Dream Chaser flight test vehicle in 2013
|Manufacturer||Sierra Nevada Corporation|
|Country of origin||United States|
|Spacecraft type||Robotic cargo vehicle|
Crewed orbital spaceplane
|Payload capacity||5,000 kg (5.0 t; 11,000 lb) pressurized, 500 kg (0.50 t; 1,100 lb) unpressurized|
|Crew capacity||0 (cargo)|
|Launched||0 (atmospheric flights only)|
|Maiden launch||NET 2021 (planned)|
|Derived from||HL-20 Personnel Launch System|
The Dream Chaser Cargo System is an American reusable lifting-body spaceplane being developed by Sierra Nevada Corporation (SNC) Space Systems. Originally intended as a crewed vehicle, the Dream Chaser Space System, to be produced after the cargo variant is operational, is capable of carrying up to seven people and cargo to and from low Earth orbit.
The cargo Dream Chaser will resupply the International Space Station with both pressurized and unpressurized cargo. It will be launched vertically on the Vulcan Centaur rocket and autonomously land horizontally on conventional runways. A proposed version operated by ESA would launch on Ariane 5.
The Dream Chaser design is derived from NASA's HL-20 Personnel Launch System spaceplane concept, which in turn is descended from a series of test vehicles, including the X-20 Dyna-Soar, Northrop M2-F2, Northrop M2-F3, Northrop HL-10, Martin X-24A and X-24B, and Martin X-23 PRIME.
In 2010, the following organizations were named as technology partners for the original passenger Dream Chaser:
On-orbit propulsion of the Dream Chaser was originally proposed to be provided by twin hybrid rocket engines capable of repeated starts and throttling. At the time, SNC Space Systems was also developing a similar hybrid rocket for Virgin Galactic's SpaceShipTwo. In May 2014, SNC involvement in the SpaceShipTwo program ended.
After the acquisition of Orbitec LLC in July 2014, Sierra Nevada Corporation announced a major change to the propulsion system. The hybrid rocket engine design was dropped in favor of a cluster of Orbitec's Vortex engines. The new engines would use propane and nitrous oxide as propellants.
The originally planned Dream Chaser Space System is a human-rated version designed to carry from two to seven people and cargo to orbital destinations such as the International Space Station. It was to have a built-in launch escape system and could fly autonomously if needed. Although it could use any suitable launch vehicle, it was planned to be launched on a human-rated Atlas V 412 rocket. The vehicle was to be able to return from space by gliding (typically experiencing less than 1.5 g on re-entry) and landing on any airport runway that handles commercial air traffic. Its reaction control system thrusters burned ethanol-based fuel, which is not an explosively volatile material, nor toxic like hydrazine, allowing the Dream Chaser to be handled immediately after landing, unlike the Space Shuttle. Its thermal protection system (TPS) was made up of silica-based tiles and a new composite material called Toughened Unipiece Fibrous Reusable Oxidation Resistant Ceramic (TUFROC).
As of 2020, the Sierra Nevada Corporation says it still plans to produce a crewed version of the spacecraft within the next 5 years. The company says it "never stopped working" on the crewed version and fully intends to launch it after the cargo version.
The cargo version of the SNC Dream Chaser is called the Dream Chaser Cargo System (DCCS) and after development completes (planned for mid-2021), will fly resupply flights to the ISS under NASA's Commercial Resupply Services-2 program. Featuring an expendable cargo module mounting solar panels, the spacecraft will be capable of returning 1,750 kg (3,860 lb) to Earth while undergoing maximum re-entry forces of 1.5G.
To meet CRS-2 guidelines, the cargo Dream Chaser will have folding wings and fit within a 5 m diameter payload fairing, in contrast to the Crewed Dream Chaser, which is intended to launch without a fairing. The ability to fit into a payload fairing allows the cargo version to launch on any sufficiently capable vehicle, such as Ariane 5 as well as Atlas V. An expendable cargo module will launch attached to the aft end of the spacecraft, expanding the cargo uplift capacity and supporting the disposal of up to 3,250 kg (7,170 lb) of trash. Total uplift is planned for 5,000 kg (11,000 lb) pressurized and 500 kg (1,100 lb) unpressurized, with a downlift of 1,750 kg (3,860 lb) contained within the spaceplane. The expendable cargo module is called "Shooting Star".
