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Author Topic: Dream Chaser for CEV requirement  (Read 37583 times)

Offline Flyaway

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Re: Dream Chaser for CEV requirement
« Reply #75 on: July 27, 2017, 01:28:14 am »
Using the dual engine Centaur configuration as to be used for manned space flight missions on the Atlas V, in this case it's for cargo in the 552 variant.

Sierra Nevada confirms ULA will launch first two Dream Chaser cargo missions

Offline Grey Havoc

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To the Stars

Offline Flyaway

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Re: Dream Chaser for CEV requirement
« Reply #78 on: November 12, 2017, 12:46:42 pm »
Sierra Nevada Corp.’s Dream Chaser space plane glides successfully through a big test

Sierra Nevada Corp. said its Dream Chaser prototype space plane glided to a successful landing in California’s Mojave Desert today after being dropped from a helicopter.

Today’s uncrewed test at Edwards Air Force Base marked the first time the Dream Chaser flew freely through the air since 2013. That earlier flight was also judged successful, but the landing gear failed to deploy correctly, which caused the winged vehicle to skid off the runway and crash.

Over the years that followed, SNC repaired and upgraded the aerodynamic test vehicle in preparation for a new series of flight tests at NASA’s Armstrong Flight Research Center, within Edwards’ property.

Offline fredymac

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Re: Dream Chaser for CEV requirement
« Reply #79 on: November 13, 2017, 03:40:43 pm »

Offline Flyaway

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Re: Dream Chaser for CEV requirement
« Reply #80 on: November 15, 2017, 11:27:45 pm »
Via NASA Spaceflight forum.

Here is a transcript of today's Q&A (on twitter) with Steve Lindsey of SNC:

Question: 1st: Congrats!!! 2nd: the left landing gear appeared to develop a, "wicked shimmy" shortly after landing. Did that actually occur or was it some kind of optical illusion or camera artifact?

Answer: I didn't see that; good rollout so maybe an artifact?

Question: Will the cargo DC still have windows (like the test article)?

Answer: No windows on the cargo version - sad for a pilot like me 😟

Question: Do you already have an aspirational target date for the demo/maiden flight of the actual (not the test article) DC?

Answer: We are currently in discussions with @Space_Station on when our first flight will occur

Question: Looking to the future: can/will Dream Chaser launch with several launch providers after its initial flights with @ulalaunch? Such as @SpaceX, @Arianespace or @blueorigin?

Answer: We are assessing multiple launch vehicles for future missions. 

Question: What are your plans for DC in the post-ISS world?

Answer: We are looking at many different types of missions, to include stand alone science missions, satellite servicing missions, and crewed missions ... just to name a few.  We intend to be flying Dream Chasers for a long, long time. 

Question: what rocket do you guys plan to launch with?

Answer: Our first mission will be on an Atlas V rocket @ulalaunch .

Question: How many Dream Chaser spaceplanes does SNC currently plan to build and operate?

Answer: Total number will depend upon the customers and types of missions we fly.  Hopefully a whole fleet of Dream Chasers!

Question: does the Dream Chaser still have the capabilities preform an ISS orbit boost?

Answer: Yes, we do. 

Question: First off, thank you for your contributions To the space program, Steve. My question to you is: What lessons were learned from drop test 1 and what changed between the first flight and now?

Answer: We learned so many lessons from the first flight, I can't possibly list them here.  The same will be true from this flight.  And this is exactly why we flight test; to make our orbital vehicle/system better. 

Question: What’s the maximum amount of time Dream Chaser could stay on orbit, docked to the ISS?

Answer: For cargo/science resupply flights, 45-75 days.  But that's based on what @Space_Station has requested in their visiting vehicle traffic manifest; we can stay docked or berthed longer than that if needed. 

Question: Do you have internships available for college students that will provide hands-on experience with projects like Dream Chaser?

Answer: YES!! Go check out the SNC website - 

Question: For crewed flights, what abort options will Dream Chaser have if an emergency occurs during launch?

Answer: We have designed the Dream Chaser to be able to abort anytime during ascent (including while sitting on the launch pad).  For missions to the @Space_Station, we also have the ability to land at runways up the east coast of the United States.

Question: What is the future of this particular Dream Chaser vehicle after its completed all testing? Donating it to a museum?

Answer: Right now we plan to keep it in 'flyable storage' so we can use it for future test flights if needed.  It is also human rated, so when we build a crewed version in the future we'll do additional atmospheric flight test.  Then maybe to a museum!

Question: Because I think all LV's in dev't now should have REUSABILITY as a basic feature, what's SNC's aspirational target for number of reuse w/ minimal refurbishment for each D.C. spacecraft?

