Author Topic: Commercial Crew (CCtCAP) - Discussion Thread  (Read 224375 times)

Offline brickmack

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Re: Commercial Crew (CCtCAP) - Discussion Thread
« Reply #900 on: 03/04/2017 12:10 AM »
The Justification mentions "Spacedesign Corporation" put in a bid. Funny that a semi-defunct software company would bid on a crew delivery vehicle. I bet NASA was unamused.

Offline psloss

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Re: Commercial Crew (CCtCAP) - Discussion Thread
« Reply #901 on: 03/05/2017 05:36 PM »
FWIW, a revision of CCT-REQ-1130, "ISS Crew Transportation and Services Requirements Document" showed up on NTRS recently:
https://ntrs.nasa.gov/search.jsp?R=20170001943

(Attached here, as well.)

Offline yg1968

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Re: Commercial Crew (CCtCAP) - Discussion Thread
« Reply #902 on: 03/06/2017 02:48 AM »
Loss of crew is now at 1 in 200 (but it includes orbital debris hazards while docked to the ISS):

Quote from: page 34 of Document CCT-REQ-1130
3.2.1 Crew Safety
3.2.1.1 Loss of Crew Risk

The CTS shall safely execute the objectives defined in Section 3.1 with the following Loss of
Crew (LOC) requirements for the various mission phases.

a. The overall LOC probability distribution for an ISS mission shall have a mean value no
greater than 1 in 200 without utilizing operational controls implemented by the ISS, such as
TPS inspections.

b. The LOC probability distribution for the combined ascent and entry phases of an ISS mission
shall have a mean value no greater than 1 in 500. [R.CTS.030]

Rationale: The LOC requirement is consistent with NASA's defined goals and thresholds for
crewed vehicles. The LOC values are part of the overall certification process for the
commercial launch vehicle and spacecraft and establish a basis for decision making relative
to safety enhancing features in the design, including failure tolerance. The LOC requirement
represents a design robustness criteria to be managed by the commercial provider alone.
« Last Edit: 03/06/2017 02:55 AM by yg1968 »

Offline AnalogMan

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Re: Commercial Crew (CCtCAP) - Discussion Thread
« Reply #903 on: 03/06/2017 10:03 AM »
Loss of crew is now at 1 in 200 (but it includes orbital debris hazards while docked to the ISS):

Quote from: page 34 of Document CCT-REQ-1130
3.2.1 Crew Safety
3.2.1.1 Loss of Crew Risk

The CTS shall safely execute the objectives defined in Section 3.1 with the following Loss of
Crew (LOC) requirements for the various mission phases.

a. The overall LOC probability distribution for an ISS mission shall have a mean value no
greater than 1 in 200 without utilizing operational controls implemented by the ISS, such as
TPS inspections.

b. The LOC probability distribution for the combined ascent and entry phases of an ISS mission
shall have a mean value no greater than 1 in 500. [R.CTS.030]

Rationale: The LOC requirement is consistent with NASA's defined goals and thresholds for
crewed vehicles. The LOC values are part of the overall certification process for the
commercial launch vehicle and spacecraft and establish a basis for decision making relative
to safety enhancing features in the design, including failure tolerance. The LOC requirement
represents a design robustness criteria to be managed by the commercial provider alone.

Revision: D-1 (March 23, 2015) has exactly the same text.

Offline yg1968

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Re: Commercial Crew (CCtCAP) - Discussion Thread
« Reply #904 on: 03/06/2017 02:03 PM »
The number recently changed. It was still 1 in 270 at the end of 2015 according to ASAP. NASA decided to reduce it to 1 in 200 in order to take into account MMOD damage while docked at the ISS. See the 2015 ASAP report for more on this:

Quote from: page 17 of the ASAP 2015 Report
The CCP has a requirement to achieve a LOC risk of no worse than 1 in 270 (1:270). Analysis of current designs indicates that they fall short of that limit. The primary risk contributor is MMOD damage. The strategy that is being taken to meet the LOC requirement is to back off to 1:200 for the spacecraft themselves, but to require that the design and vehicle capability be the sole means to achieve that level without consideration of operational adjustments. Any potential inspections or other operational workarounds will be put aside and left for later consideration. Both companies are now considering potential changes to their vehicles to address the MMOD risks. While there will always be risk from MMOD, NASA wants the providers to do as well as they can in using the spacecraft design to provide primary prevention before looking at other ways to improve safety through secondary preventive techniques such as inspection. There is some evidence that this strategy will have a positive result.

https://forum.nasaspaceflight.com/index.php?topic=39380.msg1481015#msg1481015

See also the 2016 report on the same issue:

