Was Buran better than the shuttle?

http://flightclub.jalopnik.com/did-t...did-1713379466

Not really anything new here, but always a fun discussion.

He doesn’t mention the apparent frame damage done on the one and only
landing.

As for the engines, one could make an argument that recovery permitted
inspection and the like.

Other thoughts?

In article ,
says...

http://flightclub.jalopnik.com/did-t...did-1713379466

Not really anything new here, but always a fun discussion.

He doesn?t mention the apparent frame damage done on the one and only
landing.

As for the engines, one could make an argument that recovery permitted
inspection and the like.

Other thoughts?

Claiming Buran was better in almost every respect after one unmanned
flight is a stretch. We'll never know for sure how its TPS would have
faired after repeated flights (the damage after one flight isn't a good
sign). And we all know just how problematic the space shuttle's TPS
was, especially on early fights. Actually, one could say the same about
all of Buran's systems since it only orbited earth twice before reentry.
From what I remember, the flown Buran wasn't fully equipped to carry
people (no life support system installed, or something like that).

Buran's launch vehicle, Energia, was launched only twice. So while it
was successful both times (the Polyus screwed up its orbital insertion
burn, which is why it failed to make orbit), again, no one knows for
sure how reliable it would have been in the long run.

That said, separating the launch vehicle from the orbiter did allow the
launcher to be used as a HLV, something the shuttle ET and SRBs could
never do without a huge redesign (SLS being the mother of all "shuttle
based" HLV redesigns).

The biggest problem with Energia/Buran was the price, which Russia
clearly couldn't afford.

Jeff
--
"the perennial claim that hypersonic airbreathing propulsion would
magically make space launch cheaper is nonsense -- LOX is much cheaper
than advanced airbreathing engines, and so are the tanks to put it in
and the extra thrust to carry it." - Henry Spencer

In article om,
says...

On 15-06-24 20:10, Greg (Strider) Moore wrote:
http://flightclub.jalopnik.com/did-t...did-1713379466

Not really anything new here, but always a fun discussion.

I think that the advantage of not having main engines part of the plane
was overplayed. The main engines are still part of the stack at launch
so their weight limits payload just as much.

The main difference is with on-orbit burns after separation where the
shuttle is then lighter. But what percentage of total delta-V is
imparted by OMS versus main engines ?



Also, the shuttle's main engines were re-usable and survived re-entry.
Was Energya reusable in any way ?

There were plans to reuse the liquid fueled boosters, which is why they
were designed with containers on the outside for parachutes. But, I do
not believe any were recovered and they were therefore never reused. It
was unclear how the core stage was planned to be reused.

The image I get is that Buran was far from being in production use. It
seemed more like the Enterprise, except launched from orbit instead of
from a 747.

There was also a landing test vehicle, fitted with jet engines, that was
more analogous to Enterprise.

Clearly the first orbital test vehicle was more functional than
Enterprise, which lacked major components needed for spaceflight (like a
pressurized crew cabin, engine thrust structure, engines, and etc.).
I'd place the first orbital Buran somewhere between Enterprise and
Columbia in terms of capabilities.

Supposedly a second orbiter (along with its Energia launch vehicle) was
completed and ready for orbital flight, or very close to it, when the
program was canceled and the program mothballed.

Did Buran re-enter and land on auto pilot, or remote-control ?

I believe the first flight was on "auto pilot", which is something the
US orbiter never did from launch to landing. The first Buran orbital
flight was, after all, a pre-programmed test flight.

Jeff
--
"the perennial claim that hypersonic airbreathing propulsion would
magically make space launch cheaper is nonsense -- LOX is much cheaper
than advanced airbreathing engines, and so are the tanks to put it in
and the extra thrust to carry it." - Henry Spencer

"JF Mezei" wrote in message
eb.com...

On 15-06-25 06:14, Jeff Findley wrote:

Clearly the first orbital test vehicle was more functional than
Enterprise, which lacked major components needed for spaceflight (like a
pressurized crew cabin, engine thrust structure, engines, and etc.).

Did the Enterprise pilots wear pressurised suits ? or just O2 masks ?

I believe pressure suits because of the ejection seats.

They certainly did on the first few Columbia flights.


Was Enterprise powered by hypergolics to run the moveable surfaces and
fuel cells for electricity ? Or did run electrical on batteries and
have pressurised tanks to power hydraulics for moveable surfaces ?

I'll admit I'm too lazy to pull down my copy of Space Shuttle by Jenkins,
but I believe batteries.







I'd place the first orbital Buran somewhere between Enterprise and
Columbia in terms of capabilities.

