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  Man-rating commercial cargo launch vehicles

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Author Topic:   Man-rating commercial cargo launch vehicles
Michael Davis
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From: Houston, Texas
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posted 02-06-2010 02:01 PM     Click Here to See the Profile for Michael Davis   Click Here to Email Michael Davis     Edit/Delete Message   Reply w/Quote
Could anyone explain (or point to a source to explain) the differences and issues involved in modifying commercial cargo launch vehicles (e.g. Atlas and Delta) for human use? Not necessarily for Orion, but for manned launches of any sort.

As I understand, there are no fundamental differences in the flight profiles or performance of a rocket developed primarily for unmanned payloads versus one designed specifically for a manned vehicle? In other words a rocket is a rocket when it comes to getting a payload to a particular orbit. I mean other than of course the safety features that must be incorporated into the design and construction.

ilbasso
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posted 02-13-2010 07:37 PM     Click Here to See the Profile for ilbasso   Click Here to Email ilbasso     Edit/Delete Message   Reply w/Quote
Was speaking with someone the other day who said that "man rating" basically means that you have to have the ability to save the payload (manned capsule) at any point during the launch profile. This is not a requirement for unmanned launches.

Byeman
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posted 03-24-2010 08:55 AM     Click Here to See the Profile for Byeman   Click Here to Email Byeman     Edit/Delete Message   Reply w/Quote
There is a difference in the trajectories for the EELVs but it can be changed. The EELVs were designed for the geosynchronous transfer orbit (GTO) deliver mission. They have high specific impluse (ISP) but relatively low thrust (15k-25klb) engines in the upper stages. Because of this, the first stage flight is lofted to get the vehicles out of the gravity well quicker.

If this trajectory is used for a manned mission, there are no issues for a flight with no problems. The issue is when there is an abort. With these steep trajectories, a resultant entry from an abort would subject the crew to severe g loads, sometime fatal.

The place in the trajectories where there are abort issue are the so called "black zones." But this is no real problem, all that is needed is for the trajectories to be designed to be depressed a little with some resultant loss of performance.

This was worked out in the orbital spaceplane (OSP) project and only politics kept bringing it up as a showstopper.

Michael Davis
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posted 03-27-2010 09:29 AM     Click Here to See the Profile for Michael Davis   Click Here to Email Michael Davis     Edit/Delete Message   Reply w/Quote
Thanks for that information. That explains a great deal to me. I had not considered abort scenarios as part of the constraints needed for an ascent profile on a manned launch.

issman1
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posted 06-10-2010 10:20 AM     Click Here to See the Profile for issman1     Edit/Delete Message   Reply w/Quote
Is man-rating Atlas 5 or Delta 4 prohibitive by cost, performance or time?

And, unless I'm mistaken, Falcon 9 is man-rated.

Editor's note: Threads merged.

capoetc
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From: Newnan GA (USA)
Registered: Aug 2005

posted 06-10-2010 09:31 PM     Click Here to See the Profile for capoetc   Click Here to Email capoetc     Edit/Delete Message   Reply w/Quote
quote:
Originally posted by issman1:
And, unless I'm mistaken, Falcon 9 is man-rated.
Man-rated by whom? After one flight, really? I don't think so...

Robert Pearlman
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posted 06-11-2010 07:25 AM     Click Here to See the Profile for Robert Pearlman   Click Here to Email Robert Pearlman     Edit/Delete Message   Reply w/Quote
quote:
Originally posted by capoetc:
Man-rated by whom?
SpaceX has said they have designed Falcon 9 and Dragon from the start to meet NASA's requirements (NPR 8705.2B) for man-rating.

To achieve NASA human-rating certification, additional test flights will obviously be needed (not all components have flown yet, let alone be built) but that does not mean that the design and hardware built/flown to-date are not already capable of complying to NASA's standards.

Byeman
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posted 06-11-2010 08:46 AM     Click Here to See the Profile for Byeman   Click Here to Email Byeman     Edit/Delete Message   Reply w/Quote
quote:
Originally posted by issman1:
Is man-rating Atlas 5 or Delta 4 prohibitive by cost, performance or time?
None of the above. NASA hasn't provided a requirement to ULA to man-rate Atlas 5 or Delta 4.

capoetc
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posted 06-11-2010 07:04 PM     Click Here to See the Profile for capoetc   Click Here to Email capoetc     Edit/Delete Message   Reply w/Quote
quote:
Originally posted by Robert Pearlman:
To achieve NASA human-rating certification, additional test flights will obviously be needed (not all components have flown yet, let alone be built)...
Of course, I think many/most are aware it was designed to be manrated. The claim was that it IS man rated, which is clearly not correct.

Spacefest
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From: Tucson, AZ USA
Registered: Jan 2009

posted 06-16-2010 11:01 AM     Click Here to See the Profile for Spacefest   Click Here to Email Spacefest     Edit/Delete Message   Reply w/Quote
quote:
Originally posted by capoetc:
One flight does not validate the Falcon contribution to ObamaSpace, just as one failure would not invalidate it.
What about the shuttle? It seems to have been man-rated before it even flew.

