“A Lot Higher at MECO”: Remembering the Shuttle’s First Pad Abort, 40 Years On


“A Lot Higher at MECO”: Remembering the Shuttle’s First Pad Abort, 40 Years On

An ominous cloud of smoke billows away from Pad 39A in the seconds after a problematic Main Engine Start on 26 June 1984. Photo Credit: NASA

Forty summers ago, America’s Space Shuttle Program ought to have entered its prime. Touted for over a decade as capable of flying humans to space reliably, regularly and routinely, the middle months of 1984 were expected to see three launches by shuttles Discovery and Challenger—two laden with scientific and technology payloads, the third a highly secretive mission for the Department of Defense—as the reusable fleet transitioned from experimental test flights to full operations.

In three years of shuttle operations, the shuttle had realized its potential as a scientific research platform, a satellite launching pad and a vehicle to retrieve and repair damaged spacecraft. The future seemed bright…until Tuesday, 26 June 1984.

Video Credit: National Space Society (NSS)

Shuttle Discovery’s maiden voyage, STS-41D, was ready to fly. Laden with the U.S. Navy’s Syncom 4-1 communications satellite, a large-format Earth imaging camera and the extendible OAST-1 solar array for NASA’s Office of Aeronautics and Space Technology, the mission would run for seven days.

Commanded by shuttle veteran Hank Hartsfield, the STS-41D crew also included Pilot Mike Coats, Mission Specialists Mike Mullane, Steve Hawley and Judy Resnik and Payload Specialist Charlie Walker, a civilian industry engineer from McDonnell Douglas. Yet their flight and its payload had shifted and contorted multiple times since the crew was assigned to begin training in early 1983.

Originally, they were designated “STS-12” and tasked with launching the third Tracking and Data Relay Satellite (TDRS-C)—part of a network of geostationary-orbiting sentinels to provide near-continuous voice and data coverage between shuttle astronauts and ground stations—but an Inertial Upper Stage (IUS) booster malfunction during the TDRS-A flight in April 1983 forced NASA to place all future TDRS missions on hold. TDRS-B (planned for STS-8) and TDRS-C on Hartsfield’s flight were thus deleted from the manifest.

The crew of STS-41D boasted the commercial industry’s first astronaut, Charles Walker. He is pictured at top left (next to Judith Resnik). At bottom, crew members Mike Mullane, Steve Hawley, Hank Hartsfield and Mike Coats smile for the camera. Photo Credit: NASA

Yet there were other payloads to fill the void. By the early spring of 1984, Hartsfield’s mission gained Syncom 4-1, the large-format camera, OAST-1 and a Canadian communications satellite, Anik-C1. However, the Canadian satellite disappeared quickly from the payload roster and was reassigned to another flight.

On 22 June, three days before their scheduled launch, the STS-41D crew arrived at the Kennedy Space Center (KSC) for Discovery’s maiden launch. A computer glitch on the 25th enforced a 24-hour delay, but worse was to come.

On the morning of 26 June—40 years ago today—the countdown clock ticked down without incident. At 8:44 a.m. EDT, with five minutes to go, Coats activated the shuttle’s three Auxiliary Power Units (APUs) and listened as the trio of hydraulic pumps hummed perfectly alive.

Clad in their blue flight suits, the STS-41D crew included America’s second female astronaut, Judy Resnik. Photo Credit: NASA

“The meters showed good pressure,” Mullane wrote in his memoir, Riding Rockets. “Discovery now had muscle.”

The computers automatically commanded a final series of checks of the main engines and the elevons on the wings. With two minutes to go, the astronauts closed their visors.

Commander Hank Hartsfield shook Coats’ hand and wished them all good luck, reminding them to stick to their training and keep their eyes focused on the instruments. Thirty-one seconds before liftoff, the Ground Launch Sequencer (GLS) handed over primary control of the countdown to the shuttle’s computers.

Discovery’s pad abort, 40 years ago today, provided a stark reminder that the shuttle remained an experimental, temperamental machine. Photo Credit: NASA

In the darkened middeck, Resnik and Walker clasped hands. The Solid Rocket Boosters (SRBs) underwent their final nozzle steering checks, and at T-10 seconds a flurry of sparks from hydrogen burn igniters gave way to a familiar low-pitched rumble. 

“…seven, six, five…we have Main Engine Start…,” intoned the launch commentator.

Inside Discovery’s cabin, the astronauts felt the immense vibration as turbopumps awoke, liquid oxygen and hydrogen flooded into the engines’ combustion chambers and they roared to life … and then, suddenly and shockingly, were arrested by the blaring sound of the master alarm. Something had gone badly awry.

The STS-41D mission was also the maiden voyage of shuttle Discovery. Image Credit: NASA

“Then there’s this grinding,” remembered Walker. “I cannot describe it. It sounded like … imagine in your mind the hand of God comes out of the sky, reaches down and twists the launch tower and structure outside the vehicle. It sounds like the place is being ripped apart!” Two of the main engines—No. 2 and 3, closest the aft body flap—had blazed to life, but the No. 1 engine, directly at the “top” of the pyramid, had failed to ignite.

