

Microsoft Co-Founder Paul Allen Unveils Giant Plane for Private Space Launches - sasvari
http://www.space.com/13915-paul-allen-giant-plane-stratolaunch-systems-private-space.html

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johno215
Launching at a higher altitude allows the rocket engines to be optimized for
low atmospheric pressure increasing their efficiency. In addition, the
trajectory can be turned to a more horizontal angle earlier without having to
fight drag too much.

Another benefit of air launch is the ability to launch at a location and time
of one's choosing. This is useful to avoid weather, avoid flying over land
when launching in certain directions, and not having to share a range with
other launchers.

~~~
johno215
A negative is that it is a lot harder to check-out the vehicle when it is
attached to an airplane than when it is on the ground. Also, on the ground the
successful start-up of all the engines can be verified before the vehicle is
released. If one engine fails to start, the rest can be shutdown with the
vehicle still intact on the ground. But, when an air-launching, there is no
going back once the vehicle is dropped.

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sukuriant
Perhaps you can start the engines before dropping? If only a second or so
before? Or is the force that instantaneous, that strong?

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highace
I wish we invested more into space exploration. Like, serious resources from
every country in the world. To think that we squabble over silly things on
this planet every day when there's a whole universe of stuff we can't even
comprehend out there. Things always seem so trivial when you imagine the
bigger picture, yet we worry about them anyway and I don't know why.

There's a saying that struck a note with me... "We've been born too late to
explore the earth, but too early to explore the universe".

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leoedin
The companies involved are like a supergroup of cutting edge aerospace. Scaled
and SpaceX collaborating!

It's a nice concept, and it obviously works on a smaller scale for the pegasus
guys as well as Virgin Galactic (although they're not putting anything into
orbit). Hopefully this is successful!

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martinkallstrom
Space bums... littering used fuel cans everywhere ("any orbit, any time"). How
sustainable is it to keep leaving half of every vehicle somewhere on the way
to your destination?

UPDATE: At first I was bemused that this was my reaction to their concept
video. But then I realized that all the other concepts we have seen like
SpaceX and Bezo's project actually don't litter. Isn't that correct? Other
modern commercial space programs build for returning the entire vehicle home
for reuse?

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kijin
Not exactly what you're looking for, but the Space Shuttle didn't leave any
debris in orbit. The external tank was the only part that got dumped in the
ocean, and it would shatter on impact because it's just a thin shell of
aluminum. Solid boosters were much more robust, so they were salvaged and
reused.

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DilipJ
A 385 feet wingspan! amazing. It's about time someone beat the Spruce Goose.

~~~
tomkarlo
The Spruce Goose was my first thought when I saw this (and not in a good way.)
<http://en.wikipedia.org/wiki/Hughes_H-4_Hercules>

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darklajid
I suck at physics and the article is light on details. Help me out.

What is the gain here? You're still launching a rocket, but now at
30000m/9000ft? A rocket that is supposed to be similar to what exists today?

I mean - smart people have this idea, so the benefit must be huge. Can someone
explain in slow speech (How'd you explain the novelty of this to your kid) the
incentive to me?

~~~
dalke
I'll dupe the comment I wrote on another thread
(<http://news.ycombinator.com/item?id=3349294> ) on this topic....

I hadn't realized that there already is an air-launch-to-orbit system called
"Pegasus" (<http://en.wikipedia.org/wiki/Pegasus_(rocket)> ).

It comments that air launches reduce the costs to orbit not (as ColinWright
rightly points out) through energy savings but because it 1) doesn't have as
many weather-related launch delays, 2) it can insert into almost arbitrary
orbits, 3) there's no need for a blast-proof pad and related ground equipment,
4) launches over an ocean save on insurance costs, and reduce collateral
damage should an explosion occur, and 5) the higher altitude means the first
stage engine bell doesn't need to optimized for higher pressures, and the lack
of high cross-winds means there's no need for gimbals; lighter fins suffice.

On the other hand, it also says that Pegasus is "one of the most expensive
"launch-to-orbit" vehicles" (I assume per-kilogram to orbit), but that the
flexibility in choosing the orbit makes up for it for small payloads which
otherwise must piggyback.

