Obviously any "quick fix" that could be applied to the existing fleet of shuttles (3 vehicles) is good.  I've sure that given the political pressures they have considered all that.  My point is that the falling ice problem must have been there every for the last 25 years.  After 114 flights we have one loss.  That's less than 1%.  I doubt that you can really design a heatshield system for the shuttle that would take a hit like the one in Columbia and not have serious damage.  The odds are that for the remaining missions it won't happen if it does will detect it by inspection and transfer the crew to the ISS an return by Soyuz or another shuttle mission. 

My bet is that if another shuttle is lost it will be from a third cause yet unknown rather than a repeat of the Challenger or Columbia disasters.  What really concerns me is this move to the CEV.  That basically saying the last 35 years of manned space policy was mistake! We basically could have done all of this with the Apollo back in the 1970s.  I'd like to see the development of scramjets and SSTO shuttle with no external fuel tank.

Most people tend to think that the new CEV concept is a great step backward--but let's look at this thing from the point of view of an astronaut.

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I don't see anything in CEV that could have been done 30 years ago!  Most earlier than that.  This thing is basically Apollo Redux.  Its greatest merit is that its cheaper than a true second generation shuttle.  Also, it can be used for a basic return to the Moon mission which a shuttle can't. Given the current political realities I for CEV since being against it is equivant to ending U.S. manned space.

However, I see no reason not to fully utilize the remaining shuttle capabilities we have.  Certainly there are mission like simply crewing the ISS or a shuttle rescue that the CEV would be great for doing.  As far as safety goes it is true that a CEV crew would very likely survive a propulsion system failure and is unlikely to breakup on re-entry.  However, I don't see spaceflight as an occupation for those driven primarily by safety concerns.  Perhaps that is what is wrong with the space program.  And don't forget that four people have died in capsules and three more nearly did (Apollo 13).  So capsules aren't truely safe either.

Partly this attitute probably comes from the background the astronaut corps many of whom are ex-fighter pilots.  Modern fighters are have ejection seats that can get them out of the plane under a wide variety of conditions.  Many of the same failure mode if occured in a passanger or cargo plane would result in the deaths of all on board.  So are we giving up on commercial flights? 

If we were to develop a second generation shuttle many changes could be made to relieve some of the problems what we are discussing.  Designs that won't have a tank above the orbiter and might have a crew compartment that is sort like the X-38 that could seperate (via explosive cords) to serve as an escape module.  I think that it was particularly lame to have not funded the X-33.  It also would have provided the first flight of aerospike engines to give us some improvement on specific impluse in atmosphere to space. 

The problem about the Shuttle isn't just one of taking reasonable risks or not; it's that the vehicle is inherently unsafe and inefficient.

It's not a good thing to put the crew and cargo on the same vehicle. Maybe for a few extreme mission examples it's OK to fly an orbital workshop, but the Shuttle has always been an example of flyingt a 747 to Paris, and using it as a hotel on the tarmac while it's there. Not to mention throwint a lot of it away during the course of the use. A "Shuttle" is just that - a vehicle for shuttling back & forth. It's not to be used on-site.

Using it as it has been used is very expensive -too much so. For a cheap cargo launcher, or to lift big parts of a space station, you do not need a winged, re-usable, crewed plane. Each of these requirements drives the complexity and cost up, and the combination drives it through the stratosphere! for cargo, you need a BDB.

For crew, you need something small enough to mount escape rockets on it, and a cargo launcher is too big. Everything from zero-altitude / zero-airspeed, to hypersonic sub-orbital survivability is the necessity for a safe crew launcher. The STS Shuttle should never have been anything but a special purpose experimental ship.

You don't need to treat cargo the way you treat crew. You insure a cargo, but you pamper crew and provide every possible contingency for survival, and the STS Shuttle is the worst ever launcvh vehicle: It's the first and only crewed launch vehicle ever to have no crew eject/escape capability during launch! It's a horrendous oversight that we've gone on this long relying on it for all of our crew launch needs.

 The easiest way to address the problem of the exhorbitant cost to get to space is to build the Shuttle-C for cargo. This has been known since the 1970s. The Shuttle plane is the most expensive part of the launch stack, and the first to go if you want a reliable cheap cargo lifter, or if you want an assuredly safe reliable cheap crew lifter.

No, the Shuttle should be grounded and the entire budget diverted to accelerating the CEV and something like ATK Thiokol's "Safe, Simnple, Soon" HLV development. The only thing we need the Shuttle for is the Hubble, and maybe a couple of EVA support missions to the ISS. All the other ISS payloads, the bulk of the lifting should be deferred until an Shuttle-C can be used.

"Not Culture but Perhaps a Cult", Op Ed on NASA and the Shuttle by Homer Hickam

August 29, 2003

"Much has been made over the report produced by the Columbia Accident Investigation Board (CAIB). I have since read newspaper articles that called the report "scathing." Hardly. Its polite recommendations probably had Shuttle managers who made poor decisions dancing down their office hallways with relief. Essentially, it gave them a pass by proclaiming "culture" made them do it...

