Having recently read Safe Is Not An Option, I started out intending to write a review of the book but decided to expand that out to capture some thoughts on the subject at greater length.
Firstly I think its worth noting the book’s full title – Safe Is Not An Option: Overcoming The Futile Obsession With Getting Everyone Back Alive That Is Killing Our Expansion Into Space. So a pretty uncompromising introduction right there on the cover, but any serious discussion on this subject needs to confront the subject head on and challenge our preconceptions and Simberg certainly doesn’t dodge that challenge. So why the need for this seemingly iconoclastic viewpoint?
I suspect the prevalent reaction amongst the general public regarding human spaceflight is that everything possible should be done to protect the lives of the astronauts/cosmonauts/taikonauts – that their safety should be paramount in the design and operation of any spacecraft and launch system. That just seems intuitive right? Well as a starting point it’s certainly understandable but it begs the question “how safe is safe enough?”. To this point it is vital to provide some context – a look at humanity’s previous ventures into the unknown and the attitudes that allowed us to progress to where we are today.
There is a commonly voiced opinion that exploration is an inherent human trait. In his March 2015 TED talk, Journalist and Technology forecaster Stephen Petranek said:
“…exploration is in our DNA. Two million years ago humans evolved in Africa and then slowly but surely spread out across the entire planet by reaching into the wilderness that was beyond their horizons. This stuff is inside us.”
While I don’t disagree with Petranek it’s also worth noting that curiosity alone was generally not the impetus for exploration. Environmental pressures, the search for resources, the wish to find new land to follow religious or cultural practices without constraint or simply political ambitions have all served to drive our explorations throughout history and in a high percentage of cases, exploration has opened the way for settlement. We have become expert at reaching into the wilderness that was beyond our horizons, but this has always come with attendant risk and now, as humanity looks to literally move ‘beyond the horizons’ and contemplate the settlement of other bodies within the solar system those risks have never seemed more obvious.
Any human journey into space consists of three phases, each carrying their own risks:
First there is launch – escaping the Earth’s considerable gravity well requires a huge amount of energy to propel our spaceship and passengers to orbital velocity. Currently the only means we have to do this are chemical rockets where fuel and oxidiser are mixed to produce thrust and, thanks to Newton’s third law, provide forward motion. This massively energetic process is nothing less than a contained explosion under perfect circumstances and – and occasionally a less contained, catastrophic explosion. There is little we can do to remove the risk of launch and ascent beyond planning for ways to rapidly remove any passengers from the vicinity of an accident should it occur.
Once our travellers reach space they are confronted with a second phase – survival in the near perfect vacuum where bodily liquids will boil readily from the lack of pressure, where solar radiation and cosmic rays usually filtered by our protective atmosphere and Earth’s magnetic field can travel through us unimpeded, and where the gravity so vital to our body’s development and healthy upkeep is now absent to any significant level.
Finally, space travellers will be exposed to the dangers of reentry and landing, be it on Earth or another eventual destination. Descent through an atmosphere is an extremely high energy process where speed is exchanged for heat and high G loads, both of which can rapidly become fatal if a spacecraft doesn’t perform as expected.
Of course there’s also the uncompromising nature of the environments we will find beyond Earth to consider. When early polar explorers set sail in ships laden with supplies and protective clothing, they could always rely on the wind to fill their sails and the air, however cold, to fill their lungs. In space there are few such luxuries – we won’t encounter an environment as ‘clement’ as our polar regions elsewhere in the solar system. Initially at least, everything we need must be taken with us save for the sunlight that can be harvested by solar panels and the basic force of gravity that may assist us with trajectories. In the foreseeable future In Situ Resource Utilisation (ISRU) promises to help us in our attempts to settle other worlds, indeed it will be vital if we are to make this a long-term migration. Already we know of lunar and martian ice that could be mined and converted to its component parts of hydrogen and oxygen, fuelling our onward journeys. Advances in 3D printing allow us to look to a near-future where the mining of resources from asteroids or planets can allow us to build habitats or machinery needed to assist our survival and settlements. The exploitation of extraterrestrial resources may well form a key economic driver behind our wish to visit and settle other worlds as well as granting us the means to do so in a sustainable way. (For an interesting article on this subject see: SPACE RESOURCES: PAVING OUR ROAD TO SPACE by space journalist Sarah Cruddas)
So given the risks and difficulties involved in spaceflight, how should we assess and cope with them and how should this shape our concept of safety? Our initial steps into orbit and to the Moon were conducted under a climate of competition during the Space race of the 1960s. As the Soviet Union and the United States battled for supremacy as a way of demonstrating the advantages of their chosen political systems, space exploration became a ‘crash’ programme conducted on a de facto war footing. Initial spacecraft were aerodynamically simple capsules that would ride into space atop re-purposed missiles (the exception here being the X-15 research aircraft). Initially, these capsules would be occupied by military pilots with experience of dynamic high-stress situations. Given the high-risk nature of the world these pilots were coming from (attrition rates were high for early jet pilots on both sides of the iron-curtain) the early astronauts and cosmonauts tended to display a pragmatic attitude towards their situation.
