EUVE Press Kit

8/7/2019 EUVE Press Kit

1/18

EXTREME ULTRAVIOLETEXPLORER

PRESS KIT

J U N E 1992


2/18

1

CONTENTS

PUBLIC AFFAIRS CONTACTS .................................................. 2

GENERAL RELEASE................................................................. 3

SCIENCE OBJECTIVES ............................................................ 4RESPONSIBILITIES .................................................................. 5

MISSION TIMELINE ................................................................ 6

THE INSTRUMENTS ................................................................ 7

INSTRUMENTS SCHEMATIC ................................................... 8

SPACECRAFT OPERATIONS ..................................................... 9SPACECRAFT SCHEMATIC ...................................................... 10

MISSION OPERATIONS ............................................................ 11

SCIENCE OPERATIONS ............................................................ 11PAYLOAD PROCESSING ........................................................... 12

LAUNCH OPERATIONS ............................................................ 13

LAUNCH VEHICLE SCHEMATIC .............................................. 14

LAUNCH VEHICLE .................................................................. 15

MISSION MANAGEMENT ........................................................ 16

.. .


3/18

2

PUBLIC AFFAIRS CONTACTS

Michael BraukusOffice of Space Science and ApplicationsNASA Headquarters, Washington, D.C.(Phone: 20Y453- 1549)

Dolores BeasleyGoddard Space Flight Center, Greenbelt, Md.(Phone: 30 l/286-2806)

George DillerKennedy Space Center, Fla.(Phone: 407/867-2468)

Camille TrentacosteUniversity of California, Berkeley(Phone: 510/642-9319)

Capt. Kenneth WarrenPublic Affairs Office45t h Space WingPatrick Air Force Base, Fla.(Phone: 407/494-773 1)


4/18

3

GENERALRELEASE

Release: 92-XX

EUVE SATELLITE To EXPLORE NEWLY OPENED WINDOW

The extreme ultraviolet is one of the least-studied portions of theelectromagnetic spectrum. Now, with the launch of NASA's ExtremeUltraviolet Explorer (EUVE) satellite, this new window on the Universe willbe opened to detailed study.

EUVE, NASA's 67th Explorer mission, will be the first satellite to makeboth spectroscopic and wide-band observations over the entire extremeultraviolet (EUV) region. It is scheduled for launch aboard a McDonnellDouglas Delta I1 expendable launch vehicle from Cape Canaveral AirForce Station, Fla., on June 4, 1992. EUVE is designed to operate for at least18 months from a 340-mile (550km) arth orbit and will orbit the Ea rthevery 96 minutes.

This unique satellite consists of four telescopes--the most powerful set ofEUV telescopes ever flown. Three of these instrumen ts will map the entiresky to determine the existence, direction, brightness and temperature ofsources of extreme ultraviolet radiation. The fourth instrument is designedt o make spectroscopic observations to determine the composition andtemperature of the EUV sources discovered during the sky mapping. Someof the objects EUVE is likely to detect and study are white dwarf sta rs,binary star systems and the hot outer atmospheres (coronae) of starssimilar t o our Sun.

From the many objects of astronomical interest discovered during theEUVE all-sky survey and other objects already thought to be observable inthe extreme ultraviolet, guest observers will propose t o study targets usingthe spacecraft's fourth instrument, the extreme ultraviolet spectrometer.

sized missions th at make up the Explorer program. Since the ExplorerProgram began in 1958, these missions have given scientists worldwide anew understanding of astronomy and astrophysics, providing them anopportunity t o probe nearly every region of the electromagnetic spectrum,from infrared radiation t o gamma rays.

