Return to common sense -- reusable first stage

Source: http://www.spacedaily.com/news/rocketscience-03j.html

"Named the Baikal, the first stage of a new two-stage Russian rocket
called Angara, the Russian flyback booster will rocket to about 38
miles (60 kilometers) before a second stage with payload separates
for the final lift to orbit. After separation the main booster
deploys a pair of wings and a jet engine fires up to return the
flyback booster (s) to a runway landing...

Beal Aerospace, a small rocket upstart from 1996-2000, intended on
developing a reusable first stage for its own line of rockets. More
recently SpaceX, a launch company started by entrepreneur Elon Musk,
aims to develop a two-stage launch vehicle consisting of a reusable
first stage. Starcraft Boosters Corporation has been advocating
reusable first stage boosters for the past few years. In 2002, the
company received funding from the Air Force to proceed with the
development of a small reusable technology demonstrator based on
the company's designs."

__________________________________________________ __________________

Source: http://www.spacer.com/news/launcher-russia-01j.html

"NASA says it can save up to half a billion dollars a year by
using reusable boosters."

The rocket cluster is a cluster of novel, pressure fed rockets which
have relatively large expansion ratio (about 25) and therefore
respectable specific impulse (about 330 seconds). It has less than
100 moving parts, so it is very simple and cheap. Like most other
pressure fed designs it is sturdy enough to survive splashdown.
The rocket cluster and its engine (called engine cluster)
are NOT protected by patents. Their description is posted at:
http://www.islandone.org/LEOBiblio/S...engine_cluster
and http://www.medianet.pl/~andrew/SPBI1...engine_cluster

Andrew Nowicki wrote in message ...
The rocket cluster is a cluster of novel, pressure fed rockets which
have relatively large expansion ratio (about 25) and therefore
respectable specific impulse (about 330 seconds). It has less than
100 moving parts, so it is very simple and cheap. Like most other
pressure fed designs it is sturdy enough to survive splashdown.
The rocket cluster and its engine (called engine cluster)
are NOT protected by patents. Their description is posted at:
http://www.islandone.org/LEOBiblio/S...engine_cluster
and http://www.medianet.pl/~andrew/SPBI1...engine_cluster

Huh? First stage doesnt have to be re-useable. In fact, making it
re-useable probably costs more money than throwing it away. Its only
function is to get the rest of the rocket to a reasonable altitude and
speed. All the smarts are in the second (or third) stage. First stage
should just be a big dumb throw away shell with cheapo tanks and
pumps.

(Parallax) wrote in message . com...
Huh? First stage doesnt have to be re-useable. In fact, making it
re-useable probably costs more money than throwing it away. Its only
function is to get the rest of the rocket to a reasonable altitude and
speed. All the smarts are in the second (or third) stage. First stage
should just be a big dumb throw away shell with cheapo tanks and
pumps.


The only question is over the life=cycle of the system, does a reusable first
stage result in lower life cycle costs then an expendable first stage.

The reusable first stage has a low operating cost at a reasonable flight rate,
now if you don't believe in high flight rates, well, what can I say.

"pat bahn" wrote in message
m...
(Parallax) wrote in message
. com...
Huh? First stage doesnt have to be re-useable. In fact, making it
re-useable probably costs more money than throwing it away. Its only
function is to get the rest of the rocket to a reasonable altitude and
speed. All the smarts are in the second (or third) stage. First stage
should just be a big dumb throw away shell with cheapo tanks and
pumps.


The only question is over the life=cycle of the system, does a reusable
first
stage result in lower life cycle costs then an expendable first stage.

The reusable first stage has a low operating cost at a reasonable flight
rate,
now if you don't believe in high flight rates, well, what can I say.

I don't understand the economic logic in that. High flight rates
mean that expendibles will be rolling off the assembly line, and that
means that unit costs can, with experience, become low. Reuseables
will not be manufactured in quantity anytime soon, even with high
flight rates.

Certainly the shuttle program would have had much lower costs per
launch if the flight rate had been 5x as high. But we would have
probably blown up 10 of them by now at that flight rate.

