**National Aeronautics**

**And**

**Space Administration**

**Press Kit**

![](media/image1.pct){width="1.551388888888889in"
height="1.3583333333333334in"}

### **QuikTOMS Mission**

**September 2001**

###### [Public Affairs Contacts]{.underline}

Gary Caruso Headquarters Policy. Program Office 202-358-1705

Cynthia M. O'Carroll QuikTOMS GSFC PAO 301-614-5563

Bruce Buckingham KSC Launch Operations PAO 321-867-2468

Barry Beneski Orbital Sciences Corporation 703-406-5528

###### [Table of Contents]{.underline} [Page]{.underline}

QuikTOMS Press Release

Media Services Information

QuikTOMS Quick Facts

The QuikTOMS Mission

QuikTOMS Ozone Mapping Spectrometer -- QuikTOMS

Facts About Ozone

Program Management

OuikTOMS Orbit Raising Sequence

QuikTOMS Line Drawing

QuikTOMS Image

####### Press Release to be inserted once it is approved 

####### Media Services Information

**[NASA Launch Coverage]{.underline}**

Live commentary and coverage of the QuikTOMS launch will be available on
NASA TV beginning five minutes before the launch, at approximately 2:44
p.m. EDT

(11:44 a.m. PDT). This coverage will be broadcast on NASA TV on G-2,
transponder 9C, located at 85 degrees west longitude.

Orbital will provide live commentary and launch coverage via a
commercial satellite beginning at 1:45 p.m. EDT (10: 45 a.m. PDT). This
coverage will be broadcast on: **TBD**

A live webcast of the launch will be available at Orbital Sciences
Corporation's web site: www.orbital.com

**[Briefings]{.underline}**

A pre-launch briefing is scheduled for L-1 at 3:00 p.m. EDT (12:00 p.m.
PDT) on September 20 at the Pacific Coast Club at VAFB to discuss the
details of the launch vehicle, spacecraft and the weather for launch
day. The briefing will be will be taped by Orbital and an edited version
will be shown on the day of the launch as part of the launch commentary.

**[News Center/Status Reports]{.underline}**

NASA Public Affairs will staff the News Center at VAFB beginning on L-2
and continuing about two hours after a successful launch. Recorded
status reports also will be available beginning two days before launch
by dialing **805-734-2693** or **301-286-NEWS**.

#### 

**[Media Credentials]{.underline}**

Media seeking launch accreditation should contact the Resident Office at
Vandenberg AFB, Calif., by close of business two days before the launch
at 805-606-3595, fax:805-606-8303, or e-mail:
<Rebecca.Bonilla@Vandenberg.AF.mil>

***Requests [must be]{.underline} submitted on the letterhead of the
news organization and specify the editor making the assignment to cover
the launch***

######  

###### [Internet Information]{.underline}

Detailed information about the QuikTOMS mission and the TOMS instrument
can be found at the following web sites:

http://quiktoms.gsfc.nasa.gov

http://toms.gsfc.nasa.gov

###### http://www.orbital.com 

###### QuikTOMS Quick Facts

###### 

###### Spacecraft Dimensions:

**Size:** 112 cm x 117 cm (44 in. x 46 in.) stowed

**Weight:** 168 kg (370 lb.)

**Lifetime:** 1 year with a goal of 3 years

**Orbit:** 800 km (497 mi.) Sun synchronous, 10:30 am descending mode

## Instrument

Instantaneous Field of View: 3° square (42 km at nadir)

Mass: \~32 kg

Max. Scan Angle: ±54°

Radiation: 20 krad (total dose)

Resonant Freq.: \>120 Hz

Scan Cycle Time: 6.3 sec.

Scan Steps: 37

Wavelengths Used

• Band 1 360.0 ± 0.2 nm

• Band 2 331.2 ± 0.1 nm

• Band 3 322.3 ± 0.1 nm

• Band 4 317.5 ± 0.1 nm

• Band 5 312.5 ± 0.1 nm

• Band 6 308.6 ± 0.1 nm

## Launch

Launch Vehicle: Taurus

Payload: QuikTOMS is the secondary payload for this launch. The primary
payload Orbview-4/Warfighter-1, built by Orbital will provide high
resolution panchromatic, multispectral and hyperspectral imagery to
commercial and military customers.

