NASA began a critical two-day-long test of its giant Space Launch System (SLS) rocket complete with a simulated countdown. The agency gears up to return humans to the Moon.
It is known as the “wet dress rehearsal”. It is the final major test before the Artemis-1 mission this summer. An uncrewed lunar flight that will eventually be followed by boots on the ground. It will be likely no sooner than 2026.
Data from the test ends Sunday mid-afternoon. It will be used to finalize a launch date for Artemis 1. NASA had said May could be the first window.
It is called a “wet” dress rehearsal because supercooled liquid hydrogen and liquid oxygen will be loaded into SLS from ground systems.
The 322-foot rocket is expected to be the most powerful in history at the time it is operational. It was rolled out to Launch Complex 39B at the Kennedy Space Centre in Florida around two weeks ago.
Teams are filling up a sound suppression system with water that is used to dampen acoustic energy during lift-off. They will continue to practice every operation that would be carried out in a real launch.
The SLS rocket and Orion crew capsule fixed atop both powered on. They will load up 700,000 gallons of propellant.
They won’t actually ignite the rocket’s RS-25 engines. Those were tested previously. They will halt the countdown about 10 seconds before lift-off, when launch is aborted due to technical or weather-related issues.
A few days later SLS and Orion will be rolled back to the vehicle assembly building to carry out checks on how everything went.
Test milestones will be posted on NASA’s blog for the Artemis mission. The public might be able to glimpse the rocket venting vapor on the launch pad on April 3. Agency officials plan to hold a press conference to give further information.
NASA won’t however let the public listen to live internal audio. This was because certain key information could assist other countries looking to develop long range missiles. Fall foul of export control regulations called International Traffic in Arms Regulations (ITAR).
The decision has caused some confusion as while most intercontinental ballistic missiles run on solid fuel and not liquid propellants.