Progress MS-09 set for fast-track rendezvous with ISS
Continuing a busy period for the International Space Station’s Expedition 56 crew, an automated Russian Progress cargo spacecraft is set to launch to the orbiting outpost. Liftoff is scheduled for 5:51 p.m. EDT (21:51 GMT) July 9, 2018, from Baikonur Cosmodrome in Kazakhstan.
Progress MS-09 with its nearly three tons of food, fuel and supplies, according to NASA, will be the fifth uncrewed flight to the 400-metric-ton orbiting outpost in 2018 and the second Progress of the year.
The 23.7-foot (7.2 meter) long freighter will be launched atop a Soyuz 2.1a rocket from Site 31/6. Consisting of four liquid-fueled strap-on boosters, a core stage and an upper stage, the launch vehicle will place Progress MS-09 into an initial orbit.
After the spacecraft’s solar panels and antenna deploy, the vehicle will immediately begin work to gradually raise its orbit and rendezvous with the ISS, which is expected to occur just three orbits—less than four hours—later, should the rocket launch on time. This would be an improvement from the current fast-track option of four orbits, or six hours, which previous Progress and Soyuz spacecraft have used.
If successful, this rendezvous would be the fastest ever attempted with the ISS. Roscosmos—the Russian state space corporation—was expected to attempt this technique on the previous two Progress flights, however, similar undisclosed technical issues occurred within a minute of their initial launch attempts.
Because orbital alignments for both the three- and six-orbit rendezvous require precise orbital alignments, both vehicles defaulted to the traditional 34-orbit, two-day path upon their successful launch. For various reasons, the last time a fast-track rendezvous was attempted was in September 2017 during the crewed Soyuz MS-06 flight.
Rollout and launch
Rollout of the Soyuz 2.1a rocket occurred July 7. It was transported by railed from its integration hangar to the launch pad. Once at Site 31/6, it was hydraulically lifted from its horizontal position to vertical. Umbilicals were then raised into position so that pad technicians could continue readying the vehicle for launch.
Standing 152 feet (46.3 meters) tall, the Soyuz 2.1a is a modernized version of the storied booster, which can trace its heritage back to the 1950s and the R-7 intercontinental ballistic missile.
At its base are four liquid-fueled strap-on boosters. Each are 64 feet (19.6 meters) long and 8.8 feet (2.7 meters) wide and burn liquid oxygen and rocket grade kerosene using an RD-107A engine.
Situated around an 88.9-foot (27.1-meter) long, 9.7-foot (2.95-meter) core stage, the boosters burn in conjunction with the core’s similar RD-108A engine once launched. After about two minutes into flight, the boosters fall away and the core stage continues to burn for an additional three minutes before it cuts off to allow the upper stage to continue powering toward orbit.
Meanwhile, not long after the boosters fall away, the payload fairing encapsulating the Progress MS-09 spacecraft falls away to expose the freighter to space. At that point, the rocket is high enough above Earth that the protective nose cone is no longer needed.
The upper stage, which is 22 feet (6.7 meters) long and powered by a liquid oxygen/rocket grade kerosene-consuming RD-0110 engine, burns for an additional 4.5 minutes to place the Progress in orbit.
Should all go as planned, docking with the Pirs module on the ISS should take place at 9:39 p.m. EDT (01:39 GMT July 10). It should remain attached to ISS until January 2019.
Overall, this is expected to be the 161st progress flight since its debut in 1978. Over the decades, the spacecraft design and its subsequent upgrades have serviced four space stations, including Salyut 6, Salyut 7, Mir and the ISS. Only three have failed to reach its destination, one in 2011, 2015 and 2016.
If Progress MS-09 docks when it is currently scheduled, it will be the second vehicle in a week to arrive at the space station. On July 2, a SpaceX Dragon spacecraft, CRS-15, was berthed to the outpost’s Harmony module.
In fact, once Progress docks, it will tie the record for the most visiting vehicles at the ISS—six. This number was only reached on two previous occasions: once during Space Shuttle Discovery’s STS-133 mission in 2011 (in which the Space Shuttle, a European Automated Transfer Vehicle, a Japanese Kounotori spacecraft, two Soyuz and a Progress were attached) and in 2016 during CRS-8 Dragon’s mission (in which Dragon, a Cygnus, two Soyuz and two Progress spacecraft were attached).
Should all go according to the current schedule, the vehicles at the ISS starting July 9 will be Progress MS-09, Progress MS-08, Soyuz MS-09, Soyuz MS-08, CRS-15 Dragon and OA-9 Cygnus. However, that number will be short-lived as the Cygnus spacecraft is expected to unberth on July 15.
Video courtesy of SciNews
Derek Richardson has a degree in mass media, with an emphasis in contemporary journalism, from Washburn University in Topeka, Kansas. While at Washburn, he was the managing editor of the student run newspaper, the Washburn Review. He also has a website about human spaceflight called Orbital Velocity. You can find him on twitter @TheSpaceWriter.