“The vibrations were gone,” wrote Mullane. “The cockpit was as quiet as a crypt. Shadows waved across our seats as Discovery rocked back and forth.”

From the pilot’s seat, all Coats could hear was the screeching of disturbed seagulls outside. Two red lights on the instrument panel indicated that the No. 2 and 3 engines had shut down, but the indicator for the No. 1 engine remained dark.

White-haired Commander Hank Hartsfield leads his crew out to the launch pad for their successful launch attempt on 30 August 1984. Photo Credit: NASA, via Joachim Becker/SpaceFacts.de

Instantly, Coats, whose responsibility as pilot was to monitor the engines during ascent, jabbed his finger onto the button to shut it down. The indicator did not change; it remained dark. Downstairs, Walker’s eyes were focused intently on the procedures for “Mode 1 Egress,” the instructions to open the side hatch and evacuate the vehicle.

Meanwhile, on the roof of the Launch Control Center (LCC), the astronauts’ families were watching the unfolding drama…and they were perplexed both by what they could see and what they could not. “A thick summer haze had obscured the launch pad,” wrote Mullane. “When the engines had ignited, a bright flash had momentarily penetrated that haze, strongly suggesting an explosion. As that fear had been rising in the minds of the families, the engine-start sound had finally hit … a brief roar.”

The sound echoed off the walls of the gigantic Vehicle Assembly Building (VAB) and was gone. Within seconds, it became clear what had happened.

Two months after her pad abort, Discovery roars into space on 30 August 1984. Photo Credit: NASA

“…We have a cutoff…we have an abort by the on-board computers of the orbiter Discovery,” continued the commentator’s dry tone.

Over the intercom, the astronauts heard the worrisome words “RSLS Abort,” meaning a “Redundant Set Launch Sequence.” This pointed inevitably to a main engine problem, which had forced their automatic shutdown by the General Purpose Computers (GPCs).

Intuitively, the crew knew safeguards existed to prevent the SRBs from igniting—for if that had happened, it would kill them all—but they also knew that only a few seconds existed on the countdown clock. “A couple of seconds in the world of electronics is a lifetime,” said Mullane, “and I’m sure that all the safety devices had rotated to prevent [the solids] from igniting … but in the back of your mind, you’re thinking What happens if those ignite?”

STS-41D became the first shuttle to launch as many as three communications satellites in a single mission. Photo Credit: NASA, via Joachim Becker/SpaceFacts.de

The situation was by no means under control. As if the indication that the No. 1 engine might still be burning was not enough, Launch Control now told the crew that there was a fire on the pad and the suppression equipment had been activated.

The decision over whether to unstrap and make an emergency evacuation of the orbiter was now in the hands of Hartsfield; downstairs, on the middeck, Resnik had unstrapped and was peering through the window in Discovery’s side hatch. She could see no fire.

The astronauts would have to run across the access arm to a set of seven baskets which would whisk them to safety. Listening to the communication loop, Hartsfield elected to sit tight. It was a decision which probably saved their lives. Hydrogen burns invisibly to the human eye and it had begun to ignite combustible materials on the pad surface. Subsequent inspections revealed scorched paint all the way up the launch pad structure, as far as the crew access arm.

“Glowing gold”, the OAST-1 solar sail rises prominently from the payload bay during STS-41D. Photo Credit: NASA

“The flame may have been as high as the cockpit,” Mullane continued, “but…we would not have seen it. We could have thrown open the hatch and run into a fire.”

Years later, Walker praised Hartsfield for not ordering a Mode 1 Egress that day. In his conversations with the launch director after the abort, Hartsfield realized that a lot of doubt also existed over the reliability of the slide-wire baskets and that informed their judgement-call to keep the crew aboard the orbiter.

From the flight engineer’s seat, Hawley injected a spark of humor into the proceedings. “Gee,” he said, in his thick Kansan drawl, “I thought we’d be a lot higher at MECO!”

The crew of STS-41E, a classified Department of Defense mission, later evolved into STS-51C, which flew in January 1985. Front row are Loren Shriver (left) and Ken Mattingly, with Gary Payton, Jim Buchli and Ellison Onizuka standing. Photo Credit: NASA

There had been a Main Engine Cutoff, but not at the edge of space; Discovery remained firmly shackled to Earth. T-zero had not been reached and so the SRBs had not ignited. Hawley’s joke “broke the ice and got everybody laughing,” said Coats, but did little to dissipate a pervasive sense of gloom that their mission had been aborted just four seconds prior to liftoff.

Gloom is often associated with bad weather and rain, and when the STS-41D crew finally saw the light of day and made their way out of the orbiter, they did so in a torrential downpour … not of rain, but of the waters of the fire suppression system. The entire gantry was soaked, drips from every pipe and platform, the white room ankle-deep in water.

