Dream Chaser for CEV requirement

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

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 In fact, the design pictured has been superseded by an X-15-ish design for suborbital flights, and an HL-20 derived orbital vehicle.

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

CFE said:

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 In fact, the design pictured has been superseded by an X-15-ish design for suborbital flights, and an HL-20 derived orbital vehicle.

Click to expand...

BOR-4 derived to say it correct.

Hi,

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20090024220_2009023812.pdf

Isn't that Lockheed's design?

flateric said:

BOR-4 derived to say it correct.

Click to expand...

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.

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.

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?

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:

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

Click to expand...

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

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.

Click to expand...

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.

Grey Havoc said:

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.

Click to expand...

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."

Grey Havoc said:

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.

Click to expand...

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.

Getting back to the technical side of things:

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.

Click to expand...

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?

Grey Havoc said:

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?

Click to expand...

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.

Orionblamblam said:

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.

Click to expand...

But didn't NASA carry out a shuttle avionics modernisation programme not too long ago?

...too long ago...

Besides, there are a lot of new modern systems, developed during the X-33 and CEV programs that are ready to use. But the key point is to integrate them, to put the specific configuration together and to create a solid software that can operate them.

Grey Havoc said:

Orionblamblam said:

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.

Click to expand...

But didn't NASA carry out a shuttle avionics modernisation programme not too long ago?

Click to expand...

That was only the cockpit instruments and displays. MEDS was the name of the project and it used COTS flat panel displays.

The shuttle avionics is mid 70's technology, but the GPC's were upgraded to what the B-1B used and that was early 80's technology.

Byeman said:

That was only the cockpit instruments and displays. MEDS was the name of the project and it used COTS flat panel displays.

The shuttle avionics is mid 70's technology, but the GPC's were upgraded to what the B-1B used and that was early 80's technology.

Click to expand...

I remember the cockpit interfaces side of things (being a major COTS disbeliever ) but I thought they also did some work on the three CPUs and some other elements?

Grey Havoc said:

Byeman said:

That was only the cockpit instruments and displays. MEDS was the name of the project and it used COTS flat panel displays.

The shuttle avionics is mid 70's technology, but the GPC's were upgraded to what the B-1B used and that was early 80's technology.

Click to expand...

I remember the cockpit interfaces side of things (being a major COTS disbeliever ) but I thought they also did some work on the three CPUs and some other elements?

Click to expand...

There are 5 GPC's (general purpose computers)

Most guidance systems are "COTS". OSC has developed a system "MACH", that is used in all of its vehicles.

Byeman said:

There are 5 GPC's (general purpose computers)

Most guidance systems are "COTS". OSC has developed a system "MACH", that is used in all of its vehicles.

Click to expand...

I thought most current space certified guidance systems were still custom built? As for the GPCs, I thought they had recently gone to a system of three primary CPUs (GPCs), but you're right, it's still four.

Grey Havoc said:

Byeman said:

There are 5 GPC's (general purpose computers)

Most guidance systems are "COTS". OSC has developed a system "MACH", that is used in all of its vehicles.

Click to expand...

I thought most current space certified guidance systems were still custom built? As for the GPCs, I thought they had recently gone to a system of three primary CPUs (GPCs), but you're right, it's still four.

Click to expand...

No, it is 5 (five) GPC's

There is a difference between launch vehicle guidance systems and spacecraft guidance systems

At any rate, gyros, accels, computers, data systems are all available COTS

The Sierra Nevada Corporation has issued a statement about progress on DreamChaser under their NASA CCDev contract. The start of the statement is below:

[quote author=http://www.sncorp.com/news/press/pr10/snc_ccdev_milestone.shtml]
Sierra Nevada Space Systems Successfully Competes Two
Major Nasa Human Space Flight Development Milestones

SNC fires hybrid rocket motor and begins production on Dream Chaser Vehicle

Louisville, CO – October 11, 2010 – The Sierra Nevada Corporation (SNC) Space Systems Group announces the successful completion of two critical milestones for NASA’s Commercial Crew Development (CCDev) Program. On September 21, 2010, SNC completed three successful test firings of a single hybrid rocket motor in one day. SNC’s newly opened rocket test facility in San Diego County, California, hosted NASA personnel for a rocket motor manufacturing review as well as the motor firings, including one firing under vacuum ignition conditions. The tests, which simulated a complete nominal mission profile, demonstrated the multiple restart capability of SNC’s proprietary hybrid rocket motor. This same hybrid rocket will be used as the main propulsion system on the Dream Chaser during the orbital operations.

