STS-50
| Mission Insignia | |
|---|---|
| Mission Statistics | |
| Mission: | STS-50 |
| Shuttle: | Columbia |
| Launch Pad: | 39A |
| Launch: | June 25, 1992 16:12:23.053 UTC |
| Landing: | July 9, 1992 11:42:27 UTC Kennedy Space Center, Runway 33 |
| Duration: | 13 days, 19 hours, 30 minutes, 4 seconds |
| Orbit Altitude: | 296 km |
| Orbit Inclination: | 28.5 degrees |
| Orbits: | 221 |
| Distance Traveled: | 9.2 million km | Crew photo |
STS-50 (U.S. Microgravity Laboratory 1) was a United States Space Shuttle mission, the 12th mission of the Columbia orbiter.
| Table of contents |
|
2 Mission Parameters 3 Mission Highlights 4 Mission insignia 5 Related articles 6 External links |
The U.S. Microgravity Laboratory 1 was a spacelab mission, with experiments in material science, fluid physics and biotechnology. It was the first flight of a Space Shuttle with the EDO (Extended Duration Orbiter) hardware, allowing longer flight durations.
Primary payload, U.S. Microgravity Laboratory-1 (USML- 1), made its first flight; featured pressurized Spacelab module. USML-1 first in planned series of flights to advance U.S. microgravity research effort in several disciplines. Experiments conducted were: Crystal Growth Furnace (CGF); Drop Physics Module (DPM); Surface Tension Driven Convection Experiments (STDCE); Zeolite Crystal Growth (ZCG); Protein Crystal Growth (PCG); Glovebox Facility (GBX); Space Acceleration Measurement System (SAMS); Generic Bioprocessing Apparatus (GBA); Astroculture-1 (ASC); Extended Duration Orbiter Medical Project (EDOMP); Solid Surface Combustion Experiment (SSCE).
Secondary experiments were: Investigations into Polymer Membrane Processing (IPMP); Shuttle Amateur Radio Experiment II (SAREX II); and Ultraviolet Plume Instrument (UVPI).
Major Mission Accomplishments
During Columbia's extended mission, scientist crewmembers, working inside the
Spacelab long module carried in Columbia's payload bay, conducted more than 30
microgravity investigations and tests. To maximize the scientific return from
the mission, experiments took place around-the-clock. The investigations fell
under five basic areas of microgravity science research: fluid dynamics (the
study of how liquids and gases respond to the application or absence of
differing forces), materials science (the study of materials solidification and
crystal growth), combustion science (the study of the processes and phenomena
of burning), biotechnology (the study of phenomena related to products derived
from living organisms), and technology demonstrations that sought to prove
experimental concepts for use in future Shuttle missions and on Space Station
Freedom.
Three new major experiment facilities were flown on USML-1. They were the
Crystal Growth Furnace, Surface Tension Driven Convection Experiment apparatus,
and Drop Physics Module. An additional piece of new hardware on this flight was
the versatile Glovebox, which permitted "hands-on" manipulation of small
experiments while isolating the crew from the liquids, gases, or solids
involved. Some of the USML-1 experiments are described below.
Spacelab Experiments
The Crystal Growth Furnace (CGF) is a reusable facility for investigating
crystal growth in microgravity. It is capable of automatically processing up
to six large samples at temperatures up to 1,600 degrees Celsius. Additional
samples can be processed upon performing manual sample exchange. Two methods
of crystal growth, directional solidification and vapor transport, were used on
USML-1. By analyzing the composition and the atomic structure of crystals grown
without the dominating influence of gravity, scientists will gain insight into
correlations between fluid flows during solidification and the defects in a
crystal. CGF operated for 286 hours and processed seven samples, three more
than scheduled, including two gallium arsenide semiconductor crystals. Gallium
arsenide crystals are used in high-speed digital integrated circuits,
optoelectronic integrated circuits, and solid state lasers. Crewmembers were
able to exchange samples, using a specially designed flexible Glovebox, to
provide the additional experiment operations.
The Surface Tension Driven Convection Experiment (STDCE) was the first space
experiment to use state- of-the-art instruments to obtain quantitative data on
surface tension-driven flows on the surface of liquids over a wide range of
variables in a microgravity environment. Very slight surface temperature
differences are sufficient to generate subtle fluid flows on the surface of
liquids. Such flows, referred to as "thermocapillary," exist on fluid surfaces
on Earth. However, thermocapillary flows on Earth are very difficult to study
because they are often masked by much stronger buoyancy-driven flows. In
microgravity, buoyancy-driven flows are greatly reduced permitting the study of
this phenomenon. STDCE provided the first observations of thermocapillary flow
in a curved-surface fluid and demonstrated that surface tension is a powerful
driving force for fluid motion.
The Drop Physics Module (DPM) permitted the study of liquids without the
interference of a container. Liquids on Earth take the shape of the container
that holds them. Furthermore, the materials that make up the container may
chemically contaminate the liquids under study. The DPM uses acoustical
(sound) waves to position a drop in the center of a chamber. By studying drops
in this manner, scientists have the opportunity to test basic fluid physics
theories in the areas of nonlinear dynamics, capillary waves, and surface
rheology (changes in the form and flow of matter). Crew-members, through
manipulation of the sound waves, were able to rotate, oscillate, merge, and
even split drops. In another test, the crewmembers were able to create the
first compound drop, a drop within a drop, to investigate a process that could
eventually be employed to encapsulate living cells within a semi-permeable
membrane for use in medical transplantation treatments.
