the magazine of the american astronautical society · 2016-04-20 · 2 space times • march/april...

T H E M A G A Z I N E O F T H E A M E R I C A NA S T R O N A U T I C A L S O C I E T Y

MARCH / APRIL 2007

I S S U E 1 V O L U M E 4 6

T H E M A G A Z I N E O F T H E A M E R I C A NA S T R O N A U T I C A L S O C I E T YISSUE 2 VOLUME 46

MARCH/APRIL 2007

2 SPACE TIMES • March/April 2007

T H E M A G A Z I N E O F T H E A M E R I C A N A S T R O N A U T I C A L S O C I E T Y

MARCH/APRIL 2007

ISSUE 2–VOLUME 46

6352 Rolling Mill Place, Suite 102Springfield, VA 22152-2354 U.S.A.Phone: 703-866-0020 Fax: [email protected] www.astronautical.org

AAS OFFICERSPRESIDENT

Mark K. Craig, SAICEXECUTIVE VICE PRESIDENT

Frank A. Slazer, United Launch AllianceVICE PRESIDENT–TECHNICAL

Rao S. Vadali, Texas A&M UniversityVICE PRESIDENT–PROGRAMS

Mary L. Snitch, Lockheed MartinVICE PRESIDENT–PUBLICATIONS

David B. Spencer, Penn State UniversityVICE PRESIDENT–MEMBERSHIP

Walter Faulconer, Applied Physics LaboratoryVICE PRESIDENT–EDUCATION

John E. Cochran, Jr., Auburn UniversityVICE PRESIDENT–FINANCE

Michael F. Zedd, Naval Research LaboratoryVICE PRESIDENT–INTERNATIONAL

Lyn D. Wigbels, RWI InternationalVICE PRESIDENT–PUBLIC POLICY

William B. Adkins, Adkins Strategies, LLCLEGAL COUNSEL

Franceska O. Schroeder, Fish & Richardson P.C.EXECUTIVE DIRECTOR

James R. Kirkpatrick, AAS

AAS BOARD OF DIRECTORSTERM EXPIRES 2007Paul J. Cefola, MIT/ConsultantMichael L. CianconeJohn W. Douglass, Aerospace Industries AssociationG. Allen FlyntRobert G. Melton, Penn State UniversityLinda V. Moodie, NOAAArnauld Nicogossian, George Mason UniversityFrederic Nordlund, European Space AgencyJames A. Vedda, The Aerospace CorporationThomas L. Wilson

TERM EXPIRES 2008Peter M. Bainum, Howard UniversityJohn C. BeckmanDavid A. Cicci, Auburn UniversityLynn F. H. ClineNancy S. A. Colleton, Institute for Global

Environmental StrategiesRoger D. Launius, Smithsonian InstitutionJonathan T. Malay, Lockheed MartinClayton Mowry, Arianespace, Inc.Kathy J. Nado, Computer Sciences CorporationRichard M. Obermann, House Committee on Science

TERM EXPIRES 2009Marc S. AllenSteven Brody, International Space UniversityAshok R. Deshmukh, Technica Inc.Graham Gibbs, Canadian Space AgencySteven D. Harrison, BAE SystemsSue E. Hegg, The Boeing CompanyArthur F. ObenschainIan Pryke, CAPR, George Mason UniversityRonald J. Proulx, Charles Stark Draper LaboratoryTrevor C. Sorensen, University of Kansas

SPACE TIMES EDITORIAL STAFFEDITOR, Jeffrey P. Elbel

PHOTO & GRAPHICS EDITOR, Dustin DoudPRODUCTION MANAGER, Diane L. Thompson

BUSINESS MANAGER, James R. Kirkpatrick

SPACE TIMES is published bimonthly by the AmericanAstronautical Society, a professional non-profit society. SPACETIMES is free to members of the AAS. Individual subscriptionscan be ordered from the AAS Business Office. © Copyright2007 by the American Astronautical Society, Inc. Printed in theUnited States of America.

