A technical hiccup prevented NASA’s giant moon rocket, the Space Launch System, from leaving the launch pad on Monday. So NASA will try again on Saturday in hopes that their engineers have solved the problem. Here’s what you need to know about the second attempt to start the Artemis I mission.
When does it start and how can I see it?
Launch is scheduled for 2:17 p.m. Eastern Time. In the event of unfavorable weather or technical problems, the start can be postponed by up to two hours to 4:17 p.m
NASA Television’s online coverage of the Artemis I launch begins at 5:45 am, when a commentator describes the process of filling the rocket’s huge fuel tanks. Full agency coverage begins at 12:15 p.m
Reporting in Spanish begins at 1 p.m
Forecasts show that there is a 60 percent chance of favorable weather early in the launch window, improving to 80 percent by the end of the two-hour window.
You can subscribe to The Times Space and Astronomy Calendar to be reminded of the launch and other events on your personal calendar.
When Artemis I lifts off the ground, coverage will be continued about two hours after launch by the so-called translunar injection engine to propel the Orion spacecraft from low Earth orbit onto a trajectory to the Moon.
If the launch is postponed again, NASA could also try to lift off on Monday September 5th or Tuesday September 6th. Current forecasts assume a 70 percent chance of favorable weather on Monday.
If the rocket doesn’t lift off the ground by Tuesday, NASA will have to roll it back to the Vehicle Assembly Building, which is essentially a giant garage for rocket maintenance. A launch attempt after that could be made later in September or October.
Why didn’t the rocket launch on Monday?
The launch was halted on Monday because a sensor reported that one of the rocket’s four core engines was not adequately cooled, part of the preparations needed before firing.
Temperatures of three of the engines were nearing the target of minus 420 degrees Fahrenheit, while the temperature of the fourth appeared to be about 40 degrees warmer, said John Honeycutt, the program manager overseeing development of the Space Launch System rocket. If the engine was too warm, it could have shut down during takeoff.
At a news conference Thursday, officials at the mission said analysis of other data convinced them the temperature sensor was faulty and that the engine was, in fact, sufficiently cold.
What are the Space Launch System and Orion?
For astronauts to get to the moon, they need a big rocket. The Space Launch System is that rocket — the most powerful since Saturn V took NASA astronauts to the moon in the 1960s and 1970s. The one waiting on the pad to launch Monday stands 322 feet tall and will weigh 5.5 million pounds when filled with propellants.
Known as the SLS, the rocket shares some visual similarities with the decommissioned space shuttles. This is by design: To simplify the development of their new moon rocket, NASA reused much of their space shuttle technology from the 1970s.
Monday’s Space Launch System cargo is Orion, a capsule designed for multi-week trips outside of low Earth orbit. It will not have a crew onboard for this flight, but can carry up to four astronauts. If this flight is successful, a quartet of astronauts will travel on the next mission, Artemis II.
What happens during the flight?
After take-off, several events will take place in quick succession.
A little over two minutes after leaving the ground, the two thin lateral boosters attached to the space launch system’s gigantic core stage will exhaust their solid rocket propellant and fall off, falling into the Atlantic Ocean.
After eight minutes of flight, the four engines of the core stage are shut down. That stage will then be dropped, and the second stage of the rocket and the Orion capsule (which will carry astronauts in the future) will then be alone in space.
About an hour and a half after launch, the second stage will fire again for about 18 minutes, in what is known as translunar injection. That is, the second stage will propel Orion on a course to the moon. After this engine burn, Orion will separate from the second stage.
On the sixth day, Orion begins its orbit around the moon and moves toward what is known as a distant retrograde orbit.
The exact length of the mission varies depending on the start date. When Artemis I launches on Saturday, Orion will exit distant retrograde orbit on the 27th day and begin the return journey to Earth on the 33rd day. Splashdown will take place on October 11th and will end a 38-day mission.
Why is NASA returning to the moon?
Why would NASA repeat what it did half a century ago?
NASA officials argue that the lunar missions are central to their human space program and not simply a repeat of the Apollo moon landings of 1969-1972.
“It’s a future where NASA will land the first woman and the first person of color on the moon,” NASA Administrator Bill Nelson said during a news conference this month. “And on these increasingly complex missions, astronauts will live and work in space and develop the science and technology to send the first humans to Mars.”
NASA also hopes to encourage private companies interested in pursuing a steady business flying scientific instruments and other payloads to the moon, and to inspire students to enter science and engineering fields.
For scientists, the renewed focus on the moon promises a gold mine of new data in the coming years. Of particular interest is the amount of water ice on the moon, which could be used in the future to supply astronauts with water and oxygen, as well as fuel for missions deeper into space.
Scientists don’t know how much water there is or how easy it will be to extract the water from the surrounding rock and soil. Future missions could help solve this question.