**Subsystems**:

Communications: combine science and spacecraft S-Band Data Rate -- 400
Kbs

Propulsion: Fuel -- Hydrazine

Attitude Control: 3-axis stabilized, nadir pointing

Thermal: primarily passive, augmented with heaters

Solar Array Power Output at end of life: 239 watts

Instruments: Total Ozone Mapping Spectrometer

**Mission Lifetime**: 1 year with a goal of 3 years

**Launch Site:** Western range, Launch pad 576E, Vandenberg Air Force
Base

**Launch Window:** 2:49 p.m. -- 3:06 p.m. EDT (11:49 a.m. -- 12:06 p.m.
PDT)

**Spacecraft separation**: 3:02 p.m. EDT (L+14:01 minutes)

**Solar Array Deployment:** 3:02:30 p.m. EDT (L+14:06 minutes)

**First Signal Acquisition:** 3:17 p.m. at McMurdo (L+29:01 minutes)

**On-orbit Checkout:** L+3 days through 30 days

**Launch Vehicle Provider**: OSC Space Systems Group

**Launch Operations**: OSC Orbital Launch Services Group

**Spacecraft Operations:** Orbital Sciences Mission Control Center,
Dulles, VA

**Mission Management**: NASA Goddard Space Flight Center, Greenbelt, MD

**Mission Cost**: Total mission costs are approximately \$52.6 million.
This includes all costs associated with data processing of distribution
as well as five years of mission operations.

###### 

###### 

###### 

###### 

**The QuikTOMS Mission**

The QuikTOMS satellite carries NASA's fifth Total Ozone Monitoring
Sensor

(TOMS-5). Managed by the Goddard Space Flight Center's Earth Explorer's
Program, the main Objectives of the TOMS program are:

1.  ::: Definition-Term
    To determine long term changes in global total ozone levels
    :::

2.  ::: Definition-Term
    To understand the processes related to the \"ozone hole\" formation
    in the polar regions and local anomalies across the entire globe
    :::

3.  ::: Definition-Term
    To improve understanding of processes that govern the generation,
    depletion, and distribution of global total ozone
    :::

The TOMS instrument provides data to derive daily global measurements of

Ozone, Aerosols, Erythemal UV exposure, and Reflectivity. TOMS data
products are made available to scientists throughout NASA, the US
government and the international science community to better understand
the relationship between the atmospheric ozone distribution and the
factors that alter it.

**TOMS Sensor:** The TOMS instrument, the fourth built for NASA by
Orbital Sciences Corporation, is a cross-track scanning, grating
spectrometer designed to measure sunlight backscattered from the
Earth\'s atmosphere at six different ultraviolet wavelengths. For
accurate long-term measurements, it employs a diffuser assembly to
measure the solar flux, a reflectance calibration lamp for monitoring
the reflectivity of the diffuser surfaces, and a wavelength monitor.

**Spacecraft:** The QuikTOMS spacecraft is a derivative of Orbital
Sciences Corporation's MicroStar bus, one of the most widely flown and
most reliable LEO space platforms. Originally developed to support the
ORBCOMM global communications system, the lightweight design is
optimized for shared payload missions. The QuikTOMS spacecraft consists
of two rings stacked together; a core ring carrying all spacecraft and
payload support systems, and a second carrying four propulsion tanks and
two solar arrays.

**Taurus Launch Vehicle:** The Taurus launch vehicle is a
ground-launched variant of Orbital's air-launched Pegasus rocket capable
of launching up to 3,000 pounds to low Earth orbit. Taurus has achieved
a 100% success rate with five successful launches that have delivered 9
satellites into orbit.

###### Quick Total Ozone Mapping Spectrometer \-- QuikTOMS

The Total Ozone Mapping Spectrometer (TOMS) is the primary instrument
for studying atmospheric ozone on a global scale. National Aeronautics
and Space Administration (NASA) scientists use the TOMS instrument to
continuously

monitor changes of the Antarctic ozone hole, local ozone levels, and
global ozone.

TOMS also measures sulfur dioxide and ash from large volcanic eruptions,
smoke from forest fires and from forest clearing in the tropical rain
forests, airborne dust from large sand storm events, and the flux of
ultraviolet radiation reaching the Earth's surface. The U.S. Federal
Aviation Administration (FAA) is using these measurements to prevent
aircraft from flying through volcanic ash clouds.