The EUVE is one of a long line of relatively low-cost, small-to-moderately

Goddard Space Flight Center, Greenbelt, Md., is responsible for thedesign, construction, integration , checkout and operation of EUVE. Thespacecraft's science instrumentation was designed, constructed andcalibrated by the Space Science Laboratories of the University of California,Berkeley. The EUVE s managed by Goddard for NASA's Office of SpaceScience and Applications. - end -


5/18

4

SCIENCE OBJECTIVES

Astronomers use the term "extreme ultraviolet" (EUV) to refer t o thehigh-energy end of the ultraviolet portion of the electromagnetic spectrum.Like other forms of light such as infrared and X-rays, EUV light is blockedby the E arth's atmosphere. It must be studied from space. In fact, even thevery low density gas found between the stars can block EUV light. Initiallyastronomers thought it would be impossible to detect EUV rays fromsources beyond our solar system.

However, our Sun is now known t o lie within an unusually hottransparent region of inters tellar space. This region, about 250 light-yearsin diameter, is often called the local bubble. Apart from a few small wispsof cold, opaque gas, it is mostly transparent to EUV radiation. EUV lightfrom very distant stars beyond the local bubble is unlikely t o reach theEar ths vicinity, and thus E W E will mostly detect sources in our ownstellar neighborhood.

The scientific mission of EUVE will initially consist of a six-month all-sky survey, together with a highly sensitive "deep" survey of a limitedportion of the sky. This will then be followed by a spectroscopy phase of atleast one year. In the spectroscopy phase, individual targets, whetherdiscovered in the all-sky survey o r identified from other information, will beanalyzed in detail through selected observations made with a n on-boardextreme ultraviolet spectrometer.

The EUVE surveys will be conducted by astronomers from the Center forExtreme Ultraviolet Astrophysics (CEA) a t the University of California,Berkeley, while the spectroscopic studies will be performed by guestobservers, selected through peer review.

As in the case of earlier Explorer missions, the most exciting discoveriesmay be those that a re unexpected. Objects thought t o be well understoodmay display surprising properties a t extreme ultraviolet wavelengths, andit is even conceivable tha t entirely new classes of celestial objects may bediscovered.


6/18

5

RESPONSIBILITIES

Observatory Goddard Space Flight Center

Telescopes Center for EUV Astrophysics,

University of California, BerkeleyExplorer Platform Spacecraft Fairchild Space,

Germantown, Md.

Delta I1 Launch Vehicle McDonnell Douglas, U.S. Air Forceand NASA


7/18

6

MISSION TIMELINE

Event

Liftoff

Six solid rocketmotors jettison

Three solid rocketmotors jettison

Main engine cutoff

Second stageignition

Fairing release

Second stageengine cutoff

Second stagerestart

Second stageengine cutoff (2 )

Spacecraftseparation

Time(Min:Sec)

0:o

1:02

202

4:24.5

4:38

5:05

11:11.9

6653

67: 12

71:05

Altitude(St.Miles)

0

8.7514.08 km

27.1443.6 km

64.05103.07 km

69.3111.5 km

78.5126.3 km

110.17177.3 km

328.83529.2 km

328.22528.2 km

327.99

0

1,9293,104.3 k m h

4,4927,228.9 kmh

12,68220,409.1 kmh

12,68020,405.9 kmh

12,85520,687.5 kmh

17,699.928,484.5 kmh

16,791.727,022.8 kmh

16,994.427,349.08 kmh

16,995.3527.83 km 27i350.53 kmh


8/18

7

E W E contains four telescopes, each 40 centimeters across. The threescanner telescopes and the deep survey/spectrometer telescope representthe state-of-the-art in extreme ultraviolet technology. These instruments,developed by scientists and engineers at the University of California,Berkeley, are mounted in the payload module, which is installed as a uniton the Explorer Platform spacecraft. The spacecraft was designed and builtby Fairchild Space in Germantown, Md., under Goddard management.

Each of the E W E scanner telescopes is about as large as a 55-gallon oildrum and weighs about 260 pounds (about 188 kilograms). The deep surveytelescope/spectrometr weighs about 7 10 pounds (323 kilograms).