Earlier this summer, SNC completed its second major milestone. This milestone was focused on the development of the primary tooling necessary to build the composite structure of the Dream Chaser vehicle. The tooling required under the milestone has been completed and is now being used to begin fabrication of the first critical aeroshell structures which will be tested later this year. NASA conducted a thorough review of all the elements of the two milestones and has certified milestone completion with no corrective actions.
[/quote]

They're claiming DreamChaser will be ready for operations in 2014.

FutureSpaceTourist said:

They're claiming DreamChaser will be ready for operations in 2014.

Click to expand...

We can all start taking bets now.

Here are some images relating to SNC's recent CCDev work.

Source: http://www.commercialspaceflight.org/Other%20Content/High-Resolution%20Version%20-%20CCDev%20Significant%20Hardware%20Milestones%20Reached%20-%20Nov%208%202010.pdf

NASA has been helping SNC perform drop tests of a 15% scale model of Dream Chaser:

[quote author=http://www.nasa.gov/centers/dryden/Features/dream_chaser_model_drop.html]
Dream Chaser Model Drops in at NASA Dryden 12.17.10

NASA Dryden supported helicopter air-drop flight tests of a 5-foot-long, 15-percent scale model of the Sierra Nevada Corporation's (SNC) Dream Chaser spacecraft design under a Space Act Agreement between the two organizations.

The company's planned full-size Dream Chaser vehicle, based on the NASA HL-20 lifting body, is designed to carry up to seven people to the International Space Station and back. The vehicle is slated to launch vertically on an Atlas V rocket and land horizontally on conventional runways.

Dryden provided ground and range safety support, including a T-34 chase aircraft for photo and video imagery. The Center also provided scheduling and flight test operations engineering support, along with hangar facilities and workspace.

"Working with the SNC/CU team was a privilege. Their teamwork and dedication were phenomenal, especially through a very dynamic, tiring week of testing," said Jonathan Pickrel, NASA Dryden's flight operations engineer overseeing the testing.

The captive carry and drop flights of the 88-pound model helped validate various aspects of the Dream Chaser vehicle's configuration and performance, such as flight stability and aerodynamic data for flight control surface deflections.

"Working with NASA Dryden has always been a pleasure for me personally," said Dr. Merri Sanchez, Senior Director for Space Exploration Systems at SNC. "Sierra Nevada appreciates the excellent operational support, flexibility and flight test expertise from the NASA Dryden and Air Force teams during the conduct of our scale model test flights," Sanchez said. "We're leveraging the NASA HL-20 heritage design with our Dream Chaser vehicle that we are building to meet our Nation's need for a commercial crew transportation system, and it's great that our first subscale flight was at this NASA center."

Sierra Nevada contracted with Northwest Helicopter for the Bell 206B3 Jet Ranger helicopter that carried the Dream Chaser model on a 100-ft. cable. The helicopter dropped the model from an altitude of 14,000-feet, with landing via parachute. The model was designed, built, and operated from a collaboration between SNC and the Research and Engineering Center for Unmanned Vehicles at the University of Colorado at Boulder (CU).
[/quote]

SNC have also issued a statement about their CCDev2 submission and collaboration with Virgin Galactic:

[quote author=http://thisisreno.com/2010/12/virgin-galactic-joins-in-sierra-nevada-space-systems-dream-chaser-orbital-space-vehicle-program/]
SPARKS, Nev. – Sierra Nevada Corporation announced today that Virgin Galactic, LLC (VG) has given its support to Sierra Nevada’s Space Systems Dream Chaser Orbital Space Vehicle development team and has been included in SNC’s submitted proposal response to NASA for the next phase of NASA’s Commercial Crew Development program known as CCDev2.

