Updated with second launch abort, Borisov’s remarks.Russia’s space agency Roscosmos on Wednesday called off the test launch of its Angara A5 space rocket for a second day in a row, though the exact cause of the aborted flight was not immediately known.“The command ‘abort launch’ has been issued,” a flight controller said in a live broadcast by Roscosmos, referring to the same command that had been issued during an aborted launch on the previous day. The flight controller ordered a 24-hour “shutdown” but did not give the reason for the delay.The Angara A5 heavy-lift rocket was initially scheduled for liftoff on Tuesday afternoon from the Vostochny Cosmodrome in Far East Russia’s Amur region. Previously, all three Angara A5 launches were based out of northern Russia’s Plesetsk Cosmodrome.Roscosmos head Yury Borisov said late Tuesday that the rockets’s automatic systems aborted the first attempted launch due to malfunctions in the central power unit’s oxidizer tank. He added that the launch has been rescheduled for the “tentative reserve date” of Wednesday, April 10.President Vladimir Putin has played up Angara’s role in national security, though the project has been plagued by a series of delays and technical setbacks.

Roscosmos, meanwhile, has emphasized the rocket’s smaller ecological footprint in areas near launch sites and drop zones because it does not use “aggressive and toxic propellants.” Commissioned after the dissolution of the Soviet Union over concerns that an independent Ukraine might withhold deliveries of vital components, Angara A5 is intended to succeed Russia’s Proton launcher.Late last month, the launch of a Russian Soyuz MS-25 spacecraft to the International Space Station waspostponed at the Baikonur Cosmodrome in Kazakhstan for two days. Borisov said at the time that a “voltage dip” had occurred in a chemical power source during the final pre-launch preparations.Russia’s space program has been hit by financial problems, scandals and corruption in recent years.