WASHINGTON — In an unusually busy period of visiting vehicle activity at the international space station, one commercial cargo vehicle returned to Earth Oct. 25 as another was prepared for an Oct. 27 launch.
The station’s robotic arm detached the Space Exploration Technologies Corp. Dragon vehicle from the ISS and released it at 9:59 am EDT Oct. 25. The spacecraft re-entered the atmosphere later the same day, splashing down in the Pacific Ocean about 500 kilometers west of Baja California, Mexico, at 3:39 pm EDT.
Dragon returned with nearly 1,500 kilograms of cargo from the ISS, primarily in the form of experiments that had been carried out on the station. Some of the experiments were transferred to investigators after the ship that retrieved Dragon arrived in port in Southern California late Oct. 26.
As Dragon returned to Earth, Orbital Sciences Corp. continued preparations for the launch of its latest Cygnus cargo mission to the ISS on an Antares rocket. That launch is scheduled for 6:45 pm EDT Oct. 27 from the Mid-Atlantic Regional Spaceport at Wallops Island, Virginia.
At a pre-launch briefing Oct. 26 at the NASA Wallops Flight Facility, Orbital officials said both the spacecraft and launch vehicle were ready for launch. Forecasters called for a 98 percent chance of acceptable weather at launch time.
The Cygnus spacecraft, named by Orbital the “SS Deke Slayton” after the late astronaut, is carrying 2,290 kilograms of scientific experiments, supplies, and other equipment to the ISS. Included in the Cygnus are a number of small satellites to be deployed from the station, including 26 from Earth imaging company Planet Labs and a technology demonstration satellite for asteroid mining company Planetary Resources.
If Cygnus launches on time, it will arrive at the station early Nov 2. In the interim, the Russian Progress M-25M cargo spacecraft is scheduled for an Oct. 29 launch from the Baikonur Cosmodrome, docking with the station about six hours after launch. It replaces the Progress M-24M spacecraft, which undocked from the station early Oct. 27.
That elevated level of activity was apparent at a meeting Oct. 24 of ISS partners to give approval for the Cygnus launch. “Normally, in the past we would only address a single visiting vehicle event,” Gerald Esquivel, NASA ISS Cygnus visiting vehicle integration manager, said at the Cygnus pre-launch briefing. “This time, we had to address four different visiting vehicle events in the near term.”