Two of the scanning telescopes are nearly identical t o verify observationsand t o ensure a backup capability in the event of a malfunction. They areused for observing at the high-energy end of the extreme ultraviolet spectralband (70-400 Angstroms) --the energy range within which most sources areexpected t o be detected. These telescopes have gold-plated mirrors, withvery small grazing angles to reflect the maximum amount of radiation atthese higher energies.

The third scanner is specially designed t o observe a t the low-energy endof the extreme ultraviolet spectral band (400-760 Angstroms). Its mirrorsare plated with a special nickel alloy and use larger grazing angles t oreflect the maximum amount of lower energy radiation.

The Deep Survey/Spectrometer telescope's opening, or aperture, isdivided into six equal segments. Radiation from three of these segments isfocused by the grazing-incidence mirror onto the single deep-surveydetector. During the survey phase, this telescope will make long-exposureobservations while being pointed down the dark shadow cast by the Earth,allowing i t to detect much fainter sources than the all-sky survey scanners.

Radiation from the o ther three mirror segments is intercepted bydiffraction gratings that spread the radiation into beams of differentenergy. The beams are then directed to the spectrometer's three detectors.During spectroscopy studies, the spectrometer will analyze the wavelengthdistribution of radiation from individual sources t o determine thei rtemperature and chemical composition.

T


9/18


10/18

9

SPACECRAFT OPERATIONS

The Explorer platform spacecraR, plus the science payload, comprise theExtreme Ultraviolet Explorer observatory. The observatory is thermallycontrolled to protect the science payload from extreme temperaturechanges. This protection is especially important because orbital night and

day occur about 16 times each Ear th day as the satellite circles the planet.Like most satellites, the Extreme Ultraviolet Explorer is solar powered.

Photovoltaic cells on the satellite's solar array panels convert solar energyinto electricity, which is stored in rechargeable batteries. A t the beginningof the mission, the arrays will provide the spacecraft with more than 1,000wat t s of power during its journey around Ear th. Three hundred watts willbe allotted to power the science payload -- one-fourth the power needed t ooperate a typical microwave oven.


11/18


12/18

1 1

MISSION OPERATIONS

T

During the mission, Goddard's Payload Operations Control Center(POCC) will be responsible for communications with the observatory,transmitting commands and receiving science and engineering data. Thecenter will then route all science-related information t o the University ofCalifornia, Berkeley.

NASA's Tracking and Data Relay Satellite System (TDRSS) plays a nintegral role in mission communications. The observatory first t ransmitsdata to a relay satellite, located 22,300 miles above the Earth ingeostationary orbit, which sends the information t o the TDRSS groundstation at White Sands, NM. From there, the data are relayed up t o acommercial communications satellite, also in geostationary orbit, anddown to Goddard. Finally, the scientific data are sent over telephone linesto Berkeley.

SCIENCE OPERATIONS

While the Goddard Space Flight Center controls mission operations, theCenter for Extreme Ultraviolet Astrophysics (CEA) will coordinate scienceoperations, monitor instrument performance and collect data.

CEA, which operates from a dedicated building near the Berkeleycampus, includes a Science Operations Center and a Science Data AnalysisFacility. The Science Operations Center will work closely with Goddardmission planners t o coordinate the acquisition of scientific measurementsand command the instruments. The satellite's raw science telemetry andprocessed data will be archived at the Science Data Analysis Facility.There, Berkeley scientists will produce the all-sky survey catalog and skymap and study data from the mission's deep survey.

In addition, Berkeley will support the NASA-sponsored Guest ObserverProgram during the mission's spectroscopy phase. One of Berkeley's taskswill be scheduling spectroscopic observations for the Guest Observers, whocan interpret da ta either at their home institu tions or a t the Berkeleyfacility.

