International Flight No. 79
|No.||Surname||Given names||Position||Flight No.||Duration||Orbits|
|1||Engle||Joe Henry||CDR||1||2d 06h 13m||37|
|2||Truly||Richard Harrison "Dick"||PLT||1||2d 06h 13m||37|
|1||Mattingly||Thomas Kenneth II "Ken"||CDR|
|2||Hartsfield||Henry Warren, Jr. "Hank"||PLT|
Launch from Cape Canaveral (KSC); landing on the Edwards AFB.
In the early planning stages of the Space Shuttle program, STS-2 was intended to be a reboost mission for the aging Skylab space station. However, such a mission was made impossible by delays with the shuttle's development and the deteriorating orbit of Skylab. Skylab ultimately de-orbited in 1979, two years before the launch of STS-2.
Originally, the launch had been set for October 09, 1981, but it was delayed by a nitrogen tetroxide spill during the loading of the forward Reaction Control System tanks. The spill necessitated the removal, decontamination and reapplication of over 300 thermal tiles. The tiles could be reached from platforms at Launch Pad 39A, allowing the work to take place without returning to the Orbiter Processing Facility. It was next scheduled for November 04, 1981, but was again scrubbed when high oil pressures were discovered in two of the three Auxiliary Power Units (APU) that controlled the orbiter's hydraulic system. That issue was attributed to hydrazine seepage contaminating the lubrication system in the APUs.
This mission was the second test flight of the Space Shuttle. The flight marked the first time an orbital manned space vehicle had been re-flown with a second crew.
Columbia carried out several scientific experiments including tests with the "Shuttle Imaging Radar" and of the 50-foot remote manipulator arm in space. The planned five day mission was cut, because fuel cell number one failed (producing electricity and drinking water). 90 % of mission objectives were achieved. Good results of the OSTA-1 (Office of Space and Terrestical Applications-1) Earth observation experiment, which was mounted in the Spacelab pallet in the payload bay, were brought back to the Earth.
The OSTA-1 payload developed by NASA's office of Space and Terrestrial Applications was the first science and applications payload scheduled by the Space Transportation System and will provide an early demonstration of the Space Shuttle's research capabilities.
The experiments mounted in the payload bay included the Shuttle Imaging Radar-A (SIR-A), a side-looking synthetic aperture radar which maps terrestrial features; the Shuttle Multispectral Infrared Radiometer (SMIRR) which tested a technique to determine rock types; Feature Identification and Location Experiment (FILE) which will help develop techniques to make data gathering by Earth resources satellites more efficient; Measurement of Air Pollution from Satellites (MAPS), an experiment to measure the amount of carbon monoxide in the middle and upper troposphere (12-18 km or 7.5-11 mi.) and the ocean Color Experiment (OCE), an instrument to detect differences in ocean color which may indicate concentrations of plankton and schools of fish. The two experiments carried in the crew compartment included the Heflex Bioengineering Test (HBT), designed to prepare the way for a later Spacelab experiment in micro-gravity plant growth, and the Night/Day Optical Survey of Lightning (NOSL), an instrument for observing and recording lightning discharges from the vantage point of space.
The Shuttle Imaging Radar-A antenna was the most prominent portion of the OSTA-1 payload. It sent and received microwave radiation to create map-like images of the Earth's surface. Similar radar systems have uncovered ancient Mayan canals and have flown on an ocean-surveying satellite (Seasat) to study ice flows and ocean wave patterns. This application to Earth land resource study in delineating faults and other geological formations may aid in locating oil and other mineral deposits.
The imaging radar antenna was 9.35 m (31 ft.) long, 2.16 m (7 ft.) wide, and 15 cm (5.9 in.) thick and weighed 181 kg (399 lb.). It was formed by seven epoxy fiberglass panels supported by an aluminum truss structure mounted to the pallet so that the viewing angle is 47 degrees from nadir.
The Shuttle Multispectral Infrared Radiometer complements the imaging radar instrument by working to determine the best spectral bands to use in remote sensing of rock types. That information, taken together with the delineation of geographical features provided by the radar, could help develop a global map of mineral indicators. The spectral bands investigated by the infrared radiometer could be incorporated into such remote sensing spacecraft.
