Does anyone know why the shuttle happened?

wrote:

Derek Lyons wrote:
wrote:

Mind you, this takes things into the 60s. But during the late 60s it
appears that everyone involved had become fixated on the idea that
some sort of a shuttle should replase the tried, tested and efficient
spacecaptule.

You have it precisely backwards. During the late 50's and early 60's
the idea arose that primitive and jury rigged capsules could be a
short term solution to getting into space _now_. Later they would be
replaced with more conventional spacecraft (I.E. winged and resembling
aircraft).

I see, so it was the classic rocketship 40s - 50s schi-fi idea, with
wings and all, looking somewhat like an aeroplane, except it could
supposedly fly in space, that they had at the back of theyr heads?

Not precisely - but that's the general idea.

D.
--
Touch-twice life. Eat. Drink. Laugh.

-Resolved: To be more temperate in my postings.
Oct 5th, 2004 JDL

In article om,
D. Orbitt wrote:
In my mind, the biggest problem was the military wanted to be able to
use the same design...

No, not quite right: *NASA* wanted the military to use the shuttle, for
the sake of the political support they would lend. The military had only
mild interest; when it came to launch of existing, funded programs, they
actually weren't all that unhappy with expendables. They were reluctantly
talked into it.

and they added requirements of size, capacity,
and cross-range in the landing profile that bloated the design and
upped the costs.

They certainly added those requirements. Whether it made a big difference
in the long run is harder to say.

In particular, with the final demise of the Saturn V, NASA needed the
shuttle to be capable of launching space-station modules (originally the
hardware was going to go up on Saturn Vs, and the shuttle was just the
supply ship), and so there was starting to be considerable pressure from
within NASA for a bigger ship.

NASA really didn't need the crossrange, but whether that made a big
difference depends on whether you think Max Faget's straight-wing orbiter
was going to work. There were people who had doubts about that. NASA
might have been forced to use a delta wing regardless.

Worse, after forcing all the compromises, the
Military then mostly abandoned using the shuttle for defense payloads.

True, but they had some justification. It wasn't delivering on the early
promises of frequent flights and low costs, payload mass was running well
below the spec, and worst of all, NASA had bought so few orbiters that it
wasn't practical to dedicate some of them to military service. The USAF's
single biggest problem with the shuttle was that they really wanted to
control their own vehicles, rather than having to go via NASA every time.

Had they gone with the simpler Max Faget design, I think we would have
had a better program and better results for the money, and a follow-on
higher-capacity shuttle cpould have evolved organically from that.

There is good reason to doubt that, I fear. Many of the fundamental
mistakes made on the program had nothing to do with the exact shape of the
orbiter, if that's what you're referring to, and Faget's reusable first
stage was clearly beyond the budget using NASA's assumptions. (As Len has
pointed out, those assumptions were wrong, but that wasn't obvious -- see
my previous comment about NASA having learned the wrong lessons.)

Mistake #1, for example, was the decision to go straight to an operational
vehicle, rather than getting some experience with a smaller test vehicle
first. You can argue that this was forced on NASA by circumstances, but
the circumstances were mostly NASA's own fault...
--
spsystems.net is temporarily off the air; | Henry Spencer
mail to henry at zoo.utoronto.ca instead. |

From: (Henry Spencer)
NASA really didn't need the crossrange ...

Quick question: Is the crossrange capability what allows the
shuttle to land at Edwards or Canaveral depending on weather, and
allows landing from any of several different orbits, none of which
have been tuned to fly exactly over the landing spot, and allows
aiming down the center of a narrow runway instead of just aiming
for a "ballpark" landing region at J.Random location within a large
flat area such as a dry lakebed, and which allows the landing craft
to bank and turn to land along the runway instead of whatever
direction the orbit was going?

It wasn't delivering on the early promises of frequent flights
and low costs, payload mass was running well below the spec, and
worst of all, NASA had bought so few orbiters that it wasn't
practical to dedicate some of them to military service. The USAF's
single biggest problem with the shuttle was that they really wanted
to control their own vehicles, rather than having to go via NASA
every time.

Indeed, from the very start, perhaps the biggest mistake was
failure to correctly estimate the total budget that would be
available in upcoming years. The correct methodology would have
been to estimate the available budget, state by fiat how many
orbiters are needed (for example thirty simultaneously-available
orbiters would probably have satisfied everyone about launch
frequency and dedicated military orbiters), divide budget by number
of orbiters to get per-orbiter funding available per orbiter, and
come up with a design that could achieve success within that
funding limit. With over-estimate for funding to be available, and
under-estimate of development cost, and a too-expensive design to
begin with, there's just no way they'd be able to build thirty
orbiters.

Now the main reason I'm posting he
Mistake #1, for example, was the decision to go straight to an
operational vehicle, rather than getting some experience with a
smaller test vehicle first.

The private companies seem to be going the smaller-test-vehicle
route. First a manned "sounding rocket". Next a sub-orbital hop.
Eventually maybe something that achieves orbit. I take it you fully
approve of this strategy.

wrote:

Like you say, the concept of building reusable instead of throwaway
hardware sounds really good..

There were two fundamental problems: a quantitative problem at the
level of physics, engineering,and economics -- and a psychological
problem in the *attitude* with which the US (not just NASA) the
tackled the first.

The quantitative problem was that any reusable launch system
inevitably has a smaller payload mass fraction than a corresponding
expendable launcher. Thermal protection for re-entry, landing hardware
(whether landing gear or parachute or anything else), wings or
lifting-body airframe -- those, and the general "robustness" required
for something to be used many times rather than once -- all do nothing
for thrust , while reducing payload. And since expendable launch
vehicles had already been pushed to the bleeding edge to get just a
few percent of pad weight into orbit, there wasn't much margin for
subtraction to begin with. With even smaller payload fraction, it
takes *really* high flight rates -- unbelievably high for 1970, and
IMHO still very questionable today -- to make reusability
cost-effective.

