STS-41-D
Mission insignia
Mission statistics
Mission name	STS-41-D
Space shuttle	Discovery
Launch pad	39-A
Launch date	30 August 1984 (1984-08-30), 12:41:50 UTC
Landing	5 September 1984 (1984-09-05), 13:37:54 UTC Edwards AFB
Mission duration	6 days, 56 minutes, 4 seconds
Number of orbits	97
Orbital altitude	184 nautical miles (341 km)
Orbital inclination	28.5°
Distance traveled	2,490,000 miles (4,010,000 km)
Crew photo
Back row: L-R: Walker, Resnik Front row L-R: Mullane, Hawley, Hartsfield, Coats
Related missions
Previous Subsequent STS-41-C STS-41-G

STS-41-D was the first flight of NASA's Space Shuttle orbiter Discovery. It was the 12th mission of the Space Shuttle program, and was launched from Kennedy Space Center, Florida, on 30 August 1984. Three commercial communications satellites were deployed into orbit during the six-day mission, and a number of scientific experiments were conducted.

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-6 seconds on 26 June 1984.

Crew[link]

Mission parameters[link]

• Mass:
  • Orbiter Liftoff: 263,477 pounds (119,511 kg)
  • Orbiter Landing: 201,674 pounds (91,478 kg)
  • Payload: 41,184 pounds (18,681 kg)
• Perigee: 187 nautical miles (346 km)
• Apogee: 191 nautical miles (354 km)
• Inclination: 28.5°
• Period: 90.6 min

Mission summary[link]

The launch was originally planned for 25 June 1984, but because of a variety of technical problems, including rollback to the Vehicle Assembly Building to replace a faulty main engine, the launch was delayed by over two months. STS-41-D finally launched on 8:41 am EDT on 30 August, after a six-minute, 50-second delay when a private aircraft flew into the restricted airspace near the launch pad. It was the fourth launch attempt for Discovery. The June launch attempt marked the first time since Gemini 6A that a manned spacecraft had experienced a shutdown of its engines just prior to launch.

The launch of STS-41-D.

Because of the two-month delay, the STS-41-F mission was canceled (STS-41-E had already been canceled), and its primary payloads were included on the STS-41-D flight. The combined cargo weighed over 41,184 pounds (18,681 kg), a record for a Space Shuttle payload up to that time.

The six-person flight crew consisted of Henry W. Hartsfield Jr., commander, making his second shuttle mission; pilot Michael L. Coats; three mission specialists – Judith A. Resnik, Richard M. Mullane and Steven A. Hawley; and a payload specialist, Charles D. Walker, an employee of McDonnell Douglas. Walker was the first commercially-sponsored payload specialist to fly aboard the Space Shuttle.

Discovery's primary cargo consisted of three commercial communications satellites: SBS-D for Satellite Business Systems, Telstar 3-C for Telesat of Canada, and SYNCOM IV-2, or Leasat-2, a Hughes-built satellite leased to the US Navy. Leasat-2 was the first large communications satellite designed specifically to be deployed from the Space Shuttle. All three satellites were deployed successfully and became operational.

Another payload was the OAST-l solar array, a device 13 feet (4.0 m) wide and 102 feet (31 m) high, which folded into a package 7 inches (180 mm) deep. The array carried a number of different types of experimental solar cells and was extended to its full height several times. It was the largest structure ever extended from a manned spacecraft and demonstrated the feasibility of large lightweight solar arrays for future application to large facilities in space, such as the International Space Station.

The McDonnell Douglas-sponsored Continuous Flow Electrophoresis System (CFES) experiment, using living cells, was more elaborate than the one flown on previous missions, and payload specialist Walker operated it for more than 100 hours during the flight. A student experiment to study crystal growth in microgravity was also carried out. The highlights of the mission were filmed using an IMAX motion picture camera, and later appeared in the documentary film The Dream is Alive. Because of an obstruction in the shuttle's external wastewater dumping system, a two-foot "pee-sicle" formed that Hartsfield removed with the Remote Manipulator System.^[1]

The mission lasted six days, 56 minutes, and 4 seconds, with landing taking place on Runway 17 at Edwards Air Force Base at 6:37 am PDT on 5 September 1984. During STS-41-D, Discovery traveled a total of 2,490,000 miles (4,010,000 km) and made 97 orbits. The orbiter was transported back to KSC on 10 September.

June launch attempt[link]

During the 26 June launch attempt, there was a launch abort at T-6 seconds, followed by a pad fire about ten minutes later.^[2][3]

Commentary: "We have a cut off."
"NTD we have a RSLS (Redundant Set Launch Sequencer) abort."
Commentary: "We have an abort by the onboard computers of the orbiter Discovery."
"Break break, break break, DLS shows engine one not shut down."
"OK, PLT?"
"CSME verify engine one."
"You want me to shut down engine one?"
"We do not show engine start on one."
"OTC I can verify shutdown on verify on engine one, we haven't start prepped engine one."
"All engines shut down I can verify that."
Commentary: "We can now verify all three engines have been shut down."
"We have red lights on engines two and three in the cockpit, not on one."
"All right, CSME verify engine one safe for APU shutdown."
"If I can verify that?"
"OTC GPC go for APU shutdown."
^[4]

Crewman Steve Hawley was reported as saying following the abort: "Gee, I thought we'd be a lot higher at MECO (Main Engine Cut-Off)!".^[5]

About ten minutes, later the following was heard on live TV coverage:

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 firewall screen between the engine valve and Discovery's three main engines.

While evacuating the shuttle, the crew was doused with water from the pad deluge system, which was activated due to a hydrogen fire on the launch pad.^[6] 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.^[7]

Changes to procedures resulting from the abort included more practicing of "safeing" 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, as the slidewire had not been ridden by a human.^[5]

Launch attempts[link]

Mission insignia[link]

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 OAST solar array in the payload bay) via a red, white, and blue path, signifying its maiden voyage.

Wake-up calls[link]

NASA began a tradition of playing music to astronauts during the Gemini program, 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.^[9]

Gallery[link]

• 

  SBS-D deployment

• 

  Syncom IV-2 deployment

• 

  Telstar 3-C deployment

• 

  The extended OAST-1 solar array

See also[link]

Spaceflight portal

• List of space shuttle missions
• List of human spaceflights chronologically

References[link]

 This article incorporates public domain material from websites or documents of the National Aeronautics and Space Administration.

External links[link]

• NASA mission summary
• STS 41-D National Space Transportation Systems Program Mission Report
• STS-41D Video Highlights
• The Dream is Alive IMAX film with footage from STS-41-D