The infrared radiometer equipment consisted of a telescope, a filter wheel, two detectors, two film cameras and related electronics. The entire unit weighs 99 kg (218 lb.) and measures 56 by 94 by 117 cm (22 by 37 by 46 in.). The telescope was a modified version of the Mariner instrument that gathered images of Venus and Mercury in 1973. Calibration lamps were mounted inside the telescope barrel. An opaque cover rotated over the top of the telescope to protect the instrument when the experiment is not in operation.
The Feature Identification and Location Experiment was designed to help develop equipment which will make remote sensing instruments such as Shuttle Imaging Radar-A and Shuttle Multispectral Infrared Radiometer more efficient by activating them only when conditions are right for taking data. The experiment's system consisted of a sunrise sensor, two television cameras, a decision-making electronics unit, a buffer memory, a tape recorder and a 70 mm camera.
One of the two television cameras was equipped with an optical filter for visual red; the other with a filter for the near infrared. The output of these cameras was sent to the decision-making electronics unit, where the ratio of the television camera measurements for each picture element (pixel) was determined. The experiment contained scene class counters to determine when the instrument has recorded an adequate number of scenes of a certain type and suppress further data acquisition from such scenes.
The Measurement of Air Pollution from Satellites experiment measured the distribution of carbon monoxide in the middle and upper troposphere (that part of the atmosphere from the Earth's surface to an altitude of between 12 and 18 km -- 7.5 to 11 mi.). The experiment evaluated the performance under varying conditions of techniques which may be used in later spacecraft to monitor air pollution.
The ocean Color Experiment was designed to test equipment which will distinguish high concentrations of algae in the ocean from the other obscuring reflections, such as high sediment concentration and the sea floor. By detecting the green color of chlorophyll, the dominant pigment in this basis of the ocean food chain, satellites can help locate schools of fish or point out pollution areas.
The 34-kg (74-lb.) scanner module was a cylinder 75 cm (30 in.) long flattened on one side 27 by 23 cm (11 by 9 in.) mounted on the pallet. The instrument components were mounted on an aluminum plate which is divided into four sections by bulkheads. The first section houses the motors for the scanner mirror and doors and the devices for timing pickup. The second section contained the scanner mirror and is equipped with bomb bay type doors which protect the instrument during ascent and entry. The third section contained the telescope. The fourth section housed the optics and an electronics box.
The rotating mirror on the experiment instrument scanned plus or minus 45 degrees from nadir across the direction of flight and reflects radiations into a telescope. The telescope images the scene through a 1 by 2 mm field stop and onto a diffraction grating. The diffraction light (that is, light separated into its component colors) was directed onto a bundle of 24 glass fibers, and a different spectral band was channeled through each glass fiber. The fibers were coupled to eight silicon photodiode detectors.
The Night/Day optical Survey of Lightning was one of two OSTA-1 investigations carried in the crew compartment and was involved the use of astronauts in observing and recording lightning and thunderstorms. A photo-optical system was used to record lightning flashes during the daytime passes. The system generated audio impulses which were recorded on magnetic tape.
The Heflex Bioengineering Test was not a full-blown experiment, but a preliminary test in support of a later Spacelab experiment in micro-gravity plant growth. The Spacelab Heflex (for Helianthus annus Flight Experiment) depended on dwarf sunflower plants grown to a particular height range. The test flown on STS-2 investigated the relationship between plant height and initial soil moisture content in a near weightless environment.
The primary objectives of the Aerodynamic Coefficient Identification Package (ACIP) were to collect aerodynamic data during the launch, entry and landing phases of the Shuttle, to establish an extensive aerodynamic data base for verification of and correlation with ground-based data, including assessments of the uncertainties of such data and to provide flight dynamics data in support of other technology areas, such as aerothermal and structural dynamics.
Instruments in this package included dual-range linear accelerometers and rate gyros. Also included were the power conditioner for the gyros, the power control system and the housekeeping components. The package was installed collinearly with the geometric axes of the orbiter and post-installation measurements made to establish the position within 10 arc minutes. The instruments continuously sensed the dynamic X, Y and Z attitudes and performance characteristics of the orbiter through these critical flight phases. The Aerodynamic Coefficient Identification Package also provided high rate sampling of the positions of orbiter control surfaces for recording with the package's attitude data.