In July 1999, NASA selected Orbital Sciences Corporation (Orbital) to
build, launch and operate the Quick Total Ozone Mapping Spectrometer
(QuikTOMS), so named since the QuikTOMS effort entailed the construction
and launch of a spacecraft in less than two years as compared to
traditional missions which take from three to five years. QuikTOMS was
procured by NASA's Goddard Space Flight Center's (GSFC) Rapid Spacecraft
Development Office (RSDO) and is managed by the GSFC QuikTOMS Project
Office.

###### Ozone Research

Ozone in the Earth's atmosphere absorbs virtually all of the Sun's
radiation in the biologically harmful ultraviolet (UV) wavelength range
of 200-310 nanometers (nm). Ultraviolet radiation can cause sunburn and,
more seriously, skin cancer, and cataracts. It also damages many other
life forms. The decline in global ozone levels, and the discovery of the
Antarctic ozone hole, has placed urgent emphasis on monitoring ozone
change.

Ozone data must be collected over an extended time period in order to
separate human-forced changes from natural atmospheric variations and to
help quantify the individual roles of these factors. Maintaining global,
carefully calibrated ozone measurements over decades is critical for
verifying ozone depletion and the expected

ozone recovery. These tasks are central challenges of stratospheric
research today.

Atmospheric ozone is controlled by a combination of radiative, chemical
and dynamical processes. Ozone plays an important role in these of
processes, coupling them in a complex set of feedback mechanisms. Among
the factors that affect ozone amounts are variations induced by: (1)
atmospheric dynamics (stratospheric weather); (2) solar variations; (3)
human produced gases such as chlorofluorocarbons (CFCs) and halons; and
(4) volcanic eruptions.

###### Total Ozone Mapping Spectrometer and Data

TOMS is a second-generation, ozone-sounding instrument derived from the
Backscatter Ultraviolet (BUV) Spectrometer flown aboard NASA's Nimbus-4
satellite in 1970. The first TOMS instrument was launched aboard Nimbus
7 in 1978. The Nimbus-7 TOMS operated almost continuously since its
launch until its failure in 1993, providing more than 15 years of
global, daily maps of total ozone. The Meteor-3 TOMS, ADEOS TOMS and the
Earth Probe TOMS followed the Nimbus-7 TOMS. The current operational
instrument, Earth Probe TOMS, has been in orbit for five years and
QuikTOMS will replace this aging satellite.

The QuikTOMS instrument will continue these measurements of total ozone.
These measurements will allow scientists to separate changes of global
ozone caused by natural processes from trends due to CFCs, halons, and
other trace gases. For example, theory predicts that long-term
variations of the UV output of the Sun will affect total ozone. However,
identifying these variations requires data extending over periods longer
than a decade. With this information, scientists can begin to predict
how human activity affects the environment.

Another important use of TOMS data will be to study changes of
biologically active UV

radiation that accompany changes in global ozone. The TOMS measurements
are used to determine the flux of ultraviolet sunlight at each point on
the Earth's surface at wavelengths that affect both plants and animals.
TOMS provides the information necessary for estimating biologically
active UV radiation at the Earth's surface as a function of location and
time of year.

Although the TOMS data will be used primarily to study ozone, the
information gained

from TOMS will also contribute to volcanic studies. Volcanoes generate
sulfur dioxide

(SO2) in the Earth's atmosphere and TOMS can map this gas. This gas is
rapidly transformed into sulfate aerosols, which may persist in the
stratosphere for months to years. Its effects in the stratosphere
include the red sunsets that follow major volcanic eruptions, and these
effects may be associated with climate change. TOMS

data on volcanic eruptions will make valuable contributions to studies
in several disciplines, including volcanology, meteorology and
atmospheric chemistry.

The TOMS data has many other applications. The total ozone pattern
measured by TOMS can be used in studies of severe storms to infer the
circulation patterns of the jet stream that strongly affect our weather.
TOMS can also observe smoke after it has been lofted to 3-4km altitude.
Unlike other instruments, TOMS can distinguish between smoke (or dust)
and clouds, and can be used to track the transport of smoke or dust over
long distances. TOMS ozone data can also be used for comparison with
ground stations, atmospheric correction of ocean color measurements of
pigment concentrations, studies of the UV reflectivity of Earth's
surface, and development of cloud climatology.

