Our modern society, certainly the prosperous United States, handles tragedy much more differently than ancient societies as those lived by historic figures such as Aristotle. From modern fiction to television and films, we’re practically conditioned to ignore, mask, redefine, even attempt to rewind long-term, inevitable considerations of the human condition. Works such as Hamlet, Othello or don’t resonate nearly as well with those that reside in lands where the populace is far more content in its needs–and therefore distracted from the reality of harsher qualities of life.
When tragedy does occur, some of us cry out more strongly in anger than anguish. “This is unfair!” “We want vengeance on who did this!” “Why did this have to happen!?”
Such feelings certainly existed 51 years, 32 years and 15 years ago, in the loss of the crews of Apollo 1, STS-51-L and STS-107. They still persist today, although the fog of the modern panem et circenses continues to distract, mute, or redirect these memories for many.
My opinions here aren’t intended, ethically, morally, theologically or by secular reasoning to answer the “why” of tragedy. Nor will this article rehash the events and causes of these accidents.
Rather, I’d like to remind us how death became a transforming force to improve the quality and purpose of the endeavours that later men and women pursued in the days after such events, touching on a little on what could’ve have happened in later missions if Apollo 1, the Challenger and Columbia tragedies did not occur.
The race to reach the moon was filled with changes in plan. North American Aviation was tasked in November 1961 to build the Command Module, the nerve center and only living space for three astronauts to fly to, and land on the moon.
NAA was designing the original CM with the still-challenged direct-ascent or earth-orbit rendezvous mission mode concepts. But that CM design would fit either mode that NAA expected NASA to chose.
When NASA chose a third option in selecting lunar-orbit rendezvous by July 1962, saving weight and complexity in reaching the moon, NAA was already in hardware mode, in the process of building several CMs meant for direct-ascent or earth-orbit rendezvous. So NAA began work on a revised CM. The access tunnel considered for crew ingress at launch and egress on landing on the moon or on splashdown on Earth was retooled for docking with a special lunar landing spacecraft, it’s contractor to be determined six months later in November. A decision was made to continue work on the original CM, designating it as the Block I spacecraft, which would fly up to three earth-orbit test missions. Work on the LOR variant, the Block II, was begun in haste to keep to the lunar landing timeline goal set by the president.
This was North American Aviation’s first round in building a spacecraft. You can read elsewhere from various official reports and sources on the causes that led to the fire on January 27, 1967 which asphyxiated the Apollo 1 crew and destroyed Spacecraft CM-012. Here is one well-written 2017 Ars Technica article if you wish to review (WARNING: Includes graphic images of the spacecraft interior as found in the official accident report).
But let’s be thankful for Apollo 1’s tragedy as, through its loss, a series of modifications in both the Command and Lunar Modules, a second, or even a third tragedy was likely averted on two occasions.
The launch window for reaching a specific lunar landing site with the right sun angle and returning at the right time and place to specific earthly splashdown point meant that weather considerations for launching a Saturn V were far less scrutinized than the Space Shuttle flights that started over a decade later.
Apollo 12 lifted off in a rainstorm. Naturally, the launch may have been scrubbed if there was a thunderstorm in the area but the closest threat was miles away. But NASA’s lack of understanding of the effects of triggered lightning at the time resulted in the Saturn V being struck twice by lightning as it ascended.
Thankfully, due to EECOM controller John Aaron’s historic “SCE to AUX” call as well as an important abort procedure consideration by the Flight Dynamics Officer, the mission proceeded without further incident. It’s probable that the electrical safeguards added in the wake of the Apollo 1 accident increased the vehicle’s chances of survival after the strikes, as surges could’ve caused sparks in equipment aboard the Command Module or other elements of the vehicle that could have led to a fire or explosion.
On June 4, 1968, after assembly and a battery of tests, the shelf assembly that held two oxygen tanks was installed in Service Module 106, which would become part of Apollo 10. But due to changes to avoid electromagnetic interference with other elements of the spacecraft, the shelf was removed from 106. It wasn’t a smooth removal; the tanks on the shelf were shaken badly during the process.
After the 106 shelf was removed, components modified and tests were completed, the shelf was reassigned for Service Module 109, which would eventually fly on the Apollo 13 mission.
Months before, Block I Command Module construction was halted. A sweeping series of modifications was made to all electrical wiring and components in the Block II CM and Lunar Module, particularly insulating all connections, switches and wiring to the point where the non-flammable insulation also became practically waterproof.
Because of complications in fuel cell development as seen in Gemini, as well as development delays that threatened the readiness of the lander spacecraft before the 1970 deadline, the three fuel cells slated for use in the Lunar Module were reduced from three to two before NASA directed that the fuel cells be removed altogether, replaced with batteries. This redesign also precipitated electrical modifications in both the CM and LM. A battery recharging circuit was added from the CSM’s fuel cell-powered electrical system to top off the batteries for the Lunar Module, where no such circuit had existed before.
On April 13, 1970, physical shock and hidden electrical damage to a heating element inside one of the oxygen tanks from that retooled shelf to be used on Apollo 10 came to a head when the tanks were commanded to heat and stir the liquid oxygen to avoid stratification of the oxygen so as to get a more accurate measurement of the tank’s quantity. Tank 2 exploded, and the Apollo 13 mission turned from lunar landing to emergency return of the crew back to earth before the strained resources within the Lunar Module lifeboat ran out.
Extra time was needed by the crew in the hours after the accident to activate the Lunar Module for life support and navigation. In that time, the fuel cells ceased to function from the depleted Service Module oxygen supply and one of the three batteries that powered the Command Module during re-entry were used to keep the CM’s computer, life support and navigation systems up long enough until the LM could assume these roles. Battery A was left nearly depleted, and the flight controllers that managed the life support of both spacecraft knew that Battery A had to be recharged somehow if Apollo 13 was going to return home.