On August 14, 2019, it was announced that all six Dream Chaser CRS-2 flights will be carried into orbit by ULA's Vulcan launch vehicle, with the first Dream Chaser flight being the second Vulcan flight in late 2021.
In 2019, it was announced that an expendable "Shooting Star" cargo module would be part of the Dream Chaser cargo system for CRS-2 flights. The module is a 15-foot (4.6 m) long attachment to Dream Chaser that will allow the spacecraft to carry an additional 10,000 pounds (4,500 kg) of pressurized and unpressurized cargo to ISS. The module supports disposal of unwanted cargo by burning up upon re-entry.
In addition to carrying cargo, the Shooting Star module includes solar panels that supply up to 6 kW of electrical power. It also supplies active and passive thermal management; provides Dream Chaser translation & rotation capability via six mounted thrusters; and supports berthing or docking (in different configurations) to the ISS. Access from ISS to Dream Chaser will involve crew passing through Shooting Star (which supports a shirt-sleeve environment) and through a hatch that separates Shooting Star from Dream Chaser. Sierra Nevada says the module is capable of additional types of missions in LEO or to cis-lunar destinations; they have developed a free-flying variant with additional capabilities.
In July 2020, Sierra Nevada announced a contract with the Defense Innovation Unit (DIU) to use its Shooting Star expendable cargo vehicle as a possible commercial solution for a high-powered Unmanned Orbital Outpost.
The name "Dream Chaser" had been previously used for two separate space vehicle concepts. The first was planned to be an orbital vehicle based on the HL-20, with the second suborbital vehicle proposed by the Benson Space Company for the purposes of space tourism.
The Dream Chaser was publicly announced on September 20, 2004. In April 2007, SpaceDev announced that it had partnered with the United Launch Alliance to pursue the possibility of using the Atlas V booster rocket as the Dream Chaser's launch vehicle. In June 2007, SpaceDev signed a Space Act agreement with NASA.
On 1 February 2010, Sierra Nevada Corporation was awarded $20 million in seed money under NASA's Commercial Crew Development (CCDev) phase 1 program for the development of the Dream Chaser. SNC completed the four planned milestones on time, including hybrid rocket test fires and the preliminary structure design. Further initial Dream Chaser tests included the drop test of a 15% scaled version at the NASA Dryden Flight Research Center.
Sierra Nevada proposed Dream Chaser for the CCDev phase 2 solicitation by NASA in October 2010, with an estimated project cost of less than $1 billion. On 18 April 2011, NASA awarded $80 million to Sierra Nevada Corporation for Dream Chaser. Since then, nearly a dozen further milestones have been completed under that Space Act Agreement. Some of these milestones included testing of an improved airfoil fin shape, integrated flight software and hardware, landing gear, a full-scale captive carry flight test, and a Systems Requirement Review (SRR).
By February 2012, Sierra Nevada Corporation stated that it had completed the assembly and delivery of the primary structure of the first Dream Chaser flight test vehicle. With this, SNC completed all 11 of its CCDev milestones that were scheduled up to that point. SNC stated in a press release that it was "on time and on budget."
On 29 May 2012, the Dream Chaser Engineering Test Article (ETA) was lifted by an Erickson Skycrane helicopter in a captive carry test to better determine its aerodynamic properties. In May 2013, the ETA was shipped to the Dryden Flight Research Center in California for a series of ground tests and aerodynamic flight tests. A second captive carry flight test was completed on 22 August 2013.
