5.5 Segment Ares I

[psloss]

I followed the link, but there wasn't any info about 24 segments, only pictures of 2 shuttle stacks (which looked very cool btw).

Just using the picture to note the occurrence.  The context is documented in a roundabout way; I'll bump one of those threads instead of carrying on the tangent in this one.

[psloss]

Quick question:  Do you make your morning commute with an ambulance, police car, and tanker in escort?  That's an equally obvious safety issue, and every schoolboy who's never actually driven anything anywhere might pontificate about...  Those whom practice in the real world see it for a ridiculous proposition, just like LON for a capsule launcher.

Just curious, how would you change this analogy for the shuttle?

[MrTim]

Do not forget the LON Ares I, it may not fly but it has to be waiting in an assembled form.

Where are there requirements that a LON capability must exist for the VSE or ARES-ISS launches? 

These are not orbiters and do not share the fragile TPS that drives this need on present launches.

There may not be any such written requirements now, but NASA has already effectively created them by the way they have reacted to Columbia. With STS, NASA told the public we were no longer in the test pilot stage of spaceflight (where losses are expected because you are pushing the edge of what's possible). With the destruction of the two orbiters, NASA has added bail-out capability and LON etc again signaling that we will not just leave the option of certain death when we have a reasonable alternative. In abandoning STS, NASA has told the taxpayers that even a very safe system WITH LON is still not safe enough; the agency has sold Ares/Orion as much safer than STS. If we lose a crew in Orion that could have been saved by a LON mission (but NASA has not planned for and provided the LON mission capability) I predict the end of NASA (something I am not normally inclined to do).
Consider the possible public reactions/conclusions:
1. they will  feel deceived over the replacement of orbiters with capsules
2. they may feel the whole "capsule is safer" thing was a lie and either:
    (a)  there is no good way to fly in space or
    (b) the current generation of NASA people are incompetent in being unable to reproduce the successes of 40 years ago.
3. they may finally reach a point of anger with NASA for taking such boldly stupid risks when nearly free options were available (like simply not launching an Ares I until the next one is ready to fly, it's common-sense and anybody who sees the VAB "knows" there are 4 high bays) )

I'm still curious about whether NASA will have the guts to do the WWI thing and not give the crew individual chutes (so they have an option of the mains fail). It may have flown as a concept in the 60's but I'm not so sure it'll go over well with the public of today (particularly since all orbiter crews have their own chutes and they're not expected to just trust that the vehicle's primary landing mode will work) Again, they may not have intended to box themselves in here, but NASA's reactions to the the orbiter losses have set some real precedents in the minds of the public.

[Jim]

And, how many segments do we have at the moment:
2x5.5 + 5 = 16
Thus Ares I can't go 5.5 segments!
Unless, like Scotty said, a high level NASA manager to sticks his neck out.

Do not forget the LON Ares I, it may not fly but it has to be waiting in an assembled form.

2*5.5 + 5 + 5 = 21

DIRECT will need a LON J-120/J-232.

The VAB may need modifying to take the extra segments.

No LON requirement for Orion.

[kevin-rf]

Lets not forget, LON by another name was implemented for SkyLab.

Wasn't the docking adapter on Orion supposed to be uni-sex so it could dock with another Orion. I vaguely remember a blurb somewhere about the uni-sex part of it weighing to much, thus eliminating any LON capability outside of docking with the ISS first.

LON is nice, just like having a sub rescue sub is nice. This is despite the fact that outside of coastal area's, almost all the ocean is to deep for a damaged sub to survive on the ocean floor. Outside of Orion docking with ISS, the chances of a damaged Orion surviving until help arrives are most likely the same.

[Zpoxy]

3. they may finally reach a point of anger with NASA for taking such boldly stupid risks when nearly free options were available (like simply not launching an Ares I until the next one is ready to fly, it's common-sense and anybody who sees the VAB "knows" there are 4 high bays

There will be only one mobile launcher for Ares 1

[MrTim]

3. they may finally reach a point of anger with NASA for taking such boldly stupid risks when nearly free options were available (like simply not launching an Ares I until the next one is ready to fly, it's common-sense and anybody who sees the VAB "knows" there are 4 high bays

There will be only one mobile launcher for Ares 1

That may be the current plan, and I do not personally have a problem with the notion of missions with black zones, I was just cautioning that NASA has set the public up to have VERY different expectations and they had better be thinking about that! Even Apollo, with its moon-in-a-decade-or-bust approach had multiple launchers... 40 years ago. Indeed, if future Mars missions would use more than one Orion to get the crew to the orbiting mission package, you'd need a second mobile launcher. Failure to have a second means limiting the mars mission to an unsustainable boots-and-flags gig with a crew of 6 or less.

