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Author Topic: Dream Chaser for CEV requirement  (Read 37605 times)

Offline hesham

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Dream Chaser for CEV requirement
« on: May 14, 2008, 10:34:48 am »
Hi,

the Dream Chaser is manned suborbital spacecraft and designed
by SpaceDev,it is suitable for NASA's Crew Exploration Vehicle
(CEV) requirement.

http://www.flightglobal.com/pdfarchive/view/2004/2004-09%20-%201854.html
« Last Edit: March 12, 2011, 03:28:21 pm by hesham »

Offline CFE

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Re: Dream Chaser for CEV requirement
« Reply #1 on: May 14, 2008, 10:06:37 pm »
Except that it isn't designed to survive a re-entry from lunar return velocities, and it isn't outfitted for long-duration orbital flight.  In fact, the design pictured has been superseded by an X-15-ish design for suborbital flights, and an HL-20 derived orbital vehicle.

Offline TomS

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Re: Dream Chaser for CEV requirement
« Reply #2 on: May 15, 2008, 06:37:09 am »
NASA has already selected a CEV design, and it's a capsule, not a spaceplane:

http://www.nasa.gov/mission_pages/constellation/orion/index.html


Offline flateric

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Re: Dream Chaser for CEV requirement
« Reply #3 on: July 29, 2008, 05:30:22 am »
Except that it isn't designed to survive a re-entry from lunar return velocities, and it isn't outfitted for long-duration orbital flight.  In fact, the design pictured has been superseded by an X-15-ish design for suborbital flights, and an HL-20 derived orbital vehicle.

BOR-4 derived to say it correct.
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Offline hesham

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Offline XP67_Moonbat

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Re: Dream Chaser for CEV requirement
« Reply #5 on: August 15, 2009, 11:48:39 am »
Isn't that Lockheed's design?
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Offline FutureSpaceTourist

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Re: Dream Chaser for CEV requirement
« Reply #6 on: April 30, 2010, 07:05:21 am »
BOR-4 derived to say it correct.

I hadn't realised HL-20 was derived from BOR-4, but prompted by your response I looked it up. Thanks for filling a hole in my rather patchy space history knowledge.

More recently SpaceDev have been awarded $20M of funding for DreamChaser (pic below) from the extra $50M CCDev money in the economic stimulus package (eg see http://www.spacenews.com/venture_space/100201-biggest-ccdev-award-goes-sierra-nevada.html). So hopefully there'll be some significant development, or dare I say it - even build, progress.
« Last Edit: April 30, 2010, 07:17:02 am by FutureSpaceTourist »

Offline airrocket

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Re: Dream Chaser for CEV requirement
« Reply #7 on: May 02, 2010, 08:17:29 am »
Hopefully.....yes but the design has had issues in the past. See the Ruskies Bor utilized folding wings to deal with handling hyper to subsonic issues. Seems we overlooked this when we went forward with our version. According to Paul C. the HL-20 had some major handling issues early on as well. Question is has Space Dev corrected these issues or are they still struggling with them. I have to question if Space Dev did their homework before they adopted this design. Certainly as a blunt body with traditional winglets it probably incorporates some of the severe roll-coupling tendencies found in the early lifting bodies. The final NASA lifting body X-24b which utilized a less blunt nose, flat bottom planform based on Draper FDL design avoided many of the NASA adopted blunt body faults. Flat bottom, X wing, sharp edge, rectangular body was found by Draper, DuPont and Reed through FDL wind tunnel testing to exhibit far better handling traits. Seems NASA has decided to ignore their own finding when comes to lifting body design. They still stubbornly adhere to the early lifting body blunt rounded up turned winglet planforms.
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Offline FutureSpaceTourist

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Re: Dream Chaser for CEV requirement
« Reply #8 on: May 02, 2010, 01:35:28 pm »
Hi airrocket, thanks for the extra information (regrettably beyond my technical expertise).

SpaceDev do have a Space Act Agreement with NASA from June 2007, for NASA to provide further info/technical asistance, so in theory previous experience should be learnt from (but not if as you say NASA themselves haven't learnt the lesson). I have seen one quote from the company saying "We largely kept the outer mold-line of the vehicle intact, so we were able to utilize much of the [previous HL-20] research" (see http://www.aviationweek.com/aw/generic/story_generic.jsp?channel=awst&id=news/awst/2010/02/22/AW_02_22_2010_p53-204735.xml&headline=Sierra%20Nevada%20Building%20On%20NASA%20Design).

I guess it will depend on what 'largely' means in practice and what previous research they're using?
« Last Edit: May 02, 2010, 01:41:31 pm by FutureSpaceTourist »

Offline FutureSpaceTourist

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Re: Dream Chaser for CEV requirement
« Reply #9 on: August 26, 2010, 06:28:08 am »
Some information on how SNC are spending the $20M award for Dream Chaser development at www.recovery.gov.

Here's a summary of how they intend to use the money:

Quote
Sierra Nevada Corporation (SNC) is partnering with NASA to advance the development of a commercial crew space transportation system as part of the Commercial Crew Development (CCDev) program. CCDEv is funded by the American Recovery and Reinvestment Act (ARRA) of 2009 which is an economic stimulus to aid private sector efforts to develop and demonstrate human spaceflight capabilities.

SNC was provided a $20,000,000 award on February 19th, 2010 to begin their CCDev program activities. SNC's development is based on the Dream Chaser spacecraft. SNC will be using this initial funding to further the development of the Dream Chaser craft and carry out risk reduction activities.