On 12 June 2012, SNC announced the commemoration of its fifth year as a NASA Langley partner in the design and development of Dream Chaser. The NASA/SNC team had worked on aerodynamic and aerothermal analysis of Dream Chaser, as well as guidance, navigation, and control systems. Together with ULA, the NASA/SNC team performed buffet tests on the Dream Chaser and Atlas V stack.
On 11 July 2012, SNC announced that it successfully completed testing of the nose landing gear for Dream Chaser. This milestone evaluated the impact to the landing gear during simulated approach and landing tests as well as the impact of future orbital flights. The main landing gear was tested in a similar way in February 2012. The nose gear landing test was the last milestone to be completed before the free flight approach and landing tests scheduled for later in 2012. In August 2012, SNC completed CCiCap Milestone 1, or the 'Program Implementation Plan Review'. This included creating a plan for implementing design, development, testing, and evaluation activities through the duration of CCiCap funding. By October 2012 the "Integrated System Baseline Review", or CCiCap Milestone 2, had been completed. This review demonstrated the maturity of the Dream Chaser Space System as well as the integration and support of the Atlas V launch vehicle, mission systems, and ground systems.
On 3 August 2012, NASA announced the award of $212.5 million to Sierra Nevada Corporation to continue work on the Dream Chaser under the Commercial Crew Integrated Capability (CCiCap) Program. On 30 January 2013, SNC announced a new partnership with Lockheed Martin. Under the agreement, SNC will pay Lockheed Martin $10 million to build the second airframe at its Michoud facility in New Orleans, Louisiana. This second airframe is slated to be the first orbital test vehicle, with orbital flight testing planned to begin within the next two years.
In January 2013, Sierra Nevada announced that the second captive carry and first unpowered drop test of Dream Chaser would take place at Edwards Air Force Base, California in March 2013. The spaceplane release would occur at 12,000 feet (3,700 m) altitude and would be followed by an autonomous robotic landing.
On 13 March 2013, NASA announced that former Space Shuttle commander Lee Archambault was leaving the agency in order to join SNC. Archambault, a former combat pilot and 15-year NASA veteran who flew on Atlantis and Discovery, will work on the Dream Chaser program as a systems engineer and test pilot.
On October 26, 2013, the first free-flight occurred. The test vehicle was released from the helicopter and flew the correct flightpath to touchdown less than a minute later. Just prior to landing, the left main landing gear failed to deploy resulting in a crash landing. The vehicle skidded off the runway in a cloud of dust, but was found upright with the crew compartment intact and all systems inside still in working order.
In early 2014, Sierra Nevada completed its wind tunnel testing as part of its CCiCAP Milestone 8. The wind tunnel testing involved analyzing the flight dynamics characteristics that the vehicle will experience during orbital ascent and re-entry. Wind tunnel testing was also completed for the Dream Chaser Atlas V integrated launch system. These tests were completed at NASA Ames Research Center at Moffett Field, California, CALSPAN Transonic Wind Tunnel in New York, and at NASA Langley Research Center Unitary Plan Wind Tunnel in Hampton, Virginia.
On 1 August 2014, the first completed piece of the orbital Flight Test Article (FTA) composite airframe was unveiled at a Lockheed Martin facility.
On 16 September 2014, NASA did not select the Dream Chaser for the next phase of the Commercial Crew Program. This occurred despite previous Commercial Crew Development awards in every phase since 2009, due to lack of maturity.
On 26 September, Sierra Nevada filed a protest to the US Government Accountability Office (GAO). On 22 October 2014, a Federal Judge ruled the contract awards to Boeing and SpaceX valid, allowing NASA to proceed.
On 29 September 2014, Sierra Nevada introduced the "Dream Chaser Global Project" which would provide customized access to low Earth orbit to global customers.
Despite not being selected to continue forward under NASA's Commercial Crew transportation Capability (CCtCap) phase of the effort to send crews to orbit via private companies, SNC completed the milestones assigned under earlier phases of the CCP. On December 2, 2014 SNC announced that it completed NASA's CCiCap Milestone 5a related to propulsion risk reduction for the Dream Chaser space system.
