Author Topic: Dream Chaser through critical landing test, prepares for orbital flights  (Read 6574 times)

Offline Todd Martin

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The dream of a crewed flight on Dreamchaser is still a goal of SNC.  There must be a substantial number of common parts between the cargo variant and the crew variant.  To take advantage of volume pricing, I wonder if SNC is stocking any common components for a crew variant while building the two cargo versions.  Being willing to inventory such items would help "buy down" the initial investment needed.

Offline Rocket Science

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We're going to be entertained by different sights and landing sounds as the new spacecraft return from space. The Dragon's "splash" (was hoping for a roar), the CST-100 "splat" and Dream Chaser's "double sonic boom followed by the screech"... Interesting times in my book... 8)
« Last Edit: 11/27/2017 01:59 PM by Rocket Science »
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Offline yg1968

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The dream of a crewed flight on Dreamchaser is still a goal of SNC.  There must be a substantial number of common parts between the cargo variant and the crew variant.  To take advantage of volume pricing, I wonder if SNC is stocking any common components for a crew variant while building the two cargo versions.  Being willing to inventory such items would help "buy down" the initial investment needed.

One thing that I have been wondering about is whether it would be possible to retrofit a cargo DC and make it into a crewed DC (if this retrofit were to happen, it would only be done once CRS2 is completed).
« Last Edit: 11/27/2017 02:17 PM by yg1968 »

Offline vt_hokie

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One thing that I have been wondering about is whether it would be possible to retrofit a cargo DC and make it into a crewed DC (if this retrofit were to happen, it would only be done once CRS2 is completed).

I highly doubt it, as I suspect some of the differences are inherent to the airframe itself.  I have also wondered how easily DC could be modified to become a crew return vehicle only.  No launch abort requirements, etc.  Ever since the demise of X-38/CRV I suppose I've been a believer that a lifting body direct to landing facility return vehicle makes a lot more sense as an assured crew return vehicle than a high G reentry, remote splashdown/touchdown capsule. 

Offline Rocket Science

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One thing that I have been wondering about is whether it would be possible to retrofit a cargo DC and make it into a crewed DC (if this retrofit were to happen, it would only be done once CRS2 is completed).

I highly doubt it, as I suspect some of the differences are inherent to the airframe itself.  I have also wondered how easily DC could be modified to become a crew return vehicle only.  No launch abort requirements, etc.  Ever since the demise of X-38/CRV I suppose I've been a believer that a lifting body direct to landing facility return vehicle makes a lot more sense as an assured crew return vehicle than a high G reentry, remote splashdown/touchdown capsule.
I don't see why not with an ECLSS and a docking system, the de-orbit and landing system is already automated... Might be a good interim vehicle towards a future crewed launch vehicle...
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Offline john smith 19

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One thing that I have been wondering about is whether it would be possible to retrofit a cargo DC and make it into a crewed DC (if this retrofit were to happen, it would only be done once CRS2 is completed).
Obviously depends on how different they are.

NASA say it's hugely difficult to turn a cargo vehicle in to a crewed return vehicle.

ECLSS is needed and apparently it has to be "docked" rather than berthed because there is no "unberth" mode that a vehicle can manage without the intervention of the arm (which no one would be aboard the station to operate in an evacuation) evne if it was equipped with the necessary fine guidance and RCS thrusters.
"Solids are a branch of fireworks, not rocketry. :-) :-) ", Henry Spencer 1/28/11  Averse to bold? You must be in marketing."It's all in the sequencing" K. Mattingly.  STS-Keeping most of the stakeholders happy most of the time.
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Offline Rocket Science

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One thing that I have been wondering about is whether it would be possible to retrofit a cargo DC and make it into a crewed DC (if this retrofit were to happen, it would only be done once CRS2 is completed).
Obviously depends on how different they are.

NASA say it's hugely difficult to turn a cargo vehicle in to a crewed return vehicle.

