Falcon 9 launches cargo Dragon mission to ISS (Image Credit: Space News)
WASHINGTON — SpaceX launched a cargo Dragon mission to the International Space Station as the company and NASA reaffirmed their commitment to safety.
A Falcon 9 lifted off at 9:29 p.m. Eastern Nov. 4 from Kennedy Space Center’s Launch Complex 39A. The rocket deployed the Dragon spacecraft into low Earth orbit nine and a half minutes later.
The spacecraft, flying a mission designated CRS-31 or SpX-31, is scheduled to dock with the ISS at about 10:15 a.m. Eastern Nov. 5.It will dock with the forward port on the Harmony module, which was freed up for the cargo Dragon when the Crew-9 Crew Dragon spacecraft undocked from that port and moved to the alternate zenith docking port on Harmony during a 50-minute maneuver early Nov. 3.
The cargo Dragon is delivering 2,762 kilograms of cargo to the station. That is a relatively routine mix of crew supplies, science investigations and other hardware for the station. The 56 science investigations range from an instrument called the Coronal Diagnostic Experiment (CODEX) that will be mounted on the station’s exterior to monitor the sun’s corona to ARTEMOSS, an experiment to test how an Antarctic moss handles the radiation and microgravity conditions of space to see if it could be suitable for future bioregenerative life support systems.
The mission, while relatively routine, does feature some innovations. The separation of the Dragon from the Falcon 9 upper stage took place 145 seconds earlier than on past missions. Jared Metter, director of flight reliability at SpaceX, said at a Nov. 4 prelaunch briefing that the company previously had a longer gap between shutdown of the upper stage’s engine and Dragon separation to ensure good attitude control and a lack of slosh in the stage’s propellants.
“Because we have enough data now to look at many, many missions, we can analyze and show that, through flight, we didn’t need that long period,” he said.
Another change is that Dragon will, for the first time, perform an ISS reboost maneuver while docked to the station. During that maneuver, scheduled for Nov. 8, Dragon will fire its Draco thrusters for 12 and a half minutes. NASA and SpaceX officials said at the briefing they did not know the projected change in velocity and orbit of the station from that maneuver.
“This is an important flight test objective for this mission as we continue to increase the capabilities of all the vehicles on ISS,” said Bill Spetch, ISS operations and integration manager at NASA.
Mettler added that the data collected during the reboost test will help SpaceX as it develops the U.S. Deorbit Vehicle (USDV), a derivative of Dragon that it is building for NASA to handle the final phases of the deorbiting the ISS at the end of its life around 2030. NASA awarded SpaceX a contract worth up to $843 million in June to develop the USDV.
Safety issues
NASA and SpaceX addressed safety concerns about Dragon and Falcon operations raised by NASA’s Aerospace Safety Advisory Panel (ASAP) at its Oct. 31 public meeting. During that meeting, the panel cited recent anomalies such as upper stage malfunctions on two Falcon 9 launches.
“Both NASA and SpaceX need to maintain focus on safe Crew Dragon operations and not take any ‘normal’ operations for granted, said former astronaut Kent Rominger, a member of the panel, at the meeting.
Spetch said that the agency is not changing reviews of Dragon launches in response to those anomalies or the panel’s comments. “We conduct all of our normal reviews. We work very closely with SpaceX on everything that we do relative to these Dragon launches,” he said. “I wouldn’t say we’re doing anything different.”
“One of the major benefits of having so many opportunities to launch is that every launch is an opportunity to learn,” Mettler said. “We’re going to follow our standard process to ensure we have a good mission here.”
He added that there was no evidence of what he called “crossover,” or common causes, among the recent anomalies cited by ASAP as well as any other observations noted on Falcon launches. “We identified no crossover or common theme or systemic issue common to any of these anomalies,” he said. “We see no crossover between these occurrences.”