###### Program History

The first TOMS instrument was launched in October 1978 as part of the
package of the Solar Backscattered Ultraviolet and Total Ozone Mapping
Spectrometer (SBUV/TOMS) on Nimbus-7, and operated until May 1993. The
engineering model of Nimbus-7 TOMS was refurbished and flown aboard
Meteor-3 in August 1991. Meteor-3/TOMS provided critical scientific data
until December 1994.

A new series of TOMS instruments was developed to monitor the long-term
trend of

global total ozone and to continue the study of ozone loss and the
Antarctic ozone hole. The first of these, Earth Probe TOMS, was launched
aboard Earth Probe (EP) in July 1996, and is still operating. A TOMS
instrument was also launched aboard the Japanese ADEOS satellite, in
August 1996: and operated until June 1997 when the satellite's solar
array failed.

On June 17, 1992, the United States and the Russian Federation signed an
agreement concerning cooperation in the exploration and use of outer
space for peaceful purposes. In December 1994, NASA and the Russian
Space Agency (RSA) signed an agreement to fly a TOMS aboard a Russian
Meteor-3M spacecraft. However, because of delays, NASA and RSA agreed to
halt cooperation on the mission. In order to meet the critical science
window, the primary science objectives of NASA, and the environmental
information needs of the international community, QuikTOMS was
conceived.

###### Science Objectives

The primary science objective of NASA's TOMS mission is to continue the
ongoing measurements of the Earth's atmospheric ozone begun with Nimbus
7 in 1978 and currently being measured by the NASA Earth Probe (EP)/TOMS
mission.

Secondary mission objectives are to: measure ultraviolet absorbing
tropospheric aerosols; detect and measure non-absorbing aerosol
pollution plumes; estimate surface ultraviolet irradiance and
reflectivity; and detect and measure volcanic emissions to assist the
U.S. Federal Aviation Administration (FAA).

###### QuikTOMS Management

NASA Headquarters' Office of Earth Science (OES) manages the overall
Earth Explorer and TOMS programs. The Earth Explorers Program Office is
responsible for the management of all Earth Explorers Projects assigned
to Goddard, which includes the QuikTOMS Project. The QuikTOMS Project
Office is responsible for the management of the QuikTOMS mission through
definition, development, and integration and test, launch and on-orbit
checkout.

The TOMS program is managed by NASA's Goddard Space Flight Center,
Greenbelt, and is part of NASA's Earth Science Enterprise, a coordinated
research effort to study the Earth as a global environmental system.

###### Mission Operations

QuikTOMS is a free-flying spacecraft with its own orbit adjust
subsystem. It will be

launched into an intermediate parking orbit, from which it will be
raised by a series of orbit-adjust burns, to its operational
Sun-synchronous orbit of 500 miles (800km). As soon as the spacecraft
separates from the launch vehicle, a preprogrammed sequence of commands
will be initiated to deploy the solar arrays and transition the
spacecraft to safe mode.

## 

Ground coverage for communications and tracking for the on-orbit phase
of the mission will be provided by the Universal Space Network. The NASA
Earth Observing System Polar Ground Network will be used for the launch,
checkout and orbit raising phases of the mission. Flight Dynamics and
the NASA Integrated Services Network are supplied by the Space
Operations Management Organization to support QuikTOMS. They support the
launch and on-orbit checkout phase. Orbital Sciences Corporation
provides the Mission Control Center, which is located in Dulles,
Virginia, and is responsible for the Flight Operations Team that
provides spacecraft operations (telemetry, command, and control. The
TOMS Science Operations Center, located at the Goddard Space Flight
Center in Greenbelt, Md., generates instrument

operations plans. The flight operations team integrates instrument plans
into the spacecraft operations, captures science data from the mission
control center and forwards them to the science center for data
processing and generation of data products.

###### Launch

The QuikTOMS mission will be launched from Vandenberg Air Force Base,
Calif., on a

commercial Taurus launch vehicle. QuikTOMS is a secondary payload to be
flown with the OrbView-4 spacecraft, which is the primary payload. The
QuikTOMS secondary payload services are obtained by NASA Kennedy Space
Center, Fla., via a contract with Orbital Launch Systems Group. The
launch vehicle will deploy the spacecraft in an injection orbit of 292
miles (470-km) circular, 97.3 inclination, and at a 10:30 a.m. equator
crossing (descending node). Orbital Space Systems Group will provide the
spacecraft, which is a Microstar bus, adapted for the TOMS-5 instrument.
The TOMS instrument, provided by Orbital Science Corporations Sensor
Systems Division integrated with the spacecraft, is designated the
QuikTOMS observatory.