Jim is correct in his blunt assessments of some of this (things like LON may have less utility with Orion lunar missions and may be less likely to be needed because of the architecture) but the raw, blunt engineering assessments of what is needed/justified/likely (the sort of assessments I usually favor) do not address the expectations of the public who is paying for all this (and I think that's what the original post referencing LON with Orion was getting at). When you set the customer up with certain expectations, you cannot then profess to be surprised later when he has those expectations. Ares/Orion is, unfortunately, not a purely engineering endeavor; It's supposed to be a sustainable program to support ISS, a permanently manned moon facility and Mars; it cannot be those things if it is not also wrapped in layers of good PR and unlikely to needlessly kill a crew (thus grounding it and possibly getting the whole thing canceled)

BTW: I think some of the safety requirements on Cx are actually a bit over-emphasized; Once we have a facility on the moon that can support a crew for 6 months, we gain a whole new set of mission abort and safety options we never before had (so things like return to Earth from anywhere on the moon within x hours become less important). The public may well accept some black zones for particular specific reasons if those reasons are explained and seem necessary, but I do not think it wise for NASA to have any black zones for a typical mission if there is a reasonable option (the public, and the accident investigation boards, not NASA, will get to decide what reasonable is)

[A_M_Swallow]

True the correct word is cowboys.

This is an obvious safety matter.  One to which ever schoolboy in the world knows the answer. 

No offense, but that is garbage.  The lesson learned is that you shouldn't put a fragile mission-critical subsystem alongside a launch vehicle and out in the airstream.  Further, you should NEVER put humans (or even cargo you care about) beside the lower stages.

Quick question:  Do you make your morning commute with an ambulance, police car, and tanker in escort?  That's an equally obvious safety issue, and every schoolboy who's never actually driven anything anywhere might pontificate about...  Those whom practice in the real world see it for a ridiculous proposition, just like LON for a capsule launcher.

{snip}

Quick answer.  Ambulance, police and fire vehicles exist and can be dispatched within 20 minutes during the morning commute.  The RNLI lifeboat can be launched to help ships in distress by calling the same emergency phone number.

[Richard Ellis]

the only thing irrelevant are your posts

It is refreshing to see even the most level headed contributor here can get fed up reading endless circular posts.

If I may, I would like to hijack this thread to: Re: 5.5 Segment Ares I

There is a study option to develop a 5.5 segment SRB for Ares V which some have suggested is the new baseline plan.  Subsequent to this, Constellation manager Jeff Hanley stated 'Key elements of Ares I are also down payments on Ares V - the first stage solid motors and J-2X engine will be used on the big rocket as well as Ares I, with very little if any modification.'

If both of these are true, should we expect an announcement Ares I will use a 5.5 segment SRB?  If so, how will this affect the vehicle?  Will it reduce or eliminate the payload to orbit concerns?  Will it cause more vibration issues, or less.  Will LOC, LOM estimates go up or down?

In short, what are the pros and cons likely to be with a design change to a 5.5 segment SRB?  Would it be a good idea or not?  I thank you all, in advance for your replies.

[jimvela]

Quick answer.  Ambulance, police and fire vehicles exist and can be dispatched within 20 minutes during the morning commute. 

True.

The RNLI lifeboat can be launched to help ships in distress by calling the same emergency phone number.

Non sequitur, and FALSE.  First, the obvious one that you wouldn't call 911 for a LON/rescue mission, it would be initiated by mission control and agency management for the first mission and/or a diplomatic channel if it were a foreign mission giving/needing support.

Second, you don't just launch a rescue mission anytime.  Orbital mechanics and launch logistical operations get in the way.  Even with a fully prepared and fueled vehicle sitting on another pad, there are only limited times when you could launch and still easily rendezvous with a crippled vehicle.

Remember the key constraint about LON, which is to go to an orbiter with TPS damage and retrieve the crew.  This vehicle system won't have that problem.

The far, far better option is safe haven.  Go to ISS and park.  Wait there for supplies and a ride home.  Not going to ISS, then have an intermediate destination where supplies and lifeboat can be prepositioned rather than hoping for an improbably reactionary mission.

[edkyle99]

It will fly because it has to fly.

 - Ed Kyle

Why does it have to?  Will the world end if it doesn't? 

If Ares/Orion turned into a massive program failure, a costly nightmarish public relations disaster, NASA would be out of the human spaceflight business for nearly a decade at minimum. 

So yes, it has to fly.

 - Ed Kyle

[jimvela]

The RNLI lifeboat can be launched to help ships in distress by calling the same emergency phone number.