By late December, details had emerged that "a high-ranking agency official"—"William Gerstenmaier, the agency's top human exploration official and the one who made the final decision"—"opted to rank Boeing's proposal higher than a previous panel of agency procurement experts." More specifically, Sierra Nevada asserted in their filings with the GAO that Gerstenmaier may have "overstepped his authority by unilaterally changing the scoring criteria."
On January 5, 2015, the GAO denied Sierra Nevada's CCtCap challenge, stating that NASA made the proper decision when it decided to award Boeing $4.2 billion and SpaceX $2.6 billion to develop their vehicles. Ralph White, the GAO's managing associate counsel, announced that NASA "recognized Boeing's higher price but also considered Boeing's proposal to be the strongest of all three proposals in terms of technical approach, management approach and past performance, and to offer the crew transportation system with most utility and highest value to the government." Furthermore, the agency found "several favorable features" in SNC's proposal "but ultimately concluded that SpaceX's lower price made it a better value."
In December 2014, Sierra Nevada proposed Dream Chaser for CRS-2 consideration. In January 2016, NASA announced that Dream Chaser had been awarded one of the CRS-2 contracts and committed to purchasing a minimum of six resupply missions to the ISS. The cargo spacecraft will fly alongside spacecraft from the existing CRS-1 contract holders SpaceX and Northrop Grumman Innovation Systems.
In October 2015, the thermal protection system was installed on the Engineering Test Article (ETA) for the next phase of atmospheric flight testing. The orbital cabin assembly of the Flight Test Article (FTA) was also completed by contractor Lockheed Martin.
As of August 2019[update], the first ISS flight of the Dream Chaser Demo-1 is planned for 2021. As of March 2019, completion of NASA's Integrated Review Milestone 5 (IR5) confirms that development is still on schedule.
In December 2013, the German Aerospace Center (DLR) announced a funded study to investigate ways in which Europe might take advantage of the Dream Chaser crewed spaceplane technology. Named the DC4EU (Dream Chaser for European Utilization), the project will study using it for sending crews and cargo to the ISS and on missions not involving the ISS, particularly in orbits of substantially greater altitude than the ISS can reach.
In January 2014, the European Space Agency (ESA) agreed to be a partner on the DC4EU project, and will also investigate whether the Dream Chaser can use ESA avionics and docking mechanisms. ESA will also study launching options for the "Europeanized" Dream Chaser, particularly whether it can be launched from the Guiana Space Centre, within the Ariane 5's large aerodynamic cargo fairing – or, like the Atlas V, without it. In order to fit within the fairing, the Dream Chaser's wing length will have to be reduced slightly, which is thought to be easier than going through a full aerodynamic test program to evaluate and prove it along with the Ariane for flight without the fairing. The Ariane 5 launch vehicle was designed from its inception to be crew rated, in order to launch the Hermes Spaceplane, an ESA crewed vehicle which was proposed in the 1980s and 1990s, but was cancelled.
In late January 2014, it was announced that the Dream Chaser orbital test vehicle was under contract to be launched on an initial orbital test flight, using an Atlas V rocket, from Kennedy Space Center in November 2016. This is a privately arranged commercial agreement, and is funded directly by Sierra Nevada and is not a part of any existing NASA contract.
In September 2014, SNC announced that it would, with global partners, use the Dream Chaser as the baseline spacecraft for orbital access for a variety of programs, specializing the craft as needed.
On 5 November 2014, SNC's Space Systems team publicly presented the challenges and opportunities related to landing the Dream Chaser spacecraft at public-use airports. Dream Chaser uses standard landing aids and non-toxic propellants that require no special handling.
On February 3, 2015, the Sierra Nevada Corporation's (SNC) Space Systems and OHB System AG (OHB) in Germany announced the completion of the initial Dream Chaser for European Utilization (DC4EU) study.
The study found that Dream Chaser is suitable for a broad range of space applications and could be used to advance European interests in space. The cooperation was renewed in April 2015 for an additional two years.