PERIODICALSSPACE TIMES, magazine of the AAS, bimonthly,volume 46, 2007—$80 domestic, $95 foreignThe Journal of the Astronautical Sciences, quarterly, volume55, 2007—$170 domestic, $190 foreignTo order these publications, contact the AAS business office.

REPRINTSSee a story you’d like to share? Reprints are available for allarticles in SPACE TIMES and for all papers published in TheJournal of the Astronautical Sciences.

PRESIDENT’S MESSAGEInside The Journal of the Astronautical Sciences 3

FEATURESHydrogen Pressurization of LOX: High Risk/HighReward (Preprint) 4Hydrogen safety has been an oxymoron in many circles, datingback to the catastrophic loss of the Hindenburg. Today, the passingof three generations and the maturation of certain technologies hasadvanced technologies sufficiently so that a hydrogen fuel transportationinfrastructure can be discussed constructively.by Andrew E. Turner and Aaron Leichner

The Mars Landing Approach: Getting Large Payloadsto the Surface of the Red Planet 7Some proponents of human missions to Mars say we have thetechnology today to send people to the Red Planet. But do we?Rob Manning of the Jet Propulsion Laboratory discusses theintricacies of entry, descent, and landing, and what needs to bedone in order to make human presence on Mars a reality.by Nancy Atkinson

AAS NEWSSymposium Explores Past, Present, Future SpaceExploration 15by Mike Calabrese

Call for 2007 Nominations 18

NOTES ON NEW BOOKSTwo Sides of the Moon: Our Story of the Cold WarSpace Race 20Reviewed by Mark Williamson

Where’s My Jetpack? A Guide to the Amazing ScienceFiction Future That Never Arrived 21Reviewed by Gideon Marcus

UPCOMING EVENTS 23

SPACE TIMES • March/April 2007 3

Inside The Journal of the Astronautical Sciences

Have you ever taken time to read the inside cover of our Journal of theAstronautical Sciences? It’s pretty dry stuff compared to the articles that follow. Recentarticles have covered topics such as the latest results from Mars Rover navigation, ortimely data like that for periodic orbits near Europa, or state-of-the-art solutions likeone for trajectory optimization in the presence of uncertainty, and more. All of thosefindings and insights make the Journal so valuable to the astronautics community.There is, however, a relationship between the cover and what follows.

The Journal’s inside cover lists the volunteers whose dedicated andprofessional service go above and beyond, helping to make the Journal the qualitypublication that it is. Dr. Kathleen Howell of Purdue University, the Editor-in-Chief,receives all of the papers and works with the Associate Editors to obtain reviews andevaluate revisions. She also manages the issues by assigning papers and developing special issues. Dr. Henry Pernicka of theUniversity of Missouri – Rolla is the Journal’s Managing Editor. He works with the authors to prepare accepted papers forpublication by ensuring consistency in format and style, as well as technical accuracy. The nine Associate Editors requestreviews and evaluate submitted manuscripts based on reviewer opinions and suggestions. And then, of course, our manyreviewers do yeoman’s work by applying their expertise and experience.

In addition to producing the Journal on a quarterly basis, this team is working with VP Publications Dr. David Spencerand others to lead the Society into the future with an electronic submittal and review system and, ultimately, taking the Journalonline.

We owe each one of these volunteers a profound debt of gratitude, as we do our AAS Executive Director Jim Kirkpatrickand Executive Assistant Diane Thompson, who manage and coordinate production.

When you receive the next Journal, please take a moment to read the inside cover and pass along a “thank you” tothese colleagues for an important job very well done. And as you are approached to review a paper, please do. It makes adifference.

