ESA to launch suborbital test spaceplane in 2013

On 28/02/2014 1:56 AM, Robert Clark wrote:
"Robert Clark" wrote in message
...
On Jun 22, 11:45 am, wrote:
"The European* Space Agency (ESA) has announced
that it will launch an unmanned suborbital mission in
2013 designed to test various technologies which
could be used in future on vehicles able to re-enter
Earth's atmosphere from orbit and make a landing
carrying cargo or personnel."

See:

http://www.theregister.co.uk/2011/06..._announcement/

I like this because it would provide an easy means of converting an
expendable rocket stage into a reusable one without having to add the
extra weight of wings.




Bristol Spaceplanes is starting a crowdfunding campaign to fund a
suborbital spaceplane. They are one of the few people along with SpaceX who
realizes we have to cut the cost to space by reusability:

UK company crowdfunds 'low-cost' space tourism.
SCIENCE 12 FEBRUARY 14 by LIAT CLARK

"My first job was working on reusable launchers in the 60s. They were
widely considered feasible at the time but pressures of the Cold War space
race led to their not being developed," explains Ashford. "This accident of
history created a mindset that space travel has to be risky and expensive,
and the habit of throwing away a launcher for each flight has taken a firm
hold. We maintain that combining old designs with modern technology can soon
lead to an 'airline' service to space, with the UK firmly at the helm."
...
"Spaceplanes are not in the strategic plans of major players. There is no
rational reason for space agencies not to pursue spaceplane development
vigorously -- they would save money on present programmes alone, let alone
new ones."

http://www.wired.co.uk/news/archive/...anes-crowdfund

Bristol firm enters commercial space race
David Ashford, a 74-year-old entrepreneur, is hoping to bring down the cost
of commercial space flight 1000-fold with an innovative spaceplane design.
http://www.telegraph.co.uk/finance/n...pace-race.html

The crowdfunding site:

Bristol Spaceplanes.
http://www.crowdcube.com/investment/...ceplanes-13141


Bob Clark


Their path to orbit involves a carrier aircraft and a mach-4 separation
of two airborne vehicles, the latter not exactly being proven technology.

The picture of the combined craft doesn't look plausible. There's no way
the smaller craft could be carrying enough fuel to accelerate itself
from mach-4 to orbital speed.

This is nothing more than a way to get people to fund yet another
suborbital joy-rider.

Sylvia.

In article ,
ess says...
Their path to orbit involves a carrier aircraft and a mach-4 separation
of two airborne vehicles, the latter not exactly being proven technology.



The picture of the combined craft doesn't look plausible. There's no way
the smaller craft could be carrying enough fuel to accelerate itself
from mach-4 to orbital speed.

Cite for this picture? On their website, I don't know which picture you
might be talking about. Are you talking about Spacecab? If so, I don't
see a picture of its carrier aircraft.

http://bristolspaceplanes.com/projects/

Ascender is suborbital only. Spacecab is a 2nd stage: "Spacecab is an
enlarged and refined Ascender air-launched from a supersonic carrier
aeroplane." And finally, from the description, it's not clear to me if
Spacebus is a two or three stage to orbit system.

This is nothing more than a way to get people to fund yet another
suborbital joy-rider.

Possibly, but in my mind, their notional orbital spacecraft is as
"real" as Skylon, with the exception that one little piece of Skylon's
engine (Sabre) has been tested on the ground. Both "designs" are rather
notional at this point and appear to depend greatly on supersonic air
breathing engine technologies which have yet to be developed.

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

On 1/03/2014 2:32 AM, Jeff Findley wrote:
In article ,
ess says...
Their path to orbit involves a carrier aircraft and a mach-4 separation
of two airborne vehicles, the latter not exactly being proven technology.



The picture of the combined craft doesn't look plausible. There's no way
the smaller craft could be carrying enough fuel to accelerate itself
from mach-4 to orbital speed.

Cite for this picture? On their website, I don't know which picture you
might be talking about. Are you talking about Spacecab? If so, I don't
see a picture of its carrier aircraft.

http://bristolspaceplanes.com/projects/

http://bristolspaceplanes.com/projects/spacecab/


Ascender is suborbital only. Spacecab is a 2nd stage: "Spacecab is an
enlarged and refined Ascender air-launched from a supersonic carrier
aeroplane." And finally, from the description, it's not clear to me if
Spacebus is a two or three stage to orbit system.

This is nothing more than a way to get people to fund yet another
suborbital joy-rider.

Possibly, but in my mind, their notional orbital spacecraft is as
"real" as Skylon, with the exception that one little piece of Skylon's
engine (Sabre) has been tested on the ground. Both "designs" are rather
notional at this point and appear to depend greatly on supersonic air
breathing engine technologies which have yet to be developed.

Jeff


All I can see of Spacecab is an artist's impression. With Skylon there
is a design with numbers, and, as you say, a piece, and it's an
important piece, of the engine, has been tested on the ground.

The supersonic part of the Sabre engine is the inlet. The bulk of the
engine, including the heat exchanger, operates in the subsonic regime.

Sylvia.

In article ,
ess says...

All I can see of Spacecab is an artist's impression. With Skylon there
is a design with numbers, and, as you say, a piece, and it's an
important piece, of the engine, has been tested on the ground.

When it comes to unflown hardware, one paper design is little better
than another paper design, IMHO. The proof that a launch vehicle design
works is when it actually flies and proves that it can deliver a sizable
payload to LEO for a reasonable cost.

Spacecab at least appears to be an approach that is somewhat
incremental. The philosophy of build a little, test a little, fly a
little reduces programmatic risk by tackling technical challenges in an
incremental fashion. It also provides early vehicles which, hopefully,
can be used to turn a profit which provides funding for later vehicles.

Sabre/Skylon is an "all or nothing" mega-program that will either work,
or it won't. The downside is that we won't truly know if it works or
not without first throwing billions upon billions of dollars at it. It
would be quite the shame to spend, say, 10 billion dollars on it only to
find that it underperforms so badly that it's an economic failure.

The supersonic part of the Sabre engine is the inlet. The bulk of the
engine, including the heat exchanger, operates in the subsonic regime.

Me thinks you underestimate the challenges ahead of Sabre/Skylon. Given
the track record of similar vehicles, the challenges are quite daunting
indeed.

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