Buran obviously tested the launch vehicle which Enterprise didn't.
And once in vaccuum, would have tested attitude control with thrusters
which Enterprise didn't.

Did Buran perform a de-orbit burn, or was it put into elliptical orbit
designed to re-enter by itself after 2 spins around the block ?
(de=orbit burn would imply Buran turn around, fire engines to slow down,
then turn around and get into re-entry attitude, and if it did that on
auto pilot as opposed to remote control, that is a very good
accomplishement on first flight.

When Enterprise was released from STA, I take it its speed at 40k feet
was nowhere near the multi-Mach speed a re=entering shuttle still had at
that altitude ?

So basically Enterprise only simulated the last minute of flight and
landing ?

Correct.



I believe the first flight was on "auto pilot", which is something the
US orbiter never did from launch to landing. The first Buran orbital
flight was, after all, a pre-programmed test flight.

But that would still require "auto pilot" to maintain attitude and
manage the re-entry, right ? That isn't something you can pre-program
with "fire thurster X at time index Y for z seconds".

Correct, in fact I believe it accounted for a change in wind direction
before landing and end up landing in the direction from originally planned.




--
Greg D. Moore http://greenmountainsoftware.wordpress.com/
CEO QuiCR: Quick, Crowdsourced Responses. http://www.quicr.net

In article om,
says...

On 15-06-25 06:14, Jeff Findley wrote:

Clearly the first orbital test vehicle was more functional than
Enterprise, which lacked major components needed for spaceflight (like a
pressurized crew cabin, engine thrust structure, engines, and etc.).

Did the Enterprise pilots wear pressurised suits ? or just O2 masks ?

Regular old jump suits and O2 masks. Here is a picture of Haise and
Fullerton inside the cockpit of Enterprise, as they would have been
during flight:

https://en.wikipedia.org/?
title=Space_Shuttle_Enterprise#/media/File:HaiseandFullertonEnterprise.j
pg


Was Enterprise powered by hypergolics to run the moveable surfaces and
fuel cells for electricity ? Or did run electrical on batteries and
have pressurised tanks to power hydraulics for moveable surfaces ?

According to Wikipedia:

Enterprise used fuel cells to generate its electrical power,
but these were not sufficient to power the orbiter for spaceflight.

Not sure if it had APUs to power the hydraulics for the aerodynamic
surfaces. The landing gear lacked hydraulics and used explosive bolts
and gravity to deploy (which was the back-up deployment mechanism on the
other orbiters).

Enterprise looked like a shuttle, but was actually quite a bit different
in the details, which is why it would have cost so much to refit for
orbital flight. It would have had to have been torn down nearly
completely to its underlying structure to refit. This is why the
structural test article STA-099 was ultimately chosen for refit for
flight into orbiter Challenger (OV-099) and Enterprise was ultimately
put into the Air and Space Museum in D.C. Enterprise was later moved
since the Air and Space Museum wanted a "real" space shuttle once the
program ended.

I'd place the first orbital Buran somewhere between Enterprise and
Columbia in terms of capabilities.

Buran obviously tested the launch vehicle which Enterprise didn't.
And once in vaccuum, would have tested attitude control with thrusters
which Enterprise didn't.

True, Enterprise lacked SSMEs, RCS, OMS, and etc.

Did Buran perform a de-orbit burn, or was it put into elliptical orbit
designed to re-enter by itself after 2 spins around the block ?
(de=orbit burn would imply Buran turn around, fire engines to slow down,
then turn around and get into re-entry attitude, and if it did that on
auto pilot as opposed to remote control, that is a very good
accomplishement on first flight.

I believe it had to do a de-orbit burn in order to perform a precision
reentry and landing. It certainly did better than Polyus, the other
Energia payload that did a de-orbit burn instead of an orbit insertion
burn (oops).

When Enterprise was released from STA, I take it its speed at 40k feet
was nowhere near the multi-Mach speed a re=entering shuttle still had at
that altitude ?

True, because the 747 was subsonic.

So basically Enterprise only simulated the last minute of flight and
landing ?

Yes, same as the Russian's jet engine equipped Buran that performed
similar landing tests.

I believe the first flight was on "auto pilot", which is something
the
US orbiter never did from launch to landing. The first Buran orbital
flight was, after all, a pre-programmed test flight.

But that would still require "auto pilot" to maintain attitude and
manage the re-entry, right ? That isn't something you can pre-program
with "fire thurster X at time index Y for z seconds".

Possible, but the US shuttle was never designed to do so. Several key
procedures (switch throws and the like) had to be done by an astronaut.
After the Columbia disaster, a "kit" (wiring harness) was developed
which was kept on ISS which would have allowed the ground to perform
these procedures if a shuttle crew ended up stranded at ISS and the
shuttle had to be landed via remote/autopilot.