Mark [email protected]

PRESIDENT’S MESSAGE

FRONT: A series of images taken aboard the amphibious assault ship USS Boxer (LHD 4) shows the moon during a fulllunar eclipse. The Boxer Expeditionary Strike Group is operating in the Persian Gulf conducting Maritime SecurityOperations in support of U.S. 5th Fleet. U.S. (Source: Mass Communication Specialist Seaman Joshua Valcarcel)

BACK: The NexSat satellite prepares to re-mate with the ASTRO satellite (not pictured) as part of the DARPA OrbitalExpress program to demonstrate, for the first time, fully autonomous rendezvous and capture of client spacecraft,satellite-to-satellite refueling, and replacement of battery and flight-computer orbital replacement units. (Source: DARPA)

ON THE COVER


Hydrogen Pressurization of LOX: High Risk/High Reward (Preprint)by Andrew E. Turner, Space Systems/Loral and Aaron Leichner, Microcosm Corporation

The Aquarius launch vehicle layout and predicted lifespan from liftoff, satellite delivery, to re-entry breakup.(Source: Space Systems/Loral/Microcosm Corporation)

Hydrogen safety has been an oxymoronin many circles, dating back to thecatastrophic loss of the Hindenburg. OnMay 6, 1937, a sudden fire consumed theeight hundred foot long dirigible, whichwas filled with hydrogen gas. Airshipcommercial service, enabled by relativelylow-cost hydrogen, died along with thelongest vehicle ever to fly - even thoughthousands of passengers had beentransported safely prior to that incident.Since 1937, hydrogen has had a badreputation, though less prominentapplications such as launch vehicles, fuelcells and batteries have been safe andsuccessful. Today, the passing of threegenerations and the maturation of certaintechnologies has advanced technologiessufficiently so that a hydrogen fueltransportation infrastructure can bediscussed constructively.

One beneficial application of hydrogenis pressurization of launch vehiclepropellants. In this usage, hydrogenforces the liquid propellants out of theirstorage tanks and into the combustion

chamber, overcoming combustion back-pressure and other resistance along theway. Hydrogen is the most mass-efficient way to accomplish this task.Helium is considered the safer and morereliable solution. It is more often used,although it weighs twice as much.

While the use of helium is a sensibleapproach for high-cost, high-reliabilitysystems, hydrogen is attractive forsystems that do not require highreliability. An example is Aquarius, a newlow-cost, reduced-reliability launchvehicle for low-cost consumables. Forthis vehicle, an occasional failure will betolerated.

This article discusses pressurizationof liquid oxygen (LOX) with gaseoushydrogen. Though most rocket scientistswould not attempt this, it has now beenshown to be worthy of development.

Aquarius Low-Cost LaunchThe Aquarius launch vehicle was

discussed in two previous Space Timesarticles (May/June 2001 and March/April

2006). Aquarius achieves low-cost launchby permitting reduced reliability of 0.67-0.80. It will transport low-costconsumables and low-cost spacecraft andother easily replaceable equipment tonominally 200-km orbits, as the missionprofile shows. Since high reliability is notrequired, a cost per pound to orbit of $500is feasible. This is an order of magnitudebelow that of any present launcher. Failureof a few vehicles due to hydrogen fires orexplosions would be considered acceptableif this helps keep the net cost persuccessful mission low.

The most risky aspect of using gaseoushydrogen (GH2) is pressurization of theLOX tank, since hydrogen and oxygen areeasily ignited. A literature search byMicrocosm indicates that the suddeninsertion of only 0.02 milli-joules ofenergy, equivalent to dropping a one-ounceweight a distance of 0.003 inches, couldbe sufficient to ignite a pressurized mixtureof hydrogen and oxygen. No sparksallowed here! A typical spark contains tenjoules, 500 times the energy required for


“There was concern that such tanks wouldignite due to contact between the powerfuloxidizer LOX and the carbon fiber materialcomposing the tank walls.”

ignition. Merely allowing light to shine intothe dark, cold, high-pressure interior ofthe LOX tank might be enough to igniteits contents. The sudden release of tinyquantities of heat are not the only risksthe LOX tank faces if pressurized byhydrogen gas; the tiniest metallic particlescan also catalyze ignition, with disastrousresults.