With a overtaxed environmental and life support system aboard Aquarius supporting three men for five days in addition to the chilled air of the dormant Command Module, moisture condensed throughout both spacecraft, including within the electrical systems.
Ground engineers and controllers resolved the Battery A issue by using the CM-to-LM charging circuit (which wouldn’t exist in a fuel cell-powered LM) to replenish the CM battery from the remaining LM battery power, as well shoring up the CM electrical bus for reactivation of the module’s subsystems before re-entry. The meticulous electrical insulation modifications as a result of Apollo 13 not only prevented any CM subsystems from shorting out as they were reactivated before re-entry, but also kept the vital LM subsystems from succumbing to electrical shorts during its lifeboat phase. In the Apollo 13 film, you see the condensation depicted as dropping from the Command Module’s instrumentation panels like rain against the faces of the three crewmen of Odyssey.
The lessons of the Apollo 13 accident led to quick redesigns to the Service Module. Redundant connections to the reactants that powered the fuel cells. Redesigned oxygen tanks. A third oxygen tank placed in a separate location. An auxiliary battery in the Service Module. These changes ensured greater safety on the remaining lunar missions.
The Space Shuttle
Inherent design limitations were ever-present in the lifetime of the Space Transportation System program and could never be fully eliminated. Considerations for crew safety in the event of a launch abort were based on the notion that the Orbiter could “fly away” from such a problem as would any aircraft, at least any time after the Solid Rocket Boosters were depleted and jettisoned.
For Challenger, such an abort was impossible during the STS-51-L launch. (The previous link goes to a NASA official page for the mission, without images, with links to reports, photos, films and non-NASA resources that the agency found worthy of inclusion.)
After the accident, the SRB segment joints were redesigned to resist exterior temperature changes and erosive effects of SRB burns which could damage or destroy the joint.
NASA also returned the crew to a type of space suit.
The same thoughts that the Orbiter could fly back from any calamity like a typical aircraft had also led to the elimination of space suits for the crew during launch and landing. These suits returned, primarily as an option in the crew bailing out from a damaged Orbiter after completing an extremely risky Return-To-Launch Site abort or after re-entry where the Orbiter’s landing systems are believed to be compromised.
Return-to-Launch-Site aborts were also no longer considered reliably as a survivable event. Crews were trained and Orbiters modified to allow crews to escape from an Orbiter once in the atmosphere, parachuting to safety while the Orbiter is directed to ditch in the ocean.
Seventeen years of successful Shuttle missions were completed before, on launch, a section of foam from the External Tank slammed into a leading edge of Columbia’s forward wing, mortally wounding the vehicle as STS-107 ascended to orbit on January 16, 2002. (WARNING: The link is an extensive CBS News report which does include photos of the failed re-entry and some photos of debris and a memorial at a debris recovery area.)
The pressure suits of the STS-107 crew could not help them while descending at Mach 25 and 400,000 miles above the earth as the compromised Orbiter’s port wing melted from re-entry heating, leading to vehicle breakup.
NASA was compelled to change the Orbiter’s central mission once more.
After Challenger’s loss in 1986, NASA got out of the commercial and military satellite launch business, focusing on the the Orbiter’s capacity to supply–and build–space stations and support high-level space probe and satellite launches. Triumphs of the time included the deployments of the Galileo Jupiter probe, the Hubble Space Telescope, supply visits to the Russian Mir space station, and the construction of the new International Space Station.
With Columbia’s demise in 2003, NASA would avoid flying any Orbiter that could not reach the International Space Station. The ISS would be an emergency “safe haven” for a crew with a stricken Orbiter while a “Launch on Need” rescue mission with a second Orbiter would later fly to retrieve them.
In addition, with only three surviving Orbiters in the fleet, and because the damaged Orbiter must be undocked and depart the ISS before a rescue Orbiter could dock, NASA devised an in-flight kit that would fully automate a questionable Orbiter for ground control. With commands from ground control, an unmanned Orbiter could be undocked, its payload bay doors closed, and its auxiliary power units activated for re-entry. NASA controllers would try to land the spacecraft for eventual repair, or water ditch if it could not be salvaged, all by remote control.
The agency did make one singular exception to this rule for the last Hubble Space Telescope servicing mission, but not without provisioning an STS-400 rescue launch vehicle to reach Atlantis should that Orbiter be compromised somehow and unable to safely re-enter, as that Orbiter’s orbit inclination and other logical factors would not allow it to reach the ISS as a safe haven.
In The Future
It’s not the purpose of this blog and its Facebook presence to discuss future or planned events, but only to discuss the historical highs and lows of spaceflight. That said, the events of the tragedies we commemorate each late January, and the safety decisions that came from them, reverberate with a positive sound in the planning for the first manned Commercial Crew launches, perhaps by the end of 2018, as well as the first Orion space launch sometime in 2020.
All three manned spacecraft have returned to the conical space vehicle design used by the Apollo Command Module. All three have powerful launch escape systems that can be used at any time during the launch. Re-entry systems take advantage of proven ablative and ceramic thermal protection technology.
It’s reported by some that overseeing agencies of the Commercial Crew program are questioning these safety considerations, widening what is now the longest period in United States history between the stop and restart of manned spaceflights from US soil since the end of the Apollo program the start of the Space Shuttle from 1975 to 1981.
While no fan of the space program wishes that NASA or its contractor fly with excessive risk, such oversight seems to forget that eliminating risk (versus minimizing it) is nigh-impossible.
We hope that those involved with Commercial Crew safety will work promptly with Boeing, SpaceX and NASA to ensure that the safety features and procedures are sufficient for crew and ground safety without further unnecessary analysis or excessive caution so America can just light the damn candle once more.