The Glovebox facility perhaps proved to be the most versatile new space
laboratory equipment introduced in the last few years. The Glovebox offers
crewmembers the opportunity to manipulate many different kinds of test
activities and demonstrations and materials (even toxic, irritating, or
potentially infectious ones) without making direct contact with them. The
Glovebox has a viewport (window) into a clean workspace, built-in gloves for
manipulation of samples and equipment, a negative air pressure system, a filter
system, and an entry door for passing materials and experiments into and out of
the work area. The primary use of the Glovebox was to selectively mix protein
crystals and monitor their growth. The Glovebox allowed crewmembers to
periodically change compositions to optimize the growth, a first for space.
Other tests conducted inside the Glovebox included studies on candle flames,
fiber pulling, particle dispersion, surface convection in liquids, and
liquid/container interfaces. Sixteen tests and demonstrations in all were
conducted inside the Glovebox. The Glovebox also provided crewmembers the
opportunity to perform backup operations on the Generic Bioprocessing Apparatus
which were not planned.
Another of the Spacelab experiments was the Generic Bioprocessing Apparatus
(GBA), a device for processing biological materials. The GBA processed 132
individual experiments with volumes of several milliliters. The apparatus
studied living cells, microorganisms used in ecological waste treatment, and
the development of brine shrimp and wasp eggs, and other biomedical test models
which are used in cancer research. One sample studied, Liposomes, consist of
spherical structures that could be used to encapsulate pharmaceuticals. If
this biological product can be formed properly, it could be used to deliver a
drug to a specific tissue in the body, such as a tumor.
Middeck Microgravity Experiments
The Protein Crystal Growth experiment made its fourteenth shuttle flight, but
USML-1 represented the first time crewmembers were able to optimize growth
conditions using the Glovebox facility. About 300 samples were seeded from 34
protein types including HIV Reverse Transcriptase Complex (an enzyme that is a
chemical key to the replication of the AIDS virus) and Factor D (an important
enzyme in human immune systems). About 40 percent of the proteins flown will
be used for X-ray diffraction studies. The increased size and yield can be
attributed to the extended crystal growth time provided by this mission.
Scientists on the ground will use X-ray crystallography to study each protein's
three-dimensional structure which, when determined, may aid in controlling each
protein's activity through rational drug design.
The Astroculture(TM) experiment evaluated a water delivery system to be used
for supporting the growth of plants in microgravity. Plant growth in space is
looked at as a possible method of providing food, oxygen, purified water, and
carbon dioxide removal for long-term human habitation in space. Since fluids
behave differently in microgravity than they do on Earth, plant watering
systems used on Earth do not adapt well to microgravity use.
The Zeolite Crystal Growth experiment processed 38 separate samples which were
mixed in the Glovebox. Zeolite crystals are used to purify biological fluids,
as additives in laundry detergents, and in waste clean-up applications.
Extended Duration Orbiter (EDO)
STS-50 not only marked the first U.S. Microgravity Laboratory flight, but also
the first Extended Duration Orbiter flight. To prepare for long-term (months)
microgravity research aboard Space Station Freedom, scientists and NASA need
practical experience in managing progressively longer times for their
experiments. The Space Shuttle usually provides a week to ten days of
microgravity. Thanks to the Extended Duration Orbiter kit, the Space Shuttle
orbiter Columbia remained in orbit for almost 14 days and future missions with
Columbia could last as long as a month. The kit consists of extra hydrogen and
oxygen tanks for power production, extra nitrogen tanks for the cabin
atmosphere, and an improved regeneration system for removing carbon dioxide
from the cabin air.
One of the practical aspects of remaining in space longer will be the
requirement to maintain crewmember health and performance. During STS-50,
crewmembers conducted biological tests as part of the EDO Medical Project.
Crewmembers monitored their blood pressure and heart rate and took samples of
the cabin atmosphere during the flight. They also evaluated the Lower Body
Negative Pressure (LBNP) device as a countermeasure to the normal reduction of
body fluids that takes place in space. If the beneficial effects of the LBNP
could last for 24 hours, it would improve crewmember performance on reentry and
landing.
Other Payloads
The STS-50 crewmembers also operated the Shuttle Amateur Radio Experiment
(SAREX). Through the experiment, crewmembers were able to contact short wave
radio operators, a Polynesian sailing vessel replica out in the Pacific Ocean,
and selected schools around the world.
The Investigations into Polymer Membrane Processing (IPMP) experiment has flown
previously on six Shuttle missions. It is used to study the formation of
polymer membranes in microgravity with the aim of improving their quality and
use as filters in biomedical and industrial processes.
The mission insignia shows the space shuttle in the typical flying position for microgravity. The USML banner extends from the payload bay, in which the spacelab module with the text μg - the symbol for microgravity. Both the stars and stripes on the USML letters as well as the highlighted United States on the earth below the shuttle depict the fact that it was an all-american science mission.
Crew
Mission Parameters
Mission Highlights
The Space Shuttle Columbia rocketed to orbit for the longest Shuttle flight in
history. Columbia touched down almost 14 days later returning with data and
specimens amassed from an important suite of microgravity experiments. Shuttle
mission STS-50 carried the first United States Microgravity Laboratory (USML-1)
to space, conducting long-duration microgravity experiments. Microgravity is a
term that refers to a gravitational acceleration that is small when compared to
the gravitational attraction at Earth's surface. Through the action of free
fall (e.g., Space Shuttle orbiting Earth), the local effects of gravity are
greatly reduced, thus creating a microgravity environment.
While most STS-50 experiments were conducted in the U.S. Microgravity
Laboratory, others were operating in Columbia's middeck. Included in the
middeck experiments were studies of Protein Crystal Growth, Astroculture, and
Zeolite Crystal Growth.Mission insignia
Related articles
External links
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