During the launch and entry phases of orbiter flight and in certain types of on-orbit operation, the outer skin of the vehicle was subjected to conditions that increase the surface temperatures to very high values. The thermal protection system has the function of attenuating these temperatures to an acceptable level to protect the primary structure and skin of the orbiter. This is achieved through the use of three different materials in three different manners. One material, rigidized silica fibers, was coated with one of two different coating materials to become either hightemperature reusable surface insulation or low-temperature reusable surface insulation. The second material, Nomex felt, is called flexible reusable surface insulation and was applied as a blanket to the orbiter skin surfaces that receive lower heating effects. The third material, reinforced carbon-carbon, was used in place of metal structures on the leading edges of the wings and stabilizer and on the nose cone, the surfaces which become hottest during launch and entry.
The Induced Environment Contamination Monitor (IECM) was a desk-sized detector containing 10 instruments for contaminants in and around the Space Shuttle orbiter cargo bay which might adversely affect delicate experiments being carried aboard. The on-orbit measurements included molecular return flux, background spectral intensity, molecular deposition and optical surface effects. During the other mission phases, dew point, humidity, aerosol content and trace gas were measured, as well as optical surface effects and molecular deposition. The detector operated attached to a release mechanism on the Development Flight Instrumentation pallet during the second Shuttle mission, but on the third and fourth flights it will be moved around and outside the cargo bay by the orbiter's Remote Manipulator System and then reattached. On Spacelab missions one and two, it will be attached to the Spacelab pallet.
Although the STS-2 mission had been planned for a duration of five days, with a few hours a day spent testing the Canadarm, the flight was cut short when one of the three fuel cells that produce electricity and drinking water failed. The mission was shortened to two days, and the Canadarm tests were canceled. The crew stayed awake during a scheduled sleep period and tested the arm anyway, working during the Loss-Of-Signal (LOS) periods when they were not in contact with Mission Control.
Designed as an analog to the human arm, the Canadarm has shoulder, elbow and wrist joints driven by DC electric motors controlled by the flight crew using a combination of direct visual observation and television cameras on the elbow and wrist joints. The arm may be operated in five different modes ranging from full manual to computer-controlled through hand controls and keyboard at the payload station on the flight deck. The manipulator system was installed on the left payload bay longeron for STS-2. A second one can be installed on the right longeron for specific payload tasks, although both arms could not be operated simultaneously. The arm, built of a light-weight carbon composite tubing 38 cm (15 in.) in diameter, is 15.3 m (S0.25 ft.) long, and weighs 408 kg (900 lb.). A thermal blanket provides temperature control for protecting joint-drive mechanisms and electronics. Brushless electric motors and gear trains drive the joints for pitch up/ down, yaw left/right and wrist roll motions. The "hand," called an end effector, has snare wires that engage a grapple fixture on the payload. Television cameras at the wrist and elbow provide the operator visual cues for maneuvering the end effector toward a grapple fixture or other target. Operator hand controllers are similar to those used for spacecraft maneuvers - a rotational hand controller for roll, pitch and yaw motions, and translational hand controller for up/down, left/right and fore/aft motions. When deactivated, the arm is latched into three cradle pedestals along the left longeron. If the drive mechanisms jam and the arm cannot be moved to its stowed position, and if contingency spacewalks are unsuccessful in restowing, the arm can be amputated with a pyrotechnic device.
The mission included an airlock extravehicular activity demonstration in which Joe Engle donned a Shuttle spacesuit and walk through the EVA procedures, stopping just short of airlock depressurization.
STS-2 was the first shuttle flight where O-ring blow-by was observed. After the damage was discovered, another O-ring was intentionally damaged to a further degree. It was then put through a flight simulation at three times the flight pressure. It survived the test, and was endorsed as flightworthy. This same problem would occur on fourteen more shuttle flights, before it contributed to the destruction of the Challenger orbiter in 1986.
STS-2 was the last shuttle flight to have its external fuel tank (ET) painted white. In an effort to reduce the Shuttle's overall weight, STS-3 and all subsequent missions used an unpainted tank, saving approximately 272 kilograms (600 lb). This lack of paint gave the ET a distinctive orange color, which eventually became synonymous with the Space Shuttle.
photo courtesy J.L. Pickering
Last update on September 17, 2013.