Quote from: page 8 of the ASAP 2016 Report
The ASAP was informed that the LOC goal of 1 in 270 may not be able to be met without additional spacecraft mitigations due to Micrometeoroid and Orbital Debris (MMOD)-associated risks, which are a dominant factor in the LOC calculation. Since the designs of proposed spacecraft systems are not fully mature and are still in a state of flux, it is impossible to determine what the final configurations will yield with respect to LOC. There may be a limit to what can be achieved by design considérations alone, and operational mitigations may be required to achieve the LOC goals. Also, we note that in considering LOC goals, we recognize that there is a fairly large uncertainty band around any calculated LOC number. This issue is currently under review and has the potential to impact budget, schedule, and crew safety.

https://oiir.hq.nasa.gov/asap/documents/2016_ASAP_Annual_Report.pdf

Offline A_M_Swallow

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Re: Commercial Crew (CCtCAP) - Discussion Thread
« Reply #905 on: 03/06/2017 02:34 PM »
At some point putting a Kevlar cover around visiting vehicles becomes a viable option against MMOD damage. I suspect that Bigelow will be happy to sell more of his product.

Offline AnalogMan

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Re: Commercial Crew (CCtCAP) - Discussion Thread
« Reply #906 on: 03/06/2017 04:54 PM »
The number recently changed. It was still 1 in 270 at the end of 2015 according to ASAP. NASA decided to reduce it to 1 in 200 in order to take into account MMOD damage while docked at the ISS. See the 2015 ASAP report for more on this:

[...]

Clearly the Commercial Crew Program had already decided to change the number to 1 in 200 (before operational mitigations) by the time they issued Rev D-1 of the requirements document in March 2015.

[Document attached]

Offline yg1968

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Re: Commercial Crew (CCtCAP) - Discussion Thread
« Reply #907 on: 03/06/2017 07:08 PM »
Thanks! ASAP may not have been aware that the requirements had already changed earlier in 2015.

As you say, it was changed in 2015. I didn't follow all of the changes but I know that back in 2011, it was originally 1 in 270. See below for the 2011 version:

Quote from: page 28 of 2011 version of CCT-REQ-1130
3.2.1.3 The CTS shall safely execute the objectives defined in Section 3.1 with the
following Loss of Crew (LOC) requirements for the various mission phases.
a. The overall LOC probability distribution for an ISS mission shall have a mean value no greater than 1 in 270.
b. The LOC probability distribution for the ascent phase of an ISS mission shall be no greater than 1 in 1000.
c. The LOC probability distribution for the entry phase of an ISS mission shall be no greater than 1 in 1000.

3.2.1.4 The CTS Loss of Mission (LOM) probability distribution for an ISS mission shall have a mean value of no greater than 1 in 55.
a. The overall LOC mission risk in 3.2.1.2 and the LOM risk in 3.2.2 assume docked mission duration of 210 days.
b. A spacecraft failure that requires the vehicle to enter earlier than the pre-launch planned EOM timeframe shall be considered a loss of mission.

Rationale: These LOC and LOM requirements are a direct flow down from the NASA ESMD Exploration Architecture Requirements Document (EARD) and are consistent with NASA‟s defined goals and thresholds for crewed vehicles. The overall LOC mission risk in 3.2.1.3 and the LOM risk in 3.2.1.4 assume docked mission duration of 210 days. A spacecraft failure that requires the vehicle to execute a deorbit/entry/landing earlier than the planned EOM timeframe is considered a loss of mission. Launch vehicle ascent cases that run out of fuel prior to achieving the orbit target are also considered a loss of mission. The LOC values are part of the overall certification process for the commercial launch vehicle and spacecraft and establish a basis for decision making relative to safety enhancing features in the design including failure tolerance.

https://forum.nasaspaceflight.com/index.php?topic=26489.msg795150#msg795150
« Last Edit: 03/06/2017 07:30 PM by yg1968 »

Offline yg1968

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Re: Commercial Crew (CCtCAP) - Discussion Thread
« Reply #908 on: 03/08/2017 04:01 PM »
ECLSS Systems Put to the Test for Commercial Crew Missions:
https://www.nasa.gov/feature/eclss-systems-put-to-the-test-for-commercial-crew-missions

Offline yg1968

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« Last Edit: 04/09/2017 07:05 PM by yg1968 »

Offline yg1968

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Re: Commercial Crew (CCtCAP) - Discussion Thread
« Reply #910 on: 04/09/2017 06:03 PM »
During the NAC meeting, there was a discussion between Wayne Hale and Kathy Lueders on the Shuttle LOC numbers. Lueders said that they were 1 in 90 but Wayne Hale corrected her and said that the actual numbers were 1 in 65. But I think that Wayne Hale misunderstood the numbers that Kathy Lueders was trying to quote during the NAC meeting. She was quoting the LOC probability risk assessment (PRA) numbers, not the actual numbers.