Mark N. Sirangelo, Corporate Vice President and head of Sierra Nevada Space Systems commented, “We are thrilled to have Virgin Galactic as part of our effort to make commercial orbital transportation a reality. The knowledge gained in the development and promotion of the history making SpaceShipTwo suborbital system will add considerably to our program. VG joins a growing group of world class space companies who form our Dream Chaser team and will truly enhance our efforts.”

VG will investigate ways to use its considerable expertise, reputation and experience to provide global sales and marketing services for the Dream Chaser. This effort could include the selling of seats on the vehicle as well as exploring the contracted use of VG’s WhiteKnightTwo vehicle as a carrier aircraft for the Dream Chaser during its atmospheric flight test program. This effort is an expansion of VG’s and SNC’s current multi-year relationship in which Sierra Nevada is the prime motor contractor for VG’s suborbital SpaceShipTwo program.

Commenting in Virgin’s concurrent announcement, Sir Richard Branson, founder of Virgin Galactic said: “Virgin Galactic has shown in the past few years how private sector investment and innovation can lead to a rapid transformation of stagnant technologies. We are now very close to making the dream of sub-orbital space a reality for thousands of people at a cost and level of safety unimaginable even in the recent past. We know that many of those same people, including myself, would also love to take an orbital space trip in the future, so we are putting our weight behind new technologies which could deliver that safely whilst driving down the enormous current costs of manned orbital flight by millions of dollars. Today’s announcement is an important step along the way to achieving our ultimate and long term goal of leading an industry which opens up the huge potential of space to everyone, whether it be for the experience itself, for science research, for fast and efficient transportation around the globe or for delivering payloads to space safely, cleanly and cheaply.”

George Whitesides, CEO of Virgin Galactic added, “We see the Dream Chaser Orbital Vehicle as a promising opportunity to provide safe, cost-effective low earth orbit access to a range of users. All of us at Virgin Galactic look forward to working with the SNC Dream Chaser team.”

The Dream Chaser is a human spacecraft that will transport crew and cargo to the International Space Station and will be a flexible transportation system for a variety of other commercial low Earth orbit missions. It is a reusable, piloted lifting body spacecraft that can carry seven people and critical cargo to and from orbit with a return to a standard runway landing. Dream Chaser’s heritage is based on the NASA HL-20 spacecraft and is a safe spacecraft design that features low g forces during re-entry with on-board propulsion utilizing SNC’s proprietary hybrid motor technology. SNC has been developing the Dream Chaser, as the owner and prime contractor, for over five years and in 2009 won the largest contract under NASA’s Commercial Crew Development Program (CCDev1) to advance orbital vehicle development. SNC has completed, on time and on budget, all four critical milestones under the CCDev1 program including building and testing the first vehicle structure and flight rocket motors while advancing the design of all required systems for orbital flight. SNC leads a team of eight experienced space companies and organizations working to begin commercial orbital flight operation by 2014.
[/quote]

The attached Dream Chaser graphic accompanies the article.

blackstar said:

FutureSpaceTourist said:

They're claiming DreamChaser will be ready for operations in 2014.

Click to expand...

We can all start taking bets now.

Click to expand...

...Provider OM bids one-tenth of a Quatloo.

Dream Chaser Program Overview:

http://www.ispcs.com/files/tiny_mce/file_manager/presentations/sirangelo_crew.pdf

blackstar said:

FutureSpaceTourist said:

They're claiming DreamChaser will be ready for operations in 2014.

Click to expand...

We can all start taking bets now.

Click to expand...

I'll bet $20 and a ticket for the first Commercial flight of DreamChaser!

Hey London,

Spasiba bolshoe!

I don`t see how this program would be of any progress if compared to already existing programs that were cancelled. Designwise and engineeringwise it looks like a steady degress from what was being built in 70ies or even the cancelled x-33 RLV. They need to design a solid carrier that can haul cargo and modules as well, not building tinier and tinier and tinier vehicles that rather remind a scale demonstrator than a real vehicle. Sorry, I just don`t see solid engineering behind it.