Answer: Our design goal is 15 flight reuse -- we'll get better data on their actual life once we start flying missions

Questions: 1) Has all the CFD/Modeling been done for launch/stress atop the Atlas V? 2) Were other firms' launchers modeled/tested? 3) Time/issues if converting to Astronaut Ferry Mission?

Answers: We've done a lot of CFD/Modeling work on the Dream Chaser and our Launch Vehicle.  We are investigating several different launch vehicles; this will include similar work.  We maintain a 'path to crew' with our vehicle; crew and cargo vehicles are about 85% common

Question: I am wondering; If the successful atmospheric Free-Flight test of @SierraNevCorp's Dream Chaser, on November 12, did not included a test-routine for the folding-wing design, when and how will that be tested?

Answer: We'll test the wing deployment system on the ground and in a vacuum & thermal chamber.  The wings are deployed on orbit - so they'll already be fixed in place prior to entry.

Question: My dad noted many similarities (visually) between Dream Chaser and X-38. Was that program the starting point for this one?

Answer: Similar, but different heritage from the X-38.  The Dream Chaser comes from NASA's HL-20 Program, which came from the Russian BOR-4 Program.  How's that for an interesting heritage?!

Question: In mid flight during the drop test,  the DC seemed to wobble from left to right. Was this normal?

Answer: Great question!  That 'wobbling' was actually an intentional 'Programmed Test Input', or PTI.  This set of maneuvers was designed to assess the responsiveness and stability of the vehicle and provide us better aerodynamic data.  Worked Great!!

Question: Why the lag on getting video out? It's so much easier for folks like me to retweet stuff when it's there to retweet - and we're ALWAYS hungry for webcasts!

Answer: It was Veteran's day weekend.  We flew at a closed airfield (Edwards AFB) -- and the men and women of the USAF deserved the weekend off!  We processed the video as soon as we had access to it.

Question: how many test flights do you think there will be after the most recent one?

Answer: We're assessing the data from this most recent test - our decision to execute additional test flights will be based on whether or not we accomplished all of our test objectives from this flight. 

Question: Was #DreamChaser being flown strictly via computer or was a human involved?

Answer: The Dream Chaser flew autonomously (via computers and pre-programmed commands).  However, we also had a flight control team capable of commanding the vehicle and analyzing telemetry in real time.

Question: Will the U.N. mission in 2021 land in the United States or outside the U.S?

Answer: We haven't made a decision on this -- but we are working this question with  @UNOOSA

Question: What's the transition has been like btwn space shuttle nd dream chaser...does smaller means less complicated or the reference to design, aerodynamics, propulsion etc..

Answer: We took all of the lessons learned from the Space Shuttle Program and applied them to our design; making the vehicle as robust and simple as possible.  This will make Dream Chaser more reliable and less expensive to operate.

Question: I noticed that even when #DreamChaser is in contact with the ground on all 3 landing gears it is still pitched up somewhat. Most aircraft are pitched down a little. Why is that?

Answer: Our nose skid strut is a little higher but when at rest the vehicle is pretty level.  The shuttle nose gear was much shorter, and that resulted in much firmer 'slapdown' forces.  Our derotation and nose strut touchdown is much gentler by comparison

Question: what are the 2 most important safety features redesigned in DreamChaser vs Space Shuttle?

Answer: 2 that come to mind are:- We went from toxic chemicals (such as hypergolic fuels and hydrazine) to non-toxic fuels, which make for easier access to the vehicle and safer ground processing - Improved, tougher heat shield

Offline blackstar

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Re: Dream Chaser for CEV requirement
« Reply #81 on: November 16, 2017, 06:50:32 am »
I hope someday we get to see the video of the earlier crash. I understand why they won't release it--they don't want that to be shown over and over again. But I've always thought that an open airing of the difficulties of doing this engineering is important for people on the outside, so they can understand that making it look easy is not easy.

Offline Flyaway

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Re: Dream Chaser for CEV requirement
« Reply #82 on: November 24, 2017, 03:03:43 pm »
Dream Chaser through critical landing test, prepares for orbital flights

With Sierra Nevada Corporation’s Dream Chaser spaceplane through a successful and critical Approach and Landing Test milestone, the company is now shifting gears to focus on the all-important first orbital flight of Dream Chaser No Earlier Than 2020.  That orbital flight will be part of Sierra Nevada Corporation’s fulfillment of NASA’s CRS2 Commercial Resupply Services cargo transportation effort for the International Space Station.

Offline gtg947h

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Re: Dream Chaser for CEV requirement
« Reply #83 on: November 25, 2017, 04:45:29 pm »
But I've always thought that an open airing of the difficulties of doing this engineering is important for people on the outside, so they can understand that making it look easy is not easy.