-.. -


13/18

1 2

PAYLOAD PROCESSING

The Extreme Ultraviolet Explorer flight elements arrived at Hangar AEon Cape Canveral Air Force Station (CCAF'S)at the end of January. ThePayload Module was flown into the CCAFS Skid Strip by an Air Force C-5aircraft on Jan . 27 , 1992 and the Explorer Platform w as delivered by truckon Jan. 28. Processing was accomplished in Hanga r AE, a NASA facilityon CCAF'S by the Goddard Space Flight Center's E W E NASNcontractorteam with suppor t fiom the Kennedy Space Center's Payload OperationsDirectorate. After initial checkout, the Explorer Platform was mated withthe science payload module on Feb. 24.

A milestone w as reached on March 6 when the first "Countdown plusearly orbit" mission simulation w as successfully completed. This exercisebegan at a simulated Launch minus 18-hours and continued throughLaunch plus 48 hours. A second simulation w as successfully completed onApril 21.

After achieving a simulated orbit, the EUVE Payload Operations ControlCenter (OCC) at Goddard and the EUVE Science Operations Center (ESOC),located at the University of California, Berkeley, sent simulated commandst o the spacecraft. The spacecraft w as t o be moved to the launch pad in mid-May fo r mating and integration with the Delta I1 launch vehicle.


14/18

1 3

LAUNCH OPERATIONS

The U. S. Air Force's 1st Space Launch Squadron, 45th OperationsGroup, 45th Space Wing, is responsible fo r the preparation and launch ofthe Delta I1 which will carry the Extreme Ultraviolet Explorer into orbit.

The Delta I1 underwent buildup on Pad A of Space Launch Complex 17at CCAFS in mid-April. This activity includes erecting the first stage andinterstage, mating the nine solid rocket boosters in place around its base,and then hoisting the second stage atop the first stage. The significantmechanical and electrical tests are scheduled t o run between May 10 andMay 20.

On approximately May 15, the EUVE spacecraft is scheduled to arrive atthe pad to be mated to the Delta second stage. EUVE's integrated checksatop the vehicle and final spacecraft functional tests were planned to ru nbetween May 20 and May 24. During this period, workers will insta ll thenose fairing around the spacecraft.

The hypergolic propellants will be loaded aboard the Delta second stageapproximately two days prior t o launch. The RP-1 fuel (kerosenepropellant) and the super cold liquid oxygen, used a s a n oxidizer by the firststage, will both be loaded aboard during the terminal countdown.

Launch operations will be conducted from the Complex 17 blockhouse bya joint USAF/McDonnell Douglas team under the direction of the 45thOperations Group.

As this mission involves launch of a NASA payload, the space agencyhas responsibility fo r supporting EUVE flight preparations. A NASA KSC

launch manager will represent all space agency interest s during vehiclepreparations and the launch countdown and serve as NASA liaison withthe Air Force. The launch manager will be located in the MissionDirector's Center at CCAF'S to monitor launch countdown operations and toprovide the final NASA concurrence for launch t o the USAF launchdirector.

* -


15/18

D E LTA 10-FTFA I R I N G

LAUNCH VEHICLE

Guidance Section

Nitrogen SpheresCenterbody Section

Oxidizer Tank

\

First Stage

' hrust Augmentation Solids


16/18

1 5

LAUNCH VEHICLE

A U. S. Air Force Delta I1 6920-10 expendable launch vehicle will lift theEUVE nto low-Earth orbit for NASA. Built by McDonnell Douglas SpaceSystems Company (MDSSC) of Huntington Beach, Calif., the Delta I1 has aperfect launch record.

The EUVE flight will be the second time a 10-foot (3 meters) diameterfairing has been used on a Delta vehicle. Its first use was in 1990 forlaunch of the Roentgen Satellite (ROSAT) mission. The fairing, built i nthree sections, is based on the Titan family of fairings MCSSC has built foryears.