On Sat, 19 Jun 2004 06:11:05 +0000, Perplexed in Peoria wrote:

The reusable first stage has a low operating cost at a reasonable
flight rate, now if you don't believe in high flight rates, well, what
can I say.

I don't understand the economic logic in that. High flight rates mean
that expendibles will be rolling off the assembly line, and that means
that unit costs can, with experience, become low. Reuseables will not
be manufactured in quantity anytime soon, even with high flight rates.

Isn't that the point? At the lowest non-zero flight rate of "only one
flight ever", reusables have no conceivable advantage over expendables,
because you're still not going to reuse either. At higher rates,
expendable per-flight costs should go down because you can amortize the
costs of R&D and tools over more flights, but reusable per-flight costs
should go down even faster because you can amortize the costs of R&D,
tools, and vehicle construction. Note that "tools" are still included in
that list - reducing the per-flight cost of your manufacturing doesn't
require you to spread those costs out over more vehicles, just over more
flights.
---
Roy Stogner

"Perplexed in Peoria" wrote in message ...
Certainly the shuttle program would have had much lower costs per
launch if the flight rate had been 5x as high. But we would have
probably blown up 10 of them by now at that flight rate.

Note that the expendable Soyuz is as safe (deaths per flight) as the
reusable Shuttle; and the reliability is not significantly worse
(vehicles lost per flight).

Also, one of the good things about expendables is that it is slightly
easier to redesign the vehicle- you just build it differently next
time. With the Shuttle you have to modify all the vehicles you already
have, which is likely to be more expensive. In addition the Shuttle
has potential issues with ageing, the reusables don't have that.

Parallax wrote:
Huh? First stage doesnt have to be re-useable.

Would you rather buy a reusable car, or the one
that falls apart after the first ride?

__________________________________________________ __________

Ian Woollard wrote:

Note that the expendable Soyuz is as safe (deaths per
flight) as the reusable Shuttle; and the reliability is
not significantly worse (vehicles lost per flight).

The Space Shuttle is salvageable rather than reusable.
Reusable third (last) stages do not exist because the
temperature and heat load during reentry ablate all materials
that are known to rocket engineers. Regenerative cooling
(plumbing circulating cold propellant) is too heavy.
The new Shuttle-like third stage proposals (Lockheed Martin's
Orbital Space Plane, russian Clipper, german Colibri, and
japanese Hyflex) are not reusable but salvageable.

The first stage of a rocket launcher is not exposed to
the extreme temperature and heat load during reentry, so
a perfectly reusable (no maintenance except cleaning)
first stage is feasible.

Note the great difference between the Baikal and the
engine cluster. Baikal is an expensive rocket-plane,
while the engine cluster is as simple, robust, and cheap
as a barge. It is strong enough to survive splash down.
If the Russians had an ocean east to their launch site,
they would make a reusable pressure-fed first stage
instead of the expensive Baikal.

The high reliability of russian rocket launchers is not
related to the fact that they are expendable. French rocket
launchers are just as expendable, but much less reliable.

In article ,
says...
"Perplexed in Peoria" wrote in message ...
Certainly the shuttle program would have had much lower costs per
launch if the flight rate had been 5x as high. But we would have
probably blown up 10 of them by now at that flight rate.

Note that the expendable Soyuz is as safe (deaths per flight) as the
reusable Shuttle; and the reliability is not significantly worse
(vehicles lost per flight).

However, Soyuz has a higher rate of *injuring* its passengers short of
death than the Shuttle does. In fact, IIRC, Soyuz is the *only* manned
spacecraft that has injured its passengers. Apollo killed three (not
even in flight), Shuttle has killed 14 and Soyuz has killed 4. But
Soyuz has had multiple instances of injury from failure of the earth-
landing retrorockets (specifically, they have igniting hundreds or
thousands of feet in the air on several occasions, leaving no cushion-
firing for just short of landing).

Soyuz has also injured at least one person during a launch abort --
badly enough that the cosmonaut in question never flew again. (Yes,
that was technically a malfunction of the booster and not the
spacecraft, but then again, so was Challenger.)

Doug