Progress MS-1 cargo ship launches on two-day trek to ISS
Progress MS-1, an improved variant of the venerable Progress spacecraft, launched via a Soyuz 2.1a rocket at 2:44 p.m. local Kazakh time (8:44 GMT) from Site 31/6 at the Baikonur Cosmodrome in Kazakhstan. It began a two-day chase to rendezvous with the orbital outpost on Wednesday, Dec. 23. Docking is expected to take place on the Pirs docking compartment at about 4:31 a.m. CST (10:31 GMT).
The craft will deliver about 2.5 metric tons of cargo to the space station. Contents include dry cargo, propellant, water, and compressed oxygen. It will take the two-day route, instead of the six-hour, four-orbit path, because ground teams want to do detailed in-orbit testing prior to docking.
Progress’ are manufactured by RKK Energia. The Progress MS weighs 7.25 metric tons. It has a similar size, mass, and cargo capacity as the Progress M – the most recent variant of the craft.
The new MS variant sports upgrades to a number of systems. It has a new external compartment, enabling the deployment of small satellites, backup electrical motors for docking, and improved micrometeorite protection among other things. It also has new digital communications enabling an enhanced TV camera view during docking operations.
The craft and the Progress MS-2 (launching in spring 2016) are being used to test systems that will be implemented in a new manned Soyuz variant. Soyuz MS-1 will launch in June 2016.
The Soyuz 2.1 launch vehicle is derived from the Soyuz-U booster. It first flew in November 2004 and is intended as an eventual replacement for all of the Soyuz rocket variants, including, when a human rating is complete, the Soyuz-FG, which currently launch the crewed Soyuz capsules to the ISS. No date has been set for that.
There are three variants: 2.1a, 2.1b, and 2.1v. It is 151 feet (46.1 meters) tall and has a core stage diameter of 9.68 feet (2.95 meters). It can deliver 7.8 metric tons of payload to low-Earth orbit (LEO) and up to 2.8 metric tons to geostationary transfer orbit (GTO).
The first Progress to launch on the Soyuz 2.1 was the doomed Progress M27M mission on April 28, 2015. It ended in failure after an abnormal separation with the third stage crippled the cargo ship. It re-entered the atmosphere a number of days later. As a result, the next two Progress spacecraft were launched on the Soyuz-U.
Additionally, the mishap created a visiting vehicle delay ripple throughout the space station program. That ripple is still being felt as this launch was supposed to launch in late November. Extra checks were needed to ensure that there would be no repeat of the April 2015 failure.
Progress MS-1 is expected to remain docked to Pirs for around six months.
Video courtesy of Телестудия Роскосмоса (Roscosmos TV)
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 blog about the International Space Station, called Orbital Velocity.