The mission orbit will be a sun-synchronous, 500 miles (800 km) circular
orbit, with a 10:30 a.m. Equator crossing. The spacecraft is designed
for a 3-year minimum on-orbit mission lifetime, with sufficient
consumables to support a 5-year mission.

###### The Future

To ensure that ozone data will be available throughout the next decade,
NASA will fly an advanced ozone-imaging instrument built by the Dutch
called Ozone Monitoring Instrument on the Earth Observing System AURA
spacecraft, scheduled for launch in 2003.

QuikTOMS satellite data, complemented by aircraft, balloon, and ground
data, provide a better understanding of natural environmental changes to
distinguish natural changes from human induced changes. This data, which
NASA freely distributes, is essential to making informed decisions about
our environment.

**FACTS ABOUT OZONE**

Ozone (O~3~ ) is a relatively unstable molecule made up of three atoms
of oxygen (O). Although it represents only a tiny fraction of the
atmosphere, ozone is crucial for life on Earth. Depending on where ozone
resides, it can protect or harm life on Earth. Most ozone resides in the
stratosphere (a layer of the atmosphere between 10 and 40 km above us),
where it acts as a shield to protect Earth's surface from the sun's
harmful ultraviolet radiation. With a weakening of this shield, we would
be more susceptible to skin cancer, cataracts, and impaired immune
systems. Closer to Earth in the troposphere (the atmospheric layer from
the surface up to about 10 km), ozone is a harmful pollutant that causes
damage to lung tissue, plants, and materials.

The amounts of "good" stratospheric and "bad" tropospheric ozone in the
atmosphere depend on a balance between processes that create ozone and
those that destroy it. An upset in the ozone balance can have serious
consequences for life on Earth. Scientists are finding evidence that
changes are occurring in ozone levels--the "bad" tropospheric ozone is
increasing in the air we breathe, and the "good" stratospheric ozone is
decreasing in our protective ozone layer. This article describes
processes that regulate "good" ozone levels.

# **Ozone Balance in the Stratosphere**

In the stratosphere, ozone is created primarily by ultraviolet
radiation. When high-energy ultraviolet rays strike ordinary oxygen
molecules (O~2~ ), they split the

molecule into two single oxygen atoms, known as atomic oxygen. A freed
oxygen atom then combines with another oxygen molecule to form a
molecule of ozone

There is so much oxygen in our atmosphere, that these high-energy
ultraviolet rays are completely absorbed in the stratosphere.

Ozone is extremely valuable since it absorbs a range of ultraviolet
energy. When an ozone molecule absorbs even low-energy ultraviolet
radiation, it splits into an ordinary oxygen molecule and a free oxygen
atom. Usually this free oxygen atom quickly re-joins with an oxygen
molecule to form another ozone molecule. Because of this "ozone-oxygen
cycle," harmful ultraviolet radiation is continuously converted into
heat.

Natural reactions other than the "ozone-oxygen cycle" described above
also affect the concentration of ozone in the stratosphere. Because
ozone and free oxygen atoms are highly unstable, they react very easily
with nitrogen (N), hydrogen (H), chlorine (Cl), and bromine (B)
compounds that are found naturally in Earth's atmosphere (released from
both land and ocean sources). For example, single chlorine atoms can
convert ozone into oxygen molecules and this ozone loss offsets some of
the production of ozone by high-energy ultraviolet rays striking oxygen
molecules.

In addition to the natural ozone balance, scientists have found that
ozone levels change periodically as part of regular natural cycles such
as the changing seasons, winds, and long time scale sun variations.
Moreover, volcanic eruptions may inject materials into the stratosphere
that can lead to increased destruction of ozone.

Over the Earth's lifetime, natural processes have regulated the balance
of ozone in the stratosphere. A simple way to understand the ozone
balance is to think of a leaky bucket. As long as water is poured into
the bucket at the same rate that water is leaking out, the amount or
level of water in the bucket will remain the same. Likewise, as long as
ozone is being created at the same rate that it is being destroyed, the
total amount of ozone will remain the same.