The use of lightweight, low-cost, metal-free, and linerless graphite composite tankshas already been planned for Aquarius.Tanks of this type produced byMicrocosm were demonstrated to containLOX without incident aboard a soundingrocket by Garvey Spacecraft on June 3,2000. Prior to this test, and to earliertesting performed by Wilson CompositeTechnologies, there was concern that suchtanks would ignite due to contact betweenthe powerful oxidizer LOX and the carbonfiber material composing the tank walls.

The experimental test configuration as viewed from inside the control room. Gaseous hydrogenand LOX are supplied from tanks, at left, to the tank under test located within the bunker at center.

Gasses are vented at right through the flame arrestor.(Source: Space Systems/Loral/Microcosm Corporation)

But, following Microcosm’s and Wilson’ssuccessful demos, these metal-freevessels became strong contenders forthe demonstration of combustion-lessGH2 LOX pressurization. Such ademonstration would pave the way forthe development of hydrogen gas as an

ultra-lightweight pressurant, obtainable atlow cost from the liquid hydrogen alreadyplanned for use on Aquarius.

An initial tank pressurizationdemonstration was supported as a partof a fifteen month, one million dollar

study contract awarded in June 2005. Thestudy team included Aerojet, ORBITEC,Space Systems/Loral, and Microcosm.The California Space Authority helpedobtain support for this study through theoffice of Rep. Anna Eshoo (D-CA), andfunding was channeled through existing

Air Force Research Laboratory (AFRL)activities supporting development ofadvanced launch vehicles.

Microcosm, which produces liner-less composite tanks in a wide varietyof sizes, fabricated several ten inch


Andrew Turner has been an engineerwith Space Systems/Loral in Palo Alto,California for more than 23 years.

Aaron Leichner was working as aStructural Engineer and member of theScorpius launch vehicle team at Mi-crocosm, Inc. when this paper was pro-duced.

“For the new Aquariuslaunch vehicle, the fatalevent that brought thegreatest of all airshipsdown in flames is not ashowstopper.”

Sean Kenny (AFRL) holds a duplicate of the LOX tank subjected to testing whileAaron Leichner (Microcosm, on left) and Tom Fanciullo (Aerojet) look on.

(Source: Space Systems/Loral/Microcosm Corporation)

diameter, eighteen inch long tanks of analready proven design. Testing ofhydrogen pressurization of LOX wasconducted on May 9, 2006 at theInnovative Engineering Solutions (IES)facility in Murrieta, California, wheremodest quantities of explosive mixescan be safely tested. To the authors’knowledge, this was the first time a testof this sort had ever been tried.

The tank was loaded with fortypounds of LOX and pressurized tothirty atmospheres (440 psi) with GH2.This pressurization condition wasmaintained for about six minutes,simulating the time betweenpressurization of an Aquarius launchvehicle’s main propulsion subsystemand liftoff.

To simulate the tank environmentduring regulated pressure operation forthe first two minutes of flight, anexpulsion test was conducted. Anattempt was made to maintain constantpressure within the tank by adding GH2as the LOX was drained. However, thepressure fell from 440 to 250 psibecause fresh GH2 could not be addedquickly enough to maintain constantpressure.

Following the expulsion test a blow-down test was performed during whichthe tank was not re-pressurized withgaseous hydrogen as it was drained.This simulated the second and last two-

minute span of Aquarius poweredflight. During this portion of the test,pressure decreased more rapidly. Priorto the test conclusion, the flow of LOXceased. Gaseous hydrogen and gaseousoxygen were observed to be drainingfrom the tank. No ignition or otherharmful effects were observed.

