After taking to the skies in May, the National Aeronautics and Space Agency (NASA) flies Demo-2 (DM-2) mission by astronaut launch service provider and equipment manufacturer Space Exploration Technologies Corp. (SpaceX) Dragon 2 vehicle officially departed from the International Space Station (ISS). Affectionately dubbed ‘Endeavor’ by NASA astronauts Colonel Robert Behnken and Douglas Hurley, the Dragon 2 is now being tested by the space agency to certify the spacecraft for regular flights to the ISS under NASA’s Commercial Crew Program (CCP)). This program aims to reduce the cost of launching payloads to the ISS by using the private sector to fuel the Low Earth Orbit (LEO) economy.
As the mission approaches its final stages, the Dragon 2 spacecraft is autonomously decoupled from the ISS ‘Harmony module today at 7:35 PM ET. The disconnect marks the final stages of testing for the vehicle, which was consistently evaluated at the space station over the course of the DM-2 mission.
SpaceX Dragon 2 Endeavor will crash on the coast of Pensacola, off Florida, Sunday night
As part of the decoupling sequence, Dragon Endeavor will release its twelve hooks in two sets and then fire two pulses to physically separate it from the space station. The combustion of the car in the track will be autonomous, as will the disconnection procedure. Dragon 2 will also adjust its apogee and perigee relative to the ISS, with the vehicle’s apogee located 10 kilometers below the ISS and the burns also slowly reducing its perigee. Apogee and perigee are terms used to describe the orbit of a orbiting body, where apogee is the farthest part of the plantation (in the case of Earth) and perigee is the closest part. Dragon’s phase burns will align its path with the landing site off the coast of Pensacola, Florida, with the vehicle on Sunday at 2:48 PM ET.
These phased burns will be followed by separating the hull from the spacecraft using a claw on the hull connecting different components. This allows the spacecraft to prepare to withstand the harsh environment of return. The Endeavor trunk consists of solar panels and radiant heaters that generate power and use thermal cooling loops to remove the heat generated by the on-board systems and crew. The solar panels were the primary limiting factor of the DM-2 mission due to their degradation in the harsh environment of space, and they managed to perform according to NASA’s power generation expectations, the space agency reported earlier this month.
Once the trunk has been thrown off, the vehicle begins its final orbital burn, which lasts 12 minutes, as it begins to penetrate Earth’s atmosphere. Entering the atmosphere will slow the speed to an acceptable level (350 miles per hour) for the spacecraft to deploy its two drogue parachutes when at an altitude of 18,000 feet. Once the vehicle has lost 12,000 feet of elevation and its speed has been further reduced to 119 miles per hour, Dragon 2 Endeavor will deploy its four main parachutes to ensure a safe landing in the Atlantic.
Before Dragon 2 re-enters the atmosphere, it will travel approximately 17,500 miles per hour, and on return it will experience temperatures of up to 3,500 Fahrenheit, according to NASA estimates. During re-entry, NASA and SpaceX also experience a six-minute communication interruption with the spacecraft.
The Dragon vehicles not only provide America with the ability to launch astronauts from ground to space after nine years, but also enable NASA to retrieve cargo from the ISS – a critical capability that allows scientists to identify the specificities of human understand presence in space. Since the trunk will be lost on re-entry, the Dragon 2 Endeavor spacecraft will be fitted with a brand new trunk with improved solar panels, the company confirmed in a joint press conference with NASA earlier this week.
The vehicle is slated to re-launch next spring as part of NASA’s second commercial ISS mission under the CCP called Crew-2. Crew-1 is expected to leave the ISS in September when NASA has finished evaluating the Endeavor spacecraft, while the vehicle for that mission is currently being prepared at SpaceX’s facilities in Hawthorne, California.
In free flight, the Dragon 2 spacecraft can also change its landing site, with another crucial capability that gives it more leeway to deal with potential unseen weather conditions. This varies the time it takes Behnken and Hurley to return to Earth between six and 30 hours because of the alternate landing sites. If the weather conditions become unfavorable, the vehicle will remain in Earth’s orbit for up to 48 hours before the next attempt.