NASA and Sierra Space are making progress on the first flight of the company's Dream Chaser spacecraft to the International Space Station. As part of NASA's commercial resupply service, the unmanned cargo spacecraft is scheduled to launch a demonstration mission to the International Space Station in 2024, including cargo delivery and various on-orbit testing efforts.
The Dream Chaser cargo system, manufactured by SierraSpace in Louisville, Colorado, consists of two main components: the Dream Chaser spacecraft and the Meteor cargo module. As a lifting body spacecraft, Dream Chaser can be reused up to 15 times and is modified from the HL-20 spacecraft developed at NASA's Langley Research Center in Hampton, Virginia.
Dream Chaser's cargo module, Meteor, is designed to support the delivery and handling of pressurized and unpressurized cargo to the space station. The cargo capsule can only be used once and is disposed of before re-entry.
The wings of the Dream Chaser system will be folded into a five-meter-long fairing and will be launched aboard a ULA (United Launch Alliance) Vulcan Centaur rocket from Space Launch Complex 41 at Cape Canaveral Space Station in Florida. The fairing panels will protect the spacecraft during ascent and will be removed once in orbit. Dream Chaser's cargo bay and wing-mounted solar panels deployed during an autonomous rendezvous with the space station.
During the first flight, Sierra Space will conduct an on-orbit demonstration to certify Dream Chaser for future missions. Teams at Kennedy Space Center in Florida, Johnson Space Center in Houston and Dream Chaser Mission Control in Louisville, Colorado will monitor the flight. SierraSpace flight controllers will control the spacecraft from the launch pad until it lands and is handed over to the SierraSpace ground operations team at NASA's Kennedy Space Center.
The far-field demonstration will take place near the space station before the spacecraft enters the approach ellipsoid, the 2.5 by 1.25 by 1.25 mile (4 by 2 by 2 km) invisible boundary around the orbiting laboratory. These demonstrations are required before Dream Chaser can begin joint operations with the NASA team at Mission Control in Houston. These demonstrations included demonstrations of attitude control, translational maneuvers, and abort capabilities.
The near-field demonstrations must take place closer to the space station and include activating and using the Light Detection and Ranging (LIDAR) sensor, responding to commands from the space station, retreating from the space station on command, and maintaining proximity at 1,083 feet (330 meters), 820 feet (250 meters) and 98 feet (30 meters) from the space station. After successfully completing the demonstration, Dream Chaser will move toward the space station.
As Dream Chaser approaches the orbiting laboratory, where it will make its final stop about 38 feet (11.5 meters) from the space station, station crews will use the Canadarm2 robotic arm to grab a fixture on the spacecraft's cargo bay, and ground teams will then install the cargo bay into an Earth-facing port on either Unity or Harmony.
On its first flight to the International Space Station, Dream Chaser is scheduled to transport more than 7,800 pounds of cargo. On future missions, Dream Chaser will stay at the space station for up to 75 days, transporting up to 11,500 pounds of cargo. Cargo can be loaded onto the spacecraft as early as 24 hours before launch. Upon return, Dream Chaser can return more than 3,500 pounds of cargo and experimental samples to Earth, and its cargo bay can also handle more than 8,700 pounds of garbage when reentering the atmosphere.
Dream Chaser will remain on the space station for approximately 45 days before being offloaded using Canadarm2. The spacecraft can land within 11 to 15 hours after departure, and there are landing opportunities every day if weather conditions meet the requirements. The Dream Chaser's landing weather standards generally require cross winds of less than 17.2 miles per hour (15 knots), tailwinds of less than 23 miles per hour (20 knots), and tailwinds of less than 11.5 miles per hour (10 knots). Thunderstorms, lightning, and rain within a 20-mile radius of the runway or 10 miles of the approach path are all unacceptable landing conditions. Detailed flight rules will guide controllers in determining whether a landing opportunity is favorable.
Dream Chaser's 26 Reaction Control System thrusters will fire simultaneously, allowing the spacecraft to deorbit and re-enter the Earth's atmosphere before gliding onto the runway at the Kennedy Launch and Landing Facility for a landing in the style of a NASA space shuttle, becoming the first spacecraft to land at the facility since the space shuttle's last flight in 2011.
After Dream Chaser completes its landing, it will power down and Sierra Space's ground operations team will transfer it to the Space Systems Processing Facility, conduct necessary inspections, offload remaining NASA cargo, and begin preparations for its next mission.
Sierra Space, formerly Sierra Nevada Corporation, was selected in 2016 as NASA's third commercial cargo supply spacecraft to serve the International Space Station.
Compiled source: ScitechDaily