Topic: [Discuss] Sierra Nevada Corp.'s Dream Chaser
Robert Pearlman Editor
Posts: 26895 From: Houston, TX Registered: Nov 1999
posted 08-03-2012 09:56 AM
Editor's note: In an effort to keep the topic CCDev: Sierra Nevada Corp. (Dream Chaser) focused on status updates, reader's feedback and opinions are directed to this thread.
Please use this topic to discuss Sierra Nevada Corp's development of its Dream Chaser lifting-body vehicle as a part of NASA's Commercial Crew Development (CCDev) program.
Jay Chladek Member
Posts: 2196 From: Bellevue, NE, USA Registered: Aug 2007
posted 08-03-2012 10:05 PM
All things considered, I was probably pulling for SNC the most, given that they are going with a design that probably has the highest risk, yet the capability for the highest reward in fast turnaround with it being potentially fully reuseable and capable of land landings on a runway. I just wish they could potentially have gotten more funding compared to the other two contractors.
If they are less than a year away from approach and landing tests, do they plan to conduct those with a manned vehicle, or will it be an RPV version of the craft?
Robert Pearlman Editor
Posts: 26895 From: Houston, TX Registered: Nov 1999
posted 08-03-2012 10:11 PM
According to the information released by NASA today, the only milestone under SNC's CCiCap award that involves flight testing uses an engineering test article.
Robert Pearlman Editor
Posts: 26895 From: Houston, TX Registered: Nov 1999
posted 01-30-2013 03:08 PM
Space.com reports that the Dream Chaser is slated to fly on its own for the first time in the next six to eight weeks, a key drop-test milestone in the vehicle's quest to fly astronauts on roundtrip space missions.
The Dream Chaser spacecraft, built by aerospace firm Sierra Nevada Corp., will be released by a carrier helicopter at an altitude of 12,000 feet (3,657 meters) or so, then fly back and land autonomously on a runway at NASA's Dryden Flight Research Center in California.
The unmanned 30-second drop test will kick off a series of trials that culminate in trips to low-Earth orbit and back, potentially paving the way for contracted, crew-carrying flights to the International Space Station for NASA, company officials said during a press conference today (Jan. 30).
Lou Chinal Member
Posts: 943 From: Staten Island, NY Registered: Jun 2007
posted 02-02-2013 07:31 PM
quote:Originally posted by Jay Chladek: All things considered, I was probably pulling for SNC the most...
I have to agree with you Jay.
I've done some calculations and have concluded that a small solid rocket could lift "Dream Chaser" high enough and with enough speed to make an approach to a runway. Assuming there is a runway next the launch pad. You would have to establish winds at launch for energy management.
Now the question is would you want to reenter with that engine?
Jay Chladek Member
Posts: 2196 From: Bellevue, NE, USA Registered: Aug 2007
posted 02-02-2013 10:33 PM
A solid motor for aborts likely won't be needed since the Dreamchaser will have a pair of OMS type motors onboard. Plus, the abort modes for the craft won't be as potentially nasty for the bird on an Atlas V rocket according to a couple of the Dreamchaser guys I talked with at STS-135 in 2011. Reason being, the Atlas being a liquid rocket can be shut down during an abort so the rockets needed to get the craft free don't require as much thrust. With the Orion Ares 1 stack (and indeed with SLS) with solids under thrust, the ATK designed LAS system needs to be as powerful as it is the get the capsule far away from a potentially out of control solid ASAP (or at least far enough away from the solid for range safety to detonate it).
How the Dreamchaser would fare during recovery I would say is going to depend on its ditching characteristics. Shuttle was NOT a good craft to ditch in (thank goodness nobody ever had to put that to the test in real life), but the Dreamchaser being a lighter vehicle (although one with still a rather high wing loading) might do better. Still, a runway landing would be a much better prospect for the crew to survive such a worst case scenario.
Lou Chinal Member
Posts: 943 From: Staten Island, NY Registered: Jun 2007
posted 02-03-2013 12:02 PM
Congress may insist on such a safety factor.
Jay Chladek Member
Posts: 2196 From: Bellevue, NE, USA Registered: Aug 2007
posted 02-05-2013 10:43 PM
quote:Originally posted by Lou Chinal: Congress may insist on such a safety factor.
I doubt Congress will have much say in the matter either way. Sure, they might dictate to NASA to ensure that the commercial services contractor has done as much as possible with a specific configuration for safety. But NASA would still have to make the final determination and with NASA, it will likely come down to running the numbers and statistical analysis to determine if such an abort motor system for Dreamchaser would indeed be an asset or a liability.
Dreamchaser will have its own onboard OMS motors and they will likely provide more thrust than what the shuttle's did (because shuttle was a much heavier craft). Man rating the Atlas V might also involve setting up the upper stage for use as an abort motor as well (but I am just guessing there).
Lou Chinal Member
Posts: 943 From: Staten Island, NY Registered: Jun 2007
posted 02-06-2013 07:27 PM
After everything is said and done, Congress is going to have put up the money.
dabolton Member
Posts: 201 From: Round Lake, IL, US Registered: Jan 2009
posted 05-23-2013 04:54 PM
Love the fuzzy dice in the Dream Chaser engineering test article's cockpit.
posted 08-03-2012 09:56 AM
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