As Coats walked out of the elevator at the base of the pad, it was like walking beneath a waterfall. “We got completely soaked to the skin,” he explained. “Then we got in the astronaut van, which was air-conditioned and very cold. As we were driving away, there’s a window in the back of the van and all of us were looking back at the shuttle on the launch pad, shivering and soaking wet, like drowned rats.”

The “core” NASA crew of STS-41F, scheduled for launch on 9 August 1984 for a seven-day flight. From left to right are Commander Karol “Bo” Bobko, Pilot Don Williams and Mission Specialists Dave Griggs, Rhea Seddon and Jeff Hoffman. Photo Credit: NASA, via Joachim Becker/SpaceFacts.de

As well as being cold, wet, and disappointed, the crew was also exhausted. “After a launch abort,” Mullane said later, “you could take a gun and point it right at somebody’s forehead, and they’re not even going to blink, because they don’t have any adrenaline left in them; it’s all been used up.” Coats took his wife and children to Disney World, where they later found themselves, ironically, queuing for the Space Mountain ride.

The cause of the 26 June pad abort was later traced to a problem with one of the main engines, all three of which were commanded to shut down by Discovery’s on-board computers. The immediate consequence was that STS-41D would not fly for many weeks, as the vehicle required rollback to the Vehicle Assembly Building (VAB), destacking from its boosters and fuel tank and the return of the shuttle to the Orbiter Processing Facility (OPF) for the engines to be replaced. That placed the next realistic opportunity for launch in late August 1984…and that spelled bad news for NASA’s busy summertime mission manifest.

Assuming that STS-41D had launched on time, and Hartsfield’s crew had returned safely from their seven-day flight, three more shuttle missions were targeted for July and August. First was STS-41E, a classified assignment for the Department of Defense.

The Anik-C1 and Leasat-3 satellites in their launch configuration in the Shuttle’s payload bay. Anik was deployed vertically, whilst Leasat was ‘rolled’ horizontally into space, in a frisbee motion. During their preparations for STS-41F, STS-51E and 51D, Bobko’s crew had trained extensively for both deployment procedures. Photo Credit: NASA

Astronauts Ken Mattingly, Loren Shriver, Ellison Onizuka and Jim Buchli, plus U.S. Air Force Manned Spaceflight Engineer (MSE) Jeff Detroye, had been assigned to this mission—originally designated “STS-10”—in October 1982, with a scheduled launch date in the fall of the following year. However, their payload also required the Boeing-built IUS, which was expected to be out of service for at least another year.

By this stage, Mattingly’s mission had been redesignated “STS-41E” but met with added delay. In May 1984, the mission had disappeared from the shuttle manifest and was renumbered “51C” and rescheduled for the following December.

“That is when we started to learn that the numerical sequence of the numbers of the missions didn’t mean a lot,” recalled Shriver in a NASA oral history. Similarly afflicted were Karol “Bo” Bobko’s STS-41F crew, which included astronauts Don Williams, Rhea Seddon, Dave Griggs and Jeff Hoffman. Announced in September 1983, their final payload before the STS-41D pad abort would have seen a record-setting four deployments: Syncom 4-2 for the Navy and the SBS-4 and Telstar-3C communications satellites, together with the retrievable Spartan solar physics platform.

Flying STS-51D on 12 April 1985, Karol “Bo” Bobko’s old STS-41F crew finally reached space with a very different payload and a quite different mission. Photo Credit: NASA, via Joachim Becker/SpaceFacts.de

With STS-41D off the table until the end of August, NASA faced uncomfortable decisions about the remainder of 1984. “Payloads were stacking up,” wrote Mullane in Riding Rockets. “Every day a communications satellite wasn’t in space meant the loss of millions of dollars of revenue to its operators.” Emphasis, therefore, was placed on combining two missions into one and deleting the other from the manifest, thereby affording minimum distortion to the launch schedule and ensuring continued NASA commitment to its customers.

This proved bad news for Bobko’s STS-41F crew, who had been aiming for a 9 August launch. Their entire payloadwith the exception of the Spartan—was reassigned to Hartsfield’s STS-41D.

Laden with three large communications satellites and the OAST-1 solar array, Discovery would tip the scales with the heaviest payload ever orbited by a shuttle crew: 41,180 pounds (18,680 kg). Finally, the hiatus in flights came to an end on 30 August 1984, when Hartsfield’s crew finally flew safely.

In its third incarnation, the mission of Karol “Bo” Bobko finally takes flight on 12 April 1985. Photo Credit: NASA, via Joachim Becker/SpaceFacts.de

As for the other two flights, Mattingly’s STS-41E and Bobko’s STS-41F received new designations. Mattingly’s crew launched in January 1985 and flew the shortest operational shuttle mission of only three days, whilst Bobko’s crew trained another six months before their flight—renamed “STS-51E”—was canceled again in March 1985.

This time, however, a glimmer of good fortune was on their side. Reassigned a third time, Bobko’s crew finally flew STS-51D in April 1985. But it was the events of the previous summer—1984’s “Summer of the Shuttle”—that provided a sobering reminder than the reusable spacecraft could never be fully routine.

FOLLOW AmericaSpace on Facebook and X!

Leave a Comment