~~~
demallien
Not to mention that this dramatically reduces MaxQ (the maximum dynamic
pressure on the airframe), which reduces design constraints on the
spacecraft/upper stages of the rocket.

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michaelfeathers
I thought Burt Rutan was working with Virgin Galactic on their venture.

~~~
jmcqk6
He is/was. However, Paul Allen was a partner when Rutan was going after (and
won) the X-prize. So really, they're just getting back together to work on
something new.

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nradov
I wonder why the fuselages are only joined by the wing and not at the tail?
Won't that subject the wing boxes to a lot of twisting stress?

~~~
tomkarlo
If it's a fly-by wire system, you may be able to avoid twisting stress by
varying the angles of the elevators on each tail so that you add force to
oppose that twist. Also, I don't think it's expected to undertake any really
drastic maneuvers. You'd fly it in decent weather on a relatively short
ascent, and use a very gently take-off and landing profile.

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snorkel
So ... what's the re-entry plan? Splash down? Call a Russian taxi?

~~~
InclinedPlane
Assuming that this ends up using a variant of the SpaceX dragon capsule the
re-entry plan would be a powered descent onto a targeted landing site.

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davidhansen
Could someone help me understand the space thing? Specifically the phenomenon
of rich engineers and businessmen like Allen, Carmack, Branson, Bezos,
Shuttleworth, etc spending huge amounts of money on space-travel-related
projects.

I, like many nerds, grew up with a powerful fascination with space, cosmology,
and the myriad science fiction novels based around the various problems and
possibilities of space travel. I understand the allure. I am also a
capitalist, and therefore don't begrudge these guys the opportunity to do with
their money as they see fit.

What I _don't_ get is why we never hear of wealthy engineers spending their
money on technology projects that would have a much much larger benefit to
humanity, and arguably cooler than spaceflight. Things like nanotech,
robotics, and hell, even cold fusion come to mind.

Why space?

~~~
DougWebb
Could someone help me understand the Atlantic Ocean thing? Specifically the
phenomenon of rich royalty and businessmen like Columbus, Queen Isabella, etc
spending huge amounts of money on ocean-travel-related projects.

I, like many nerds, grew up with a powerful fascination with oceans, foreign
lands, and the myriad mythology stories based around the various problems and
possibilities of ocean travel. I understand the allure. I am also a
capitalist, and therefore don't begrudge these guys the opportunity to do with
their money as they see fit.

What I don't get is why we never hear of wealthy royalty spending their money
on technology projects that would have a much much larger benefit to humanity,
and arguably cooler than ocean travel. Things like medicine, farming, and
hell, even waterwheel-powered machinery come to mind.

Why cross the Atlantic?

~~~
T-hawk
Profit was the motive for funding Columbus to cross the Atlantic, by finding a
faster or easier trading route to the Oriental sources of spices and silk.
Profit was still the motive for later explorers of the Americas, in mining or
stealing Aztec gold and silver, then tobacco and cotton and sugar plantations.

It's unclear yet where feasible profit opportunities exist for development in
space. (Also, we can _see_ space with telescopes, there isn't a Pacific Ocean
on the other side of space that we have to send someone to discover.) If you
want to see some real space industry, hope that somebody discovers a gold
asteroid.

Finally, remember that from Columbus to Jamestown elapsed over a hundred
years. Less than half of that timespan has yet elapsed since Yuri Gagarin.
These things take time.

~~~
NickPollard
>> If you want to see some real space industry, hope that somebody discovers a
gold asteroid.

They already have [1]. And a platinum asteroid. And a palladium asteroid. And
an Iron, Nickel, whatever-mineral-you-want asteroid.

"At 1997 prices, a relatively small metallic asteroid with a diameter of 1.6
km (0.99 mi) contains more than 20 trillion US dollars worth of industrial and
precious metals."

"A comparatively small M-type asteroid with a mean diameter of 1 km could
contain more than two billion metric tons of iron-nickel ore, or two to three
times the annual production for 2004."

Supposedly the asteroid '433 Eros' contains more gold than has ever been mined
from the Earth in the history of mankind (I can't find a source for this apart
from an earlier HN comment though, the paper I found on it was behind a
paywall).

[1] <http://en.wikipedia.org/wiki/Asteroid_mining>