ECLSS is needed and apparently it has to be "docked" rather than berthed because there is no "unberth" mode that a vehicle can manage without the intervention of the arm (which no one would be aboard the station to operate in an evacuation) evne if it was equipped with the necessary fine guidance and RCS thrusters.
Mark Sirangelo at SNC is on record stating that they have the ability to produce a Dream Chaser in multiple configurations in which it is aided by being a composite structure... I see this as the way to go rather than a re-fit...
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Offline rayleighscatter

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The cargo version doesn't have windows, which would mean a converted crew version could only operate autonomously. And I wouldn't want to cut into an already flown composite body.

Production really isn't that expensive. It wouldn't really surprise me if the cost of new vs converted was nearly the same, or even cheaper.

Offline yg1968

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One thing that I have been wondering about is whether it would be possible to retrofit a cargo DC and make it into a crewed DC (if this retrofit were to happen, it would only be done once CRS2 is completed).
Obviously depends on how different they are.

NASA say it's hugely difficult to turn a cargo vehicle in to a crewed return vehicle.

ECLSS is needed and apparently it has to be "docked" rather than berthed because there is no "unberth" mode that a vehicle can manage without the intervention of the arm (which no one would be aboard the station to operate in an evacuation) evne if it was equipped with the necessary fine guidance and RCS thrusters.

The cargo version can either be docked or berthed according to SNC. 
« Last Edit: 11/28/2017 08:46 PM by yg1968 »

Offline yg1968

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The cargo version doesn't have windows, which would mean a converted crew version could only operate autonomously. And I wouldn't want to cut into an already flown composite body.

Production really isn't that expensive. It wouldn't really surprise me if the cost of new vs converted was nearly the same, or even cheaper.

I don't know if the windows are a requirement but I suppose that a periscope (or cameras) could also be used.

Sirangelo said (a while ago) that making a DC wasn't that expensive. So you are right about that. But I sort of wonder if you don't make the crewed DC right away, is that capability lost after a while?
« Last Edit: 11/28/2017 08:50 PM by yg1968 »

Offline rayleighscatter

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The cargo version doesn't have windows, which would mean a converted crew version could only operate autonomously. And I wouldn't want to cut into an already flown composite body.

Production really isn't that expensive. It wouldn't really surprise me if the cost of new vs converted was nearly the same, or even cheaper.

I don't know if the windows are a requirement but I suppose that a periscope (or cameras) could also be used.

Sirangelo said (a while ago) that making a DC wasn't that expensive. So you are right about that. But I sort of wonder if you don't make the crewed DC right away, is that capability lost after a while?

The knowledge will be lost over time as engineers retire or leave but the production methods are now common at many aerospace companies. It wouldn't be hard to farm out production of another craft.

I suppose the hybrid abort engines would be the most likely place to lose both knowledge and production ability.
« Last Edit: 11/28/2017 08:58 PM by rayleighscatter »

Offline whitelancer64

The cargo version doesn't have windows, which would mean a converted crew version could only operate autonomously. And I wouldn't want to cut into an already flown composite body.

Production really isn't that expensive. It wouldn't really surprise me if the cost of new vs converted was nearly the same, or even cheaper.

I don't know if the windows are a requirement but I suppose that a periscope (or cameras) could also be used.

Sirangelo said (a while ago) that making a DC wasn't that expensive. So you are right about that. But I sort of wonder if you don't make the crewed DC right away, is that capability lost after a while?

The knowledge will be lost over time as engineers retire or leave but the production methods are now common at many aerospace companies. It wouldn't be hard to farm out production of another craft.

I suppose the hybrid abort engines would be the most likely place to lose both knowledge and production ability.

Sierra Nevada switched from hybrid engines to liquid fueled engines. The redesign and subsequent delay to their development program is one reason why they were not selected for the commercial crew contract.
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Offline Rocket Science

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The cargo version doesn't have windows, which would mean a converted crew version could only operate autonomously. And I wouldn't want to cut into an already flown composite body.

Production really isn't that expensive. It wouldn't really surprise me if the cost of new vs converted was nearly the same, or even cheaper.

I don't know if the windows are a requirement but I suppose that a periscope (or cameras) could also be used.

