Link to First Installment: https://chrisprophet.substack.com/p/spacex-evolution
There are certain uncomfortable truths concerning the prior space effort which probably need to be referenced for completeness. If you would prefer to believe NASA is the perfect vehicle for space exploration with a glorious past…probably best skip Appendix D altogether.
Apollo 1 Fire
The Apollo 1 fire needs a little background, because some of its causes date back to the seminal Mercury program. On 21st July 1961, Virgil "Gus" Grissom launched into space, on the second Mercury crew mission. After a short suborbital flight, the Mercury capsule splashed down in the Atlantic Ocean, in what appeared a completely successful mission. While waiting to be picked up by helicopter, the capsule hatch unexpectedly burst open, causing it to rapidly take on water. Unfortunately the capsule became too heavy to be lifted by helicopter as planned, so it had to be abandoned, after which they managed to winch the rather forlorn Gus Grissom aboard a second helicopter. This was a double blow for NASA, not only had they lost the Mercury capsule with its treasure trove film and data but the entire episode had been aired live on national television. Overall a PR disaster for NASA, as it struggled to find its feet while fighting to be accepted by the establishment. After a long investigation they concluded Gus Grissom must have panicked after landing and used the emergency egress procedure. This used a strip of mild detonating fuse embedded between the inner and outer seal of the hatch to blow it open, allowing the astronaut to quickly escape a failing vehicle. Many in the astronaut office believed Grissom’s story, that the hatch had unaccounted burst open, in other words the accident was caused by a vehicle failure. But with all material evidence lost, the NASA engineers decided their hardware wasn’t at fault, hence it must be the pilot... Essentially Grissom became a scapegoat, leaving an indelible stain on his character.
However, the helicopter winchman observed an electrostatic arc when they first made contact with the capsule.1 This arc coincides with the moment the capsule door ejected, which suggests there might be more to this than pilot error. In contemporary times, after the capsule was recovered from the seabed, it revealed more vital evidence. Investigators discovered no burn marks around the 70 explosive bolts used to secure the hatch, suggesting they hadn’t been activated by Grissom.2 In addition the titanium frame for the hatch had been warped by some extreme force. Occam’s razor suggests the static discharge from the recovery helicopter caused the mild detonating fuse embedded in the door sill to explode. This burst the explosive bolts, which had been purposefully weakened to fail, releasing the hatch prematurely.
Fast forward to January 27, 1967; NASA was testing the Apollo 1 capsule, in preparation for the first crew flight of their moon landing program. The North American Corporation had been contracted by NASA to build the Apollo capsules, i.e. NASA had specified their requirements for the spacecraft, leaving North American responsible for design and manufacture. Earlier capsules like Gemini and Mercury had used a pure oxygen atmosphere but as part of their contract bid North American proposed a nitrogen/oxygen mix would be safer, because pure oxygen was a known fire accelerant. However, after NASA awarded the contract they insisted the capsule should use pure oxygen, overriding North American’s safety concerns. In addition NASA instructed North American to fit a plug type hatch which would open into the capsule’s interior, in addition to the more conventional outward opening hatch (similar to those used on the Gemini and Mercury capsules). In theory this design change would make the capsule more secure, although it necessitated the interior hatch was fastened from the inside using bolts, which only the astronauts could unfasten, through a relatively slow and laborious process. Gus Grissom was slated to go on this maiden flight and effectively NASA engineers made sure there would be no repetition of the ‘pilot error’ experienced on Mercury, by removing any possibility of fast egress.
During ground tests, NASA insisted the capsule’s internal pressure should be set at 2 psi (pounds per square inch) higher than the exterior pressure, to simulate the pressure difference experienced by the vehicle when operating in the vacuum of space. Unfortunately when you compress oxygen it creates conditions similar to a combustion chamber, in which even the slightest spark can ignite flammable materials – like the paper, plastics and acrylics used in the capsule interior. The Apollo capsule controls consisted of around 566 individual switches, many of which would need to be operated as part of the ground test procedures – and when any electrical contact is opened it usually creates a small spark… When the inevitable happened, the fire quickly spread through the control compartment leaving the three-man crew little time to egress the vehicle. However, even if they had managed to release the securing bolts on the hatch, it still couldn’t be opened because the elevated pressure inside the capsule meant the hatch was held in-place by tons of pressure. So this accident was caused by one primary failure: NASA’s insistence on using pressurized oxygen for a crew in vehicle test, compounded by their decision to add a plug hatch ‘for safety,’ which ensured escape was impossible. Three NASA astronauts, the best of the best, were lost: Gus Grissom, Edward H. White II, Roger B. Chaffee.
