Dream Chaser flight test vehicle in 2013
| |
| Manufacturer | Sierra Nevada Corporation |
|---|---|
| Country of origin | United States |
| Operator | NASA |
| Applications | ISS resupply |
| Specifications | |
| Spacecraft type | Unmanned cargo vehicle |
| Payload capacity | 5,000 kg (5.0 t; 11,000 lb) pressurized, 500 kg (0.50 t; 1,100 lb) unpressurized |
| Crew capacity | 0 |
| Production | |
| Status | In development |
| Related spacecraft | |
| Derived from | Unmanned HL-20 Personnel Launch System |
 | |
| Manufacturer | Sierra Nevada Corporation |
|---|---|
| Related spacecraft | |
| 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. The Dream Chaser is designed to resupply the International Space Station with both pressurized and unpressurized cargo. The vehicle will launch vertically on an Atlas V or Ariane 5 rocket, and autonomously land horizontally on conventional runways. Potential further development of the spaceplane includes a crewed version called the Dream Chaser Space System, which would be capable of carrying up to seven people to and from low Earth orbit.
Design
Propulsion
On-orbit propulsion of the Dream Chaser was supposed to be provided by twin hybrid rocket engines fueled with non-toxic and storable hydroxyl-terminated polybutadiene (HTPB) and nitrous oxide. Unlike solid rockets, Dream Chaser's hybrid fuel system would allow the motor to stop and start repeatedly and be throttleable. SNC Space Systems was also developing a similar hybrid rocket, RocketMotor Two, for Virgin Galactic's SpaceShipTwo, as a subcontractor to Scaled Composites. In May 2014 their involvement in the program ended after Virgin Galactic
elected to replace SNC's version of RocketMotorTwo, powered by HTBD
rubber fuel, with its own internally developed hybrid motor using a polyamide plastic fuel, while continuing to use the same nitrous oxide oxidizer.
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.
Dream Chaser Space System
Artist's conception of the Dream Chaser Space System in the launch configuration
Dream Chaser Space System is a planned human-rated version designed to carry from two to seven people and cargo to orbital destinations such as the International Space Station. It is to have a built-in launch escape system and could fly autonomously if needed. Although it could use any suitable launch vehicle, it is currently planned to be launched on a human-rated Atlas V 412 rocket. The vehicle is 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 burn 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) will be made up of silica-based tiles and a new composite
material called Toughened Unipiece Fibrous Reusable Oxidation Resistant
Ceramic (TUFROC).
A second round of Dream Chaser flight tests at NASA's Armstrong Flight Research Center was scheduled to continue during 2017.
History
An artist's impression of the X-20 Dyna-Soar being launched using a Titan booster, with large fins added to the Titan's first stage
The historical antecedents of the Dream Chaser in the U.S. go back to the mid-twentieth century X-20 Dyna-Soar concept of 1957 and the 1966 Northrop M2-F2 and Martin X-23 PRIME lifting bodies. Its design is derived from NASA's 1990 HL-20 lifting body design which was itself similar to the 1980s Soviet BOR-4, which in turn was considered by NASA engineers as influenced by the late 1960s HL-10, and the Soviet "Spiral"(Mikoyan-Gurevich MiG-105), a military spaceplane concept, the latter having been studied as a means to develop a Cold War Soviet counterpart to the US's X-20 Dyna-Soar.
The name "Dream Chaser" has been used for two separate space vehicles. One, planned to be an orbital vehicle based on the NASA HL-20,
originated at SpaceDev when Jim Benson was still there. The second, a
suborbital vehicle, was the result of Jim Benson's having reused the
name when he formed the Benson Space Company for the purposes of space tourism.
On 24 June 2011, SNC announced it had achieved two critical
milestones for NASA's CCDev program. The first was a Systems Requirement
Review (SRR), where SNC validated their requirements based on NASA's
draft Commercial Crew Program Requirements. The SRR was successfully
completed on 1 June 2011, with participation from NASA and SNC industry
partners. The second milestone was a review of the improved airfoil fin
shape for Dream Chaser used to aid its control through the atmosphere.