The Shuttle's LOC probability risk assessment numbers towards the end of the program were estimated at 1 in 90 according to a 2011 NASA risk report. See these links:
https://msquair.files.wordpress.com/2011/05/nasashuttleriskreview-excerpt.pdf
https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20110004917.pdf
https://usatoday30.usatoday.com/tech/science/space/2011-02-13-nasa-underestimated-risk_N.htm

Obviously and as Wayne Hale pointed out during the NAC meeting, the real numbers for the Shuttle were 1 in 65 but these weren't the PRA LOC numbers for each new Shuttle flight in 2011 (which were still estimated at 1 in 90).

For commercial crew, NASA decided that it needed to be 3 times as safe as Shuttle at 1 in 270 (90 x 3). So that's were that LOC number comes from:
https://www.nasaspaceflight.com/2015/05/nasa-evaluating-commercial-loss-crew-mishap/

During the NAC meeting, Lueders indicated that NASA may allow NASA contractors to choose between the 1 in 270 (with a separate number for MMOD risks) and the 1 in 200 LOC numbers (which would include the MMOD risks).
« Last Edit: 04/09/2017 07:03 PM by yg1968 »

Offline Comga

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Re: Commercial Crew (CCtCAP) - Discussion Thread
« Reply #911 on: 04/10/2017 07:48 PM »
Update on commercial crew:
https://www.nasaspaceflight.com/2017/04/commercial-crew-tight-achievable-timeline-2018/

This article just got picked up by the AIA dailyLead ( aia@dailylead.com ) for April 10
What kind of wastrels would dump a perfectly good booster in the ocean after just one use?

Online FutureSpaceTourist

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Re: Commercial Crew (CCtCAP) - Discussion Thread
« Reply #912 on: 04/12/2017 06:07 AM »
By Jeff Foust:

Quote
COLORADO SPRINGS — One of the NASA astronauts training to fly on test flights of commercial crew vehicles said he expects the agency to make flight assignments for those missions as soon as this summer.

In a discussion with reporters here April 6 outside a simulator of Boeing’s CST-100 Starliner commercial crew vehicle, Robert Behnken said those upcoming crew assignments will allow astronauts who have been training on both the Starliner and SpaceX’s Dragon v2 to specialize on one vehicle.

http://spacenews.com/commercial-crew-flight-assignments-could-come-this-summer/

Offline Hog

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Re: Commercial Crew (CCtCAP) - Discussion Thread
« Reply #913 on: 04/17/2017 02:46 PM »
During the NAC meeting, there was a discussion between Wayne Hale and Kathy Lueders on the Shuttle LOC numbers. Lueders said that they were 1 in 90 but Wayne Hale corrected her and said that the actual numbers were 1 in 65. But I think that Wayne Hale misunderstood the numbers that Kathy Lueders was trying to quote during the NAC meeting. She was quoting the LOC probability risk assessment (PRA) numbers, not the actual numbers.

The Shuttle's LOC probability risk assessment numbers towards the end of the program were estimated at 1 in 90 according to a 2011 NASA risk report. See these links:
https://msquair.files.wordpress.com/2011/05/nasashuttleriskreview-excerpt.pdf
https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20110004917.pdf
https://usatoday30.usatoday.com/tech/science/space/2011-02-13-nasa-underestimated-risk_N.htm

Obviously and as Wayne Hale pointed out during the NAC meeting, the real numbers for the Shuttle were 1 in 65 but these weren't the PRA LOC numbers for each new Shuttle flight in 2011 (which were still estimated at 1 in 90).

For commercial crew, NASA decided that it needed to be 3 times as safe as Shuttle at 1 in 270 (90 x 3). So that's were that LOC number comes from:
https://www.nasaspaceflight.com/2015/05/nasa-evaluating-commercial-loss-crew-mishap/

During the NAC meeting, Lueders indicated that NASA may allow NASA contractors to choose between the 1 in 270 (with a separate number for MMOD risks) and the 1 in 200 LOC numbers (which would include the MMOD risks).
Wow if Shuttles probability for a LOC event was 1 in 90 as the SSP was flying in 2011, I shudder to think of the numbers for the test missions for STS-1 through STS-4.  Perhaps STS-5 would have been the riskiest mission as the ejection seats and pressure suits were discarded and the original First Manned Orbital Flight engines ME-2005, ME-2006, ME-2007 were still being used as the Phase-1 SSME upgrades didn't come into effect until STS-6 through STS-51L?
(Phase-1 SSMEs Phase I engine offered increased service life and was certified for 104% RPL)?