Bigger and BetterThe successful completion of this test

validates the general concept of hydrogenpressurization of the LOX tank for the

low-cost/reduced-reliability Aquariuslaunch vehicle. Furthermore, it sets thestage for more ambitious testing involvinglarger tanks and more stringentenvironments which are morerepresentative of conditions expectedduring launch. It is expected that the nextseries of tests will involve re-use of thesame tanks used in the test described here,but the tanks will be mounted on a shakertable to simulate the launch vibrationenvironment. The concept involvesMicrocosm manufacturing a larger tankof an already proven all-composite design.With a volume of fourteen cubic feet, testswith a much larger volume of LOX andGH2 will be possible.

Shedding the Hindenburg StigmaSensible use of hydrogen for air and

space transportation is progressing as newtechnologies involving non-metallic, non-flammable tank materials help to overcomethe stigma of the Hindenburg disaster.

For the new Aquarius launch vehicle,the fatal event that brought the greatest ofall airships down in flames is not ashowstopper. It is merely a cautionary tale,and perhaps a challenge. Aquarius cantolerate the risk, as it will carry no people.It will carry only easily replaceablesupplies and low-cost, research-classspacecraft. High reliability is not requiredfor Aquarius’ economic success; in fact,the costs required for high reliability coulddoom true low-cost access to space forlow-cost payloads. Accepting the risk ofusing hydrogen as a pressurizing gas forliquid propellants, including LOX, helpsrealize the reward of low-cost access tospace.


The Mars Landing Approach: Getting LargePayloads to the Surface of the Red PlanetSome proponents of human missions to Mars say we have the technology today to send people to the Red Planet.But do we? Rob Manning of the Jet Propulsion Laboratory discusses the intricacies of entry, descent and landingand what needs to be done in order to make human presence on Mars a reality.By Nancy Atkinson

Space is Scary

Six Minutes of Terror; Engineers for the Mars ExplorationRovers described the entry, descent, and landing (EDL) phaseof the mission as six minutes of terror. The rovers entered Mars’atmosphere at 19,300 kilometers per hour (12,000 mph). Withinsix minutes, airbags slowed to the landers to a speed of twenty-four meters per second (fifty-four miles per hour) beforeimpacting the surface. The landers encountered extremeheat, deceleration pulses, and high winds. They relied onprecise performances of the heat shield, parachute, retrorockets, and airbags. Says Rob Manning, “In reality, the stresslasts much longer than six minutes.” JPL produced aHollywood-style trailer detailing EDL, entitled “Six Minutes ofTerror.” View it at http://marsrovers.nasa.gov/gallery/video/challenges.html.

The Great Galactic Ghoul; Early missions to Mars wereplagued with difficulties and failures, both for the US andUSSR. Engineers from JPL jokingly determined that there mustbe a space creature, a Great Galactic Ghoul, gobbling up thespacecraft heading to Mars. The phrase is usually attributedto the engineering team from Mariner 4. This spacecraft wasthe first to perform a successful flyby of Mars on July 14, 1965.

There’s no comfort in the statistics formissions to Mars. To date, over 60% ofthe missions have failed. The scientistsand engineers of these undertakingsinvented phrases like “Six Minutes ofTerror,” and “The Great Galactic Ghoul”to illustrate their experiences, evidence ofthe anxiety that’s evoked by sending arobotic spacecraft to Mars - even amongthose who have devoted their careers tothe task. Mention sending a humanmission to land on the Red Planet, withpayloads several factors larger than anunmanned spacecraft, and the trepidationamong that group grows even larger.Why?

The answer is that nobody knows howto do it.

Surprised? Most people are, says RobManning, the Chief Engineer for the MarsExploration Directorate. Manning ispresently the only person who has ledteams to land three robotic spacecraftsuccessfully on the surface of Mars.

“It turns out that most people aren’taware of this problem, and very few haveworried about the details of how you getsomething very heavy safely to thesurface of Mars,” explains Manning.