The psychological problem was the legacy of Apollo: having done
something so remarkable in less than a decade, we convinced ourselves
that surely we could do it again. Compared to the moon 240,000 miles
away, robust access to orbit just 200 miles up *looked* like an easier
challenge. And it was -- if you ignore those words above,
"cost-effective," with all their direct implications for flight rate,
and their secondary implications for a slow learning process, refining
the design again and again, in *getting* to that flight rate.

We committed to an *operational* shuttle, a DC-3 of space access, one
that would take over all the jobs of expendable rockets and do them
much more cheaply, on the very first try. That was flatly impossible,
but we went ahead and declared victory after the first four flights.

Everything since then has been an exercise in denial. What I find
disturbing today is that the denial is still going on in new forms:

- that there's nothing intrinsically hard about RLVs, it's only that
NASA blew it (or Congress didn't give them enough money)

- that demand for really high flight rates is just about to manifest
itself

- that the yearned-for "sweet spot" design, the DC-3 of space, is
sitting on someones' drawing board today (instead of something that
will emerge in small steps over decades)

Rand Simberg wrote:

Don't use a single point (the Shuttle) to draw general conclusions
about anything. There were many reasons that it was a failure, but
not because it was reusable, per se.

IMO, the big reason the shuttle failed was because there was no good prospect
it would be used enough to justify building it. Successful technologies
advance along a broad front, with adequate perceived demand to justify
parallel efforts, not in a single resource-starved project that is all
that we're collectively willing to fund.

Paul

On Sat, 07 Jul 2007 11:48:15 -0500, in a place far, far away, "Paul F.
Dietz" made the phosphor on my monitor glow in such a
way as to indicate that:

Rand Simberg wrote:

Don't use a single point (the Shuttle) to draw general conclusions
about anything. There were many reasons that it was a failure, but
not because it was reusable, per se.

IMO, the big reason the shuttle failed was because there was no good prospect
it would be used enough to justify building it. Successful technologies
advance along a broad front, with adequate perceived demand to justify
parallel efforts, not in a single resource-starved project that is all
that we're collectively willing to fund.

Yes, which is why ISS failed as well. As will Ares/Orion.

Mind you, this takes things into the 60s. But during the late 60s it
appears that everyone involved had become fixated on the idea that
some sort of a shuttle should replase the tried, tested and efficient
spacecaptule. There were during the 60s done a number of flights of so
called lifting bodies, which do have certain at the least superficial
similarities.

At a political level, I have read from several sources that Nixon was very
concerned about astronauts dying on his watch. So much so, that he was
instrumental in continuing the cutting of funding to NASA during his
administration.

Mind you, he was more than willing to be there for the successes, like
talking to the Apollo 11 astronauts on the Moon and being there to greet
them on the aircraft carrier when they returned. He just didn't like paying
for Buck Rogers.

In an effort to find a mission for manned spaceflight after Skylab, NASA
proposed to Nixon several options: Mars and/or Venus using improved Apollo
hardware, Skylab II, return to the Moon with improved Apollo hardware to set
up a moonbase and, as something as a lower priority afterthought, a space
shuttle. Nixon shot down all of them except for the space shuttle and one
of the reasons for his approval of it was that he felt that shuttle flights
would not take place until after he was out of office, if at all.

Imagine where we could be right now if instead of the space shuttle, we had
kept the Apollo project going, even if only in Earth orbit. Imagine what
that hardware would be capable of now after 40 years of evolutionary
improvements...

On Sat, 7 Jul 2007 13:53:56 -0400, in a place far, far away, "Vincent
D. DeSimone" made the phosphor on my monitor
glow in such a way as to indicate that:


Mind you, this takes things into the 60s. But during the late 60s it
appears that everyone involved had become fixated on the idea that
some sort of a shuttle should replase the tried, tested and efficient
spacecaptule. There were during the 60s done a number of flights of so
called lifting bodies, which do have certain at the least superficial
similarities.

At a political level, I have read from several sources that Nixon was very
concerned about astronauts dying on his watch. So much so, that he was
instrumental in continuing the cutting of funding to NASA during his
administration.

Your sources are wrong.

Can you provide a citation?

If he were really that concerned, he'd have stopped flights after
Apollo XI.

h (Rand Simberg) wrote:

IMO, the big reason the shuttle failed was because there was no good prospect
it would be used enough to justify building it. Successful technologies
advance along a broad front, with adequate perceived demand to justify
parallel efforts, not in a single resource-starved project that is all
that we're collectively willing to fund.

Yes, which is why ISS failed as well. As will Ares/Orion.

Whoa -- Paul, you and me in simultaneous wholehearted agreement.

Quick, somebody -- bronze us!

"Vincent D. DeSimone" wrote:

Imagine where we could be right now if instead of the space shuttle, we had
kept the Apollo project going, even if only in Earth orbit.

After the escape tower fiasco on Apollo XXV (and subsequent crippling
of the Command Pilot when the CM touched down in a parking lot), the
death of the crew of Apollo XXXII when the CM crew was killed by fumes
in from the RCS system after reentry... President Carter made it a
priority of his second term to reform NASA. When the Apollo Review
Committee made public the problems encountered during the 60's -
public outcry over NASA's ongoing deception made reform and
continuation of the Apollo Program essentially impossible.

The Review Committee recommended to the President that after Skylab IV
was complete that the Apollo program be terminated until NASA could
replace capsules with something better and safer.

D.
--
Touch-twice life. Eat. Drink. Laugh.

-Resolved: To be more temperate in my postings.
Oct 5th, 2004 JDL