The Spaceflight Meteorology Group consists of 8 NOAA / National Weather Service meteorologists, one Consolidated Space Operations Contract (CSOC) meteorologist, and an administrative assistant. All meteorologists have at least a B.S. in meteorology, although a few have M.S. degrees in meteorology or related fields. SMG Lead Forecasters typically have at least 10 years of forecasting experience before being hired as an SMG forecaster. The current SMG staff has over 60 years of combined Shuttle landing weather support experience. Two of SMG's lead forecasters have over 17 years of experience (as of Jan. 2002) in shuttle landing weather forecasting. SMG Technique Development Unit (TDU) meteorologists have backgrounds in computer system applications, meteorological technique development, and technology transfer.

SMG is contracted by NASA to support the manned spaceflight program and operates on a "reimbursable" agreement between NASA and NOAA/NWS.

In addition, a small group of CSOC software and electrical engineers provide support to SMG's Meteorological Interactive Data Display System (MIDDS).

2. Who provides operational weather analysis and forecasts to the space program?

Two organizations provide most of the operational weather support to NASA manned space programs:

SMG is an integral part of the Flight Control Team in the Mission Control Center at the Johnson Space Center in Houston, Texas. The JSC Flight Director leads the flight control team and is responsible for all operational decisions regarding orbital flight and Shuttle landings. The Flight Director has immediate, direct interface with SMG forecasters who monitor weather conditions at all the possible landing sites. On occasion SMG forecasters will provide meteorologic advice for Earth observation photography and other experiments.

Flight Directors and Flight Control Team members work directly with SMG meteorologists between missions to evaluate and revise weather Flight Rules, receive in-depth weather training, participate in Shuttle landing simulations, review launch and landing times based on climatology, and resolve weather questions and issues concerning all Shuttle landing sites.

For Shuttle, the 45WS evaluates Shuttle Launch Commit Criteria (LCC) and supports the KSC Launch Director. SMG forecasts for abort landing sites and End-of-Mission landings based on landing weather Flight Rules (FR). SMG supports the JSC Flight Director. LCC and FR are separate sets of rules with differing criteria. One significant difference is that Flight Rules must be satisfied with both observed and forecast weather; LCCs must be satisfied with observed weather only. So in order to launch the Shuttle, weather LCCs must be observed GO at KSC, and weather FRs must be observed and forecast GO for KSC and for at least one TAL site.

Despite the different set of rules and customer requirements, there is a tremendous amount of pre-launch coordination between SMG and 45WS forecasters concerning weather in the KSC area.

For Shuttle landings, only weather Flight Rules are considered. SMG has the final responsibility for landing weather forecasts and advice to the Flight Control Team.

Other Department of Defense organizations provide weather observation support to the NASA manned space programs. Notably, the USAF 412OSS at Edwards AFB, the White Sands Missile Range Meteorology Branch, and various units assigned to the Department of Defense Manned Spaceflight all provide surface weather observations, upper air measurements, and other support at shuttle landing sites all around the world.

3. How can SMG forecast the weather for worldwide landing sites from Houston?

SMG accesses, decodes, and displays a tremendous amount of data for the Shuttle landing sites. This includes a full suite of digital model output from the National Center for Environmental Prediction (NCEP), mesoscale network data, worldwide surface and upper air observations, NWS and military text data, and high-resolution weather satellite imagery from GOES-East, GOES-West, METEOSAT-7, and GMS. Many of these datasets are integrated and displayed via the NWS Advanced Weather Information Processing System (AWIPS) and the JSC Meteorological Interactive Data Display System (MIDDS). SMG receives a full suite of WSR-88D radar products via a dedicated line to NWSO Melbourne, FL and NWSO Houston/Galveston, TX. During launch and landing countdowns, SMG has hot-line access to landing site observers, and can direct the flight paths of weather reconnaissance aircraft flown by astronauts deployed to landing sites.

SMG routinely forecasts for ALL shuttle landing sites between missions to develop skill, maintain proficiency, and generate a verification database. SMG forecasters give Shuttle weather support highest priority.

• Weather training for flight controllers and astronauts
• Meteorological and computer training/professional development
• Participate in NASA flight control Simulations
• Computer systems management
• Document past missions
• Resolve issues from past missions
• Prepare for future missions
• Climatology studies
• Technology transfer
• Technique development
• Weather flight rule inputs and evaluations
• Support various NASA panels and working groups
• Pilot weather briefings for astronauts
• Local weather advisories for JSC and Ellington Field
• Daily forecasts and verification for all Shuttle landing sites
• Coordinate work of contract software engineers and hardware technicians
• Coordinate/collaborate with the NASA Applied Meteorology Unit (AMU)
• Coordinate landing site instrumentation upgrades

Many kinds of weather can be hazardous to the Shuttle when it is landing. Thunderstorms, rain, hail, high winds, turbulence, low clouds, fog, and other weather can pose problems for the Shuttle.

Thunderstorms may contain extreme turbulence and wind shears that could structurally damage the Shuttle. Natural or triggered lightning could disrupt flight avionics or damage the structure. Precipitation such as rain can damage the thermal protection system when flown through at high speeds, interfere with navigation and communication systems, and block pilot visibility of the landing runway. Since the Shuttle is flown manually just before landing, the flight crew must be able to see visual navigation cues and the runway on approach so clouds must be sufficiently few in coverage and high in altitude above the ground (typically cloud ceilings must be greater than or equal to 8000 feet). Although the Shuttle is equipped with numerous landing aid systems, it is essentially a glider and has no capability to "go around" should problems arise. The headwind and tailwind components of the wind affect the landing energy of the Shuttle and the touchdown point on the runway. The crosswind component of the wind may cause the Shuttle to "crab" on final approach and may cause wear on the Shuttle landing gear and tires. This is only a short discussion of the landing weather hazards.