The United Nations Office for Outer Space Affairs (UNOOSA) selected the cargo Dream Chaser for its first space launch. This launch is intended to last for at least two weeks in freeflight to provide space access to United Nations member states that have no space programs of their own. The proposed mission, carrying up to 35 payloads, would launch in 2024.
|Image||Serial||Name||Status||Flights||Time in flight||Notes||Cat.|
|ETA||“Eagle”||Retired||1||Engineering Test Article (ETA). Atmospheric drop test.|
|FTA||“Ascension”||Unknown||0||None||Flight Test Article (FTA)|
|01||“Tenacity”||Active||0||None||Spacecraft to be flown on SNC Demo-1 mission.|
|02||None||Under construction||0||None||Sierra Nevada vague in response to NASA OIG report.|
|Test vehicle Spaceflight vehicle|
“During a visit to Sierra Nevada in June 2017, company officials told us (OIG Staff Auditors) they had no plans to build a second Dream Chaser. In August 2017, ISS Program officials said Sierra Nevada was considering building a second Dream Chaser to be completed by 2021, but no decision had been made as of October 2017. In the event of a failure, Sierra Nevada officials told us in June 2017 that a second spacecraft could be built from spare parts without additional costs to NASA.
In our judgment (OIG Audit Staff), it is highly unlikely Sierra Nevada could build another Dream Chaser after a launch failure in time to meet its CRS-2 cargo delivery requirements of six missions by 2024. Additionally, anomalies during any of the flights could adversely impact future Sierra Nevada cargo missions because the company cannot launch its sole spacecraft until all issues are resolved.”
|#||Mission||Payload||Variant||Launch date||Rocket||Payload mass||Outcome||Ref.|
|0||Dream Chaser Demo-1||Dream Chaser Demo-1
SNC Demonstration Flight
|Second Vulcan launch, with first (demonstration) flight of Dream Chaser to ISS.|
|1||Dream Chaser 1||Sierra Nevada CRS-2 Flight 1||TBD||Vulcan Centaur||TBA||TBA|
|2||Dream Chaser 2||Sierra Nevada CRS-2 Flight 2||TBD||Vulcan Centaur||TBA||TBA|
|3||Dream Chaser 3||Sierra Nevada CRS-2 Flight 3||TBD||Vulcan Centaur||TBA||TBA|
Other ISS cargo vehicles:
Other ISS crew vehicles:
...The HL-20's baseline design has evolved from manned lifting bodies flown for the Defense Dept, during the 1960s and owes much of its overall layout to the Martin X-24A...
...The lifting-body program came to an official end in 1975. Yet like a Phoenix rising from the ashes, the concept has appeared several times since then in proposed NASA spacecraft. When the Langley Research Center revealed its HL-20 design for an emergency crew return vehicle or small mini-Shuttle in 1990, the shape was remarkably similar to the HL-10 and X-24A designs...
...A mock-up of the proposed "space taxi," called the HL-20 Personnel Launch System, closely resembles a Soviet subscale spaceplane flown on four orbital missions in the 1980s...However, Piland, chief of the space systems division at the Langley Research Center, was quick to point out the Soviet test vehicle seems to have evolved from U. S. lifting-body configurations flown from 1966 to 1975—such as Northrop's HL-10, M2-F2 and M2-F3 and Martin's X-24A and X-24B....
...The NASA lifting-body program has been well documented in about 100 technical reports on the program's 222 flights and 20,000 hours of wind-tunnel tests. Many of these publications are unclassified. The Soviet Union purchased copies of these reports from NASA Headquarters in Washington, D.C., then designed its own lifting body. In 1982, the Soviets flight-tested an unpiloted, 10-foot-long, subscale version of their lifting body, the BOR-4, including a maneuvering re-entry over the Indian Ocean from space orbit. The flight test of the BOR-4 closely resembled that of our PRIME (X-23) vehicle in 1966...
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