Robert Pearlman
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posted 06-16-2010 11:14 AM     Click Here to See the Profile for Robert Pearlman   Click Here to Email Robert Pearlman     Edit/Delete Message   Reply w/Quote
The space shuttle pre-dates (what is now considered) NASA's man-rating requirements and as such (technically) could not be man-rated before it flew (one might even make the argument that the shuttle would never have flown crewed on its first mission had NASA's present-day process been in place).

Spacefest
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posted 06-16-2010 03:55 PM     Click Here to See the Profile for Spacefest   Click Here to Email Spacefest     Edit/Delete Message   Reply w/Quote
Okay, when did the procedures start?

Robert Pearlman
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posted 06-16-2010 04:03 PM     Click Here to See the Profile for Robert Pearlman   Click Here to Email Robert Pearlman     Edit/Delete Message   Reply w/Quote
From what I can discern, the certification process was first published in 2005.

(That's not to say there weren't man-rating efforts for Atlas, Titan and other legacy rockets (even shuttle), but those procedures were developed as part of the process of designing the vehicle, as opposed to the current system where any new vehicle must meet a set of requirements already defined.)

Spacefest
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posted 06-17-2010 12:55 PM     Click Here to See the Profile for Spacefest   Click Here to Email Spacefest     Edit/Delete Message   Reply w/Quote
Sounds like this was squarely aimed at SpaceX. An Apollo astronaut told me Mike Griffin had a Von Braun complex. Ares was to be his legacy.

Robert Pearlman
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posted 06-17-2010 01:07 PM     Click Here to See the Profile for Robert Pearlman   Click Here to Email Robert Pearlman     Edit/Delete Message   Reply w/Quote
If I recall correctly, the original impetus to draft human-rating requirements came out of the X-33 program (someone please correct me if I am mistaken), before Griffin became administrator or SpaceX was on NASA's radar. Besides, the same human-ratings requirements apply to all vehicles, including Ares.

mercsim
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From: Phoenix, AZ
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posted 06-17-2010 02:25 PM     Click Here to See the Profile for mercsim   Click Here to Email mercsim     Edit/Delete Message   Reply w/Quote
quote:
Originally posted by Robert Pearlman:
If I recall correctly, the original impetus to draft human-rating requirements came out of the X-33 program
Here is a link to a paper I have a hard copy of that discusses "man rating" just a few years earlier...

There was a similar paper written in the early 60's but I can't find a link to it. I'll try to dig up the hard copy and reference it.

Robert Pearlman
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posted 06-17-2010 02:36 PM     Click Here to See the Profile for Robert Pearlman   Click Here to Email Robert Pearlman     Edit/Delete Message   Reply w/Quote
As I wrote up-thread, of course there were man-rating efforts for legacy rockets like Redstone, but in those cases, the process was carried out in tandem with the development of the vehicle, not as a set of predefined universal requirements that existed even before the vehicle is proposed.

Spacefest
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posted 06-17-2010 03:23 PM     Click Here to See the Profile for Spacefest   Click Here to Email Spacefest     Edit/Delete Message   Reply w/Quote
Seems like man-rating is just a bureaucratic paper chase. It appears to be common sense: Reliability, performance, and safety (abort system.) Oh - in the Mercury days, it added a satisfactory monkey launch.

Performance (the ability to get x to x), and reliability are pretty much a given. I'd be curious what the abort requirements are.

Automatic abort, as with Mercury? or pilot-choice, as with Gemini, Apollo, and so on. Big choices. Shouldn't take years to accomplish.

The X-33 was unmanned.

Robert Pearlman
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posted 06-17-2010 03:33 PM     Click Here to See the Profile for Robert Pearlman   Click Here to Email Robert Pearlman     Edit/Delete Message   Reply w/Quote
quote:
Originally posted by Spacefest:
The X-33 was unmanned.
The X-33 was unmanned, but its intended follow-on commercial vehicle, Lockheed Martin's VentureStar was proposed to carry humans in its cargo bay.

Jay Chladek
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posted 06-20-2010 01:31 PM     Click Here to See the Profile for Jay Chladek   Click Here to Email Jay Chladek     Edit/Delete Message   Reply w/Quote
One factor with shuttle that was different in its man rating is for the first four test flights, it had ejection seats available through about the first minute of flight and the final approach and landing phases. In a sense, the man rating for it was to make it capable of carrying more then just two crew members as the orbiter was intended to be the escape system.

That being said, considering what we know now about shuttle, it is highly doubtful if such a project were undertaken today that it would fly manned on its first launch. NASA's culture got increasingly bolder throughout the 1970s and 80s. One could potentially trace it back to Apollo 8, which flew manned after the Apollo 6 booster experienced bad pogo vibrations, engine shutdowns. But still the arguement was made that the fixes would mean the Saturn V would work with a crew on it. After that, things got bolder.

The current man rating culture seems to be more based on what it was for Mercury and Gemini with the escape system being certified and tested (Little Joe and ejection seat tests) seperate from the launch vehicle and at least two all up test flights before putting a test crew onboard. Could things be done quicker, yes. But just because one can doesn't mean one should.

As an example, what if Ariane V had been man rated with a crewed spacecraft onboard (it was intended for the cancelled Hermes shuttle) for its maiden flight? Every bit of testing before the flight showed the new stuff would work and the old stuff from Ariane 4 was already certified to work. Well, then the inertial guidance system (taken from Ariane 4 and having no major failures over its flight history) failed, the rocket had to be self destructed and further testing showed the failure was inevitable.

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