ADVANCEDBOY said:

1. I don`t see how this program would be of any progress if compared to already existing programs that were cancelled. Designwise and engineeringwise it looks like a steady degress from what was being built in 70ies or even the cancelled x-33 RLV.

2. They need to design a solid carrier that can haul cargo and modules as well, not building tinier and tinier and tinier vehicles that rather remind a scale demonstrator than a real vehicle.

3. Sorry, I just don`t see solid engineering behind it.

Click to expand...

1. Nothing was built in the 1970's. Everything was canceled. So if Dreamchase flies, there is nothing that compares to it, except X-37 and it is unmanned

2. there is no need for a winged vehicle to haul cargo and modules (the shuttle paradigm, which was wrong). Existing launch vehicles can do that better and cheaper.

3. then you understand the basis needs of spaceflight.

Byeman said:

2. there is no need for a winged vehicle to haul cargo and modules

Click to expand...

Indeed. Wings are for coming *back.* And there is no such thing (excepting crew) as a payload in space that would be more valuable on the ground. I think LDEF was the last such payload, and nothing like that is planned.

If the time comes when space industry starts shipping product down to the surface, like perhaps refined metals from asteroid mining, there are cheaper ways to do it. Hell, for metal the thing to do would be to form it into a large hollow ball, sort of a thick-walled bubble, and clad it with melted carbonaceous chondrite "rock" and simply drop the thing into artificial lakes or old military testing grounds. The hollow design lowers density, aerothermal heating and terminal velocity; the rock coating serves as a cheap and expendable ablative. Since it's just metal, if it shatters on impact... who cares?

Years ago, plans were to manufacture computer chips, chemicals and crystals in zero g. Spaceflight never got any damned cheaper to allow this to happen... while Earthbound manufacturing *did.*

Reuseable and runway lander after a trip to space is all the justification I require. Certainly not the lifting body planform or booster system of choice nor is the X-37B. However when combined with modern avionics they appear to get it done.

Sorry to go off-topic for a sec.

Scott, that's a good idea! Now, how to turn that into something you could drop onto say, a Chinese carrier battle group, for example.

Back to Dreamchaser now.

I consider that going places `wingless` is a waste of energy. using air as a cushion for lift is the way you can save energy. So going straight vertically up is not saving energy at all. Maybe piggy backing on next generation Supercargo plane and then going `places` using wings to at least 35km up( probably much higher air would bee too low pressure to use lift), before launching into space , is the way to go, unless the wings are so heavy that weight issue drags the whole `savings ` issue down. Just guessing, anyway, the wings are useless in space, yet they would be no issue dragwise or weightwise.

NASA have just announced SNC as one of four recipients of CCDev2 awards, $80 million for SNC alone (see http://www.secretprojects.co.uk/forum/index.php/topic,9348.msg122205.html#msg122205). I still don't buy 2014 though!

They're Trying to Make a Dream Come True06.23.11 The story began on June 3, 1982, when a camera in an Australian P-3 patrol plane captured images of a Soviet ship recovering a space craft from the Indian Ocean.

It continued Wednesday, when Sierra Nevada Corp. honored the employees -- many now retired -- at NASA's Langley Research Center who used those photos to carve a cherry wood model of the Soviet craft, a BOR-4, then used that model as the jumping-off point to the HL-20 (for horizontal lander) personnel space vehicle.



› Learn More About the HL-20
› More About NASA Commercial Crew & Cargo Program
› More About Dream Chaser
A proper ending, says Sierra Nevada chairman, Mark Sirangelo, would be for its version of the HL-20, the "Dream Chaser," to ferry crews from Earth to the International Space Station and back.

On April 18, NASA awarded Sierra Nevada -- a Louisville, Colo., firm -- $80 million to continue work on the Dream Chaser after it was judged among four winners of the second round of the Commercial Crew Development (CCDev) program.

"I had made a promise that if we ever got to the point where the program was beginning to go to the next level, that we would find a way to come back and thank all of those people who enabled this," Sirangelo told an assembly at Langley's Pearl Young Theater.

In the audience was Bobby Braun, now NASA's chief technologist. In the early 1980s, he was among several at Langley who tested access and egress of the cabin on the HL-20 mockup.