Starting another thread as Shuttle discussion is off topic for this Commercial Crew Discussion thread.
http://forum.nasaspaceflight.com/index.php?topic=42758.msg1667784#msg1667784
« Last Edit: 04/17/2017 02:57 PM by Hog »
Paul

Offline yg1968

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Re: Commercial Crew (CCtCAP) - Discussion Thread
« Reply #914 on: 04/23/2017 05:45 PM »
At 14m30s, Vern Thorp from ULA said that they were making modifications, this year, to the White Room for other customers in the future.

It's not clear what he meant by other customers. Presumably, he meant modifications for space tourist flights but he may have meant for other companies such as SNC:

« Last Edit: 04/23/2017 06:22 PM by yg1968 »

Offline Star One

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Commercial Crew (CCtCAP) - Discussion Thread
« Reply #915 on: 04/23/2017 05:56 PM »
Thanks for the link. I am not sure how much is to be gained in speculating on what he meant at this time as it seemed to me he was just talking in purely hypothetical terms with nothing in his comment to extract any data from.
« Last Edit: 04/23/2017 06:00 PM by Star One »

Offline yg1968

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Re: Commercial Crew (CCtCAP) - Discussion Thread
« Reply #916 on: 04/23/2017 06:17 PM »
He said other customers in the future. So he may have meant that ULA wants to be able to service other companies (other than Boeing) should the need ever arise. Technically, Boeing is ULA's customer for commercial crew (not NASA) since Boeing is the prime contractor and ULA is a subcontractor.

I wish that someone had asked a follow-up question on this.
« Last Edit: 04/23/2017 06:25 PM by yg1968 »

Offline Star One

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Re: Commercial Crew (CCtCAP) - Discussion Thread
« Reply #917 on: 04/23/2017 07:05 PM »
He said other customers in the future. So he may have meant that ULA wants to be able to service other companies (other than Boeing) should the need ever arise. Technically, Boeing is ULA's customer for commercial crew (not NASA) since Boeing is the prime contractor and ULA is a subcontractor.

I wish that someone had asked a follow-up question on this.

It's odd that no one did that when he came out with that kind of statement.

Online Zed_Noir

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Re: Commercial Crew (CCtCAP) - Discussion Thread
« Reply #918 on: 04/23/2017 07:16 PM »
He said other customers in the future. So he may have meant that ULA wants to be able to service other companies (other than Boeing) should the need ever arise. Technically, Boeing is ULA's customer for commercial crew (not NASA) since Boeing is the prime contractor and ULA is a subcontractor.

I wish that someone had asked a follow-up question on this.
:)
Maybe ULA & SX have reached an agreement to loft up each other's commercial crewed capsule for contingencies.
:)

Re: Commercial Crew (CCtCAP) - Discussion Thread
« Reply #919 on: 06/05/2017 05:29 PM »
Crew Dragon Trainer Takes Shape at Kennedy

https://blogs.nasa.gov/kennedy/2017/06/05/crew-dragon-trainer-takes-shape-at-kennedy/

Quote
NASA and SpaceX engineers are working together at NASA’s Kennedy Space Center in Florida to build a full-scale Crew Dragon model, or Recovery Trainer, that will be used by the U.S. Air Force to perform flight-like rescue and recovery training exercises in the open ocean later this year.

The model, shown above with astronauts Dan Burbank and Victor Glover inside, is built to mimic the Crew Dragon spacecraft that SpaceX is developing with NASA’s Commercial Crew Program to fly astronauts to and from the International Space Station. In certain unusual recovery situations, SpaceX may need to work with the U.S. Air Force to send parajumpers to recover astronauts from the capsule. The Recovery Trainer will be used by the Air Force to prepare procedures and train for this contingency scenario. The trainer also has two working hatches and other simulated components similar to the ones astronauts and support teams will encounter in real missions.

Scott Colloredo, deputy director of Kennedy’s Engineering Directorate, said the engineers adapted SpaceX designs of internal elements to be compatible with the trainer and worked with Kennedy’s Prototype Development Lab to produce the parts quickly and install them inside the trainer. The Prototype Development Lab designs, fabricates and tests prototypes, test articles and test support equipment. The lab has a long history of providing fast solutions to complex operations problems. The lab’s teams of engineers use specialized equipment to produce exacting, one-of-a-kind items made from a range of materials depending on the design.

“We perform things that complement what the partners and programs provide,” Colloredo said. “The team delivered right to the minute.”

SpaceX is now finalizing modifications to the trainer to ensure it floats in water in the same way as the Crew Dragon spacecraft. Following those modifications, the trainer will enter service as the primary training vehicle for Crew Dragon astronaut recovery operations.

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