Recently, Elon Musk shared a picture on Instagram showing one of the Crew Dragon capsules in an anechoic chamber for electromagnetic immunity (EMI) testing before being sent to the NASA Plum Brook vacuum chamber for simulated space testing.

The release of the picture is exciting to many space enthusiasts not only due to the level of detail of the new vehicle that can be seen in the image, but also because this is evidence of just how close the vehicle is for actual flight into space. Currently the first (uncrewed) demonstration mission is scheduled for August then an In-Flight Abort test and a crewed demonstration mission in the following months.

SpaceX Crew Dragon capsule (SpaceX)

Of course, with this update, and other updates from NASA, much ado has been made of the safety risks that SpaceX is taking and the danger to future crew members. To be fair, there have been issues facing SpaceX during the development of the Crew Dragon capsule and human-rating the Falcon 9 launcher. Some of these issues have led to a loss of vehicle, while others were detected during tests and post flight inspections of the boosters. Still others were just a matter of SpaceX approaching matters in a very non-traditional manner.

One of the areas of risk that NASA and their independent Aerospace Safety Advisory Panel (ASAP) identified early on with SpaceX is that they don’t operate like a traditional Aerospace company. For the company (and one could argue the entire space flight industry), this is advantageous. It has allowed the company to innovate rapidly and dramatically improve the Falcon 9 since its initial launch on June 4, 2010. However, the fact they don’t use the traditional Systems Engineering and Integration (SE&I) approaches that NASA is accustomed to was a point of concern to ASAP. In the April 2018 ASAP Quarterly meeting, Captain Brent Jett highlighted this when he stated that “along with those successes, there have been failures

that could be attributed at least in part to gaps or lapses in these SE&I principles”. Specifically, the CRS-7 resupply mission was lost due to a faulty bracket that allowed a helium tank to become loose and rupture the second stage of the Falcon 9 139 seconds after lift off. Had proper quality assurance monitoring, a part of SE&I processes, been in place prior to CRS-7, that mission would likely have been a success.

To this end, many pundits believed that NASA should be more flexible and embrace new ways of accomplishing things. Others feel that SpaceX needed to mature and embrace the traditional approaches. Ultimately, as is usually the case, both organizations have met somewhere in the middle. NASA has taken steps to speak in SpaceX’s language and SpaceX has taken steps to improve their SE&I discipline and processes. To this regard, while there is always room to improve processes, NASA is pleased with the progress that SpaceX is making in this area.

NASA Astronaut Suni Williams trains aboard the Crew Dragon (SpaceX)

Another area of concern, that is often brought up is matter of cracks in the turbo pumps. In the SpaceX Merlin engines, turbo pumps are the machinery that move the rocket fuel and propellant into the engine. During post-test inspections, tiny cracks were discovered in the turbine. For NASA, this was a serious matter, but as Gwynne Shotwell put it, “for us, the concern was not the cracks, but do they grow over time? Would these cracks cause a flight failure?” Ultimately, SpaceX fixed the issue via a combination of software updates and a redesign of the turbine wheel and has been flying this configuration since the Summer of 2016.

Early version of the Merlin turbo pump (SpaceX)

A much more visible issue, has been the matter of the composite overwrapped pressure vessels (COPVs) that SpaceX utilizes to store nitrogen and helium in the Falcon 9 rocket. These are the items that caused the AMOS-6 explosion in September 2016. It is suspected that solid oxygen built up within the composite wrapping and ignited, causing the rest of the rocket to explode. NASA is, of course, concerned about the same sort of event happening with crew on board. Even though the Crew Dragon launch escape system (LES) would speed the astronauts away to safety if such a thing were to happen, the loss of a rocket is something that SpaceX would like to avoid. To this end, they, in conjunction with NASA, have been developing COPV 2.0. Elon Musk indicated in a recent conference call prior to the launch of the Bangabandhu-1 satellite — the first launch of the Block 5 variant of the rocket — that the new COPVs are “probably the most advanced pressure vessel ever developed by humanity.”

It was expected that the first launch of the Block 5 would feature these new COPVs, but new information indicates that they were not available at the time the rocket was being assembled. NASA and ASAP consider this to be a very high priority item to complete, but admit that they are very comfortable with the progress being made in both understanding the materials science involved, identifying the hazards, and the engineering involved in addressing the issues.

A shot of the inside of the 2nd stage of the Falcon 9. The black cylinders are the COPVs (SpaceX)

A final concern that is often raised and frequently draws ire from space flight enthusiasts is the process in which SpaceX fuels the Falcon 9, a procedure termed ‘Load-and-Go’. As part of the process of improving the Falcon 9 rocket, SpaceX has adapted the vehicle to use “densified” liquid oxygen (LOX) that is just above its freezing point. The advantage of this is that LOX, becomes denser as it gets colder, allowing the Falcon 9 to carry more of it without lengthening the rocket and adding dry weight. This allows for better performance which in turn allows for larger payloads or more challenging orbits. It also allows for successful landings.

The challenge with the super-cooled LOX is that it must be loaded very quickly immediately before launch, otherwise it warms up too much and the densification advantages evaporate. For non-human payloads, this is not an issue; however, it is a departure from the processes that NASA has traditionally used for their crewed launches. In part, this was due to the amount of fuel being loaded and the time it took to load it. Both the Saturn V and the Shuttles took a few hours to load fuel. That’s far too long to expect astronauts to remain seated, buckled in, and prepared for the LES to fire in the case of a disaster. So in these cases, the crew was loaded while fueling was still in process. With the Falcon 9, SpaceX can secure the crew into the empty rocket, arm the LES, fuel the rocket, and then launch — all in less than an hour. There is also the added advantage that the ground crew will not be present so the LES can be used without risking the lives of people on the pad.

SpaceX test of the launch escape system (SpaceX)

For most people, this would seem to be a no-brainer. The earlier systems were a compromise between time and safety. The Falcon 9 doesn’t need to compromise, so why the concern? Mainly, it was a matter of understanding the risks. The issue of Load-And-Go surfaced around the same time as the COPV failure that doomed the AMOS-6 satellite during a static fire test. NASA needed to know that if SpaceX had a bad day while fueling, the astronauts would be safe. To that end, the NASA Engineering and Safety Center (NESC) conducted an in-depth analysis of the process and identified the hazards and controls involved. While NASA hasn’t made a final decision, the ASAP team has decided to advise NASA that Load-And-Go is acceptable.

Ultimately, NASA will not launch on a commercial vehicle that has significant safety issues. While there has been some admission from the agency that perhaps they have become too risk adverse, they have insisted on placing the safety of their astronauts above all else. In addition, SpaceX is striving to accomplish airliner level service with their Falcon 9 and Falcon Heavy (and later the BFR) rockets. You don’t accomplish such a feat by taking foolish chances that results in the loss of a vehicle and possibly grounding of the fleet. As such, they are working very diligently to produce the safest and most robust launch vehicle they possibly can.

So yes, SpaceX will soon be launching astronauts into space, but not amid safety concerns — after they have surmounted them.