The US Accounts Chamber warns: SpaceX and Boeing are waiting for new delays, it is possible that the United States will have a break in flights to the ISS
Last week, a forty-seven-page report by the Accounts Chamber of the United States about what is happening in the Commercial Crew Program was released. The conclusions are alarming - auditors believe that today's certification dates for SpaceX and Boeing ships will be shifted by more than a year. Worse, since the seats on the Soyuz end in early 2019, American astronauts may lose the opportunity to fly to the ISS for 9 months.
Recent tests of the parachute system Boeing Starliner (left) and SpaceX Crew Dragon (right). Dragon is experiencing an accident scenario with non-disclosure of one parachute out of 4. Photo by NASA, SpaceX
The NASA contracts with SpaceX and Boeing are designed so that before you start taking astronauts to the ISS, ships need to be certified - companies must prove to NASA that ships meet the requirements for functionality and security. At the same time, SpaceX and Boeing repeatedly stated directly that they set ambitious, rather than realistic, goals. This can motivate the team and looks good in the news, but in reality leads to constant postponements. Since the signing of the contracts in 2014, 13 quarterly inspections of the progress of the work took place. And Boeing reported deadlines on 7 checks, and SpaceX by 9. Certification dates have already moved from 2017 to 2019, and according to the NASA risk assessment methodology, the likelihood that any of the companies meet them is zero. The average expected estimated certification period is for Boeing - December 2019, and for SpaceX - January 2020.
The schedule of delays, the circle is the original date, the square is the current expected date, the range with an asterisk on the right is the certification time for calculating NASA risks. GAO image
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Today, for both companies there are risks that may further delay certification.
For Boeing:
For SpaceX:
A separate claim of the Accounts Chamber was NASA’s reluctance to talk about the estimated time of certification to Congress and the lack of backup plans for delays. The fact is that the space on the "Unions" will end a little earlier than half of the estimated period, and in the worst case, 9 months, American astronauts will not be able to fly to the ISS.
Turquoise zone - the range of calculated dates of certification of at least one ship. GAO image
It is already too late to receive new places at Soyuz, production of the ship and the purchase of places take about three years, and only one remains. In March 2018, the terms of the contract with Boeing changed - NASA was able to add a third crew member to the first test flight and extend its duration if necessary. Those. The first Starliner manned flight can be flown directly to the ISS, but this will only work if the Boeing spacecraft has no delays. Now NASA is pondering how to shift the landing of the Soyuz to the last available place from November 2019 to January 2020, but this is also only a partial solution covering two months from the potential nine.
And finally, the Accounts Chamber criticized the lack of a single safety metric for ships. In 2011, the permissible probability of death of the crew was set at 1/150. However, in the following documents, the more difficult attainable probability is 1/270. Worse, in 2014 they updated the model of space debris, which is used to assess the likelihood of a disaster. The new model is more dangerous than the old one, and Boeing with SpaceX may not keep within 1/270. The situation is complicated by the fact that four different divisions of NASA use three different probabilities - 1/150, 1/200, 1/270, and for different models of space debris and other conditions. To avoid a paradox, when the contracting company can fulfill the requirements of 1/270 for the old model for one department, but fails certification to 1/150 with the new model in another department, it is necessary to restore order in this area.
The report also contains NASA's response to the five recommendations of the Accounts Chamber on the basis of the audit:
The fact that, according to estimates of NASA, Starliner and Crew Dragon should fly much later than the announced dates is a minor sensation. However, the estimated range from May 2019 to August 2020 is large enough for Boeing or SpaceX to hit its left side without serious problems. But for large and technically complex projects, delays and postponements are the norm, so the intrigue - who will fly first and when, remains.
Recent tests of the parachute system Boeing Starliner (left) and SpaceX Crew Dragon (right). Dragon is experiencing an accident scenario with non-disclosure of one parachute out of 4. Photo by NASA, SpaceX
Obstacle certification
The NASA contracts with SpaceX and Boeing are designed so that before you start taking astronauts to the ISS, ships need to be certified - companies must prove to NASA that ships meet the requirements for functionality and security. At the same time, SpaceX and Boeing repeatedly stated directly that they set ambitious, rather than realistic, goals. This can motivate the team and looks good in the news, but in reality leads to constant postponements. Since the signing of the contracts in 2014, 13 quarterly inspections of the progress of the work took place. And Boeing reported deadlines on 7 checks, and SpaceX by 9. Certification dates have already moved from 2017 to 2019, and according to the NASA risk assessment methodology, the likelihood that any of the companies meet them is zero. The average expected estimated certification period is for Boeing - December 2019, and for SpaceX - January 2020.
The schedule of delays, the circle is the original date, the square is the current expected date, the range with an asterisk on the right is the certification time for calculating NASA risks. GAO image
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Risks and delays
Today, for both companies there are risks that may further delay certification.
