Russia Just Launched the Fastest Cargo Mission Ever to the Space Station .

The Russian cargo ship Progress 70 successfully docked with the International Space Station at 9:31 p.m. EDT. Read our latest story here: Russian Cargo Ship Sets New Record for Fastest Trip to Space Station

A Russian Progress cargo spacecraft launched to the International Space Station (ISS) today (July 9) to deliver supplies to the crew of Expedition 56 in record time.

Packed with nearly 3 tons (2.7 metric tons) of food, fuel and other supplies, the uncrewed Progress cargo ship lifted off from the Baikonur Cosmodrome in Kazakhstan on a Russian Soyuz rocket at 5:51 p.m. EDT (2151 GMT; 3:51 a.m. July 10 local time).

"We have liftoff of the Progress resupply ship, heading into the express lane, bound for the International Space Station," NASA spokesman Rob Navias said during live commentary. 

The vessel, known as Progress 70 or Progress MS-09, is expected to arrive at the space station tonight at 9:39 p.m. EDT (0139 GMT on July 10), completing the trip in a record time of 3 hours and 48 minutes. "The less-than-4-hour trip will demonstrate an expedited capability that may be used on future Russian cargo and crew launches," NASA officials said in a statement. [How Russia's Progress Spaceships Work (Infographic)]

When it arrives at the ISS, the Progress spacecraft will dock at the Russian Pirs module. NASA TV will provide live coverage of the spacecraft's arrival and docking at the ISS, and you can watch it live here starting at 9 p.m. EDT (0100 GMT).

After the spacecraft docks, the six crewmembers of Expedition 56 will spend the next few months unloading the cargo, which includes 1,170 lbs. (530 kilograms) of propellant, 115 lbs. (52 kg) of oxygen gas, 930 lbs. (420 kg) of water, and 3,450 lbs. (1,565 kg) of other "dry" cargo like food and other equipment, NASA public affairs officer Dan Huot told Space.com in an email.

The spacecraft will remain docked at the ISS until January 2019, NASA officials said in the statement. Usually, Progress capsules are sent away to burn up in Earth's atmosphere after ISS crewmembers stuff the vessels with waste. But when Progress 70 undocks from the ISS, it will take something else back home with it: the entire Pirs docking compartment.

Russia's space agency, Roscosmos, is getting rid of the 17-year-old module to make room for the new Multipurpose Laboratory Module (MDM), also known as Nauka, which has yet to launch to the ISS. The new module was originally scheduled to launch in 2007 but has suffered several delays over the last decade. It is currently scheduled to launch in August 2019, but that may be postponed again, to 2020, according to the Russian news agency Sputnik International.

Roscosmos first launched Progress cargo missions to the ISS in 2000; back then, it would take about two days for one of the spacecraft to chase down the orbiting lab after launch. However, the space agency found a way to reduce that travel time to just under 6 hours in 2013. With today's launch, Roscosmos aims to demonstrate that an even faster trip is feasible.

Today's launch marks the third attempt to send a Progress cargo ship to the ISS via this new fast track. Roscosmos first planned to launch the Progress 68 spacecraft on this 4-hour flight in October 2017, but a last-minute delay forced flight controllers to revert to the old two-day route due to the orbital mechanics involved in reaching the ISS.

The same thing happened with the Progress 69 cargo launch in February. Because the launch was aborted during the final moments of the countdown, the mission missed its chance to take the fast route to the ISS. Again, that Progress spacecraft flew with the old two-day flight profile instead.

But it seemed that fortune favored Progress 70.

"A perfect launch," Navias said of Progress 70's liftoff. "Third time was the charm."

Navias added that Roscosmos officials hope to fly several more superfast Progress flights to the space station before using the 2-orbit flight profile for crewed missions on the agency's Soyuz spacecraft.

Russia's Progress spacecraft are not the only vehicles that transport crew supplies and science gear to the ISS. The next cargo shipment is scheduled to arrive in September on a Japanese Kounotori spacecraft, also known as the H-2 Transfer Vehicle (HTV). That mission, HTV-7, will take about 4 hours to reach the ISS after launching from Japan's Tanegashima Space Center.

NASA doesn't have its own rockets or vehicles to use in sending cargo to the ISS. However, NASA has contracted private spaceflight companies to launch the agency's cargo shipments. Northrop Grumman Innovation Systems will launch a Cygnus cargo mission to the ISS for NASA in November, followed by a SpaceX Dragon spacecraft later that month. 

The European Space Agency has also launched cargo to the ISS with that agency's Automated Transfer Vehicle, the last of which flew in 2014. Another Progress cargo-delivery mission, Progress 71, is scheduled to launch in late October.

Space.com