Challenger Disaster
On Space Shuttle Challenger’s tenth flight, it unexpectedly exploded during ascent, resulting in the loss of seven crew. The subsequent Rogers Commission Report suggested the vehicle was exposed to unusually cold conditions as it waited for flight, concluding this was the primary cause of the disaster. The Shuttle used solid fuel rocket boosters, which were manufactured in seven cylindrical sub-sections, then stacked either at the manufacturer (Thiokol) or at the Cape. Two concentric O-rings were used to provide a seal between each sub-section of the booster, to ensure hot exhaust gases didn’t leak at the joint. The report concluded cold weather had caused these O-rings to fail, producing a gout of flame which weakened both the aft strut used to attach the powerful booster, and the wall of the external propellant tank (which contained a substantial quantity of hydrogen and oxygen). Most crew launch vehicles are designed with a structural safety factor of 1.4 to save weight, hence this blowtorch-like leak quickly caused the booster to separate and the external tank to fail.
However, one of the commissioners, an exceptional physicist called Richard P. Feynman, didn’t entirely agree with these findings, in fact he concluded a NASA safety test had contributed to the failure. He had discovered that prior to launch, NASA inspectors had injected pressurized gas between these O-rings to perform a leak-check, to prove there was a good seal at each booster joint. The booster manufacturers, Thiokol, used a pressure of 50 psi for this test but NASA chose to use 200 psi, four times the safe recommended pressure.3 Feynman concluded this excess pressure had likely disrupted the O-ring seating, causing the seal to fail in flight. This conclusion was deemed too damning for NASA, hence excluded from the official report. In fact when Feynman printed his own version of the report to set the record straight, he was only allowed to include this probable cause in the appendix. Again this Loss Of Crew and Vehicle (LOCV) was likely caused by NASA’s key decision to use excess pressure for their O-ring leak check procedure. But whatever the cause, NASA was the responsible authority, hence ultimately responsible for the Challenger disaster and the deaths of all seven crew: Francis R. Scobee, Michael J. Smith, Ronald McNair, Ellison Onizuka, Judith Resnik, Gregory Jarvis and Christa McAuliffe – a civilian teacher specially recruited by NASA for this mission.
Columbia Disaster
The Space Shuttle was effectively designed by committee, hence far from out of the woods, despite a stringent overhaul of safety procedures following the Challenger disaster. The vehicle was massively complex, which made it unreliable, hence it could sit on the pad for days prior to launch, while they worked to resolve all the issues. The external tank (which contained cryogenic hydrogen and oxygen propellant) could accumulate a significant quantity of ice during these long wait periods, deposited from water vapor suspended in the air. This ice could detach during launch and potentially damage the Shuttle Orbiter or boosters, hence NASA added a thick layer of insulation foam to the external tank to reduce ice formation and propellant boil-off. Following many days of delay caused by technical problems, Space Shuttle Columbia finally rose from the pad on January 16, 2003, in what appeared a picture-perfect launch to low Earth orbit. However, when NASA reviewed video of the ascent they discovered a large chunk of insulation foam had fallen from the external tank and impacted the leading edge of Columbia’s left wing, possibly causing serious damage to this flight critical area. NASA reasoned there wasn’t much they could do because any serious damage couldn’t be repaired in space due to the vehicle’s complexity and their inflexible safety standards. Consequently they decided not to inform the crew of their predicament, in case it affected their judgment. Instead they decided to inform Chris Hadfield (a seasoned astronaut undergoing Soyuz training in Russia) of the situation to gauge his reaction. He of course was horrified by this news but NASA managed to persuade him they had the situation safely under control. Fortunately shuttle Atlantis was being prepared for launch at this time, which could have been used to perform a rendezvous and rescue mission.4 Unfortunately, that would require the many pre-flight operations and checks to be accelerated. NASA is essentially a huge bureaucracy, so had an aversion to any rescue attempt because it required haste and additional risk. In addition, the necessary preparation work was largely carried out by contractors, so any change in schedule could hardly remain secret, which meant the whole world would discover their predicament. So after Columbia completed its mission, NASA ordered its return, hoping their fears were unfounded about the severity of the damage. Then during reentry, heat build-up along the wing’s fractured leading edge caused the wing to fail (the Shuttle’s airframe was constructed of flammable aluminum alloy) resulting in LOCV. Fundamentally NASA made a series of mistakes, starting with an overly complex design for the vehicle, through lack of contingency planning, to the final cover-up. Again this resulted in the loss of seven invaluable crew: Rick D. Husband, William C. McCool, Michael P. Anderson, Kalpana Chawla, David M. Brown, Laurel Blair Salton Clark and Ilan Ramon, the first Israeli astronaut.