I do not believe there is a NASA culture other than a willingness by its engineers to work their butts off to keep us in space. It might be said, however, that there is a Shuttle cult. It is practiced like a religion by space policy makers who simply cannot imagine an American space agency without the Shuttle. Well, I can and it is a space agency which can actually fly people and cargoes into orbit without everybody involved being terrified of imminent death and destruction every time the Shuttle lifts off the pad.

With some important reservations, the CAIB recommended to keep the Shuttles flying but with more inspections, more bureaucracy... and more money. But I think piling on more inspections and people and dollars won't make the Shuttle any safer... The truth is no amount of arm-waving and worrying about "culture" can fix a flawed design. Every engineer knows a design that tries to bypass the realities of physics, chemistry, and strengths of materials by applying complexity will fail eventually no matter how much attention is given to it.

(cont'd at link)

It doesn't seem to me that Homer Hickman's position differs that much from mine.  I didn't say Shuttle forever...I said let it fly.  I don't think we are gaining that much about freting about every possible falling piece of ice.  That stats clearly show that there is slightly less than a 2% chance of loss in a shuttle mission.  This is a dangerous business.  So is flying combat sorties against an enemy or going on patrol in the infantry, etc. 

The lack of an escape system certainly isn't one of the Shuttle's stronger points.  However, as I have pointed out before this is also true of airliners, cargo aircraft, private planes, helicopters, etc.  Escape systems should be considered on the replacement system.  Hopefully they will be feasible but we need to press on with the Shuttle for now.  Even with ejection seats we still have a significant number of fatalities in figher jets.

It is past time to be working on what comes after the Shuttle.  This project should have been underway since at least 2000.  What we have instead is a major return to the past with the CEV.  Of course given the realities of the current situation I support the CEV (somewhat reluctantly) as the practical alternative is the end of manned U.S. spaceflight.  It is useful to allow a return to return to the Moon and it would be very nice to have two means to access space so that if the primary one is out of commission all activity would not need to stop.

I would like to see more R&D on scramjets as a way to replace those troublesome SRBs.  So far we have had some very subscale experimentation conducted over a period of years.  It would seem that a more aggressive program might yield results.  Even if the Shuttle engines reuseability has proven uneconomical, we need to develop reusable engine concepts to have economical spaceflight.  I would hope that thirty years of progress might yield something better that glue-on tiles as heat shielding. 

John wrote:

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The lack of an escape system certainly isn't one of the Shuttle's stronger points.  However, as I have pointed out before this is also true of airliners, cargo aircraft, private planes, helicopters, etc. 

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Space daily opinion piece

http://www.spacedaily.com/news/oped-03l.html

That's one of my points.  The ISS was designed so the its modules would be orbited in the shuttles bay rather than on unmanned rockets.  We need the shuttle for that and also for a few other missions.  I see no reason not to keep the shuttle alive while introduction the CEV for pure personel transfer operations (and rescue) and future trips to the Moon.  Of course I'm probably projecting a NASA budget higher the goverment is will to support at this time.

I think that we really should be working on a next generation shuttle as well.  After all the shuttle is basically early '70s technology with a tight budget.  The replacement shuttle could consider better configurations, heat shielding, escape systems, propulsion concepts, etc.  I could proceed in concept development phase in parallel with the CEVs full scale development.  Then enter its on full scale development when the CEV becomes operational.

It seems to be agreed that the really large payloads (and possibly the really small ones too) should be launched with dispossable bosters.   So the shuttle should most likely be sized to handle say those payloads within one standard deviations from the median plus several people.  Also, it must have at least the safety for the crew and passenger that a capsule system would have.  Also, it should have a clear economic advantage over disposable systems.  We need to take into account operations and support costs as well as the cost of the vehicles. 

It would be nice to have engines and fuel pumps that are not so pushed to the limit that they have very short high maintainence life cycles.  Perhaps we need a multimode ram/scram/rocket jet technology in order to achieve this goal.  If we didn't need to carry all of the oxidizer on the vehicle which for a LH2 and O2 system is 8/9s of the propellant mass we would have a much smaller vehicle.  The problem is that little has been done with this technology todate.

> I thought one of the facts on the NASA problems site was very interesting and that is that the Soyuz and the Shuttle have about the same safety rates!  Yet we are just going to abandon the Shuttle to go to a Soyuz-like CEV because of its safety.

>give that we have three workable shuttle vehicles that are as safe as the alternative (capsules) I see no reason to abandon them.

Please point out to me that part. I'm sure there's a lot more to it than you're stating.

the main point: "no reason to abandon them". How about the fact that they're overcomplex, that several primary design criteria are fabricated (re-usable main engines supposedly saving money among others), they're demonstrably not close to ideal for either crew launch or cargo launch (not survivable for crew, too complex and deliberately over-expensive for cargo).

