[LINK] Finally up to date on the Shuttle

Chirgwin, Richard Richard.Chirgwin@informa.com.au
Fri, 14 Feb 2003 13:01:04 +1000


Yeah, I know this is an old thread, but while trying to answer a question
from my son, I came across some info relevant to this:
> 5. HOTOL (Horizontal take off - jet-ramjet-rocket - horizontal 
> landing) and other alternatives are much more viable now, much 
> cheaper in terms of fuel loads and the like, much more efficient and 
> theoretically much safer, and can theoretically carry higher payloads 
> as less on-board space needs to be devoted to fuel.storage.

Frank, 
HOTOL also has penalties. One of the aims of the launch is to get the
spacecraft ouut of the atmosphere as quickly as is feasible. This way, the
heat/vibration load of atmospheric flight is minimised.

To achieve a similar result in a HOTOL environment would require extremely
high velocity at ground level; and (according to NASA), we don't have either
the tyres or the runways able to survive hotol spaceflight launch
velocities.

A question in return, - I seem to see contradictory information about the
relationship between shuttle velocity and altitude. On the one hand, orbital
calculators make it quite clear that a body at a lower orbit has higher
velocity than one at higher orbit. Look at 
http://liftoff.msfc.nasa.gov/academy/rocket_sci/orbmech/vel_calc.html
to check me (the moon's orbital velocity is slow compared to a shuttle for
eg).

However, in discussing Shuttle flight, re-entry is achieved by slowing the
shuttle down so its orbit decays.

There seems, to someone whose physics needs work, to be a contradiction
here. Anyone good enough at aerospace to sort me out?

