The safe return and landing of space vehicles from orbit is of paramount concern to the Flight Control team at Johnson Space Center. The Spaceflight Meteorology Group (SMG) provides forecasts for landings of both the Space Shuttle and the Russian Soyuz capsule attached to the International Space Station (ISS). Thunderstorms and lightning have been identified as critical elements for landing forecasts for both vehicles.

The Space Shuttle weather-related Flight Rules describe the weather conditions that are acceptable for various planned and emergency landing situations. Under the flight rules, the Space Shuttle must avoid thunderstorms, lightning, and other potentially hazardous conditions by specified distances during landing. These distances vary by the phase of the mission (launch, landing, or emergency) to account for the minimum distance for which the phenomena may present a hazard to the Orbiter, the forecast accuracy, and the management of other risks (for example, loss of oxygen or fuel) to the safety of the crew.

The Soyuz is used both for routine transport of crews to the ISS and as a “life boat” in the event of an emergency. An emergency landing site is identified for each ISS orbit. General landing sites are located in pre-selected areas throughout the world, but the exact location and landing time varies from orbit-to-orbit and day-to-day. Each day, SMG issues forecasts of significant weather events including thunderstorms for each potential landing site for the 15 to 16 orbits occurring within subsequent 24 hours. In the event of an emergency, SMG could be required to provide an updated forecast for the landing.

Examples shown in the paper will demonstrate the use and limitations of various lightning observing systems for support to the Shuttle and ISS programs. Long-range lightning detection data integrated routinely into SMG’s weather display systems include the US National Lightning Detection Network, the UK Meteorological Office Sferic’s detection network, and the Spanish Instituto Nacional de Meteorologia Lightning Detection Network. Internet products available from EUCLID (European Cooperation for Lightning Detection) and the World Wide Lightning Location Network (operated by LF*EM of New Zealand partnering with the University of Washington) also provide some information for areas not covered by SMG’s routine lightning detection data. SMG has access to an experimental gridded total lightning product from the Lightning Detection and Ranging (LDAR) system for mesoscale lightning data at Kennedy Space Center (KSC). SMG is working on integrating higher resolution total lightning data from both the KSC LDAR and the White Sands Lightning Mapping Array into operations. The significance of lightning data for the Space Shuttle Columbia accident investigation will also be discussed -- particularly as related to the occurrence of mesospheric phenomena associated with thunderstorms. Finally, the authors comment on the need for lightning detection systems to support future re-entry/landing vehicles such as the Crew Exploration Vehicle.