Expert: Delays in manned missions are common, astronautics is still not a routine activity

In the case of the Ax-4 mission with a Polish astronaut, we have quite a lot of delays, more than usual. However, they happen very often in the launches of manned spacecraft, especially in the USA. Let's remember that astronautics is still not a routine activity - Prof. Paweł Moskalik from CAMK PAN told PAP.

NASA and Axiom Space announced on Thursday that they are postponing the launch of the Ax-4 mission to the International Space Station (ISS). The delay is this time due to a leak in the Russian Zvezda service module on the ISS.

"We actually have quite a lot of delays in this flight, more than usual. However, we must remember that they have different causes. This Russian module is one of the oldest parts of the International Space Station. This part is over 20 years old and, in fact, Russian modules start having problems after such a long time. The same was with the MIR station, and this is exactly the same technology," Prof. Paweł Moskalik from the Nicolaus Copernicus Astronomical Center of the Polish Academy of Sciences told PAP.

The launch of the Ax-4 mission, in which Polish astronaut Sławosz Uznański-Wiśniewski will fly to the International Space Station, has already been postponed three times. The Falcon 9 rocket, which is to carry the Dragon capsule with the mission crew into orbit, was originally planned for May 29, and then for June 8, 10 and 11. The new launch date is not yet known.

The reasons for the delay were previously unfavorable weather - too high wind strength in the upper parts of the atmosphere in the rocket's flight corridor, problems with the Dragon capsule and a liquid oxygen (LOx) leak in the first stage of the Falcon 9 launch vehicle.

"Such things happen, but this (oxygen leak - PAP) is already a serious defect. You can't fly with such a leak, because it can end in a catastrophe. There can be a fire in the engine compartment and an explosion. Such things should also be caught and removed. For this purpose, SpaceX conducts a test firing of the engines a few days before the launch to check if they are tight and functional. And generally everything is fine. This time it turned out that there was a problem, which surprises me a little, because this rocket had a similar defect previously. I am a little surprised that the problem is back," the astronomer noted.

Delays, he pointed out, are very common in manned spacecraft launches, especially in the United States. "In Russia, it works better. The Soyuz system is very resistant to various failures. Delays due to technical reasons are rare in Russia," he said.

As he mentioned, the American shuttles were particularly unreliable, with the probability of launching on schedule being about 50 percent. This was due to both technical and weather problems.

Prof. Moskalik reminded, however, that SpaceX is currently conducting a "massive operation". "Last year, this company launched over 130 rockets. This is a huge pace, so the more often they do it, the greater the chance of various types of defects. This worries me a bit, because it would be better if it was slower, but safer," he emphasized.

As he explained, good space rockets have a failure rate of less than 1 percent, meaning a failure occurs less than once in 100 launches. Heavy rockets have a failure rate of 3 percent. "The Falcon 9 rocket is rather heavy, but for now it has quite good statistics, clearly better than those three failures in a hundred flights," he said.

In the case of manned flights, it is different from the case of unmanned missions launching cargo into orbit. Manned spacecraft are equipped with rescue systems that have already come in handy several times, especially for the Russians. If a failure occurs during launch, the rescue system separates the capsule from the rocket, allowing the crew to survive despite the destruction of the rocket itself.

"Space travel is still very risky, because the probability of a catastrophe is about 1 percent. Nobody would get on a plane that crashes once in a hundred flights. Let's not let ourselves be convinced that astronautics is a routine activity. It is not and will not be for a long time," concluded Prof. Moskalik.

Ewelina Krajczyńska-Wujec (PAP)

Science in Poland

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