No. If it were not for what Hickham called a "Shuttle Cult" within NASA management, they should have gone over to something like the HL-20 when it was first designed, before the Discovery took off following the re-design after the Challenger disaster. Fly cargo up on the Shuttle-C to keep using the launch infrastructure, but make it several times cheaper to launch more cargo since the flying-cost-overrun orbiter is left behind.

It was purely a money politics decision to return to the Shuttle following the Challenger (ditto for the post-Columbia era). A bureaucracy's primary mission is self-preservation, and the Shuttle keeps them employed, and it's simply not in their best financial interest to do things any differently. For the mountains of money we throw at it, we could operate a fleet of cheap crew vehicles and an assembly line operation of the Shuttle-C. The design of the present Shuttle is conducive to the pressure to go ahead and fly even though it is inherently dangerous -the same "Go Fever" that killed Challenger, killed Columbia, and it what's driving things now. If we keep trying to fly 15+ more Shuttle missions to the ISS, we have no choice but to ignore serious inherent design flaws and safety hazards, and we'll lose another crew to "Go Fever". All the while spending far too much money to do too little work (the one thing the Shuttle orbiter is ideal for).

The Shuttle as we know it is fraud, deception and it is graft. Graft and big money is its main purpose and the only reason we're still using it.

All these ideas of SCRamjets and such "second Generation" future Shuttle follow-ons are irrelevant to discussion of the present fix we're in regarding only one hyper-expensive, very risky manned spacecraft, and it's scheduled to be grounded permanently in only a few years.

The worst thing about it is that it has been touted as the best way to do it for 30 or so years, flagrantly defying the best engineering and aeronautical thinking to the contrary. Solely as a NASA government jobs program to the subcioontractors in the most congression districts possible (if they'd made it simpler and cheaper, it wouldn't let them keep so may people employed -honestly or not- or provide so much political graft). Many aspects of its design and operations principles are meant to be over-complex and not to actually assist in the agency's mission, to further the exploration of space. It's not necessary or even relevant to continuing with the Moon/Mars plans, it's in the way of real science -including precursor missions in advance of manned missions, it's probably not necessary to the ISS -cutting the Shuttle's involvement with ISS might even make it run more smoothly and efficiently since they wouldn't be operating under the primary assumption that they've got an infinite share of NASA's budget to burn. Make the ISS operate by assembly flights from unmanned Shuttle-C (delivering 3-4 times as much payload as a Shuttle, more cheaply than the Shuttle) and crews flown safely in Soyuz/CEV flights. The only thing the Shuttle itself is desperately needed for at present is 2 more flights to the ISS, and NASA is dragging their feet about even admitting that their decision to let it die was basically fraudulent.

 It's not possible to upgrade or improve the Golden Goose in any meaningful ways, without drastically changing major factors of it. As for the spaceplane, the best (only) thing to do is to defy the Astronatics Corps and remove crewed piloting functions and put crew in escape pods. At that, it would drastically reduce the cost of flying the Golden Goose, and maybe make it less egregiously a rip-off to keep operating it at all. Aside from that, the best thing to do is to abandon it as a crewed launcher, and use the infrastructure of the STS by flying the booster as the Shuttle-C.

This is a fairly good recent look at what they're doing:

from the editors of Scientific American

Pawning NASA's Crown Jewels

...(snipped)

The most egregious budget lines are the two surviving programs that are being maintained on billions of dollars of life support--the space shuttle and the International Space Station (ISS). A question: In NASA's budgetary calculus, is it necessary or logical to maim the successful, scientifically productive and visionary part of the space program to feed the cost overruns of the Shuttle/ISS programs, which are scheduled to be canceled in 2010 anyway? Put more metaphorically, this concern was voiced by Rep. Sherwood Boehlert (R-N.Y.), chairman of the House Committee on Science when he said that "Science funding should not be taking a backseat to operational programs that have much less impact. We have to be sure that we are not demonstrating that science is a 'crown jewel' of NASA by seeing how much we can get for it at the pawnshop."

There is no easy way to quantify the science returned by the robots, but there's no question it goes way beyond what the shuttle and ISS can do. Despite some nominal science done on some shuttle missions, and its invaluable employment to place and maintain in orbit one of the most productive telescopes in observatory astronomy, the Hubble Space Telescope, it is not much of a scientific or space exploration system. And as for the science output past, present and future on the ISS, only few scientists would consider it on the positive side of cost versus benefit.

So in trekking through Washington's lunar-cold budgetary landscape, NASA obviously had to make some hard decisions. We will go on with manned missions, our goal to return to the moon and then on to Mars. This is good, very good. But first there is that little hurtle: we have got finish up the shuttle program, which, apart from fixing Hubble, serves no greater purpose except to service and complete the ISS as it circles above, on its way to where it was 90 minutes ago, waiting to be completed so it can be decommissioned.

...(cont'd)