Richard Chirgwin


> -----Original Message-----
> From: Frank O'Connor [mailto:foconno1@bigpond.net.au]
> Sent: Monday, 3 February 2003 14:56
> To: Howard Lowndes
> Cc: Chirgwin, Richard; Link
> Subject: RE: [LINK] Finally up to date on the Shuttle
> 
> 
> My thoughts on the shuttle generally coincide with what I've seen 
> here ... with a few added musings:
> 
> 1. A lot of the uses to which the shuttle has been put didn't really 
> require it ... more often than not launching satellites, telescopes 
> etc etc could have just as easily been done by cheaper (even on a per 
> launch basis) and more safe unmanned boosters
> 
> 2. The shuttle program currently absorbs the lions share of NASA's 
> budget - even after 22 years.
> 
> 3. The shuttle is 1960's/70's technology, horrendously complicated, 
> and comprised of literally millions of parts that are basically 
> sub-contracted to the lowest bidder.
> 
> 4. Vertical launch technology may have been the go in 1970, but 
> sitting 7 people on top of a million parts, and a hydrogen bomb's 
> worth of rocket fuel and expecting things to go right every time 
> isn't realistic. The VL part of the shuttle concept is what incurs 
> the most expense, the most risk and the most danger.
> 
> 5. HOTOL (Horizontal take off - jet-ramjet-rocket - horizontal 
> landing) and other alternatives are much more viable now, much 
> cheaper in terms of fuel loads and the like, much more efficient and 
> theoretically much safer, and can theoretically carry higher payloads 
> as less on-board space needs to be devoted to fuel.storage.
> 
> 6. In terms of time between launches, preparation time and effort, 
> cost-per-launch, actual rather than projected re-usability and 
> convenience/efficiency the shuttles have not exactly had a stellar 
> record. I mean if they had been Boeing airliners, airlines would have 
> given up the ghost years ago as carriers of people or freight.
> 
> 7. NASA's main kudos over the last 30 years has been gained from 
> robotic and probe based missions.
> 
> I was not a shuttle fan from the moment I saw the concept on paper 
> ... it seemed like a lot of very complicated fuss and bother to get 
> stuff into low orbit then (even if the economics NASA put to Congress 
> had panned out), it absorbed too much of the budget that could 
> otherwise have been devoted to exciting stuff like Lunar and 
> planetary manned missions, it never postulated being able to do more 
> than build limited size orbiting space stations (and to date we have 
> how many?) and in many ways the technology wasn't even on par with 
> the Apollo technology that they wanted to shut down.
> 
> Since the shuttle NASA has largely become an inefficient low orbit 
> hauler with very few what I'd call great achievements.
> 
> I suppose I'm a bit of a romantic ... but I miss those days in the 
> 60's when the Russian and US space programs made the whole world hold 
> their breath. When the world would stop and wonder and what was 
> achievable by us as a species if those brave men and women could do 
> what they did on an almost monthly basis. I remember seeing Sputnik 
> sail over Melbourne, those huge Russian Inergia boosters, Glenn in 
> the night sky, the massive Apollo boosters,  the day we all watched 
> the Armstrong and Aldrin and Collins land on the moon, Mariner and 
> Voyager during the 70's ... everything seemed achievable them. The 
> feeling was basically 'can do' and seriously idealistic.
> 
> The shuttle took a lot of that away from NASA (and the breakup of the 
> USSR effectively canned the Russian program) ... and for that I'll 
> probably always be a bit resentful. Then again, NASA may have decided 
> that it achieved it's raison d'etre after it had fulfilled Kennedy's 
> 1961 commitment ... and just decided that something else was needed 
> to keep the budget intact ... so maybe blaming the NASA hierarchy 
> rather than the shuttle is the go.   :)
> 
> 				Regards,
> 
> At 1:39 PM +1100 3/2/2003, Howard Lowndes wrote:
> >On Mon, 3 Feb 2003, Chirgwin, Richard wrote:
> >
> >>  Noting Jeff Fulton's correction about the company name, 
> thanks for the
> >>  history, Stil.
> >>
> >>  Jan, you're right - it's not 'just a Yank thing'. It's a 
> "manager thing".
> >>
> >>  Not only do managers resent any engineering advice that 
> might cost money,
> >  > but there's a more general resentment and even propaganda against
> >>  engineering and scientific expertise in general. The 
> immortal quote from
> >>  some goof in Sydney Water at the time of the giardia 
> crisis stays with me,
> >>  "But engineers always want to gold-plate everything" 
> (which was said AFTER
> >>  the cost-cut purification systems failed and gave people 
> a life-threatening
> >>  illness).
> >>
> >>  Over the next few days, all manner of ignorant people 
> will defend their
> >>  decisions; and they will do their best to hide the fact 
> that their sole
> >>  expertise comes from the whisperings of an accountant at 
> one elbow and a
> >>  lawyer at the other.
> >
> >You can probably add to that management performance bonuses 
> focussed on
> >bringing such tasks in under budget.
> >
> >Common sense says that whilst the accountant would have 
> sought economy
> >and cost cutting, the lawyer would have sought arse-covering 
> and caution.
> >
> >...but then I must be wrong as I use "common sense" and 
> "lawyers" in he
> >same sentence.
> >
> >
> >>
> >>  Richard
> >>
> >>  > -----Original Message-----
> >>  > From: Stilgherrian [mailto:contour@prussia.net]
> >>  > Sent: Monday, 3 February 2003 07:20
> >>  > To: Link
> >>  > Subject: Re: [LINK] Finally up to date on the Shuttle
> >>  >
> >>  >
> >>  > Just on the O-ring point...
> >>  >
> >>  > At 07:47 +1100 3/2/03, Jan Whitaker wrote:
> >>  > >Re the O-rings, I know a guy here who did a complete 
> analysis of the
> >>  > >chain of events on that for future risk management preparation.
> >>  > >Actually, Ann, certain people knew 100% that the 
> O-rings weren't
> >>  > >engineered to these conditions.  The problem was that 
> the top brass
> >>  > >ignored the engineering advice -- but I can't remember 
> the reason
> >>  > >for ignoring it -- there was one.
> >>  >
> >>  > The decision to "not mention" to O-ring problem wasn't 
> made by NASA
> >>  > but by the contracting firm that produced the 
> solid-fuel boosters.
> >>  > (From memory it was General Dynamics, but don't quote 
> me on that.)
> >>  > The engineers within the company were aware of and 
> worried about the
> >>  > problem because of the low air temperature at 
> Challenger's launch,
> >>  > and they wanted to scrub the launch on that basis.
> >>  >
> >>  > However the company in question had previously had reliability
> >>  > problems with the solid-fuel ballistic missiles they were also
> >>  > producing (Minuteman?), and feared that a reliability 
> problem with
> >>  > their shuttle boosters too would screw their chances of further
> >>  > lucrative missile contracts. So management "make a  management
> >>  > decision" to not pass on the engineers' concerns.
> >>  >
> >>  >
> >>  > And on this point...
> >>  >
> >>  > >I'm also not sure that it's a 'yank' problem, either.  
> You gotta
> >>  > >admit that the US space program is one of the most 
> highly engineered
> >>  > >things ever done.  It just isn't perfect.  Not much 
> is.  The public
> >>  > >just doesn't appreciate how high risk those flights 
> have always been.
> >>  >
> >>  > Agreed thoroughly. There have been two shuttles lost 
> since they were
> >>  > first introduced. Isn't that actually within the 
> expected loss rate?
> >>  >
> >>  > Stil
> >>  >
> >>  >
> >>  > --
> >>  > Stilgherrian <contour@prussia.net>
> >>  > Internet, IT and Media Consulting, Sydney, Australia. ABN 25
> >>  > 231 641 421
> >>  > mobile 0407 623 600 (international +61 407 623 600)
> >>  > fax 02 9516 5630 (international +61 2 9516 5630)
> >>  > _______________________________________________
> >>  > Link mailing list
> >>  > Link@mailman.anu.edu.au
> >>  > http://mailman.anu.edu.au/mailman/listinfo/link
> >>  >
> >>  _______________________________________________
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> >>
> >
> >--
> >Howard.
> >LANNet Computing Associates - Your Linux people 
<http://www.lannetlinux.com>
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