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U.S. astronauts are climbing back into space capsules. Here's howthey've improved over the past 50 years



 
 
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  #1  
Old September 15th 17, 06:59 PM posted to sci.space.policy
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Default U.S. astronauts are climbing back into space capsules. Here's howthey've improved over the past 50 years

"In 1961, an American astronaut reached space for the first time and soared
through the heavens in a gumdrop-shaped capsule.

Since then, people have flown to the moon, created space planes and designed
rockets that return to Earth for precision landings. But when astronauts lift off
next year from U.S. soil for the first time in six years, their vehicle of choice
will be another capsule."

See:

http://www.latimes.com/business/la-f...htmlstory.html




How do the benefits of capsules and spaceplanes compare?
  #2  
Old September 15th 17, 07:44 PM posted to sci.space.policy
Fred J. McCall[_3_]
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Posts: 10,018
Default U.S. astronauts are climbing back into space capsules. Here's how they've improved over the past 50 years

wrote:

"In 1961, an American astronaut reached space for the first time and soared
through the heavens in a gumdrop-shaped capsule.

Since then, people have flown to the moon, created space planes and designed
rockets that return to Earth for precision landings. But when astronauts lift off
next year from U.S. soil for the first time in six years, their vehicle of choice
will be another capsule."

See:

http://www.latimes.com/business/la-f...htmlstory.html




How do the benefits of capsules and spaceplanes compare?


Capsules have lower dry mass for the cargo they carry, since you're
not carrying along all that lifting structure. I was rather
disappointed to see SpaceX back away from a powered landing on land
for the Dragon V2, since that would have addressed one of the
advantages of spaceplanes in that they don't require 'recovery forces'
to fish them out of the water. Small spaceplanes tend to be more
'reusable' than capsules. However, the fiasco that was the Space
Shuttle backed everyone away from the idea of spaceplanes.


--
"The reasonable man adapts himself to the world; the unreasonable
man persists in trying to adapt the world to himself. Therefore,
all progress depends on the unreasonable man."
--George Bernard Shaw
  #3  
Old September 15th 17, 10:51 PM posted to sci.space.policy
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Posts: 687
Default U.S. astronauts are climbing back into space capsules. Here's howthey've improved over the past 50 years

On Friday, September 15, 2017 at 11:44:09 AM UTC-7, Fred J. McCall wrote:
wrote:

"In 1961, an American astronaut reached space for the first time and soared
through the heavens in a gumdrop-shaped capsule.

Since then, people have flown to the moon, created space planes and designed
rockets that return to Earth for precision landings. But when astronauts lift off
next year from U.S. soil for the first time in six years, their vehicle of choice
will be another capsule."

See:

http://www.latimes.com/business/la-f...htmlstory.html




How do the benefits of capsules and spaceplanes compare?


Capsules have lower dry mass for the cargo they carry, since you're
not carrying along all that lifting structure. I was rather
disappointed to see SpaceX back away from a powered landing on land
for the Dragon V2, since that would have addressed one of the
advantages of spaceplanes in that they don't require 'recovery forces'
to fish them out of the water. Small spaceplanes tend to be more
'reusable' than capsules. However, the fiasco that was the Space
Shuttle backed everyone away from the idea of spaceplanes.


--
"The reasonable man adapts himself to the world; the unreasonable
man persists in trying to adapt the world to himself. Therefore,
all progress depends on the unreasonable man."
--George Bernard Shaw



The USAF still likes spaceplanes:

https://www.space.com/25275-x37b-space-plane.html

https://www.space.com/36985-darpa-xs...m-express.html



There's also Dreamchaser:

https://www.space.com/37636-dream-ch...v-rockets.html



The Chinese and Europeans also have spaceplane projects:

https://www.theverge.com/2016/10/5/1...rism-20-people

http://www.bbc.com/future/story/2017...nside-a-rocket




But SpaceX, NASA, and the Russians are still sticking with capsules.

  #4  
Old September 16th 17, 01:29 AM posted to sci.space.policy
Fred J. McCall[_3_]
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Posts: 10,018
Default U.S. astronauts are climbing back into space capsules. Here's how they've improved over the past 50 years

wrote:

On Friday, September 15, 2017 at 11:44:09 AM UTC-7, Fred J. McCall wrote:
wrote:

"In 1961, an American astronaut reached space for the first time and soared
through the heavens in a gumdrop-shaped capsule.

Since then, people have flown to the moon, created space planes and designed
rockets that return to Earth for precision landings. But when astronauts lift off
next year from U.S. soil for the first time in six years, their vehicle of choice
will be another capsule."

See:

http://www.latimes.com/business/la-f...htmlstory.html




How do the benefits of capsules and spaceplanes compare?


