STS-70 (Discovery)

Background

Space Shuttle mission STS-70 occupies an unusual place in the history of American spaceflight: it is remembered almost as much for what happened on the launch pad before ignition as for what the crew accomplished in orbit. Assigned to the orbiter *Discovery*, the mission carried a five-person crew and a single critical payload — the seventh Tracking and Data Relay Satellite (TDRS-7) — whose deployment would complete the first generation of a relay network that had been under construction since the early 1980s. That network, operated by NASA, provides near-continuous communications coverage for low-Earth-orbit spacecraft, including the Space Shuttle itself, and finishing it represented a meaningful milestone for the agency's infrastructure.

The crew selected for STS-70 was experienced and well-rounded. Commander Terence Henricks and Pilot Kevin Kregel shared the flight deck, while Mission Specialists Donald Thomas, Nancy Currie, and Mary Ellen Weber rounded out the team. For Weber, it was her first spaceflight. For the others, it was another step in careers that spanned some of the most productive years of the Shuttle program.

The Woodpecker Delay

Few pre-launch anomalies in Shuttle history have attracted as much public attention — or generated as much wry commentary — as the one that held *Discovery* on the pad in the weeks before launch. In late June 1995, yellow-shafted northern flickers, a species of woodpecker native to Florida, discovered the spray-on foam insulation covering *Discovery*'s large external tank and found it an attractive site for excavation. The birds drilled more than 200 holes into the foam, some of them substantial in depth, before ground crews could intervene. The external tank's foam insulation is a safety-critical component: it prevents ice from forming on the cryogenic propellant tanks and, equally important, must remain intact so that debris does not strike the orbiter's thermal protection tiles during ascent.

NASA engineers inspected the damage carefully and determined that the foam had to be repaired before the vehicle could fly. The necessary work pushed the launch date from late June into July. The agency also implemented protective measures — including visual deterrents and noise-making devices — to discourage the birds from returning while technicians worked. The episode prompted broader conversations within NASA about wildlife management at Kennedy Space Center, which sits within the Merritt Island National Wildlife Refuge and has long coexisted with a remarkable diversity of animal species.

*Discovery* finally lifted off on July 13, 1995, carrying its crew into a clear Florida sky. The woodpecker delay had cost several weeks, but the vehicle and its payload were intact.

The Flight

Ascent proceeded nominally. Approximately eight and a half minutes after liftoff, *Discovery* reached orbit, and the crew began the standard series of post-insertion checkouts. The primary objective of the mission was the deployment of TDRS-7, and that event came relatively early in the flight, approximately ten hours after launch. The satellite was released from the payload bay and, using its own propulsion, subsequently maneuvered to its operational position in geostationary orbit.

TDRS-7's deployment was the capstone of a long effort. The Tracking and Data Relay Satellite System had been conceived as a replacement for an extensive global network of ground stations, consolidating relay functions into a small number of geostationary satellites that could provide near-continuous contact with low-orbiting spacecraft. Earlier satellites in the first-generation series had been delivered by previous Shuttle missions, and some had experienced significant difficulties — TDRS-1, launched in 1983, had suffered a propulsion failure that required extraordinary effort to salvage. By the time TDRS-7 was in place, the constellation offered reliable, broad-coverage communications service that would support not only the Shuttle but also science missions including the Hubble Space Telescope.

With the primary objective accomplished, the crew conducted a package of biomedical and scientific investigations during the remaining days in orbit. The mission's science complement was modest compared to dedicated Spacelab flights, but the crew made productive use of their time. After approximately nine days aloft, *Discovery* performed its deorbit burn and re-entered the atmosphere, touching down at Kennedy Space Center to complete the flight.

Legacy

STS-70 endures in spaceflight memory on two distinct levels. On the operational side, the successful deployment of TDRS-7 closed out the first generation of a communications architecture that would serve NASA for years. The relay satellite system it completed was subsequently augmented and eventually succeeded by second-generation TDRS spacecraft, but the infrastructure whose final piece flew on *Discovery* in the summer of 1995 had by then already supported hundreds of missions and become a foundational element of American human and robotic spaceflight operations.

On the cultural side, the woodpecker incident became one of the more charming footnotes in Shuttle history — evidence that even the most technologically sophisticated program must occasionally negotiate with the natural world. Kennedy Space Center's location within an active wildlife refuge has always meant that launches share their environment with alligators, bald eagles, manatees, and dozens of other protected species. The flickers that attacked *Discovery*'s external tank were simply the most consequential wildlife visitors the program ever encountered. NASA's response, methodical and ultimately successful, demonstrated the kind of problem-solving flexibility that characterized the agency at its best.

For the five members of its crew, STS-70 represented mission objectives met and, for at least one of them, the beginning of a career that would extend across further flights. The mission stands as a compact illustration of the Shuttle era: ambitious infrastructure goals, a diverse and capable crew, and the occasional reminder that no launch schedule is immune to the unexpected.