Starting in the early 1970's, however, scientists found evidence that
human activities are disrupting the ozone balance. Human production of
chlorine-containing chemicals such as chlorofluorocarbons (CFCs) has
added an additional factor that destroys ozone. CFCs are compounds made
up of chlorine, fluorine and carbon bound together. Because they are
extremely stable molecules, CFCs do not react easily with other
chemicals in the lower atmosphere. One of the few forces that can break
up CFC molecules is ultraviolet radiation. In the lower atmosphere, CFCs
are protected from ultraviolet radiation by the ozone layer itself. CFC
molecules thus are able to migrate intact up into the stratosphere.
Although the CFC molecules are heavier than air, the air currents and
mixing processes of the atmosphere carry them into the stratosphere.

Once in the stratosphere, the CFC molecules are no longer shielded from
ultraviolet radiation by the ozone layer. Bombarded by the sun's
ultraviolet energy, CFC molecules break up and release chlorine atoms.
Free chlorine atoms then react with ozone molecules, taking one oxygen
atom to form chlorine monoxide and leaving an ordinary oxygen molecule.

If each chlorine atom released from a CFC molecule destroyed only one
ozone molecule, CFCs would pose very little threat to the ozone layer.
However, when a chlorine monoxide molecule encounters a free atom of
oxygen, the oxygen atom breaks up the chlorine monoxide, stealing the
oxygen atom and releasing the chlorine atom back into the stratosphere
to destroy more ozone. This reaction happens over and over again,
allowing a single atom of chlorine to act as a catalyst, destroying many
molecules of ozone.

Fortunately, chlorine atoms do not remain in the stratosphere forever.
When a free chlorine atom reacts with gases such as methane (CH ~4~), it
is bound up into a molecule of hydrogen chloride (HCl), which can be
carried downward from the stratosphere into the troposphere, where it
can be washed away by rain. Therefore, if humans stop putting CFCs and
other ozone-destroying chemicals into the stratosphere, the ozone layer
eventually may repair itself.

# **Ozone Depletion**

The term "ozone depletion" means more than just the natural destruction
of ozone, it means that ozone loss is exceeding ozone creation. Think
again of the "leaky bucket." Putting additional ozone-destroying
compounds such as CFCs into the atmosphere is like increasing the size
of the holes in our "bucket" of ozone. The larger holes cause ozone to
leak out at a faster rate than ozone is being created. Consequently, the
level of ozone protecting us from ultraviolet radiation decreases.

During the last 15 years, an additional mechanism was found in the areas
over the Antarctic and Arctic that rapidly destroys ozone. Over the
Earth's poles during their respective winters, the stratosphere cools to
very cold temperatures and polar stratospheric clouds (PSCs) form. In
the polar stratosphere, nearly all of the chlorine is in the form of
inactive or "reservoir" gases such as hydrogen chloride (HCl) and
chlorine nitrate (ClONO~2~ ) that do not react with ozone or each other.
However, chemical reactions of these "reservoir" chlorine gases can
occur on the polar stratospheric cloud particle surfaces, converting the
chlorine "reservoir" gases into very reactive forms that rapidly destroy
ozone. This "polar chemistry" on the stratospheric cloud particles has
caused very large decreases in ozone concentrations over Antarctica and
the Arctic. In fact, ozone levels drop so low in spring over Antarctica
that scientists describe this loss as the "Antarctic Ozone Hole."

# **Monitoring Ozone from Space**

Since the 1920's, ozone has been measured by ground-based instruments.
Scientists place instruments at locations around the globe to measure
the amount of ultraviolet radiation getting through the atmosphere at
each site. From these measurements, they calculate the concentration of
ozone in the atmosphere above that location. These data, although useful
in learning about ozone, are not able to provide an adequate picture of
global ozone concentrations.

The amount and distribution of ozone molecules in the stratosphere
varies greatly over the globe. Ozone molecules are transported around
the stratosphere much as water clouds are transported in the
troposphere. Therefore, scientists observing ozone fluctuations over
just one spot could not know whether a change in local ozone levels
meant an alteration in global ozone levels, or simply a fluctuation in
the concentration over that particular spot. Satellites have given
scientists the ability to overcome this problem because they provide a
picture of what is happening daily over the entire Earth. The United
States satellite measurement program for ozone, run jointly by NASA and
the National Oceanic and Atmospheric Administration (NOAA), has measured
ozone distribution by season, latitude, and longitude, and has observed
long-term changes over more than 20 years using a variety of satellite
instruments. The instruments in use today will be replaced over the next
five to ten years by a new generation of improved, more sophisticated
instruments.