Lori Garver, deputy NASA administrator, represented the agency and put the role of the space taxi competition into perspective.


Click to enlarge
NASA Deputy Administrator Lori Garver (right) speaks with engineer Bill Piland, who worked on the HL-20 program and spoke at the recognition ceremony. Credit: NASA/Sean Smith
"After we retire the space shuttle, we will be relying on our international partners to provide this capability to and from the space station," she said. "In the not-too-distant future we believe that we will have that U.S. capability to take American astronauts to and from the space station as we envisioned more than 20 years ago."

That vision began after the photos from the Australian plane came to Langley, via American intelligence.

"We spent a long time trying to figure out what it was," said Del Freeman, who was one of the few people at the center who had the compartmentalized security clearance to see the photos.

"We were 'reverse-engineering it.' Finally, we got enough information to build a model and we put it into (a wind) tunnel. When we tested it, we really figured out that we had something."

More tests showed that the lifting body design could carry the plane through a range of speeds with little or no effect on control, said George Ware, who tested the model from Mach 0.3 to Mach 4.6.

From the reverse-engineering came more ideas. One was to enable the vehicle to land like an airplane.

The HL-20 evolved, then stalled when NASA moved on to other things. Then the idea of a space taxi stalled altogether.

It's back, with commercial interests.


Click to enlarge
NASA Chief Technologist Bobby Braun talks to guests at the recognition ceremony. Credit: NASA/Sean Smith
Sierra Nevada was casting about for ideas and considered four concepts before turning to the HL-20.

"The HL-20 had the best combination: a lot of history, a lot of testing done on it," Sirangelo said. "Also, the people who worked on it are still alive and around and engaged, so we had a chance to get that history."

One of the first steps was seeing the mockup, which was done by students and researchers from North Carolina State University and North Carolina A&T, under the eyes of NASA personnel.

"A little over seven years ago, we visited Langley and had the opportunity to see the HL-20, which was, at that time, in the back of a warehouse covered with a lot of dust and other stuff," Sirangelo said.

"A lot of people told us we needed to get a clear sheet and start all over again. We decided we didn't want to do that. We wanted to build on something."

More background told them they were on the right path. Sierra Nevada entered into a Space Act Agreement with NASA Langley. Agreements with six other NASA centers followed.

"We realized that the vehicle was one of the most tested and reviewed vehicles that had never flown," Sirangelo said. "Among its missions, it was initially meant to be the lifeboat to the space station."

It could be again.

Sierra Nevada has built its own test article and, next year, intends to drop test it in the atmosphere, either from a helicopter or an airplane.


Click to enlarge
Langley Center Director Lesa Roe (center) speaks with Sierra Nevada Space Systems Chairman Mark Sirangelo (right) at the recognition ceremony. Credit: NASA/Sean Smith
A suborbital test is scheduled for 2013, with an orbital test in 2014, in part depending on Sierra Nevada's progress through NASA's system of winnowing out contenders to find the commercial space taxi that it can support.

There were 25 companies when the competition began.

At first glance, the testing schedule appears ambitious, but, Sirangelo points out, "when you think about it, these guys did 10 years of work on it. We've been working on it for seven years. So it will be the 20th year of the vehicle when it goes into orbit."

The spacecraft of two decades ago and today's "Dream Chaser" look remarkably alike.

"You'd be surprised at how little it's changed," Sirangelo said. "The more we got into it, the more we realized how smart you all were."

The Sierra Nevada party was given a Langley tour before the ceremony and seemed to be taken with it all.

"We decided today, perhaps in an emotional manner, that we're going to take one of the seats on the (mockup) and turn it into an HL-20 seat," Sirangelo said, just before inviting all of the NASA Langley participants to the eventual launch of the "Dream Chaser."

It could offer an opportunity for something few anticipated after the HL-20 program ended: actually seeing the craft fly.

"We knew it was a viable concept then, early on," Freeman said. "It's got a lot of merit."