Testing in a wind tunnel and computational fluid dynamics analyses
allowed the fin selection to pass the NASA milestone.
As of October 2011, Sierra Nevada Corp had completed four of the 13 milestones set out in the CCDev Agreement.
The most recent milestones accomplished include: a System Requirements
Review, a new cockpit simulator, finalizing the tip fin airfoil design
and most recently,
a Vehicle Avionics Integration Laboratory (VAIL), which will be used to
test Dream Chaser computers and electronics in simulated space mission
scenarios.
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 24 April 2012, Sierra Nevada Corporation announced the successful
completion of wind tunnel testing of a scale model of the Dream Chaser
vehicle.
On June 12, 2012 SNC announced the commemoration of its fifth year as a NASA Langley partner in the design and development of Dream Chaser. Together with ULA, the NASA/SNC team performed buffet tests on the Dream Chaser and Atlas V stack. To date, the Langley/SNC team has worked on aerodynamic and aerothermal analysis of Dream Chaser, as well as guidance, navigation, and control systems. On July 11, 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 January 30, 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 2014, SNC announced it had signed a launch contract to fly
the first orbital test vehicle on a robotically controlled orbital test flight in November 2016.
In January 2013, Sierra Nevada also 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 March 13, 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 April 29, 2013, Virgin Galactic's SpaceShipTwo sub-orbital vehicle was propelled on its first ever powered flight by SNC's Hybrid Rocket
Motor. SNC manufactures the main oxidizer valve and the hybrid rocket
motor, plus the nitrous oxide dump and pressurization system control
valves. The hybrid rocket motor and oxidizer valve system are
manufactured at an SNC facility in Poway, California, where motors for
both Space Ship Two and Dream Chaser are produced.
SpaceDev Dream Chaser proposal
Commercial Orbital Transportation Services
The Dream Chaser was publicly announced on September 20, 2004 as a candidate for NASA's Vision for Space Exploration and later Commercial Orbital Transportation Services Program (COTS).
When the Dream Chaser was not selected under Phase 1 of the COTS Program, SpaceDev founder James Benson stepped down as Chairman of SpaceDev and started Benson Space Company to pursue the development of the Dream Chaser. 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.
Commercial Crew Development
About two weeks after Benson's October 10, 2008 death, SpaceDev agreed to be acquired by Sierra Nevada Corporation, a privately owned company operated by Fatih Ozmen and Eren Ozmen, on October 21, 2008 for US$38 million. On February 1, 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.
Of the $50 million awarded by the CCDev program, Dream Chaser's award
represented the largest share of the funds. SNC completed the four
planned milestones on time which included program implementation plans, manufacturing readiness capability, 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.
The 1.5 m (5 ft) model was dropped from an altitude of 14,000 feet
(4,300 m) to test flight stability and collect aerodynamic data for flight control surfaces.
For the CCDev phase 2 solicitation by NASA in October 2010, Sierra Nevada proposed extensions of Dream Chaser spaceplane
technology. According to head of Sierra Nevada Space Systems Mark
Sirangelo, the cost of completing the Dream Chaser should be less than
$1 billion.
On April 18, 2011, NASA awarded nearly $270 million in funding
for CCDev 2, including $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
the airfoil fin shape, integrated flight software and hardware, landing gear, and a full-scale captive carry flight test.
Commercial Crew integrated Capability
On
August 3, 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.
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
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.
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.
September 2014 CCtCap non-selection by NASA
After being involved with the NASA Commercial Crew Development
program since 2009—and being selected as one of the contract award
recipients in each prior phase of the program—NASA did not select the
Dream Chaser for the next phase of the Commercial Crew Program announced
September 16, 2014 due to lack of maturity.
Sierra Nevada filed a protest to the US Government Accountability Office
(GAO) on September 26. Boeing and SpaceX were asked by NASA to "stop
work" on the crewed spacecraft during the protest resolution.
However, on October 22, 2014, a Federal Judge ruled that NASA could
proceed with contracts with Boeing and SpaceX to develop their "space
taxis", while the GAO continued to consider Sierra Nevada's protest of
NASA's original decision.