Contemporary NASA
Some might argue these prior failures are all historical in nature hence not indicative of modern-day NASA, following these hard lessons learned. However, their recent experience managing the Europa Clipper, a “Large Strategic Science Mission” that aims to send a science probe to the Jupiter moon Europa, suggest otherwise. During the design phase of this mission NASA engineers determined the SLS launch vehicle would induce excessive torsional loads on the Europa Clipper payload, in other words the violent vibrations caused by the solid rocket boosters could threaten to damage the spacecraft. This problem was so serious that NASA asked for the law to be changed to allow them to use another launch vehicle, because congress had mandated they use SLS for Europa Clipper in a previous spending bill. Fortunately NASA was given the latitude to use a substitute launch vehicle, SpaceX’s Falcon Heavy costing $178 million – saving the US taxpayer up to $2bn in launch services compared to SLS.5 Unfortunately NASA still intend to use SLS for their Artemis program, which aims to send crew missions to the moon, starting in 2026. From this outcome we can imply NASA value the hardware on Europa Clipper more than the safety of their astronauts, whose spacecraft will be unavoidable exposed to violent vibrations from SLS on these hazardous lunar missions. From NASA’s perspective this probably seems quite reasonable, they need Europa Clipper to go off without a hitch, because they rely on these frontier pushing missions to grab the headlines and maintain their budget; in the final analysis the bureaucracy must come first.
Arguably both Space Shuttle disasters can be directly or indirectly attributed to these solid rocket boosters, because the booster seal suffered a catastrophic failure on Challenger and a combination of extreme vibration and acceleration likely caused the insulation foam to separate on Columbia, which then compromised the thermal protection system. Now, for whatever reason, NASA has decided to use an even more powerful version of the solid rocket boosters on the SLS, despite the extreme vibration problem, which has been known about for decades.
Fundamental Flaws
Overall NASA appear to have adopted a hierarchy of values, i.e. public appearance comes first, preserve the vehicle second, and astronaut safety last... In addition, their experts seem to consist of frustrated engineers who actually believe they design the vehicles they use, rather than the prime contractor responsible for its construction. Their failure to comprehend the subtleties of the system’s architecture result in poor engineering choices when they arbitrarily alter the specifications of these vehicles. Overall this is no way to run a space program, no wonder they went from exploring the moon in the sixties, to low Earth orbit in the eighties, then ended up losing the ability to send astronauts to space for almost a decade. What seemed like liberality on their part, allowing SpaceX to carry their astronauts to LEO, concealed the fact they are now incapable of building practical spacecraft and mounting coherent space operations, due to myriad systemic flaws and internecine conflict. As each day passes it becomes increasingly apparent that space exploration requires the agility and drive possessed by companies like SpaceX, not the sclerotic bureaucracy espoused by NASA.
Succinctly: NASA – step away from the rocket!
Prognosis
In the coming years NASA’s influence over the space effort will likely wane as Space Force finds its wings, aided in large part by SpaceX technology. Government bureaucracies are difficult to disestablish after they have been established over decades, therefore it seems likely NASA will transition from managing engineering projects into pursuing purely scientific goals, in order to retain some valid purpose in the realm of aerospace. No doubt they will purchase the operational services they require for their science missions from commercial companies like SpaceX, Tesla, et al, and give up the premise of building their own launch systems and spacecraft. This promises to inject new life into the space effort, allowing it to grow organically – on a more sustainable commercial path and accelerated timetable.
1 https://www.astronomy.com/space-exploration/did-static-electricity-not-gus-grissom-blow-the-hatch-of-the-liberty-bell-7-spacecraft/
2 https://www.sfgate.com/news/article/mystery-unhatched-a-kansas-museum-has-new-clues-3312238.php
3 https://www.adaptivecapacitylabs.com/2006-Starbuck.pdf
4 https://arstechnica.com/science/2016/02/the-audacious-rescue-plan-that-might-have-saved-space-shuttle-columbia/
5 https://arstechnica.com/science/2021/07/spacex-to-launch-the-europa-clipper-mission-for-a-bargain-price/