“If we die, we want people to accept it. We are in a risky business, and we hope that if anything happens to us it will not delay the program. The conquest of space is worth the risk of life.”
Grissom’s words proved sadly prophetic as he and his colleagues Ed White and Roger Chaffee were to die in a launchpad fire during pre-flight tests.
During these early programmes the concept of ‘human rating’ systems grew up. Initially this was due to very real concerns that the early missiles simply weren’t safe enough for people to ride on. The Redstone, Atlas and Titan 2 missiles all exhibited characteristics which could have put astronauts at risk if not addressed. These required structural fixes which in many cases went on to improve the missiles general performance as well as its role as a space launcher. Often though a major element of human rating was to ensure that potentially serious anomalies could be detected and assessed rapidly and, if deemed sufficiently threatening to the flight, would initiate a launch escape system. The use of launch escape systems was in itself a high-risk venture, so was only to be undertaken under the most extreme circumstances. For Mercury, Apollo and Soyuz capsules, a launch escape rocket atop the spacecraft would pull the crewed capsule to a safe distance where the parachutes could deploy lowering the occupants to a safe landing. For Gemini and Vostok capsules, an altogether riskier ejection seat escape was employed – the Soviet Voskhod spacecraft did away with launch escape completely, leaving the cosmonauts to put their faith entirely in the nominal performance of their booster and the skill of the engineers.
As Simberg points out, the whole question of human rating became far less well-defined during the Shuttle programme. This was a system that, beyond the initial test-flights, offered no means of direct launch escape from the pad. The Shuttle had to ride out the initial boost phase under the power of the solid rocket boosters with abort options (some of which were extremely high-risk in their own right) becoming available only once these had detached. As history records, the crew of Challenger were lost in January 1986 when O ring burn-through in one of the SRBs melted an attachment point to the external fuel tank, causing the booster to rupture the tank. A catastrophic explosion followed, placing loads on the Orbiter that it was unable to survive. There was no effective launch-escape system that could have been retro-fitted to the shuttle to prevent an incident of this type. What could be changed though was the management culture at NASA that had allowed the flight to go ahead outside of the recommended flight parameters and against the warning of engineers.
Tragically a second shuttle, Columbia, was lost on STS-107 during January 2003 due to another launch anomaly, although in this case the actual damage caused to the Orbiter by foam shed from the external tank only became apparent during re-entry. Again this was an incident where warnings had gone unheeded. A dangerous assumption prevailed that the lack of serious damage from previous incidents meant that foam-shedding could be tolerated.
Following the announcement of cancellation of the shuttle, a new spacecraft was envisaged to send America on a journey beyond LEO. Orion was part of what became known as the Constellation programme. It was to be launched atop a new booster, the Ares 1, derived from Shuttle technology. Here we began to see a problematic schism in the human rating argument. The wish to create a safer spacecraft than the Shuttle, yet the assumption that Shuttle derived components could be used to achieve this. While the Ares 1 booster had its own serious issues, an elaborate launch-escape system was developed for Orion. Initially reminiscent of the Apollo capsule and launch escape system, Orion’s version consists of a large shroud over the capsule to which a tractor rocket is attached. During operation the rocket fires upwards, thrust then being deflected downwards through four nozzles. The whole system must then perform a ‘flip’ after burnout followed by separation of the shroud at which point Orion’s parachutes can lower the craft safely to the ground.
Other capsule-based systems currently under development, notably the SpaceX Dragon and Boeing Starliner use push based launch escape systems, with rocket engines within or below the capsule thrusting it away from the booster. As such, they may appear simpler and have fewer failure modes than the proposed system for Orion, but does this make them safer? Both commercial systems, having been selected by NASA for crew resupply to the ISS are undergoing final development an testing, much of which is mandated by NASA at the behest of congress to prove their safety. Currently both systems are running behind their original schedules and it seems unlikely we will see an American launched system taking astronauts to the ISS until 2018. While these commercial capsules go through the thorough testing to parameters set by NASA as directed by Congress, astronauts must continue to fly on Russian Soyuz capsules – subject to no such regulation. Could these commercial systems, especially SpaceX’s Dragon (a version of which already visits the station for uncrewed supply missions) have been pressed into service sooner?
