Aday after Nasa scrubbed a planned spacewalk over threat to astronauts from space debris, the agency has scheduled it for Thursday. Astronauts Thomas Marshburn and Kayla Barron will walk out of the airlock to replace a faulty antenna system on the station’s truss structure that has lost connections with Earth.

The decision to go ahead with the spacewalk on Thursday came after Nasa determined the orbit of the debris does not pose a risk to astronauts. “Delaying the spacewalk provided an opportunity for engineers to evaluate the risk from the debris,” Nasa said in a blog post on Wednesday.

The spacewalk was delayed on Tuesday after the American space agency received a debris notification for the International Space Station. Due to the lack of opportunity to properly assess the risk it could pose to the astronauts, it was decided to delay the spacewalk. “The space station schedule and operations are able to easily accommodate the delay of the spacewalk,” it said.

The spacewalk is required to replace an S-band Antenna Subassembly (SASA) with a spare already available on the station’s truss structure. The antenna recently lost its ability to send signals to Earth via Nasa’s Tracking and Data Relay Satellite System.

The agency has said that although its degradation has had a limited impact on station operations, mission managers decided to install a new antenna to ensure communications redundancy.

Meanwhile, it remained tight-lipped on the nature of debris and whether it was from the anti-missile test conducted by Russia in Orbit in November this year. Mission control was alerted that the US military’s Space Surveillance Network had detected debris that could collide with the space station.

A Nasa spokesman, Gary Jordan, told Reuters that there was no information available about the size of the debris, its proximity to the space station, which is orbiting about 250 miles (402 km) above the Earth, or whether one or more objects were involved. “We have no indications that this is related” to the Russian missile test weeks earlier, Jordan added in an email to Reuters.

The anti-satellite missile test by Moscow led to an international uproar with countries blaming it for polluting the orbit, threatening assets including the Space Station and astronauts.

Following the test, astronauts had to take refuge in the Soyuz and the Dragon capsule in case the debris led to an emergency situation. The residual debris cloud from the blasted satellite has since dispersed, according to Dana Weigel, NASA deputy manager of the space station program.

According to plans, Marshburn will work with Barron while positioned at the end of a robotic arm operated from inside the station by German astronaut Matthias Maurer of the European Space Agency, with help from Nasa crewmate Raja Chari.

The four arrived at the station on November 11 in a SpaceX Crew Dragon capsule launched from the Kennedy Space Center in Florida, joining two Russian cosmonauts and a NASA astronaut already aboard the space laboratory.