Enough so that Sierra Nevada is trying to end the story by having the "Dream Chaser" perform as a taxi between Earth and the International Space Station.
http://www.nasa.gov/topics/technology/features/hl20-recognition.html

Dream Chaser

The Dream Chaser model and its Atlas V launch vehicle is another potential means of transporting future crew members and cargo
to station. It is part of NASA’s Commercial Crew Development program’s effort to regain the American capability to launch astronauts safely to station. Sierra Nevada Space Systems is developing the craft under a Space Act Agreement with NASA. The Dream Chaser model and its launch vehicle are undergoing final preparations at the Aerospace Composite Model Development Section’s workshop for buffet tests at the Transonic Dynamics Tunnel at NASA Langley Research Center (LRC). The reusable spacecraft would carry as many as seven astronauts to the space station.

Hundreds of strategically placed sensors will help engineers from Sierra Nevada Corporation, United Launch Alliance and LRC analyze pressure fluctuations along the two vehicles during ascent, particularly at transonic speeds. Transonic wind-tunnel testing of large, highly instrumented scale models is the only method of determining the buffet environments of launch vehicles with complex shapes, such as Dream Chaser.

PHOTO CREDIT: NASA EDGE/RON BEARD

Source: NASA's June 2012 issue of Round Up

Sierra Nevada tests Dream Chaser design near Rockies

By Rebecca ReganSpaceport News

Sierra Nevada Corporation (SNC) Space System's Dream Chaser design passed one of its most complex tests to date with a successful captive-carry test conducted near the Rocky Mountain Metropolitan Airport in Jefferson County, Colo., on May 29.

Just like the space shuttle before it, SNC's Dream Chaser will go through extensive testing to prove its wings will work. The company
built a full-scale flight vehicle of the Dream Chaser spacecraft to carry out the evaluations.

Backdropped by skyscraping summits, an Erickson Air-Crane helicopter lifted the full-scale orbital crew vehicle to verify proper aerodynamic flight performance. Future plans call for the flight vehicle to be released to evaluate the design's handling during the landing phase of a mission.

The captive-carry test marks the completion of another milestone for Sierra Nevada Corporation (SNC) Space Systems' Dream Chaser flight vehicle is lifted by an Erickson Air-Crane helicopter near the Rocky Mountain Metropolitan Airport in Jefferson County, Colo., on May 29, during a captive-carry test.

the Dream Chaser Space System as part of the Commercial Crew Development Round 2 (CCDev2) agreement with NASA's Commercial Crew Program (CCP).

"This is a very positive success for the Dream Chaser team and their innovative approach. I applaud and encourage the designers and engineers to continue their efforts in meeting the objectives of the rest of their CCDev2 milestones," said Ed Mango, CCP program manager.
SNC is one of seven companies working to develop commercial crew transportation capabilities to ferry U.S. astronauts to and from low Earth orbit and the International Space Station. The Dream Chaser is designed to carry as many as seven astronauts to space, and is the only spacecraft under CCDev2 that incorporates wings and is designed to land on a conventional runway.

"The successful captive-carry flight test of the Dream Chaser full-scale flight vehicle marks the beginning of SNC's flight test program, a program that could culminate in crewed missions to the International Space Station for NASA," said Steve Lindsey, former NASA astronaut and head of Dream Chaser's flight operations for SNC.

Before the company took to the Rocky Mountain skies, it conducted an interface test to demonstrate the release mechanism between the Dream Chaser prototype and the heavy-lift helicopter. It also conducted a ground-based landing gear drop test and a thorough flight test readiness review with engineers, technical experts and representatives from SNC and NASA.

Another recent milestone included an evaluation of the separation system compatibility of Dream Chaser with its initial launch vehicle, the United Launch Alliance Atlas V rocket, which would be used to release the spacecraft from the rocket’s second stage after it has placed the spacecraft into low Earth orbit.

Data from the captive-carry test will provide the company an early opportunity to evaluate and prove hardware, facilities and ground operations in preparation for approach and landing tests scheduled for later this year.

All of NASA’s CCDev2 partners, including SNC, continue to meet their established milestones in developing commercial crew transportation capabilities.

Photo courtesy of Sierra Nevada Corp.

Source: Spaceport News Vol. 52, No. 11 (June 1, 2012)
For more information about NASA's Commercial Crew Program, visit http://www.nasa.gov/commercialcrew