In other words, the US space shuttle could have landed without a crew on
board, with a few minor modifications, but this was never attempted.

Jeff
--
"the perennial claim that hypersonic airbreathing propulsion would
magically make space launch cheaper is nonsense -- LOX is much cheaper
than advanced airbreathing engines, and so are the tanks to put it in
and the extra thrust to carry it." - Henry Spencer

In article ,
says...

"JF Mezei" wrote in message
eb.com...

On 15-06-25 06:14, Jeff Findley wrote:

Clearly the first orbital test vehicle was more functional than
Enterprise, which lacked major components needed for spaceflight (like a
pressurized crew cabin, engine thrust structure, engines, and etc.).

Did the Enterprise pilots wear pressurised suits ? or just O2 masks ?

I believe pressure suits because of the ejection seats.

Nope, regular old flight suits and pressure masks, like you might see
any USAF pilot wearing while flying a fighter at high altitudes.

They certainly did on the first few Columbia flights.

Yes, because these flights would have been at speeds and altitudes far
greater than those which the B-747 could impart.

Jeff
--
"the perennial claim that hypersonic airbreathing propulsion would
magically make space launch cheaper is nonsense -- LOX is much cheaper
than advanced airbreathing engines, and so are the tanks to put it in
and the extra thrust to carry it." - Henry Spencer

In article om,
says...

Could they have made SRB-like segments that had the Saturn 5 engines and
kerosene tanks instead of the solid fuel ? This would have allowed those
segments to be ditched roughly 2 minutes into flight to reduce weight of
remaining stack (as was the case with SRBs).

SRBs were cheaper and faster to develop than liquids and NASA had a
development schedule and budget to stick to. But the bigger reason was
that politics entered the equation, so Morton Thiokol (now Orbital ATK)
in Utah got the contract for the SRBs.

Much the same reasoning remains for the SLS "design". Its design
reflects politics far more than sane engineering.

Jeff
--
"the perennial claim that hypersonic airbreathing propulsion would
magically make space launch cheaper is nonsense -- LOX is much cheaper
than advanced airbreathing engines, and so are the tanks to put it in
and the extra thrust to carry it." - Henry Spencer

"Fred J. McCall" wrote in message
...

JF Mezei wrote:

On 15-06-25 21:24, Fred J. McCall wrote:

Were it up to me, I would have built something different from either
system, but that's just me.

Would it be fair to state that the generic shape of the shuttle was
basically the optimal design ?


Given the size, I think the shape sort of followed. Form follows
function and all that.

I recall because the COG was different (w/o the extra weight in the tail
end) they changed the wing some but yeah, if you want a 15'x60' cargo bay
and similar range, you're probably not going to change things much.

Different materials for the heat shield may allow a different shape if you
can come hotter, but again, yeah, form pretty much follows function.




If a new one were built today with modern materials, would this
represent a "revolution" or just "evolution" in terms of weight savings
? I note the Boeing 787 turned out to be just an evolution in weight
savings.


If it was built to the same size with the same sorts of crossrange
requirements, etc, it would probably look very similar.


From a launcher point of view, looks like SRBs produced 6.6 millions
pounds of thrust (3.3 * 2). And SSMEs produced 0.418 million pounds of
thrust each.

It appears that Saturn 5 first state produced 7.6 million pounds of
thrust.

Pardon my ignorance here, but why did they not use the saturn 5 engines
below the ET and not need any SRBs ? (yea, I realise, needs bigger ET
with bigger LOX tank, and separate kerosene tanks for those engines).


Using a liquid stage would have involved having to carry more fuel.
Solids tend to manage a higher energy density.


Could they have made SRB-like segments that had the Saturn 5 engines and
kerosene tanks instead of the solid fuel ? This would have allowed those
segments to be ditched roughly 2 minutes into flight to reduce weight of
remaining stack (as was the case with SRBs).


Personally I'd have built a heavy booster (Saturn V or Energia
derived) and a much smaller orbiter for people.


Engineering wise, probably.
The alternative given the politics would probably have been to try to go a
more evolutionary route:
Build OV-10x to be as re-usable as possible, don't worry about payload. But
focus on usability. Get the costs down so you can fly more.
THEN build OV-20x where you can start to lighten the design and focus on
payload.

But of course they basically got it backwards and were never able to build
an OV-20x.



--
Greg D. Moore http://greenmountainsoftware.wordpress.com/
CEO QuiCR: Quick, Crowdsourced Responses. http://www.quicr.net