STS-41-D (formerly STS-14) was the 12th flight of NASA's Space Shuttle program, and the maiden flight of Space Shuttle Discovery. It was launched from Kennedy Space Center, Florida, on August 30, 1984, and landed at Edwards Air Force Base, California, on September 5, 1984. Three commercial communications satellites were deployed into orbit during the six-day mission, and a number of scientific experiments were conducted, including a prototype extendable solar array that would eventually form the basis of the main solar arrays on the International Space Station (ISS).

The mission was delayed by more than two months from its original planned launch date, having experienced the Space Shuttle program's first launch abort at T−4 seconds on June 26, 1984.

Crew

Crew seat assignments

{| class="wikitable" style="text-align:center"

! Seat

! Launch

! Landing

|rowspan=8| 150px<br />Seats 1–4 are on the flight deck.<br />Seats 5–7 are on the mid-deck.

|-

! 1

|colspan=2| Hartsfield

|-

! 2

|colspan=2| Coats

|-

! 3

| Mullane

| Resnik

|-

! 4

|colspan=2| Hawley

|-

! 5

| Resnik

| Mullane

|-

! 6

|colspan=2| Walker

|-

! 7

|colspan=2 style="background-color:lightgray"| Unused

|}

Mission background

The launch was originally planned for June 25, 1984, but because of a variety of technical problems, including rollback to the Vehicle Assembly Building (VAB) to replace a faulty Space Shuttle Main Engine (SSME), the launch was delayed by over two months. The June 26, 1984, launch attempt marked the first time since Gemini 6A that a crewed spacecraft had experienced a shutdown of its engines just prior to launch.

June 1984 launch attempt

During the June 26, 1984, launch attempt, there was a launch abort at T−4 seconds, followed by a pad fire about ten minutes later. Because the center engine had not started when the abort was triggered, confusion ensued as the flight controllers were unable to verify its state:

<blockquote>

Commentary: "We have a cut off".<br/>

"NTD [NASA Test Director] we have a RSLS [Redundant Set Launch Sequencer] abort".

Commentary: "We have an abort by the onboard computers of the orbiter Discovery".<br/>

"Break break, break break, GLS [Ground Launch Sequencer] shows engine one not shut down".<br/>

"OK, PLT [pilot]?"<br/>

"CSME [Space Shuttle Main Engines] verify engine one".<br/>

"You want me to shut down engine one?"<br/>

"We do not show engine start on one".<br/>

"OTC [Orbiter test conductor] I can verify shutdown on verify on engine one, we haven't start prepped engine one".<br/>

"All engines shut down I can verify that".

Commentary: "We can now verify all three engines have been shut down".<br/>

"We have red lights on engines two and three in the cockpit, not on one".<br/>

"All right, CSME verify engine one safe for APU [auxiliary power unit] shutdown".<br/>

"If I can verify that?"<br/>

"OTC GPC [General Purpose Computer] go for APU shutdown".

</blockquote>

Mission Specialist Steve Hawley was reported as saying following the abort: "Gee, I thought we'd be a lot higher at MECO (Main Engine Cut-Off)!". About ten minutes later, the following was heard on live TV coverage:

<blockquote>

"We have indication two of our fire detectors on the zero level; no response. They're side by side right next to the engine area. The engineer requested that we turn on the heat shield fire water which is what could be seen spraying up in the vicinity of the engine bells of Discoverys three main engines".

</blockquote>

While evacuating the shuttle 20 minutes later, the crew was doused with water from the pad deluge system, which was activated due to a hydrogen fire on the launch pad caused by the free hydrogen (fuel) that had collected around the engine nozzles following the shutdown and engine anomaly. Because the fire was invisible to humans, had the astronauts used the normal emergency escape procedure across the service arm to the slidewire escape baskets, they would have run into the fire.

Changes to procedures resulting from the abort included more practicing of "safing" the orbiter following aborts at various points, the use of the fire suppression system in all pad aborts, and the testing of the slidewire escape system with a real person (Charles F. Bolden Jr.). It emerged that launch controllers were reluctant to order the crew to evacuate during the STS-41-D abort, as the slidewire had not been ridden by a human.

The mission lasted 6 days, 0 hour, 56 minutes, and 4 seconds, with landing taking place on Runway 17 at Edwards Air Force Base at 06:37:54 a.m. PDT on September 5, 1984. During STS-41-D, Discovery traveled a total of and made 97 orbits. The orbiter was transported back to KSC on September 10, 1984. Ominously, STS-41-D was the first Shuttle mission in which blow-by damage to the SRB O-rings was discovered, with a small amount of soot found beyond the primary O-ring. Following the Challenger disaster, Morton Thiokol engineer Brian Russell called this finding the first "big red flag" on SRB Joint and O-ring safety.

Launch attempts

Mission insignia

The 12 stars within the blue field indicate the flight's original numerical designation as STS-12 in the Space Transportation System's mission sequence. A representation of Discovery's namesake is manifested in a sailing ship, which is linked to the Shuttle (with the OAST solar array in the payload bay) via a red, white, and blue path, signifying its maiden voyage.

Wake-up calls

NASA began a tradition of playing music to astronauts during the Project Gemini, and first used music to wake up a flight crew during Apollo 15. Each track is specially chosen, often by the astronauts' families, and usually has a special meaning to an individual member of the crew, or is applicable to their daily activities.

{| class="wikitable"

|-

! Flight Day

! Song

! Artist/Composer

|-

| Day 2

| "Anchors Aweigh"

| Charles A. Zimmerman

|-

| Day 3

| "Telstar"

| The Ventures

|-

| Day 4

| "Mr. Spaceman"

| The Byrds

|-

| Day 5

| "Hair"

| Broadway cast

|-

| Day 6

| "Eight Miles High"

| The Byrds

|}

<gallery>

File:STS41D-36-034.jpg|SBS-D deployment

File:STS41D-36-111.jpg|Syncom IV-2 deployment

File:STS41D-37-050.jpg|Telstar 3C deployment

File:Sts-41d landing 41d-03299.jpg|Discovery lands at Edwards Air Force Base

</gallery>

See also

  • List of human spaceflights
  • List of Space Shuttle missions

References

  • STS-41-D mission summary NASA
  • STS-41-D National Space Transportation Systems Program Mission Report NASA
  • STS-41-D video highlights
  • The Dream Is Alive (1985) IMDb
  • https://www.nasa.gov/mission_pages/shuttle/shuttlemissions/archives/sts-41B.html