Non sequitur, and FALSE.  First, the obvious one that you wouldn't call 911 for a LON/rescue mission, it would be initiated by mission control and agency management for the first mission and/or a diplomatic channel if it were a foreign mission giving/needing support.

OK, I'm wrong about the RNLI lifeboat, as it turns out it's a UK charity, and they do launch rescue vessels at sea.  That still turns out to have bupkis in common with a rescue mission in space, and all of the other points in my reply are valid.

Sorry about my ignorance of UK facilities, some day I'd love to spend some time touring your country.

[MrTim]

There is a study option to develop a 5.5 segment SRB for Ares V which some have suggested is the new baseline plan. (snip) If so, how will this affect the vehicle?  Will it reduce or eliminate the payload to orbit concerns?  Will it cause more vibration issues, or less.  Will LOC, LOM estimates go up or down?

In short, what are the pros and cons likely to be with a design change to a 5.5 segment SRB?  Would it be a good idea or not?  I thank you all, in advance for your replies.

Should not change the LOC/LOM "numbers". Oh, I'm sure somebody will do some "calculations" to arrive at new "numbers" (justified by, for example, a change in the number of joints) but in general you will be replacing one SRB that has no flight history with another one that has no flight history, and IMHO this big issue dwarfs the impact of lesser details. Put another way: I am sufficiently skeptical of precision in LOC/LOM "numbers" that the difference would be a small portion of last bit of wand-waving by any wizard offering such numbers. Marginally more risk from the motor itself, perhaps marginally more issues with overall vehicle dynamics, possible inter-stage structural issues as vehicle becomes even longer, but possibly minor added safety from better mass margins? It will not eliminate TO issues (all solids have them) but will likely change them enough to alter the mitigation plans (not necessarily the method of mitigation, but the details). If Ares V is going to 5.5, then it's probably a good idea to look at them for Ares I, but they had better decide soon; the Ares I-X test shot is less than a year away and the primary justification for that shot is that it is essentially a 1-up wind tunnel run on the OML of the Ares I. If the Ares I OML will grow with a 5.5seg SRB, they'd better squeeze that extra .5 into the I-X not just for good data but also for credibility.

[MrTim]

Second, you don't just launch a rescue mission anytime.  Orbital mechanics and launch logistical operations get in the way.  Even with a fully prepared and fueled vehicle sitting on another pad, there are only limited times when you could launch and still easily rendezvous with a crippled vehicle.

True, but NASA does not refuse to plan an STS LON because there are some situations where it would not work. The unforgivable sin in the eyes of the public is to not plan one for the times when one would work. If NASA kills a crew it could have saved, it had better prepare for a public outcry for prosecutions. This would be a very different thing from Columbia or Challenger where the public accepted that the disaster was unexpected/unanticipated and there was no way at the time of the disaster to save the crew.

Remember the key constraint about LON, which is to go to an orbiter with TPS damage and retrieve the crew.  This vehicle system won't have that problem.

But because it is made by man, and man is imperfect, it will have problems of its own which none of us here and now know about. As a capsule with a service module, I am sure it will be just as ferpect as Apollo-13 was. 

The far, far better option is safe haven.  Go to ISS and park.  Wait there for supplies and a ride home.  Not going to ISS, then have an intermediate destination where supplies and lifeboat can be prepositioned rather than hoping for an improbably reactionary mission. 

I think you're getting a bit too picky about the definition of LON (Launch On Need). For all but Hubble, the current LON plans assume the 1st vehicle would go to (or stay at) ISS and the LON vehicle would go there... so in that regard an ISS-bound-Orion LON would be no different than an ISS-bound-STS LON but might just be for different reasons (like some catastrophic service module failure). Keep in mind that the whole point of such missions is to deal with unplanned emergencies, so by definition we do not today know what might cause an Orion LON mission, just as folks in the 70's did not plan for the current LON mission scheme in response to wing leading edge failures. It's not going to work to go hat-in-hand to the voters after the 1st Orion kills a crew and say "sure we might have saved them, but we decided not to and, well, at least they died in a capsule and not in one of those winged space-plane thingies"

Also, a LON mission might not even be safety-related; If we get a full Mars mission package assembled in LEO and ready to go, but the crew aborts with a 2nd stage engine failure, having another Orion with a backup crew ready to go could save a pile of cash and taxpayer patience.

Some plans should be made precisely because you do not know what will happen.