Capsules have lower dry mass for the cargo they carry, since you're
not carrying along all that lifting structure. I was rather
disappointed to see SpaceX back away from a powered landing on land
for the Dragon V2, since that would have addressed one of the
advantages of spaceplanes in that they don't require 'recovery forces'
to fish them out of the water. Small spaceplanes tend to be more
'reusable' than capsules. However, the fiasco that was the Space
Shuttle backed everyone away from the idea of spaceplanes.


The USAF still likes spaceplanes:

https://www.space.com/25275-x37b-space-plane.html

https://www.space.com/36985-darpa-xs...m-express.html


The USAF thinks they're made of money and note that it doesn't do
anything that either a capsule OR a regular spaceplane would do.


There's also Dreamchaser:

https://www.space.com/37636-dream-ch...v-rockets.html


Assuming they finish it. Note that Dragon carries 20% more cargo (by
weight) and is available now vice Dream Chaser perhaps being available
in 2021. That difference in payload as well as the Dream Chaser
decision to launch on ULA launchers is going to make it significantly
more expensive per launch.


The Chinese and Europeans also have spaceplane projects:

https://www.theverge.com/2016/10/5/1...rism-20-people


Not an orbital system and still largely dreamware.


http://www.bbc.com/future/story/2017...nside-a-rocket


Like the USAF system. Too small to do much (assuming they finish it).


But SpaceX, NASA, and the Russians are still sticking with capsules.


Because they're all in the business of actually putting stuff in
orbit.


--
"The reasonable man adapts himself to the world; the unreasonable
man persists in trying to adapt the world to himself. Therefore,
all progress depends on the unreasonable man."
--George Bernard Shaw
  #5  
Old September 20th 17, 11:49 AM posted to sci.space.policy
Greg \(Strider\) Moore
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Posts: 752
Default U.S. astronauts are climbing back into space capsules. Here's how they've improved over the past 50 years

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

wrote:

"In 1961, an American astronaut reached space for the first time and
soared
through the heavens in a gumdrop-shaped capsule.

Since then, people have flown to the moon, created space planes and
designed
rockets that return to Earth for precision landings. But when astronauts
lift off
next year from U.S. soil for the first time in six years, their vehicle of
choice
will be another capsule."

See:

http://www.latimes.com/business/la-f...htmlstory.html




How do the benefits of capsules and spaceplanes compare?


Capsules have lower dry mass for the cargo they carry, since you're
not carrying along all that lifting structure. I was rather
disappointed to see SpaceX back away from a powered landing on land
for the Dragon V2, since that would have addressed one of the
advantages of spaceplanes in that they don't require 'recovery forces'
to fish them out of the water. Small spaceplanes tend to be more
'reusable' than capsules. However, the fiasco that was the Space
Shuttle backed everyone away from the idea of spaceplanes.



My understanding is that NASA is the one insisting on a water landing for
Dragon V2, but SpaceX for its own missions still plans to ultimately do land
landings.

I expect we'll eventually see us move back towards small spaceplans/lifting
body designs in a few decades, but it'll take some time.


--
Greg D. Moore http://greenmountainsoftware.wordpress.com/
CEO QuiCR: Quick, Crowdsourced Responses. http://www.quicr.net
IT Disaster Response -
https://www.amazon.com/Disaster-Resp...dp/1484221834/

  #6  
Old September 20th 17, 12:13 PM posted to sci.space.policy
Jeff Findley[_6_]
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Posts: 2,307
Default U.S. astronauts are climbing back into space capsules. Here's how they've improved over the past 50 years

In article ,
says...

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

wrote:

"In 1961, an American astronaut reached space for the first time and
soared
through the heavens in a gumdrop-shaped capsule.

Since then, people have flown to the moon, created space planes and
designed
rockets that return to Earth for precision landings. But when astronauts
lift off
next year from U.S. soil for the first time in six years, their vehicle of
choice
will be another capsule."

See:

http://www.latimes.com/business/la-f...htmlstory.html




How do the benefits of capsules and spaceplanes compare?


Capsules have lower dry mass for the cargo they carry, since you're
not carrying along all that lifting structure. I was rather
disappointed to see SpaceX back away from a powered landing on land
for the Dragon V2, since that would have addressed one of the
advantages of spaceplanes in that they don't require 'recovery forces'
to fish them out of the water. Small spaceplanes tend to be more
'reusable' than capsules. However, the fiasco that was the Space
Shuttle backed everyone away from the idea of spaceplanes.



My understanding is that NASA is the one insisting on a water landing for
Dragon V2, but SpaceX for its own missions still plans to ultimately do land
landings.


This has changed somewhat recently. Reportedly SpaceX is the one who
shelved development of Dragon V2 vertical landing. The reasons for this
aren't terribly clear, but there are hints from SpaceX that this is
because they've decided to change the (Mars) landing mode of their
(eventual) Mars vehicle.