The question of crew support for the ISS also forms the basis for another of Simberg’s central arguments. As previously mentioned the only current means for crew to reach the ISS is the Soyuz which can carry a maximum crew of 3. Only 2 Soyuz craft can currently be docked to the ISS at any time (their duration on-orbit is also limited) and this limits the maximum crew for the ISS to 6. Were a seventh crew member to be present, the amount of research that could be done would dramatically increase strengthening one of the key justifications for the station’s existence, but until the commercial crew vehicles (both with a higher crew capacity than Soyuz) are available this is not possible unless we accept a situation where a member of the crew would be lost in the case of a catastrophic incident. Simberg is a strong advocate for this approach arguing the benefit that could be derived via the extra research would far outweigh the loss of a single life should such a catastrophe occur. While such a move may prove too much for most to contemplate it would be interesting to know what the attitudes of the astronauts and cosmonauts involved would be (Presumably under such an arrangement the old maritime paradigm of the captain remaining with the ship would apply meaning the ISS commander would be the one to remain with the station?)
Interestingly, this would not be an issue had the planned X-38 Crew Return Vehicle (CRV) not been cancelled under the Core Complete cost-saving exercise in the early 2000s. The CRV would have been able to carry 7 crew back to Earth. While comfort would not have been the paramount consideration, it was a means of return that currently doesn’t exist.
In the latter stages of the book Simberg discusses the question of regulation for the emerging commercial spaceflight sector. He points towards existing maritime self-regulation as potentially offering a better solution than the extension of the FAAs powers beyond the atmosphere. Specifically the establishment of an equivalent of the Classification societies which were set up to develop standards of seaworthiness would be useful, although as he points out much work remains to ensure the legal framework under which these could effectively operate with regards to liability. Certainly, whatever system does develop will need to encourage the proliferation of space access rather than stifle the sector as only the development of a wide array of approaches, of which some will succeed, will truly help us become a spacefaring species.
For the short-term our perceptions of acceptable risk may be best served by placing a monetary value on human life – however uncomfortable this may feel. If we decide to place life at such high value that the measures required to safeguard it become so expensive as to outstrip the budgets available for space travel, then we must call into question how serious we really are about making the journey.
Conclusions
During the initial flight tests of the X-15, General Marcus Cooper, then Commander of the Air Force Flight Test Centre at Edwards AFB said:
“…there is a very fine line between stopping progress and being reckless….The answer, in my opinion, is what I refer to as ‘thoughtful courage’. If you don’t have that, you will very easily fall into the habit of ‘fearful safety’ and end up with a very long and tedious type solution at the hands of some committee.”
I feel Cooper’s sentiments here are as relevant now as they were in the early 1960s. Similarly, in his book Simberg certainly isn’t espousing that we progress in a reckless fashion knowingly endangering those who fly on present or future spacecraft. Nor is he suggesting we make overly optimistic assessments as to the safety of systems that may create a false impression that all risk has been mitigated and space travel can have ‘airline-like’ levels of safety. But he is strongly warning against ‘fearful safety’ and the lack of progress that surely leads to. Now, as we look towards a new era of human spaceflight in a generation of commercial vehicles, it is instead a time to employ Cooper’s ‘thoughtful courage’.
Safe Is Not An Option provides a valuable service to the reader in that it challenges them to re-examine their own attitudes to the subject. I’m sure many may disagree with some of Simberg’s opinions but the subject is far healthier for being throughly aired and reconsidered. Lives will be lost and we should never forget to honour those who fall in expanding our knowledge during this difficult journey, but as history has shown us valuable lessons will be learnt and new opportunities realised.
NOTE: Simberg’s book finishes with an early examination of some of the more contradictory aspects of the SLS, a subject which I’m sure he will expand upon in greater length soon. You can read that essay online HERE.
Safe Is Not An Option: Overcoming The Futile Obsession With Getting Everyone Back Alive That Is Killing Our Expansion Into Space is available via Amazon and other outlets
Rand Simberg describes himself as a ‘recovering aerospace engineer‘ having worked for the Aerospace Corporation and Rockwell International during his professional career. His personal thoughts on safety and a variety of other subjects can be found at Transterrestrial.com
The High Frontier 