Future Robotic Shuttles?

I really don't understand the prevalant attitude that because the
Shuttle was a failure, then all systems which combine crew and cargo
will be, too. *That's a bunch of hooey, and another item for the
"wrong lessons learned from the Shuttle" file (which already has the
old standby "reusable spacecraft aren't feasible" and "wings on
spacecraft are bad" entries.)

Brian


Well the compromises made for the shuttle to haul people plus
substantial cargo made the vehicle LESS SAFE FOR HUMANS

compromises like dropping launch boost escape to save weight for more
cargo.....

decisions like this caused long term troubles and likely the death of
2 crews.

In article 9ae49e88-3345-416c-8da9-
, says...

I really don't understand the prevalant attitude that because the
Shuttle was a failure, then all systems which combine crew and cargo
will be, too. *That's a bunch of hooey, and another item for the
"wrong lessons learned from the Shuttle" file (which already has the
old standby "reusable spacecraft aren't feasible" and "wings on
spacecraft are bad" entries.)

Brian


Well the compromises made for the shuttle to haul people plus
substantial cargo made the vehicle LESS SAFE FOR HUMANS

compromises like dropping launch boost escape to save weight for more
cargo.....

decisions like this caused long term troubles and likely the death of
2 crews.

Not really. The design philosophy was such that the shuttle orbiter was
the escape system during launch (hence the various abort modes and abort
landing sites).

What destroyed Challenger was the design decision to use large segmented
solid rocket boosters instead of liquids for the parallel staged
boosters. It lowered design costs, but opened up the system design to
the possibility of catastrophic failure due to the unique failure modes
of large segmented solid rocket boosters. At least with liquids you can
safely shut them down without adding complex, often pyrotechnic
activated, thrust termination systems (which have their own failure
modes).

Columbia was also a launch failure in my book because the damage to the
orbiter's TPS was caused during the launch. The root cause of the
damage was foam shedding from the ET. Foam shedding was treated like a
maintenance issue but should have been treated as a safety issue all
along. Foam shedding from the ET wasn't adequately addressed until
after the Columbia disaster. Actually, the program to reduce shedding
foam has been largely successful. Had such a program been implemented
early in the shuttle program, a Columbia like failure would have been
far less likely.

A launch escape system may not have helped the Columbia crew, since the
damage went unnoticed during the launch and depending on the details a
*launch* escape system may not be suitable for use during reentry. It's
easy to say in hindsight that such a system should be designed to work
during reentry, but I don't think that observation would have been
obvious during the shuttle development. Case in point, Mercury, Gemini,
and Apollo's launch escape systems wouldn't have worked in the middle of
re-entry either, so past experience wouldn't have helped here.

Jeff
--
42

On Mon, 11 Oct 2010 13:31:33 -0700 (PDT), bob haller safety advocate
wrote:


compromises like dropping launch boost escape to save weight for more
cargo.....

decisions like this caused long term troubles and likely the death of
2 crews.

There is very little reason to believe a Launch Escape System would
have saved either crew. Challenger happened too quickly with almost no
real time warning and Columbia's damage was ignored by NASA managers
who told worried engineers to basically 'shut up and color'.

Brian

On Oct 11, 9:00*am, Jeff Findley wrote:
In article 068117cd-76f3-4aa8-82d5-


Crew and cargo on separate launch vehicles is not a (correct) lesson
that shuttle has taught us. *You can't take a single data point and draw
this sort of sweeping conclusion. *


Wrong, it is a correct lesson. Aside from station logistics (Tang,
toilet paper and t-shirts), payload design and construction is
compromised by the presence of a crew on the vehicle. The addition of
needless factors of safety and safety inhibits detract from the
payload's prime mission. Additionally, going back to station
logistics, why put a crew at risk for Tang, toilet paper and t-shirts
when it can be done cheaper on an unmanned vehicle. Lose a payload of
Tang, toilet paper and t-shirts, no big deal.

Also, the risk is NOT worth it for spacecraft delivery and it is
applicable in all cases not "only in the case where the cargo and crew
aren't going to the same destination."
TDRS, UARS, GRO, it makes no difference where the final destination
(which only makes a difference in the amount of propellant on the
payload) those spacecraft would have been better served by an ELV.

