CAPE CANAVERAL, Fla. (AP) – NASA aimed for a Saturday launch of its new moon rocket, after patching fuel leaks and working around a bad engine sensor that thwarted the first attempt.
The inaugural flight of the 322-foot (98-meter) rocket — the most powerful ever built by NASA — was delayed late in Monday’s countdown. The Kennedy Space Center clocks started ticking again as executives expressed confidence in their plan and forecasters gave favorable weather forecasts.
On top of the rocket is a crew pod containing three test dummies that will fly around the moon and back over the course of six weeks — NASA’s first such attempt since the Apollo program 50 years ago. NASA wants to wring out the spacecraft before tying up astronauts for the next scheduled flight in two years.
NASA administrator Bill Nelson said he is more confident in this second launch attempt, given everything engineers have learned from the first attempt.
So is astronaut Jessica Meir, who is on NASA’s short list for one of the first moon crews.
“We’re all looking forward to this going, but the most important thing is that we go when we’re ready and doing it right because the next missions will have people on board. Maybe me, maybe my friends,” Meir told the Associated Press on Friday.
The engineers responsible for the Space Launch System rocket insisted on Thursday night that all four of the rocket’s main engines were good and that a faulty temperature sensor made one of them look like Monday was too hot. The engines must match the min-420 degrees Fahrenheit (min-250 degrees Celsius) of the liquid hydrogen fuel on takeoff, otherwise they could be damaged and shut down in flight.
“We have convinced ourselves beyond any doubt that good quality liquid hydrogen passes through the engines,” said John Honeycutt, the rocket’s program manager.
Once refueling begins Saturday morning, the launch team will conduct another engine test – this time earlier in the countdown. Even if that suspicious sensor indicates that one engine is too hot, other sensors can be relied upon to make sure everything is working correctly and to stop the countdown if there’s a problem, Honeycutt told reporters.
NASA was unable to conduct those kinds of engine tests in dress rehearsals earlier this year because of fuel leaks. More fuel leaks surfaced on Monday; technicians found and tightened some loose connections.
The engine temperature situation adds to the risk of the flight, as does another problem that surfaced Monday: cracks in the rocket’s foam insulation. If bits of foam break off on takeoff, they can hit the strap-on boosters and damage them. Engineers consider the likelihood of this small and have accepted these small additional risks.
“This is an extremely complicated machine and system. Millions of parts,” NASA chief Nelson told the AP. “There are indeed risks. But are those risks acceptable? I’ll leave that to the experts. My role is to remind them that you don’t take risks that aren’t acceptable.”
The $4.1 billion test flight is NASA’s first step to send astronauts around the moon by 2024 and land them on the surface by 2025. Astronauts last walked on the moon in 1972.
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