Also, SpaceX is supposed to have a press briefing about the changes in
their Mars program sometime this fall. Hopefully we'll get more
information then which will allow us to "connect the dots".

I expect we'll eventually see us move back towards small
spaceplans/lifting body designs in a few decades, but it'll
take some time.


Possibly. Sierra Nevada Corporation is still working on Dreamchaser,
but it's only under a cargo contract with NASA, so it will lack the
ability to carry people. Also, SNC isn't exactly a "big player" in
aerospace. You're playing (quite) long odds if you think they'll
eventually dominate manned space travel.

The USAF is funding Experimental Spaceplane program (XS-1), which sounds
really cool, but it's nothing more than a (smallish) winged reusable
first stage. It's very hard for me to see this thing being cheaper than
a reusable Falcon 9 first stage. There are several reasons for this.
First the contractor is Boeing. Second, the thing will use what's left
of the parts of old SSMEs assembled into working engines (i.e. the bits
NASA isn't planning on using for SLS) and the SSME is not known for
being a "cheap" engine by any stretch of the imagination. Third, LH2 is
not a very dense fuel so this will result in a quite large "space
plane" when compared to say a LOX/kerosene stage. Fourth, winged
landing vehicles are more complex than a VTVL in aerodynamics,
structures, dynamics and control, and etc. Costs scale more closely
with complexity than size, but in the case of the XS-1, it's got
complexity and size as its drawbacks.

So, any way you run the accounting, I have a feeling XS-1 is going to be
a dismal (economic) failure. Despite the prejudices of the USAF, there
is nothing magic about wheels on a runway that will make "spaceplanes"
inexpensive to operate.

So, from my point of view, we're not sitting on the cusp of a resurgence
in "space planes". They're just too expensive to develop and too
expensive to fly compared to their simpler, cheaper, VTVL counterparts.

I'd also note that in the consumer world, the market of small flying
machines is dominated by quad copters, not fixed wing aircraft. VTVL
tech has literally matured to the point where it's cheap enough and easy
enough to fly that you can buy one in the children's toy aisle for less
than $100.

Jeff
--
All opinions posted by me on Usenet News are mine, and mine alone.
These posts do not reflect the opinions of my family, friends,
employer, or any organization that I am a member of.
  #7  
Old September 20th 17, 10:17 PM posted to sci.space.policy
Fred J. McCall[_3_]
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Posts: 10,018
Default U.S. astronauts are climbing back into space capsules. Here's how they've improved over the past 50 years

"Greg \(Strider\) Moore" wrote:

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

wrote:

"In 1961, an American astronaut reached space for the first time and
soared
through the heavens in a gumdrop-shaped capsule.

Since then, people have flown to the moon, created space planes and
designed
rockets that return to Earth for precision landings. But when astronauts
lift off
next year from U.S. soil for the first time in six years, their vehicle of
choice
will be another capsule."

See:

http://www.latimes.com/business/la-f...htmlstory.html




How do the benefits of capsules and spaceplanes compare?


Capsules have lower dry mass for the cargo they carry, since you're
not carrying along all that lifting structure. I was rather
disappointed to see SpaceX back away from a powered landing on land
for the Dragon V2, since that would have addressed one of the
advantages of spaceplanes in that they don't require 'recovery forces'
to fish them out of the water. Small spaceplanes tend to be more
'reusable' than capsules. However, the fiasco that was the Space
Shuttle backed everyone away from the idea of spaceplanes.


My understanding is that NASA is the one insisting on a water landing for
Dragon V2, but SpaceX for its own missions still plans to ultimately do land
landings.


They changed that plan in the last few months. It's apparently too
hard to get it certified as safe so that they're allowed to launch
with that intent, so it's all water landings for everyone now and
they're not working on powered landings anymore.


I expect we'll eventually see us move back towards small spaceplans/lifting
body designs in a few decades, but it'll take some time.


I think the best approach is small spaceplanes for people and small
cargos and big dumb expendables for big cargo. But I think the
Shuttle soured the spaceplane punch for a long while to come.


--
"We come into the world and take our chances.
Fate is just the weight of circumstances.
That's the way that Lady Luck dances.
Roll the bones...."
-- "Roll The Bones", Rush
  #8  
Old September 20th 17, 10:23 PM posted to sci.space.policy
Fred J. McCall[_3_]
external usenet poster
 
Posts: 10,018
Default U.S. astronauts are climbing back into space capsules. Here's how they've improved over the past 50 years

JF Mezei wrote:

On 2017-09-20 07:13, Jeff Findley wrote:

The USAF is funding Experimental Spaceplane program (XS-1), which sounds
really cool, but it's nothing more than a (smallish) winged reusable
first stage.


Would a winged 1st stage have far greater landing range after it
released it load? (SpaceX has to have a barge out in ocean for certain
launches because stage1 doesn't have fuel to return to land).


