Space X's Falcon Rocket is once again ready to launch after an aborted attempt on Saturday, when a faulty check valve forced a shut down of the rocket's engines.

“We had a nominal countdown right until about T minus 0.5 seconds,” SpaceX president Gwynne Shotwell said during a news briefing following the abort. “Software did what it was supposed to do, aborted engine five, and we went through the remaining engine shutdown.”

“During rigorous inspections of the engine, SpaceX engineers discovered a faulty check valve on the Merlin engine,” officials said in the statement.

The check valve that shut down the rocket’s engines Saturday one-half-second before lift-off has been replaced and the next scheduled launch attempt will take place tomorrow at 3:44 am May 22nd Eastern time. The faulty valve, found on the Merlin engine, had detected high pressure in the rocket’s engine 5 combustion chamber. The launch attempt took place at Florida’s Cape Canaveral.

The payload that the Falcon Rocket will power into space, Dragon, an un-manned capsule, if successful, will be the first non-government spaceship to rendezvous with the space station.

CEO for Space X, Elon Musk, says that they have their fingers crossed, he calls the weather favorable for launch tomorrow and that they are trying their best to assure no further problems occur with the coming launch.

The capsule, if successful, will deliver supplies, such as food, clothes, and science equipment to the station. Tuesday’s launch will be the first of 12 such delivery missions. The company has a contract with NASA for the missions for a pricetag of $1.6 billion.

The Falcon 9 rocket can deliver 23,000 pounds into orbit on its nine Merlin engines delivering 350 metric tons of force.