SNC will be partnering with several leading aerospace companies on this effort including Boeing, United Launch Alliance, and Draper Laboratories. SNC has four milestones that are tied to the CCDev funding:

Milestone 1 - Program Implementation Plan Review.
Milestone 2 - Manufacturing Readiness Review of Aeroshell Tooling.
Milestone 3 - Space Vehicle Propulsion Module Test Firings.
Milestone 4 - Dream Chaser Engineering Test Article Primary Structure Load Proof Testing.

In addition to these four milestones, SNC will be supporting these additional activities on this award:

a.) Requirements definition for Dream Chaser systems design & major subsystems.
b.) Build & Test Spacecraft Primary Structure.
c.) Integrated Loads Definition & CFD.
d.) Main Propulsion Motor Build & Test.
e.) RCS Thruster Prototype Build & Test.
f.) Develop Atmospheric and Orbital GN&C architecture.
g.) Flight Algorithms & Software Assurance Plan.
h.) TPS Trades.
i.) Atlas V Integration analysis.
j.) Wind Tunnel Model Build

Progress in the last quarter (to end of June 2010) was:

Quote
The Sierra Nevada Corporation (SNC) Commercial Crew Development (CCDev) program continued to make excellent progress per plan during the 2nd quarter of 2010.

In the month of April, SNC traveled to NASA Langley for an Avionics summit. Team members from Boeing, Draper Laboratories, and Langley Research Center attended. The purpose of this summit was to finalize the trade study of the avionics architecture. Modifications to SNC's Louisville, CO facility were completed and the CCDev team moved into a dedicated office space. Newly hired engineering personnel came up to speed and began actively contributing to accomplishing the program objectives.

In the month of May, a preliminary design review for the Dream Chaser spacecraft structure was conducted at our Intelligence, Surveillance, and Reconnaissance (ISR) facility in Centennial, Colorado with team members from Straightflight and Adamworks attending.

In the month of June, a human rating Technical Interchange Meeting (TIM) was conducted at SNC's Louisville facility. This TIM included members from SNC's CCDev partners, NASA agencies, and industry representatives. Also in June, SNC successfully conducted and completed the Milestone 2 Manufacturing Readiness Review for the aeroshell tooling. This meeting was conducted and SNC's ISR facility with several NASA representatives in attendance. All aeroshell tooling including the lower and upper aeroshell tooling was completed in June. Fabrication for the pressure vessel and bulkhead tooling was also started in June.

Offline Grey Havoc

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Re: Dream Chaser for CEV requirement
« Reply #10 on: August 29, 2010, 10:43:33 am »
One big problem is, that what congressional support there is for Obama's current plans for NASA and commercial spaceflight is liable to evaporate come November.
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Offline Triton

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Re: Dream Chaser for CEV requirement
« Reply #11 on: August 29, 2010, 11:09:55 am »
One big problem is, that what congressional support there is for Obama's current plans for NASA and commercial spaceflight is liable to evaporate come November.

I don't want Overscan to lock this thread because it becomes political. Let us continue discussing the Dream Chaser and keep the politics of spaceflight in "The Bar."

Offline Orionblamblam

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Re: Dream Chaser for CEV requirement
« Reply #12 on: August 29, 2010, 11:11:41 am »
One big problem is, that what congressional support there is for Obama's current plans for NASA and commercial spaceflight is liable to evaporate come November.

This is the big flaw in American space policy: over-reliance upon government controls. Because the government changes direction faster than the space bureaucracy can get things done.

There is, however, a solution: go to a "prize" approach. If the current administration believes that some particular goal is in the nation's interest (let's say, a super-X-Prize... a vehicle capable of launching 6 astronauts into ISS orbit on 6 hours notice, and for a per-pound of payload direct operating cost of $100 or less), then the adminstrations experts can determine how much a program to develop that goal is (let's say $20 billion). Then the administration appropriates that entire amount right up front, puts it in some unraidable trust (perhaps in the form not of a specific dollar amount, but a specific mass of gold to be kept at Ft. Knox), and whatever company reaches the requirements first, gets the whole sum. If nobody attains the requirements, then the taxpayers don't spend a dime. If the first company to build a vehicle that fullfills the requirements does so for, say, $2 billion.... then that companies stockholders are going to be in for one hell of a dividend.

Done this way, programs will go a *lot* faster, the results will be a lot better, the effort will be a *lot* cheaper, and there'll be a lot less cancellation of programs halfway through.
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Offline Grey Havoc

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Re: Dream Chaser for CEV requirement
« Reply #13 on: August 29, 2010, 11:19:32 am »
Getting back to the technical side of things:

Quote
The purpose of this summit was to finalize the trade study of the avionics architecture. Modifications to SNC's Louisville, CO facility were completed and the CCDev team moved into a dedicated office space. Newly hired engineering personnel came up to speed and began actively contributing to accomplishing the program objectives.

I just wondering, wouldn't they save quite some time and resources on the initial prototype by using off the shelf NASA (esp. shuttle) avionics hardware with suitably modified/ customised software?
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Offline Orionblamblam

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Re: Dream Chaser for CEV requirement
« Reply #14 on: August 29, 2010, 02:40:57 pm »

I just wondering, wouldn't they save quite some time and resources on the initial prototype by using off the shelf NASA (esp. shuttle) avionics hardware with suitably modified/ customised software?

Probably the only place to get "off the shelf" shuttle avionics would be museums and eBay. Probably best to buy stuff actually manufactured in this century.
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