On Tue, 12 Oct 2010 08:36:42 -0700 (PDT), Me
wrote:

Crew and cargo on separate launch vehicles is not a (correct) lesson
that shuttle has taught us. *You can't take a single data point and draw
this sort of sweeping conclusion. *


Wrong, it is a correct lesson. Aside from station logistics (Tang,
toilet paper and t-shirts), payload design and construction is
compromised by the presence of a crew on the vehicle. The addition of
needless factors of safety and safety inhibits detract from the
payload's prime mission. Additionally, going back to station
logistics, why put a crew at risk for Tang, toilet paper and t-shirts
when it can be done cheaper on an unmanned vehicle.

To increase reliability and to return the cargo vehicle for re-use.

Why put crews at risk delivering Tang from General Foods, Toilet Paper
from Charmin, and t-shirts from Hanes to your local grocery store? We
do, and sometimes tractor-trailers crash killing the sleep-deprived or
distracted driver. Sometimes they crash into other vehicles and kill
their occupants as well. Should we demand freight delivery on Earth be
turned over to unmanned trucks?

Again, you're learning the wrong lesson from Shuttle. Shuttle was a
failure as a reusable space transport, as the first generation of such
that is hardly surprising. So let's build a better reusable space
transport, not give up on the whole notion. Start with a much simpler
cargo bay, then get rid of hypergolics and solid propellant boosters.

Brian

In article 96522f1c-9808-4385-a2dd-
,
says...

On Oct 11, 9:00*am, Jeff Findley wrote:
In article 068117cd-76f3-4aa8-82d5-


Crew and cargo on separate launch vehicles is not a (correct) lesson
that shuttle has taught us. *You can't take a single data point and draw
this sort of sweeping conclusion. *


Wrong, it is a correct lesson. Aside from station logistics (Tang,
toilet paper and t-shirts), payload design and construction is
compromised by the presence of a crew on the vehicle. The addition of
needless factors of safety and safety inhibits detract from the
payload's prime mission. Additionally, going back to station
logistics, why put a crew at risk for Tang, toilet paper and t-shirts
when it can be done cheaper on an unmanned vehicle. Lose a payload of
Tang, toilet paper and t-shirts, no big deal.

On station assembly flights. All of that hardware going up has already
been "compromised", as you put it, by the presence of a crew on the
vehicle. Furthermore, many of those flights required EVA's (i.e. extra
crew) in order to properly attach and configure the delivered hardware.
Whether that extra crew arrives on the same vehicle or another doesn't
seem to matter much.

Again, the shuttle design is a single data point. In the future it
looks like cargo would be underneath a payload shroud underneath the
Orion capsule. Absence or presence of cargo under the Orion compromises
safety of the crew how?

Also, the risk is NOT worth it for spacecraft delivery and it is
applicable in all cases not "only in the case where the cargo and crew
aren't going to the same destination."
TDRS, UARS, GRO, it makes no difference where the final destination
(which only makes a difference in the amount of propellant on the
payload) those spacecraft would have been better served by an ELV.

The final destination of those flights was not LEO, so sticking them on
a crewed launch vehicle never made sense compared to launching them on
another vehicle. Commercial payloads were banned from NASA launch
vehicles, so we won't be in that situation again.

What I'm interested in talking about is future flights of SDLV with
Orion on top.

Jeff
--
42

On Tue, 12 Oct 2010 15:12:40 -0400, Jeff Findley
wrote:


TDRS, UARS, GRO, it makes no difference where the final destination
(which only makes a difference in the amount of propellant on the
payload) those spacecraft would have been better served by an ELV.

The final destination of those flights was not LEO, so sticking them on
a crewed launch vehicle never made sense compared to launching them on
another vehicle.

UARS and GRO were. Although GRO would have been lost without a crew on
board (the main antenna failed to deploy until an EVA freed it.)

Brian

In article , bthorn64
@suddenlink.net says...

On Tue, 12 Oct 2010 15:12:40 -0400, Jeff Findley
wrote:


TDRS, UARS, GRO, it makes no difference where the final destination
(which only makes a difference in the amount of propellant on the
payload) those spacecraft would have been better served by an ELV.

The final destination of those flights was not LEO, so sticking them on
a crewed launch vehicle never made sense compared to launching them on
another vehicle.

UARS and GRO were. Although GRO would have been lost without a crew on
board (the main antenna failed to deploy until an EVA freed it.)

True enough.

Jeff
--
42

So if a crew capsule had been in the columbia payload bay would the
crew survived?

On Tue, 12 Oct 2010 16:11:10 -0700 (PDT), bob haller safety advocate
wrote:

So if a crew capsule had been in the columbia payload bay would the
crew survived?

No, they wouldn't have been in it, because management didn't believe
there was a problem.

Brian