Two weeks after losing the Commercial Crew Transportation
Capability (CCtCap) competition to SpaceX and Boeing on September 16,
2014, Sierra Nevada Corporation announced it has designed a launch system that combines a scale version of the company's Dream Chaser space plane with the Stratolaunch Systems air launch system.
Earlier the same week, 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 is still completing
milestones 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."
Dream Chaser Global Project
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 November 5, 2014 during the Space Traffic Management Conference at Embry–Riddle Aeronautical University,
SNC's Space Systems team presented the challenges and opportunities
related to landing the Dream Chaser spacecraft at public-use airports.
According to the presentation, "Unlike the Space Shuttle, the Dream
Chaser does not require any unique landing aids or specialized equipment
as it uses all non-toxic propellants and industry standard subsystems."
Stratolaunch and Dream Chaser
In late November 2014, Vulcan Aerospace released the results of the SNC/Stratolaunch space transportation
architecture, which indicated that the reduced-size Dream Chaser in
conjunction with the Stratolaunch-based launch system mission
capabilities. The system would have an outbound range of 1,900
kilometers; 1,200 miles (1,000 nmi) away from the airport where the
aircraft departed. The launch vehicle would be a modified air-launched Orbital Sciences
rocket that is approximately 37 m (120 ft) in length. The Dream Chaser
payload would be a 75-percent sized version of the vehicle previously
proposed to NASA—while maintaining the relative outer mold line-6.9 m
(22.5 ft) in length with a wingspan of 5.5 m (18.2 ft), which could
carry 2 to 3 crewmembers plus a variety of scientific and research
payloads.
Dream Chaser for European Utilization
In 2013, SNC and OHB entered into an agreement to study the
feasibility of using SNC's Dream Chaser spacecraft for a variety of
missions. The DC4EU study thoroughly reviewed applications for the Dream
Chaser including crewed and uncrewed flights to low-Earth orbit (LEO)
for missions such as microgravity science, satellite servicing, and
active debris removal (ADR).
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.
According to Dr. Fritz Merkle, member of the Executive Management Board of OHB AG:
"The inherent design advantages of the Dream Chaser reusable lifting body spacecraft make it an ideal vehicle for a broad range of space applications. We partnered with SNC to study how the design of the Dream Chaser can be used to advance European interests in space. The study results confirm the viability of using the spacecraft for microgravity science and ADR. DC4EU can benefit the entire international space community with its unique capabilities. We look forward to further maturing our design with SNC as we expand our partnership."
The cooperation was renewed in April 2015 for additional two years.
United Nations missions
The United Nations Office for Outer Space Affairs (UNOOSA), which has never launched a space mission of its own, selected the cargo Dream Chaser for at least one mission for United Nations member states
that have no space access or space programs of their own. The mission
would last for at least two weeks in freeflight, to allow the payloads a
microgravity environment, without docking with the International Space Station. The proposed mission would launch as soon as 2021.
Hubble Telescope service mission
The Trump Administration is currently considering the applications to use a crewed version of the Dream Chaser to service the Hubble Space Telescope sometime in the 2020s.
Dream Chaser Cargo System
Artist's conception of the Dream Chaser Docked to ISS
The cargo variant of the SNC Dream Chaser is called the Dream Chaser Cargo System.
Featuring an expendable cargo portion, containing solar panels, the
cargo version of the spacecraft will be capable of returning 1,750 kg
(3,860 lb) to Earth, undergoing re-entry forces of 1.5G. It has been proposed for the Phase II program for cargo resupply of the International Space Station.
January 2016 CRS2 selection by NASA
In December 2014, Sierra Nevada proposed Dream Chaser for CRS-2 consideration. It is in competition with the existing CRS-1 contract holders SpaceX Dragon capsule and Orbital Sciences Cygnus capsule, as well as fellow CCDev competitor Boeing CST-100. In January 2016, NASA announced that Dream Chaser
had been awarded one of the contracts under CRS2. NASA committed to
purchasing a minimum of six resupply missions to the ISS from Sierra
Nevada.
