every inch of the vehicle, checked over by the Damage Assessment Team (DAT) on the ground.
Post undocking Late Inspections again utilize the OBSS for a final check of the TPS, ahead of clearance for re-entry, with post flight inspections and reviews ensuring any lessons learned from the previous flight are taken onboard for the upcoming mission. The resulting details, even for the slightest anomaly, are nothing short of impressive.
Unfortunately, the shuttle is a hugely complex vehicle, and is by its very design “unsafe”, but so is space flight in general. Protecting against the threats, to the greatest possible extent, is – without any doubt – being carried out by the engineers and managers tasked with caring for the vehicles and their crews.
Examples can be seen almost on a daily basis, where dissent is welcomed and problems are discussed, as opposed to hidden or shouted down, an allegation of “bad culture” cited by the investigations into the losses of Challenger and Columbia.
Any engineer can now call a “Time Out” and managers can call for a “Safety Stand Down”, should there be the slightest concern about a process being carried out on the flight hardware, an example of which occurred just last week.
“Had instances in operations over last couple of weeks that appear to have a common element – little errors on the part of techs,” noted a recent Shuttle Stand-Up/Integration Report on L2, relating to a small issue with the processing of the Reusable Solid Rocket Motors (RSRM).
“In an effort to refocus people and take a time out and think about that, they had a Safety Stand Down Thursday morning.”
“Leadership went out into various areas and talked to folks about some of those instances; made a plea for them to take a deep breath and focus on the task at hand. Think this was a positive thing.”
Examples of the intense process of ensuring the next mission is safe to proceed towards its launch date can be seen during the FRR (Flight Readiness Review) period, which results in literally 1000s of pages of documentation on each and every aspect of the vehicle and her mission.
The importance of the FRR process, and its ability – more so insistence – on full and frank communication, can be seen in a rallying call from Mission Management Team (MMT) co-chair Leroy Cain, who – alongside shuttle manager John Shannon – are carrying on the impressive management of the program, since taking over from former SSP manager Wayne Hale.
“Had a good (SSP) FRR last week. We know the work we have going forward, and have some new work probably that we weren’t aware of at the FRR,” noted Mr Cain on last week’s Stand-Up report. “It is going to be a very busy week to get ready for the (Agency) FRR next week in Florida.
“Please work very hard to that end (preparing their documentation for the FRR). I think the team is doing great; communication is really, really good. From the few items we have going on, I’m seeing great communication up and down, and back and forth across the teams. We really need to continue that.”
Mr Cain went on to note to the extensive shuttle team that he understands there is a lot going on with the Agency, with a new administrator still to be chosen, the possibility of the shuttle program being extended, doubts over the future of the Constellation program – and asked the team to continue to stay focused on the most important upcoming event – STS-119.
“Outside the work we are doing here, as it pertains to getting ready for STS-119/15A, there is a whole lot of distraction outside of our SSP world and ISS world that is easy for us to get mired down in,” he added. “But we have one mission in front of us right now that we need to keep focused on.
“I’m very happy to say that I see the team has our focus set in the right place, the right way. Please continue that; please continue to emphasize that with your troops.
“We must fly the best mission we can on STS-119. That is our focus right now; that is the only thing that matters right now to the team. Everything else will sort itself out over time. That is our number one priority.
“So please stay focused, keep doing great work, keep talking to each other, and let’s have a good week.”
While the risk of losing another vehicle is sometimes in the lap of the Gods, there is no doubt the teams are doing their absolute best to ensure Columbia’s legacy is one of safe and successful missions until the fleet is retired, and beyond.