NASA fbnded the development of the 10-foot fairing to accommodate theROSAT, EUVE and other payloads requiring a larger volume tha n offeredby the 9.5-foot and 8-foot (2.8 meters and 2.3 meters) fairings regularly flownon Delta.

The EUVE launch is scheduled to be the 24th flight fo r the Delta 11.Delta's origins reach back t o the mid-1950s when the U. S. Air Forcedeveloped the Thor intermediate-range ballistic missile. NASA la te rmodified the Thor, a single-stage, liquid-fueled missile fo r the Delta launchvehicle.

The two-stage Delta I1 carrying EUVE consists of four major assemblies,th e first stage, including nine strap-on solid rocket motors, the interstage,the second stage and the payload fairing.

The Delta I1 is 123.4 feet tall and 8 feet (37.4 meters and 2.3 meters) indiameter. The payload fairing is 26 feet tall and 10 feet (7.8 meters and 3

meters) in diameter. The first stage main engine has a liftoff th ru st of207,000 pounds (93,150 kilograms) and each of the nine solid strap-onmotors has a sea-level th rust of 97,070 pounds (43,681 kilograms). Themain engine and six of the nine solid motors are burning at liftoff,providing a total thrus t of 789,420 pounds (355,239 kilograms).

The second set of three solid strap-on motors is ignited during the firststage burn. The second stage engine ha s a vacuum-rated thrust level of9,645 pounds (4,340 kilgrams).

T

Several major subcontractors t o MDSSC contributed to the Delta vehicle.The Rocketdyne Division of Rockwell, Canoga Park, Calif., is responsible

for the first stage engine. Aerojet Techsystems Co. of Sacramento, Calif.,builds the second stage engine. Morton Thiokol of Huntsville, Ala.,manufactures the solid rocket boosters and Delta Systems of Goleta, Calif.,produces the guidance computer.


17/18

1 6

MISSION MANAGEMENT

NASA Headquarters:

Dr. Lennard A. Fisk, Associate Administrator, Office of Space Science and

Dr. Charles J. Pellerin, Jr., Director, Astrophysics DivisionJohn Lintott, Program ManagerDr. Robert Stachnik, Program ScientistCharles Gunn, Director, Expendable Launch Vehicle a nd Upper Stages

Applications

Office

Goddard Space Flight Center:

Dr. John Klineberg, Center DirectorJa me s Barrowman, Project Manager, Explorers and Attached PayloadsFrank Volpe, Associate Project Manager for EUVE

Dr. Yoji Kondo, Project ScientistPe te ONeill, Project Manager, Satellite Servicing ProjectLlewellyn Nicholson, EUVE Flight Operations DirectorRobert Spiess, EUVE Spacecraft ManagerJohn Beckham, Delta Project Manager

University of California, Berkeley:

Prof. Stu art Bowyer, EUVE Science Principal InvestigatorDr. Roger Malina, Instrument Principal InvestigatorDr. Carol Christian, EUVE Guest Observer Project Scientist

Kennedy space centex

Robert L. Crippen, Center DirectorJohn T. Conway, Director of Payload Management and OperationsJ. L. Womack, Director, Expendable Vehicles, NASA Launch ManagerJoAnn H. Morgan, Director, Payload Projects ManagementThomas Rucci, EUVE Launch Site Support Manager

USAF 45th Space Wing, Patick AFS:

Brig. Gen. Jimmy R. Morrell, CommanderCol. Michael R. Spence, Commander 45th Operations GroupLt. Col. Randolph M. Moyer, Commander, 1st Space Launch Squadron,

Launch Director


18/18

1 7

McDonnellDouglas Space Systems Company:

Rich Murphy, Director, NASNSDIO and Commercial ProgramsLyle Holloway, Director, Launch SitesJerry Winchell, Program Manager, NASA ProgramsJ a y Witzling, Deputy Director, N A S N S D I O an d Commercial ProgramsJa ck Dodds, Launch Conductor

Documents

EUVE Press Kit