To meet CRS2 guidelines, the cargo Dream Chaser will feature
foldable wings, to fit within a 5m cargo fairing, unlike the passenger
Dream Chaser, which did not use a cargo fairing. The ability to fit in a
cargo fairing allows launches from Ariane 5 as well as Atlas V
rocket launcher vehicles. To expand the cargo uplift capacity, an
expendable cargo module is affixed aft, which will not support downlift,
but can be used for disposal of up to 3,250 kg (7,170 lb) of trash.
Total uplift is planned for 5,000 kg (11,000 lb) pressurized, 500 kg
(1,100 lb) unpressurized, with downlift of 1,750 kg (3,860 lb) wholly
within the spaceplane.
Testing
Engine
Sierra Nevada completed an initial test phase on the Dream Chaser
rocket engine in 2010, under the CCDev1 program, including three
successful test firings on a single hybrid motor in a single day.
A second phase of testing began in June 2013, with a motor firing and ignition test in order to validate the newly modified test stand, as a start to the Commercial Crew Integrated Capability (CCiCap) contract test phase.
Wind tunnel
In
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.
Flight test program
In May 2013, The Dream Chaser Engineering Test Article (ETA) was shipped to the Dryden Flight Research Center in California for a series of ground tests and aerodynamic flight tests. This move to Dryden came about a year after a captive carry test that was conducted near the Rocky Mountain Metropolitan Airport on May 29, 2012. During that test, an Erickson Skycrane was used to lift the Dream Chaser to better determine its aerodynamic properties. A second captive carry flight test was completed on August 22, 2013.
On October 26, 2013, the first free-flight occurred. The test
vehicle was released from the "skycrane" 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.
In a press teleconference a short while later, Mark Sirangelo,
corporate vice president of Sierra Nevada, told reporters that the view
of the ETA was obscured by the dust as it skidded off the runway, but
that the vehicle was found upright, with the crew compartment intact,
and all systems inside still in working order. Sierra Nevada corporation
engineers do not believe that the ETA flipped over.
On August 1, 2014, the first completed piece of the orbital test
vehicle's composite airframe was unveiled at the Lockheed Martin Michoud
Assembly Facility in Louisiana.
In October 2015, the thermal protection system was installed on the ETA
for the next phase of atmospheric flight testing. The orbital cabin
assembly of the FTA orbital test vehicle was also completed by
contractor Lockheed Martin.
The first two Dream Chasers — the ETA and the Flight Test Article
(FTA) — have been given internal and external names, with some sources
reporting that the ETA will be named Eagle, while the FTA was originally named Ascalon before being changed to Ascension.
Dream Chaser model being tested at NASA Langley.
In 2014, an initial orbital test flight of the Dream Chaser orbital
test vehicle was planned for November 1, 2016, launching on an Atlas V rocket from Kennedy Space Center Launch Complex 41.
On November 11, 2017, the Dream Chaser successfully completed a
glide test, after being released from an altitude of 3,700 m and landing
at Edwards AFB.
NASA indicated that the first commercial cargo flight by any provider
under the CRS-2 contract will not occur until 2019. As of January 2019,
the first ISS flight of the Dream Chaser is planned for 2020.
Status
In January 2016, Sierra Nevada signed a contract with NASA to provide at least six CRS2 missions to the space station.
As of March 2019, the validation of NASA’s Integrated Review Milestone 5 (IR5) confirms that development is still ongoing at a nominal pace.
The cargo Dream Chaser was selected by UNOOSA
in 2016 for the first United Nations space mission, to allow nations
without access to space to fly microgravity experiments. First flight is
planned no earlier than 2021.
Technology partners
The following organizations were named as technology partners in 2010 for the original passenger Dream Chaser:
- Aerojet – reaction control system technology
- AdamWorks – composites
- Boeing Phantom Works – construction of some early test articles
- Charles Stark Draper Laboratory – guidance, navigation, and control
- Lockheed Martin – airframe construction and human rating of the spaceplane
- MDA – systems engineering
- University of Colorado – human-rating
