On December 8, SpaceX became
the first commercial company in history to re-enter a spacecraft from
Earth orbit. SpaceX launched its Dragon spacecraft into orbit atop a
Falcon 9 rocket at 10:43 AM EST from Launch Complex 40 at the Cape
Canaveral Air Force Station in Florida. The Dragon spacecraft orbited
the Earth at speeds greater than 7,600 meters per second (17,000 miles
per hour), reentered the Earth’s atmosphere, and landed just after 2:00
PM EST less than one mile from the center of the targeted landing zone
in the Pacific Ocean.
The Dragon spacecraft landed in
the Pacific Ocean 3 hours, 19 minutes and 52 seconds after
liftoff--less than a minute after SpaceX had predicted and less than
one mile from the center of the landing target. Photo: Kevin Mock /
SpaceX. Click photo for video of mission highlights.
This marks the first time a commercial
company has successfully recovered a spacecraft reentering from Earth
orbit. It is a feat previously performed by only six nations or
government agencies: the United States, Russia, China, Japan, India,
and the European Space Agency.
As the very first flight under the
Commercial Orbital Transportation Services (COTS) program, COTS Demo 1
followed a nominal flight profile that included a roughly 9.5-minute
ascent, two Earth-orbits, reentry and splashdown. Falcon 9 delivered
Dragon to orbit with an inclination of 34.53 degrees--a near bull’s-eye
Image above illustrates COTS
Demo 1 mission orbital path. The yellow triangle over the Atlantic
ocean marks Dragon’s initial separation from Falcon 9, and the yellow
square off the Western coast of the United States marks the location
where Dragon landed.
Dragon’s first-ever on-orbit
performance was 100% successful in meeting test objectives including
maintaining attitude, thermal control, and communication activities.
While in orbit, eight free-flying payloads were successfully deployed,
including a U.S. Army nanosatellite—the first Army-built satellite to
fly in 50 years.
The Falcon 9 launch vehicle carrying the Dragon spacecraft, climbing from the launch pad. Photo credit: Chris Thompson/SpaceX
Liftoff marked the second flight of
SpaceX’s Falcon 9 rocket, which performed nominally during ascent. Nine
Merlin engines, which generate one million pounds of thrust in vacuum,
powered the first phase of flight. The rocket reached maximum dynamic
pressure (the point at which aerodynamic stress on a spacecraft in
atmospheric flight is maximized, also known as Max Q) approximately 1.5
minutes after launch. The first stage separation occurred a little
over three minutes into flight. The single Merlin Vacuum engine of
Falcon 9’s second stage then ignited to continue carrying the vehicle
towards its targeted orbit.
After stage separation, flames are
barely visible around nozzle as the second stage engine ignites and the
first stage falls back to the Earth below. Photo credit: SpaceX
After stage separation, the nose cap at
the front of the Dragon spacecraft safely jettisoned. The second stage
fired for another four and a half minutes, until it achieved orbital
velocity, and then the Dragon spacecraft separated from the second
stage to begin its independent flight.
High contrast view of the Dragon
spacecraft (circle at center) viewed from the top of the second stage
as it departs over the curved horizon of the Earth. The rectangles
indicate locations of three of the nano satellite deploying P-PODs
carried on this mission. Photo Credit: SpaceX
After separation of the Dragon
spacecraft, the second stage Merlin engine restarted, carrying the
second stage to an altitude of 11,000 km (6,800 mi). While restart of
the second stage engine was not a requirement for this mission (or any
future missions to the ISS), it is important for future Geosynchronous
Transfer Orbit (GTO) missions where customer payloads need to be
positioned at a high altitude.
Shortly after separating from the second
stage, the expected loss of signal occurred as the Dragon spacecraft
passed over the horizon as viewed from the launch site We reacquired
Dragon's video signal as expected as it passed over Hawaii, delivering
the first ever video sent from Dragon on orbit.
View from orbit from the side
window of the Dragon spacecraft, received via video as it passed over
Hawaii during its first orbit. Photo Credit: SpaceX. Click photo for video.
Draco thrusters, each capable of
producing about 90 pounds of thrust, began the six minute deorbit burn
at T+2:32. For this particular mission, we could have lost two entire
quads and still returned to Earth with only 8 or 10 engines working,
but all thrusters performed nominally during the COTS Demo 1 flight.
Illustration showing Draco
thrusters firing as the Dragon spacecraft travels around the Earth.
Dragon is equipped with numerous redundant systems to ensure mission
success even if primary systems fail. Photo Credit: SpaceX
Dragon’s PICA-X heat shield protected
the spacecraft during reentry from temperatures reaching more than
3,000 degrees F. SpaceX worked closely with NASA to develop PICA-X, a
SpaceX variant of NASA’s Phenolic Impregnated Carbon Ablator (PICA)
SpaceX chose PICA for its proven
ability. In January 2006, NASA's Stardust sample capsule returned
using a PICA heat shield and set the record for the fastest reentry
speed of a spacecraft into Earth's atmosphere — experiencing speeds of
28,900 miles per hour.
NASA made its expertise and specialized
facilities available to SpaceX as the company designed, developed and
qualified the 3.6 meter PICA-X shield it in less than 4 years at a
fraction of the cost NASA had budgeted for the effort. The result is
the most advanced heat shield ever to fly. It can potentially be used
hundreds of times for Earth orbit reentry with only minor degradation
each time – as proven on this flight -- and can even withstand the much
higher heat of a moon or Mars velocity reentry.
Artist’s rendition of Dragon,
thermally protected by SpaceX’s PICA-X advanced heat shield, reentering
Earth’s atmosphere. Photo Credit: SpaceX
At about 10,000 feet, Dragon’s three
main parachutes, each 116 feet in diameter, deployed to slow the
spacecraft's decent to approximately 16-18 ft/sec, ensuring a
comfortable return ride that will be required for manned flights.
Oversized parachutes are critical in ensuring a safe landing for crew
members. Even if Dragon were to lose one of its main parachutes, the
two remaining chutes would still ensure a safe landing.
Dragon’s three main
parachutes fully deployed. Below float two drogue parachutes which
deployed first to slow and stabilize the spacecraft.
The SpaceX crew brought Dragon back to the barge where the crane lifted it from the water. Photo: Mike Altenhofen / SpaceX
The Dragon spacecraft, in
excellent condition after its 50,000 mile mission, rests in its cradle
for the 500 mile ride back to Los Angeles. Photo: Mike Altenhofen /
This was the first flight under NASA’s
COTS program to develop commercial resupply services to the
International Space Station. After the Space Shuttle retires, SpaceX
will fly at least 12 missions to carry cargo to and from the
International Space Station as part of the Commercial Resupply Services
contract for NASA.. The Falcon 9 rocket and Dragon spacecraft were
designed to one day carry astronauts; both the COTS and CRS missions
will yield valuable flight experience toward this goal.
With recovery of the Dragon spacecraft,
SpaceX became the first company in history to successfully re-enter a
spacecraft from Earth orbit. SpaceX has only come this far by building
upon the incredible achievements of NASA, having NASA as an anchor
tenant for launch, and receiving expert advice and mentorship
throughout the development process.
SpaceX would like to extend a special
thanks to the NASA COTS office for their continued support and guidance
throughout this process. The COTS program has demonstrated the power
of a true private/public partnership and we look forward to the
exciting endeavors our team will accomplish in the future. For more
information on the COTS Demo 1 flight, check out the mission press kit
located here: http://www.spacex.com/downloads/cots1-20101206.pdf.