[Lampyridae]

There's an alternative to LON which is called reliability engineering. Increase the fault tolerance of your systems, reduce the number of potential failure modes. Ares I has minimal stage separations but Orion has been stripped of safety features. Not to mention how the oscillation environment affects the rest of the stack. Increasing mass for extra safety features on the Orion IMHO is safer than having a minimal stage sep. Yes, it can blow up on the pad but that's what escape towers are for. What you do not want is an electrical fire 300 000km from Earth.

[jeff.findley]

Where's the LON for Soyuz? Where was it for Mercury, Gemini or Apollo? LON exists for one reason only - the fragility of the shuttle TPS. Carrying that requirement on into other programs that don't suffer the same weakness is a waste of resources and effort.

Safety can be taken too far.

How do you count the plans for a rescue Apollo CSM flight to Skylab in case the CSM docked to Skylab developed a serious problem?  The hardware "kit" for that mission was built and ready for use, should the need arise.  In that case, Skylab had enough supplies to keep the crew alive until the rescue mission could be flown.

Jeff

[MrTim]

Where's the LON for Soyuz? Where was it for Mercury, Gemini or Apollo? LON exists for one reason only - the fragility of the shuttle TPS.  (snip)

How do you count the plans for a rescue Apollo CSM flight to Skylab in case the CSM docked to Skylab developed a serious problem?  The hardware "kit" for that mission was built and ready for use, should the need arise. (snip)

The point is that LON was not a program requirement. It wasn't until Skylab that the possibility of LON even emerged, and it still wasn't a program requirement.

The congress, and NASA have become far more risk-averse now and would probably not tolerate those earlier architectures today. LON does not exist now because thermal tiles are fragile (they were always fragile and this has always been known, indeed the glue that held them on was even an issue in the early flights) The real reason for LON now is not some hardware detail, it is a change in tolerance for stupid, avoidable LOC risks. The shuttle has always had some big bold black zones (which the public accepts because we all know there is no possible rescue method) and Ares/Orion lunar flights will have some too, but any failure mode where a recovery would be reasonably possible but which NASA does not prepare for is simply no longer acceptable. Flying shuttles is far safer today than it was at the beginning of the program but the increasing safety has not been able to stay ahead of the increase in risk-aversion. This is a large part of why STS is being retired (safer than it ever was, but now considered too unsafe).

Just imagine what the public outcry would have been if the following been true:
1. The hole in Columbia's wing detected on flight day 1
2. NASA had been aware of the possibility from before Enterprise was built
3. A method to save the crew in that circumstance had always been known and would have been relatively simple
4. Each orbiter was effectively capable of such a rescue by virtue of having the proper docking hardware designed and built-in from the beginning of the program (so a rescue would not even require a single spacewalk)
5. The crew rescue would have only required a second mobile launcher (which was also needed by other future aspects of the program) and change in program management which would stack each system in time to be a LON vehicle instead of just in time to fly its own mission. (no more stackings per year, just a schedule change in stacking dates and launch dates)
6. (and finally) The agency announced that it could have saved the crew but had decided not to bother and to just count on redundant systems (which had failed), the crew were a bunch of risk-taking silk-scarfed test pilots anyway, so the crew was simply going to be allowed to die in a few days.

BZZZZT! Wrong answer. Congressional inquiries and court cases to follow.

We are not in the 60's anymore. Rescue in the early missions with their primitive technology was generally accepted by the public  as impossible (everybody knew that NASA was pushing the edges of what was humanly possible at that time), but that's not the case today and NASA has made that very point by having LON missions available for STS; this is called "setting a precedent"

[MrTim]

There's an alternative to LON which is called reliability engineering. Increase the fault tolerance of your systems, reduce the number of potential failure modes. (snip)

Yup, worked really well for Challenger and Columbia. Works so well that NASA will not bother with LON plans for the Hubble mission.... errr.... no, wait.... scratch that 
There is a big difference between, on the one hand, doing everything you can to make your systems as safe as possible and, on the other hand, planning a way to rescue people when your "safe" system fails. These two things are not mutually exclusive, and only a complete idiot does the first and not the second in today's society. The public can forgive you for not trying the second when it's not possible, but they are unlikely to forgive you if it is both possible and not even particularly expensive or inconvenient but you choose not to even try.

[Jim]

this is called "setting a precedent"

BZZZZT! Wrong !!!!
Which not applicable to the CEV and future missions. 

The CEV will be able to stay attached the ISS for 6 months.  No need to scramble for an LON. 

LON is not applicable to lunar missions. 

[A_M_Swallow]

Since LON is off topic for the thread title and there has been more than 3 replies I have created a new topic in the General Discussions section called "Space Rescue Missions and Vehicles".
http://forum.nasaspaceflight.com/index.php?topic=13604.0