New lifting vehicles...

I have been lurking here for what seems to be ethernity, hoping that I woild
get a glimpse into wha is coming in the midterm future, but it seems that
there is no consensus about right way to do things in the future (regarding
space shuttle replacement, travel to mars/moon etc)...

So, I have a question. Wouldn't it be optimal for majority of presently not
covered needs to develop one disposable_big_ass_heavy_lifter through
multinational effort instead of all this varie ty ?

Cost of launch is not proportional to rocket size or propelant quantity, so
why wouldn't we optimize things for bigger payloads ?

For ISS this would mean probably less ressuply missions, but those would be
massively bigger and if done this way, everything could be bigger. ISS
modules could be bigger and more robust, we could have way bigger ISS and
much more people there, doing real bussiness instead of janitor work.

Since payload weight would be less of an issue for many (especially LEO)
missions, we could use cheaper materials for sattelites etc and save a few
bucks there.

With such vehicle, only constraint for mars (and any other) ambitious misson
would be the time to get to money, needed for launch and not time to develop
special launch vehicle itself.

Furhtermore, no one would care obout reuseability, since cost of hte rocket
could be much lower, compared to the cost of the payload, so there would be
no need for superfluous cash spending on heatshealds etc.

In essence, we only need new generation of big, efficient and above all
reliable rocket motors.

Missions with small payloads could be served efficiently with existing
vehiclees (Arriane, Sojuz etc)


Is this what NASA is about to do with their newest space plan ?


Regards,


Branko

On Thu, 1 Apr 2004 01:50:05 +0200, "SIOL" wrote:
I have been lurking here for what seems to be ethernity, hoping that I woild
get a glimpse into wha is coming in the midterm future, but it seems that
there is no consensus about right way to do things in the future (regarding
space shuttle replacement, travel to mars/moon etc)...

So, I have a question. Wouldn't it be optimal for majority of presently not
covered needs to develop one disposable_big_ass_heavy_lifter through
multinational effort instead of all this varie ty ?

Cost of launch is not proportional to rocket size or propelant quantity, so
why wouldn't we optimize things for bigger payloads ?

For ISS this would mean probably less ressuply missions, but those would be
massively bigger and if done this way, everything could be bigger. ISS
modules could be bigger and more robust, we could have way bigger ISS and
much more people there, doing real bussiness instead of janitor work.

Since payload weight would be less of an issue for many (especially LEO)
missions, we could use cheaper materials for sattelites etc and save a few
bucks there.

With such vehicle, only constraint for mars (and any other) ambitious misson
would be the time to get to money, needed for launch and not time to develop
special launch vehicle itself.

Furhtermore, no one would care obout reuseability, since cost of hte rocket
could be much lower, compared to the cost of the payload, so there would be
no need for superfluous cash spending on heatshealds etc.

In essence, we only need new generation of big, efficient and above all
reliable rocket motors.

Missions with small payloads could be served efficiently with existing
vehiclees (Arriane, Sojuz etc)


Is this what NASA is about to do with their newest space plan ?

No. NASA is working on concepts which are all smaller than Shuttle.

What you're describing has been called a Big Dumb Booster.
While it appears that cost per pound to orbit could be significantly
reduced using a BDB, cost per flight becomes very significantly
higher.

If you could combine all the payloads launched by all the launch
systems now in existence for a year, put them all on one BDB
and launch them, it would be significantly cheaper. But few of
those payloads want to be in the exact same orbital location
as other payloads.

So one flight is out. You'd need many flights to reach the various
different orbits payloads want to be in. And since cost per flight
for BDB is significantly higher, the economics don't work.

A very heavy lift vehicle is attractive for payloads that require very
heavy lift, but very few do, and modular design with on orbit docking
and assembly could insure none do. So there isn't a large enough
market for very heavy lift to amortize the development, and absorb
the significantly higher per launch costs, of a BDB, at least not now,
or in the foreseeable future.

Gary

What you're describing has been called a Big Dumb Booster.
While it appears that cost per pound to orbit could be significantly
reduced using a BDB, cost per flight becomes very significantly
higher.

If you could combine all the payloads launched by all the launch
systems now in existence for a year, put them all on one BDB
and launch them, it would be significantly cheaper. But few of
those payloads want to be in the exact same orbital location
as other payloads.

So one flight is out. You'd need many flights to reach the various
different orbits payloads want to be in. And since cost per flight
for BDB is significantly higher, the economics don't work.

A very heavy lift vehicle is attractive for payloads that require very
heavy lift, but very few do, and modular design with on orbit docking
and assembly could insure none do. So there isn't a large enough
market for very heavy lift to amortize the development, and absorb
the significantly higher per launch costs, of a BDB, at least not now,
or in the foreseeable future.

Gary


Ahh the lower cost to orbit could be cost effective for a lunar mars program
and station.

Reduce the cost per pound and more will be willing to travel.

The realtively small modukles of ISS make them cramed with hard to service
hard to reach equiptemeent.

a large spacious station without the weight volumbe constraints could be a much
better cheaper to operate beast
Hey this is my opinion

"SIOL" wrote in message
news
I have been lurking here for what seems to be ethernity, hoping that I
woild
get a glimpse into wha is coming in the midterm future, but it seems that
there is no consensus about right way to do things in the future
(regarding
space shuttle replacement, travel to mars/moon etc)...

The simple answer to above is that there cannot be consensus on this as
there is no right or wrong way to do any of the things you mention - they
all work. The problem people are facing is, essentially, political - trying
to convince enough people that 'their' method is superior for whatever
reason (see below).


--
Alan Erskine
We can get people to the Moon in five years,
not the fifteen GWB proposes.
Give NASA a real challenge