What the words you’ll hear during the moon mission launch really mean

Sep 3, 2022, 8:00 AM
NASA launch lingo...
FILE: NASA’s Space Launch System (SLS) rocket with the Orion spacecraft aboard is seen at sunrise atop a mobile launcher at Launch Complex 39B, Monday, April 4, 2022, as the Artemis I launch team conducts the wet dress rehearsal test at NASA’s Kennedy Space Center in Florida. (NASA/Joel Kowsky)
(NASA/Joel Kowsky)
Originally Published: 28 AUG 22 13:14 ET
Updated: 02 SEP 22 17:29 ET

(CNN) — Few things are more exciting than watching a spacecraft lift off the launchpad and set off on a cosmic quest, as NASA’s Artemis I mission is poised to do Saturday.

But if you’re a casual observer, it may be that few things are more confusing than hearing some of the jargon used by mission control.

For everyone who’s not a NASA scientist or amateur astrophysicist, here are some of the terms you might hear during the historic launch — and what they mean.

Liftoff lingo

NASA is aiming to launch Artemis I on Saturday. If the launch is a “go,” that means things are on track. If it’s a “no go,” the launch may be postponed.

As mission teams go through the countdown, they’ll be using phrases and shorthand that may be unfamiliar. Expect to hear “SLS” to indicate the rocket, rather than Space Launch System, and “nominal” to mean that things are normal or going as planned.

When the rocket is being loaded with cryogenic (supercold) liquid oxygen and liquid hydrogen to fuel liftoff, the shorthand is “LO2” for oxygen and “LH2” for hydrogen.

There’s a good chance the Artemis launch team will mention “ICPS,” which refers to the interim cryogenic propulsion stage. This upper segment of the rocket will give Orion the propulsion it needs in space after the two solid-fuel rocket boosters and core stage, or backbone, of the rocket separate from the spacecraft.

The core stage of the rocket includes engines, propellant tanks and avionics, or aviation electronic systems.

During the countdown, teams will refer to “L Minus” and “T Minus” times.

“L Minus” is used to indicate the time until liftoff in hours and minutes, while “T Minus” corresponds with the events included in the launch countdown.

If the launch team announces a “hold,” it’s a natural pause in the countdown intended to allow for tasks or waiting for a specific launch window that doesn’t disrupt the schedule. During a hold, expect the countdown clock and T Minus time to stop, while the L Minus time will continue.

Postlaunch shorthand

After the launch, the team may refer to the solid rocket boosters as “SRB” and the launch abort system as “LAS.” Two of the launch abort system’s three engines can be used to return the Orion crew module safely to Earth in the event of a malfunction or systems failure during launch. The third engine is used to jettison the launch abort system, which occurs shortly after launch if all goes well.

Several “burns,” which take place when the propulsion system fires up, likely will get a mention post-liftoff.

READ MORE: Artemis I by the numbers

The “perigee raise maneuver” will occur about 12 minutes after launch. That’s when the ICPS experiences a burn to raise Orion’s altitude so it doesn’t reenter Earth’s atmosphere.

Shortly afterward is the “trans-lunar injection burn,” when the ICPS boosts Orion’s speed from 17,500 miles per hour (28,163 kilometers per hour) to 22,600 miles per hour (36,371 kilometers per hour) to escape the pull of Earth’s gravity and set off for the moon. After this burn, the ICPS will separate from Orion.

Around 9:45 p.m. ET Saturday, Orion will make its first “outbound trajectory correction burn” using the European Service Module, which provides the spacecraft with power, propulsion and thermal control. This maneuver will put Orion on a path to the moon.

During its journey, Artemis I will venture farther beyond the moon than any spacecraft intended to carry humans. It is expected to spend 37 days in space, entering a distant retrograde orbit around the moon before splashing down in the Pacific Ocean off San Diego on October 11.

It’s just the beginning of the Artemis program, which aims to return humans to the moon and eventually land crewed missions on Mars.

™ & © 2022 Cable News Network, Inc., a Warner Bros. Discovery Company. All rights reserved.

Today’s Top Stories


The wafer with the etched Book of Mormon on it, made by BYU students...
Samantha Herrera

BYU engineering students put ‘world’s smallest Book of Mormon’ on 4 inch disc

The entirety of the Book of Mormon is now on display on a gold-plated 4-inch disc in the Clyde Building at BYU. It'll last millions of years.
6 days ago
Researchers at UNLV say rocks with volcanic ash as old as 12 million years have been discovered at ...
Adam Small

Ancient volcanic ash found at Lake Mead, researchers say

Rocks with volcanic ash that could be 12 million years old have recently been found at Lake Mead, according to researchers from UNLV.
7 days ago
An illustration shows NASA's DART spacecraft and the Italian Space Agency's LICIACube before the co...
Ashley Strickland, CNN

NASA’s DART mission successfully slams into an asteroid

Deemed as a success, a NASA spacecraft intentionally slammed into an asteroid in the first attempt of planetary defense.
8 days ago
artemis cost...
Ashley Strickland, CNN

Next launch attempt of Artemis I set for Tuesday, but could delay due to tropical depression

The Artemis I rocket will get its third launch attempt on Tuesday, September 27, but Tropical Depression Nine could change that.
12 days ago
James Webb Space Telescope...
Ashley Strickland, CNN

Webb telescope shares its first observations of bright Mars

The James Webb Space Telescope's main goal is to detect faint light from distant galaxies, but it recently observed one of the brightest objects in the night sky: Mars.
16 days ago
Canyons School District offices are pictured in Sandy. A teacher from the district has been selecte...
Mark Jones

Utah teacher picked for NASA-affiliated teacher-training program

Utah teacher Jennifer Muir, a science educator at Draper Park Middle School, left Monday for a five-day NASA-affiliated teacher-training program, the Canyons School District said.
23 days ago

Sponsored Articles

Young woman receiving laser treatment...
Form Derm Spa

How facial plastic surgery and skincare are joining forces

Facial plastic surgery is not only about looking good but about feeling good too. The medical team at Form Spa are trained to help you reach your aesthetic outcomes through surgery and through skincare and dermatology, too.
large group of friends tohether in a park having fun...
BYU MBA at the Marriott School of Business

What differentiates BYU’s MBA program from other MBA programs

Commitment to service is at the heart of BYU’s MBA program, which makes it stand out among other MBA programs across the country.
a worker with a drill in an orange helmet installs a door in the house...
Price's Guaranteed Doors

Home improvement tip: Increase the value of your home by weatherproofing doors

Make sure your home is comfortable before the winter! Seasonal maintenance keeps your home up to date. Read our tips on weatherproofing doors.
Curb Appeal...
Price's Guaranteed Doors

How to have the best of both worlds for your house | Home security and curb appeal

Protect your home and improve its curb appeal with the latest security solutions like beautiful garage doors and increased security systems.
A paper reading IRS, internal revenue service is pictured...
Jordan Wilcox

The best strategies for dealing with IRS tax harassment | You have options!

Learn how to deal with IRS tax harassment. This guide will teach you how to stop IRS phone calls and letters, and how to handle an IRS audit.
spend a day at Bear Lake...
Bear Lake Convention and Visitors Bureau

You’ll love spending the day at Bear Lake | How to spend a day at Bear Lake

Bear Lake is a place that needs to be experienced. Spend a day at Bear Lake.
What the words you’ll hear during the moon mission launch really mean