# **Predicting Ozone Levels**

Stratospheric ozone is being depleted worldwide--partly due to human
activities. Scientists now know that the large polar ozone losses are a
direct result of the effects from human-produced chemicals. However,
scientists still do not know how much of the mid-latitude loss is the
result of human activity, and how much is the result of fluctuations in
natural cycles.

Measurements and research are being used to improve models for
predicting ozone levels. In fact, early model predictions have already
aided policy makers

in determining solutions to the ozone depletion problem. Faced with the
strong possibility that CFCs could cause serious ozone depletion, policy
makers from

around the world signed the Montreal Protocol treaty in 1987, limiting
CFC production and usage. By 1992, the growing scientific evidence of
ozone loss prompted diplomats to strengthen the Montreal Protocol. The
revised treaty called for a complete phase out of CFC production in
developed countries by 1996. As a result, most CFC concentrations are
slowly decreasing around the globe.

Much remains to be learned about the processes that affect ozone. To
create accurate models, scientists must study simultaneously all of the
factors affecting ozone creation and destruction. Moreover, they must
study these factors from space continuously, over many years, and over
the entire globe.

NASA's Earth Observing System (EOS) will allow scientists to study ozone
in just this way. The EOS series of satellites will carry a
sophisticated group of instruments that will measure the interactions
within the atmosphere that affect ozone. Building on the many years of
data gathered by previous NASA and NOAA missions, these measurements
will increase dramatically our knowledge of the chemistry and dynamics
of the upper atmosphere and our understanding of how human activities
are affecting Earth's protective ozone layer.

**Related Web sites**:

Internet TOMS (Total Ozone Mapping Spectrometer)

http://toms.gsfc.nasa.gov

EOS Aura Project Homepage

http://aura.gsfc.nasa.gov

Ozone Dance

http://asd-www.larc.nasa.gov/edu_act/

ozone_dance.html

NASA's Earth Observatory - Ozone

http://earthobservatory.nasa.gov/Library/Ozone/

Atmospheric Chemistry Data & Resources

http://daac.gsfc.nasa.gov/CAMPAIGN_DOCS/

ATM_CHEM/ac_outline.html

Studying Earth's Environment from Space

Stratospheric Ozone

http://see.gsfc.nasa.gov/edu/SEES/strat/strat.htm

Related NASA Web sites

###### PROGRAM MANAGEMENT 

NASA Headquarters' Office of Earth Science (OES) manages the overall
Earth Explorer and TOMS programs. The Earth Explorers Program Office is
responsible for the management of all Earth Explorers Projects assigned
to Goddard, which includes the QuikTOMS Project. The QuikTOMS Project
Office is responsible for the management of the QuikTOMS mission through
definition, development, and integration and test, launch and on-orbit
checkout

NASA coordinates the launch of the spacecraft with Orbital Sciences
Corporation and the U.S. Air Force. The NASA Earth Observing System
Polar Ground Network will be used for the launch, checkout and orbit
raising phases of the mission. Flight Dynamics and the NASA Integrated
Services Network are supplied by the Space Operations Management
Organization to support QuikTOMS. They support the launch and on-orbit
checkout phase. Orbital Sciences Corporation provides the Mission
Control Center, which is located in Dulles, Virginia, and is responsible
for the Flight Operations Team that provides spacecraft operations
(telemetry, command, and control. The TOMS Science Operations Center,
located at the Goddard Space Flight Center in Greenbelt, Md., generates
instrument operations plans. The flight operations team integrates
instrument plans into the spacecraft operations, captures science data
from the mission control center and forwards them to the science center
for data processing and generation of data products.

**NASA Program Management:**

**Headquarters**

Dr. Ghassem Asrar, Associate Administrator of the Office of Earth
Science

Dr. Michael J. Kurylo, HQ QuikTOMS Program Scientist

**Goddard Space Flight Center**

Kenneth Schwer, QuikTOMS Project Manager

Dr. P.K. Bhartia, QuikTOMS Project Scientist

Dr. Richard McPeters, QuikTOMS Principal Investigator

**QuikTOMS Orbit Raising**

![](media/image2.pct){width="7.9in" height="5.292361111111111in"}

###### QuikTOMS Line Drawing

###### 

###### 

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##### ![](media/image4.pct){width="7.6in" height="5.144444444444445in"}QuikTOMS Animation