Cygnus resupply spacecraft reaches ISS with four tons of supplies, experiments

Aug. 6 (UPI) -- Northrup Grumman's Cygnus resupply spacecraft reached the International Space Station early Tuesday morning, delivering some four tons of supplies to the orbiting laboratory, NASA said.

Cygnus completed installation on the ISS at 5:33 a.m. EDT, NASA said .

It brought 8,200 pounds of scientific investigation and cargo to the ISS's orbiting laboratory on the 21st resupply mission carried out by Northrup Grumman.

"Cygnus will remain at the space station until January when it departs the orbiting laboratory at which point will dispose of several thousand pounds of debris through its re-entry into Earth's atmosphere where it will harmlessly burn up," NASA said.

NASA said Cygnus carried up tests for water recovery technology and a process to produce stem cells in microgravity, studies of the effect of spaceflight on microorganism DNA and liver tissue growth.

The experiments delivered include Rotifer-B2, which will examine the impacts of spaceflight on the repair mechanisms of the Adineta vaga species of rotifer, which are "tiny but complex organisms known for their ability to withstand harsh conditions including radiation doses 100 times higher than human cells can survive," according to NASA.

Cygnus left Cape Canaveral via the SpaceX Falcon 9 rocket on Sunday.

It reached the ISS safely despite a little bit of uncertainty , officials said. The space freighter missed an engine burn after it left the Falcon 9's upper stage and then aborted a rescheduled burn less than an hour later.

After Northrup Grumman engineers investigated the data, they confirmed the readings were acceptable and Cygnus was allowed to perform the new engine burns needed to get the spacecraft back on course.