What are the Space Launch System and Orion and why are they important?
The Space Launch System and Orion are key components of NASA’s plans to get astronauts to the lunar surface in the years to come. Getting there would require a rocket powerful enough to launch a large spacecraft from low Earth orbit to the Moon, some 240,000 miles away. Orion is a capsule designed to carry astronauts on space flights lasting up to a few weeks.
What problems did you encounter during the dress rehearsal?
NASA rolled the SLS rocket to the launch pad for the first time in mid-March. In early April, I attempted a “rehearsal” of the countdown procedures, including loading more than 700,000 gallons of liquid hydrogen fuel and liquid oxygen. However, technical glitches, including a hydrogen leak on three practice attempts, shortened the countdown.
NASA then returned the rocket to the Vehicle Assembly Building for repairs. In June, the rocket returned to the launch pad for another test run. This test on June 20 found another hydrogen leak in the fuel line connection to the rocket’s boost stage. However, the fuel tanks were full for the first time and the controllers were able to continue the rehearsal until the countdown expired 29 seconds ago. Originally the goal was to stop the countdown in less than 10 seconds when the engines would actually start to start.
Despite the leak, NASA officials determined that all critical systems had been adequately tested and declared the test a success. The missile again returned to the vehicle assembly building for final preparations, including the installation of a flight termination system that would detonate the missile if anything went wrong during launch and eliminate the possibility of a collision with a populated area.
The batteries for the flight cancellation system installed on Aug. 11 are normally only rated to last 20 days, but the portion of the US Space Force that oversees launches from Florida has given NASA a waiver that covers the Period extended to 25 days. This allows for a launch date of August 29th, as well as backup opportunities on September 2nd and 5th.
NASA is hoping to fix the hydrogen leak, but won’t know for sure until the Aug. 29 countdown, when the fuel line will cool to freezing temperatures, which cannot be tested in the Vehicle Assembly Building.