Sirangelo said (a while ago) that making a DC wasn't that expensive. So you are right about that. But I sort of wonder if you don't make the crewed DC right away, is that capability lost after a while?
Docking was supposedly with hand controls and viewing though a window in the rear hatch IIRC for a crewed version...
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Offline john smith 19

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The cargo version can either be docked or berthed according to SNC.
I did not know that. The whole berthed/docked thing seemed a very big thing in the cargo Vs Crew Dragon designs. IOW a big thing demarcating a cargo vehicle from a crew vehicle.

I don't know if the windows are a requirement but I suppose that a periscope (or cameras) could also be used.

Sirangelo said (a while ago) that making a DC wasn't that expensive. So you are right about that. But I sort of wonder if you don't make the crewed DC right away, is that capability lost after a while?
Good question. Another issue is how much such a craft is actually "piloted"

"Solids are a branch of fireworks, not rocketry. :-) :-) ", Henry Spencer 1/28/11  Averse to bold? You must be in marketing."It's all in the sequencing" K. Mattingly.  STS-Keeping most of the stakeholders happy most of the time.
So you're going to Mars to seek a better life. What does that mean to you? Always spot a fanbois by how they react to their idols failures.

Offline JAFO

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I don't know if the windows are a requirement but I suppose that a periscope (or cameras) could also be used.

Sirangelo said (a while ago) that making a DC wasn't that expensive. So you are right about that. But I sort of wonder if you don't make the crewed DC right away, is that capability lost after a while?
Good question. Another issue is how much such a craft is actually "piloted"

As much or little as they design into it. Shuttle was not capable of autoland, Buran was fully autonomous. Heavy airliners can do fully automated CAT IIIb/Land 3 (0' vertical vis, 150' horizontal) approaches, I imagine that would be easy to build into Dream Chaser.
« Last Edit: 11/28/2017 11:56 PM by JAFO »
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Offline yg1968

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The cargo version doesn't have windows, which would mean a converted crew version could only operate autonomously. And I wouldn't want to cut into an already flown composite body.

Production really isn't that expensive. It wouldn't really surprise me if the cost of new vs converted was nearly the same, or even cheaper.

I don't know if the windows are a requirement but I suppose that a periscope (or cameras) could also be used.

Sirangelo said (a while ago) that making a DC wasn't that expensive. So you are right about that. But I sort of wonder if you don't make the crewed DC right away, is that capability lost after a while?

Answering my own question but it seems that windows are a requirement for commercial crew:


Quote from: 2016 CCT-REQ-1130
3.8.4.4 Windows for Crew Tasks

The spacecraft shall provide windows that are available for use by the crew through all phases of
flight that provide direct, non-electronic, through-the-hull viewing and the unobstructed fields of-view
necessary to perform crew viewing tasks. [R.CTS.177]

Rationale: Windows provide direct, non-electronic, through-the-hull viewing and are
essential to mission safety and success, as well as to maintaining crew situational awareness
and psychological and physical health and safety. They do not have the failure modes
associated with cameras and display systems that may not be operable during emergencies
when most needed and are essential for piloting and photography. They also permit stellar
navigation, vehicle anomaly detection and inspection, and environmental and scientific
observations. NASA experience is that two piloting windows are required to achieve the field
of view necessary to accomplish the breadth of piloting tasks. Because of the criticality of
windows to crew safety and success of the mission, windows must be a part of the spacecraft
design and available through all flight phases without obstructions to their use. Fixed
equipment, such as window instrumentation, hardware, or a condensation prevention system,
that would obstruct or obscure the field-of-view of the window from the normal crew viewing
position will interfere with crew tasks and must not be placed within the sight lines through
the window; however, the following are not considered obstructions: hardware used in
conjunction with piloting, such as a head's up display (HUD), crew optical alignment system
(COAS), or other similar equipment; the outer mold line and hull structure of the vehicle
itself; other windows and window mullions; and instrumentation applied to the window itself
within 13 mm (~0.5 in.) of the perimeter of the clear viewing area. For detailed design
considerations for inboard and outboard window view obscuration exclusion zones, consult
Sections 8.6.3.3 and 8.6.3.4 in NASA/SP-2010-3407, Human Integration Design Handbook
(HIDH), which also provides extensive guidance for window design considerations.

