New returns – Dream Chaser on atop Atlas V (402) scheduled on 1st November 2016

ULA is launch service provider for a new project by Sierra Nevada Corporation. Dream Chaser, new reusable lifting-body spaceplane will be launched on atop Atlas V rocket (402 configuration) on 1st November 2016. Planned launch site will be Cape Canaveral Air Force Station, Florida, USA.

After retiring Space Shuttles, NASA without their proud and one of most recognizable symbol of space program, becomes dependent on spacecrafts. Dragon in manned version after modernization could probably take on the role of lifting men on the orbit. Rockets like Atlas, Falcon or Delta are successfully utilized as cargo launch vehicles. But without Space Shuttle NASA remains without any alternative solution of lifting men and cargo to space. Dragon is still in testing phase - as far as it is still promising construction, it has all cons of spacecraft. It is not offering capability of autonomic flight, it is not able to land on conventional runway. It has not versatility of spaceplane - using it as a crewed vehicle limits its cargo capabilities. Also it does not allow supporting crew members during spacewalk, what was useful during Hubble Space Telescope servicing missions. Rockets are able to lift cargo, but it should be prepared and ready to operating like satellite. It is interesting why since first Space Shuttle flight in 1981 until nineties, Space Shuttle remained only spaceplane of NASA without any alternative. After Challenger disaster in 1986 it turned out that considered as most reliable and safe space vehicle ever created is not perfect. Other defects than not sufficient rescue system started coming to light. Costs of maintenance were growing with age of Space Shuttles. Develop in spacecrafts and rocket design caused that they became very competitive in terms of launch cost. Columbia disaster in 2003 finally gave evidence for retiring Space Shuttles in 2011. It is worth to take a look on other aspect of the Space Shuttle to explain why in spite of increasing number of cons they have been remaining operational until 2011 without developing any comparable alternative solution. After spending over $209 billion for shuttle project (this sum will probably grow if we add costs of lifting-body planes and X-15 projects from fifties and sixties) NASA was not to easily give up with Space Shuttle. Maybe not necessary most important but also significant was question of prestige. Soviet and later Russian, conception was based on rockets and spacescrafts. They proved to be more reliable , easier to modify and paradoxically cheaper than Space Shuttle oriented in its origins on cost reducing (one launch of Space Shuttle cost in 2011 around $450 million, but still in the beginnings of Space Shuttle concept spacecrafts offered limited cargo capacity with similar costs per launch). Granted that such expensive project turned out to be inconsistent with their objectives would be huge failure of NASA. Mistake extremely unnecessary during time after the Cold War when budgets of research agencies started to shrink.

In 2004 it seemed that conception of spaceplane would reborn in form of the HL-20 project (previous name of Dream Chaser). After acquisition of the project from NASA by commercial company SpaceDev it was finished in 2005. SpaceDev announced that HL-20 will be their response for COTS (Commercial Orbital Transportation Services) program. Unfortunately HL-20 was rejected, but it was still developed by SpaceDev. After SpaceDev was bought by Sierra Nevada Corporation in 2008 NASA announced Commercial Crew Program. Sierra Nevada with HL-20 was awarded with biggest support (amount of $ 20 million) in first phase of the project. Also NASA announced that HL-20 will utilize ULA Atlas V rocket.  Next success was finishing all required tests of propulsion and reaching third phase called Commercial Crew integrated Capability (CCiCap). Hard times came when NASA announced in 2014 that Sierra Nevada was not able to meet demands and donations were divided only between SpaceX and Boeing. Sierra Nevada announced that further develop of Dream Chaser could result in attractive solution for various space programs. In 2015 Sierra Nevada stated that will participate in Dream Chaser for European Utilization (DC4EU) with OHB System AG and Space Administration of the German Aerospace Center (DLR). It seems that there is a chance to see Dream Chaser in the colors of ESA someday.

Concept of spaceplane materialized for the first time in the form of X-15 experimental plane. Since then only few spaceplane were successful: Space Shuttle, Buran,  SpaceShipOne and X-37. It is hard to give example of "ideal" spaceship, because of fact that they represent different approaches and conceptions. Space Shuttle and Buran were large vehicles utilizing huge rockets for vertical start. X-15 was small vehicle lifted to specific height by modified B-52 bomber, similar to SpaceShipOne. X-37 is unmanned and designed to be lifted under rocket fairing. HL-20 is quite similar to concept X-23 plane designed by Northrop for lifting-body testing. General conception of single rocket with spaceplane on atop was firstly presented by Boeing during designing X-20 Dyna-Soar (1957-1963). But HL-20 is designed to offer capability of lifting cargo or crew; maybe not so impressive payload as Space Shuttle, but still enough to take over many of its tasks. HL-20 (Dream Chaser) was designed as reusable spaceplane for lifting up to seven crew members and/or cargo and possibility of landing on airport runways. Built with composites, will have detachable thermal shield (thermal protection system detachable as one element, not part after part like in Space Shuttle) for easy maintenance and cost reducing (shorter time necessary for maintenance between flights). It is equipped with safe reaction control system thrusters fueled with non-explosive ethanol-based fuel. Main propulsion is twin hybrid rocket motors also fueled with non-explosive propellant (hydroxyl-terminated polybutadiene (HTPB) and nitrous oxide). It is planned to equip Dream Chaser in advanced rescue system capable to be used in every moment of flight. Engines will be throttable and have possibility of stopping and starting if necessary. Dream Chaser length is 9 m, wing span is 7 m and it weighs at 11300 kg. As planned lifting rocket was considered Atlas V (412) in version certificated to manned missions.

It is worth considering why NASA returned to conception of spaceplane. It is probable, that NASA would like to give impetus to development conception of Space Shuttle or spaceplane to commercial space industry. It is doubtful that any company will go in such expensive technology without a good reason (chances for launch contracts). Good explanation is also fact that Space Shuttle was good concept but simply too modern for its times. Designed and built in sixties and seventies it was very ambitious project limited with contemporary possibilities for then industry (for example computers in seventies were mostly mainframe systems - in eighties computers become portable and multiple times more powerful). Soviet Space Shuttle based on American experiences (and probably on industrial espionage) and built in eighties was huge technical success. Buran was designed as a more reliable, more modern and safer vehicle than American Space Shuttle in spite of collapsing economy and lack of latest computer technologies in USSR. But it had something more: ten years of intensive development of space technologies. It was equipped with safer liquid fueled engines and computers able to control shuttle during start, flight, reentry and landing (first and only flight of Buran was unmanned). It would be unfair to say that American Space Shuttle was poor design - it was just impossible to find enough powerful computers, reliable engines and many different instruments and materials in years of its design. NASA, despite the best efforts to modify the Space Shuttle, was unable to change design limitations of the project. Maybe now it is good moment to reconsider concept of spaceplane?

Resources:
https://en.wikipedia.org/wiki/Boeing_X-20_Dyna-Soar
https://en.wikipedia.org/wiki/Human-rating_certification
https://en.wikipedia.org/wiki/Dream_Chaser#cite_note-50
http://www.sncorp.com/AboutUs/NewsDetails/749
https://en.wikipedia.org/wiki/Sierra_Nevada_Corporation

Dream Chaser aims to use Space Shuttle’s legacy to its advantage


https://en.wikipedia.org/wiki/Space_Shuttle_program

 

 

 

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