Unlikely. What it would do is decrease the amount of fuel you'd have
to reserve for recovery, since it could use aerodynamic forces
instead.

snip


It's very hard for me to see this thing being cheaper than
a reusable Falcon 9 first stage.


From a software point of view, would designing landing system for winged
vehicle be simpler than a pure rocket? It took SpaceX a while to develop
and a number of failures to fine tune the system.


It's probably somewhat easier, but remember that SpaceX issues were
largely related to how throttleable their engines were.


--
"The reasonable man adapts himself to the world; the unreasonable
man persists in trying to adapt the world to himself. Therefore,
all progress depends on the unreasonable man."
--George Bernard Shaw
  #9  
Old September 21st 17, 12:41 PM posted to sci.space.policy
Jeff Findley[_6_]
external usenet poster
 
Posts: 2,307
Default U.S. astronauts are climbing back into space capsules. Here's how they've improved over the past 50 years

In article . com,
says...

On 2017-09-20 07:13, Jeff Findley wrote:

The USAF is funding Experimental Spaceplane program (XS-1), which sounds
really cool, but it's nothing more than a (smallish) winged reusable
first stage.


Would a winged 1st stage have far greater landing range after it
released it load? (SpaceX has to have a barge out in ocean for certain
launches because stage1 doesn't have fuel to return to land).
or would it have the exact opposite of limiting launch flexibility so it
can return to a specific landing spot?


XS-1 will surely glide to a landing, so the launch trajectory will have
to be tailored such that it doesn't go too far downrange if the goal is
to land (close) to the launch site. Whether or not this is better than
a barge landing is debatable. The USAF has a bias towards wheels on
runways, but that doesn't mean glide landings are better than vertical
powered landings.

If this is Air Force related, I assume they want some ability to try

to
make it hard to know exactly where the stage left its payload. Would a
winged return vehicle help with a "random" path that makes it hard to
know where it came from ?


It's quite easy to track launches and orbital payloads. "Amateurs" do
it all the time and post the results publicly.

It's very hard for me to see this thing being cheaper than
a reusable Falcon 9 first stage.


From a software point of view, would designing landing system for winged
vehicle be simpler than a pure rocket? It took SpaceX a while to develop
and a number of failures to fine tune the system.


Not in my opinion. Reusable first stages like these have to deal with
speeds ranging from hypersonic to supersonic to subsonic (including
landing). That's a p.i.t.a. to do with a winged vehicle from an
aerodynamics and dynamics and control point of view.

SpaceX had to deal with this as well, but with the addition of
relatively simple "grid fins" to the top of the stage, they gained all
the control authority they need. Wings and vertical stabilizers with
their various associated control surfaces are more complex, IMHO. Add
to that the necessary capability to perform glide landings in crosswinds
and XS-1 certainly won't be a cake walk to develop.

Jeff
--
All opinions posted by me on Usenet News are mine, and mine alone.
These posts do not reflect the opinions of my family, friends,
employer, or any organization that I am a member of.
  #10  
Old September 21st 17, 12:46 PM posted to sci.space.policy
Jeff Findley[_6_]
external usenet poster
 
Posts: 2,307
Default U.S. astronauts are climbing back into space capsules. Here's how they've improved over the past 50 years

In article ,
says...

JF Mezei wrote:

On 2017-09-20 07:13, Jeff Findley wrote:

The USAF is funding Experimental Spaceplane program (XS-1), which sounds
really cool, but it's nothing more than a (smallish) winged reusable
first stage.


Would a winged 1st stage have far greater landing range after it
released it load? (SpaceX has to have a barge out in ocean for certain
launches because stage1 doesn't have fuel to return to land).


Unlikely. What it would do is decrease the amount of fuel you'd have
to reserve for recovery, since it could use aerodynamic forces
instead.


You're essentially trading fuel, oxidizer, and a bit of extra tankage
for the mass of wings, vertical stabilizer, and etc. Since the former
is less complex, it should be cheaper to develop and maintain. Cost
scales more closely with complexity than mass.


It's very hard for me to see this thing being cheaper than
a reusable Falcon 9 first stage.


From a software point of view, would designing landing system for winged
vehicle be simpler than a pure rocket? It took SpaceX a while to develop
and a number of failures to fine tune the system.


It's probably somewhat easier, but remember that SpaceX issues were
largely related to how throttleable their engines were.


They eventually overcame that problem with better software. The "hover
slam" approach was almost certainly harder for the dynamics and control
guys to deal with, but it got the propulsion guys off the hook since
they didn't need to develop "deep throttling" for Merlin. It was an
engineering trade off that (eventually) paid off for SpaceX.

Jeff
--
All opinions posted by me on Usenet News are mine, and mine alone.
These posts do not reflect the opinions of my family, friends,
employer, or any organization that I am a member of.
 




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