For Boeing:
- Rescue system can not cope with the management of the ship. It turned out that in some scenarios the capsule may begin to tumble, which may be dangerous for the crew. To combat this problem, Boeing conducted extensive testing in a wind tunnel and is going to test the rescue system from the launch pad in July 2018.
- In a parachute system, the front heat shield after a drop can strike the ship and damage the parachutes. According to Boeing's calculations, this can happen only if one of the two brake parachutes of the cover is not opened, and even in this case, the chances of hitting are negligible. However, NASA calculations show that this can happen even if both parachutes are successfully deployed. If the risk is considered unacceptable, for Boeing, this would mean a remake of the parachute system and at least a six-month delay.
- The launch vehicle is one of the biggest risks of the program and the safety of astronauts. It is not known whether enough information will be obtained from the launch vehicle operator, the United Launch Alliance, to determine the risk of potentially catastrophic cracks. This may take up the entire fourth quarter of 2018. Also, information on the RD-180 engine is limited to a separate RF-US agreement, and work is still underway to obtain the necessary data for certifying the launch vehicle.
For SpaceX:
- The composite pressurized tanks of the launch vehicle, due to which the accident occurred in 2016, were replaced by new ones, but they have not yet been qualified. The risk lies in the possible problems and delays in confirming the suitability and safety of new tanks.
- The cracks in the turbopumps should be fixed in the Block 5 version of the Falcon 9 launch vehicle, but the rocket has not yet passed qualification testing at NASA. Cracks, according to NASA, are an unacceptable risk for manned flights, and if the problem is still not resolved, you will have to change the design again.
- Filling a rocket with fuel when astronauts are already in the ship is a potential risk, because earlier astronauts boarded a ship standing on a rocket already filled. SpaceX agreed to demonstrate the refueling process on the final configuration of the rocket and the ship five times before manned flight (the unmanned launch and testing of the rescue system on the flying rocket also counted), this may introduce additional delays.
Plan B for ISS
A separate claim of the Accounts Chamber was NASA’s reluctance to talk about the estimated time of certification to Congress and the lack of backup plans for delays. The fact is that the space on the "Unions" will end a little earlier than half of the estimated period, and in the worst case, 9 months, American astronauts will not be able to fly to the ISS.
Turquoise zone - the range of calculated dates of certification of at least one ship. GAO image
It is already too late to receive new places at Soyuz, production of the ship and the purchase of places take about three years, and only one remains. In March 2018, the terms of the contract with Boeing changed - NASA was able to add a third crew member to the first test flight and extend its duration if necessary. Those. The first Starliner manned flight can be flown directly to the ISS, but this will only work if the Boeing spacecraft has no delays. Now NASA is pondering how to shift the landing of the Soyuz to the last available place from November 2019 to January 2020, but this is also only a partial solution covering two months from the potential nine.
Probability distribution
And finally, the Accounts Chamber criticized the lack of a single safety metric for ships. In 2011, the permissible probability of death of the crew was set at 1/150. However, in the following documents, the more difficult attainable probability is 1/270. Worse, in 2014 they updated the model of space debris, which is used to assess the likelihood of a disaster. The new model is more dangerous than the old one, and Boeing with SpaceX may not keep within 1/270. The situation is complicated by the fact that four different divisions of NASA use three different probabilities - 1/150, 1/200, 1/270, and for different models of space debris and other conditions. To avoid a paradox, when the contracting company can fulfill the requirements of 1/270 for the old model for one department, but fails certification to 1/150 with the new model in another department, it is necessary to restore order in this area.
Feedback
The report also contains NASA's response to the five recommendations of the Accounts Chamber on the basis of the audit:
- With the first recommendation - to make your estimated estimate of terms in the quarterly report to the Congress. NASA did not agree. According to the agency, the current practice of using contractors' estimated terms is correct. And as the launch dates approach, NASA will ensure that agency estimates and contractor schedules remain consistent.
- The second recommendation concerned the development of a backup plan to prevent a gap in the flights of American astronauts on the ISS. Here NASA agreed, stated that it was already working in this direction and is awaiting their completion by the end of 2018.
- The third recommendation was on the difference in risk assessment. Here, NASA partially agreed, stating that, although the presence of several documents with different requirements may be confusing, the main thing in this case is HEOMD-CSD-10001 with a probability of 1/270
- The fourth recommendation was to document the situation with different estimates of probability for the future. Here the agency agreed.
- And finally, the fifth recommendation related to the reorganization of units to avoid combining technical and programmatic duties, with which NASA agreed, now these will be two separate posts.
Conclusion
The fact that, according to estimates of NASA, Starliner and Crew Dragon should fly much later than the announced dates is a minor sensation. However, the estimated range from May 2019 to August 2020 is large enough for Boeing or SpaceX to hit its left side without serious problems. But for large and technically complex projects, delays and postponements are the norm, so the intrigue - who will fly first and when, remains.
Source: https://habr.com/ru/post/417249/
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