Quote from: 2016 CCT-REQ-1130
3.10.14.2 Hatch Windows

The CTS shall provide a window on all sealable hatches for direct non-electric visual observation
of the environment on the opposite side of the hatch. [R.CTS.174]

Rationale: Direct visual observation of the environment on the opposite side of a hatch
allows the crew to determine the conditions or obstructions, such as the presence of fire or
debris, on the other side of the hatch for safety purposes. Visibility is also needed for ground
crew viewing into the vehicle during pad operations and post-landing. Windows do not have
the failure modes associated with cameras and display systems that may not be operable
during emergencies when most needed.

https://forum.nasaspaceflight.com/index.php?topic=26489.msg1650808#msg1650808
« Last Edit: 11/29/2017 01:30 AM by yg1968 »

Offline Rocket Science

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I don't know if the windows are a requirement but I suppose that a periscope (or cameras) could also be used.

Sirangelo said (a while ago) that making a DC wasn't that expensive. So you are right about that. But I sort of wonder if you don't make the crewed DC right away, is that capability lost after a while?
Good question. Another issue is how much such a craft is actually "piloted"

As much or little as they design into it. Shuttle was not capable of autoland, Buran was fully autonomous. Heavy airliners can do fully automated CAT IIIb/Land 3 (0' vertical vis, 150' horizontal) approaches, I imagine that would be easy to build into Dream Chaser.
Slight correction, the Shuttle was capable but never fully utilized... Except for the gear which you had to deploy... From out friend Wayne Hale:
https://waynehale.wordpress.com/2011/03/11/breaking-through/
« Last Edit: 11/29/2017 01:18 AM by Rocket Science »
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Offline JAFO

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I don't know if the windows are a requirement but I suppose that a periscope (or cameras) could also be used.

Sirangelo said (a while ago) that making a DC wasn't that expensive. So you are right about that. But I sort of wonder if you don't make the crewed DC right away, is that capability lost after a while?
Good question. Another issue is how much such a craft is actually "piloted"

As much or little as they design into it. Shuttle was not capable of autoland, Buran was fully autonomous. Heavy airliners can do fully automated CAT IIIb/Land 3 (0' vertical vis, 150' horizontal) approaches, I imagine that would be easy to build into Dream Chaser.
Slight correction, the Shuttle was capable but never fully utilized... Except for the gear which you had to deploy... From out friend Wayne Hale:
https://waynehale.wordpress.com/2011/03/11/breaking-through/


Fair enough. (We have to drop the gear ourselves, too.)
Anyone can do the job when things are going right. In this business we play for keeps.
Ernest K. Gann

Offline john smith 19

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As much or little as they design into it. Shuttle was not capable of autoland, Buran was fully autonomous. Heavy airliners can do fully automated CAT IIIb/Land 3 (0' vertical vis, 150' horizontal) approaches, I imagine that would be easy to build into Dream Chaser.
You missed the X37b. AFAIK all its landings are autonomous.
"Solids are a branch of fireworks, not rocketry. :-) :-) ", Henry Spencer 1/28/11  Averse to bold? You must be in marketing."It's all in the sequencing" K. Mattingly.  STS-Keeping most of the stakeholders happy most of the time.
So you're going to Mars to seek a better life. What does that mean to you? Always spot a fanbois by how they react to their idols failures.

Online nacnud

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As much or little as they design into it. Shuttle was not capable of autoland, Buran was fully autonomous. Heavy airliners can do fully automated CAT IIIb/Land 3 (0' vertical vis, 150' horizontal) approaches, I imagine that would be easy to build into Dream Chaser.
You missed the X37b. AFAIK all its landings are autonomous.
I think that is a safe bet, unless the airforce is keeping very quiet about its alternative manned program.

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