Manning believes many peopleimmediately come to the conclusion thatlanding humans on Mars should be easy.After all, humans have landedsuccessfully on the Moon, and we cansafely return human-carrying vehiclesfrom space to Earth for landing. SinceMars falls between the Earth and theMoon in size and also amount ofatmosphere, it seems that the middleground of Mars should be easy. “There’sthe mindset that we should just be able to

connect the dots in between,” saysManning.

As of now, the dots must connectacross a large abyss.

“We know what the problems are. Ilike to blame the god of war,” quipsManning. “This planet is not friendly orconducive for landing.”

The real problem is the combination ofthe Martian atmosphere and the size ofspacecraft needed for human missions.So far, our robotic spacecraft have beensmall enough to enable at least somesuccess in reaching the surface safely. Butwhile the Apollo lunar lander weighedapproximately ten metric tons, a human


This artist’s conception depicts the Mars Exploration Rover’s landing sequence during the last few seconds of the spacecraft’s journey.Approximately thirty to fifty feet above the Martian surface, retro-rockets are fired to slow the parachuting, airbag-padded rovers.

(Source: NASA/JPL-Caltech)


Rob Manning is the Chief Engineer for the JPL Mars ExplorationDirectorate and is the only person who has led teams to land three robotic

spacecraft successfully on the surface of Mars.(Source: Rob Manning/JPL)

“The real problem is thecombination of the Martianatmosphere and the size ofspacecraft needed for humanmissions.”

mission to Mars will require three to sixtimes that mass, given the restraints ofstaying on the planet for a year. Landingsuch a heavy payload on Mars is currentlyimpossible, using existing capabilities.“There’s too much atmosphere on Marsto land heavy vehicles like we do on themoon, using propulsive technologycompletely,” says Manning, “and there’stoo little atmosphere to land like we doon Earth. So, it’s in this ugly, grey zone.”

But what about airbags, parachutes, orthrusters? These have been used on thesuccessful robotic Mars missions. Whatabout a lifting body vehicle similar to thespace shuttle?

None of these will work, either aloneor in combination, to land payloadsupwards of one metric ton on the Martiansurface. This problem affects not onlyhuman missions to the Red Planet, butalso larger robotic missions for purposessuch as sample return. “Unfortunately,that’s where we are,” says Manning.“Until we come up with a whole newtrick, a whole new system, landinghumans on Mars will be an ugly and scaryproposition.”

Road MappingIn 2004, NASA organized a Road

Mapping session to discuss the currentcapabilities and future problems of landinghumans on Mars. Manning co-chaired thisevent along with Apollo 17 astronautHarrison Schmitt and the late ClaudeGraves from the Johnson Space Center.Approximately fifty other people fromNASA, academia, and industry attendedthe session. “At that time, the ability toexplain these problems in a coherent waywas not as good,” explains Manning.“The entry, descent and landing processis actually made up of people from manydifferent disciplines. Very few peoplereally understood, especially for large scalesystems, what all of the issues were. Atthe Road Mapping session, we were ableto put them all down and talk about them.”

The major conclusion that came fromthe session was that no one has yet figured

out how to safely get large masses fromspeeds of entry and orbit down to thesurface of Mars. “We call it theSupersonic Transition Problem,” saysManning. “Unique to Mars, there is avelocity-altitude gap below Mach 5 [Seefigure, page 10]. The gap is between thedelivery capability of large entry systemsat Mars, and the capability of supersonicand subsonic decelerator technologies toget below the speed of sound.”

Plainly put, with current capabilities, alarge, heavy vehicle, streaking throughMars’ thin, volatile atmosphere only has

about ninety seconds to slow from Mach5 to under Mach one. During this time, avehicle must change and re-orient itselffrom a being a spacecraft to a lander. Itmust deploy parachutes to slow downfurther. Thrusters must then be used in

order to translate to the landing site, andfinally, gently touch down.

No AirbagsWhen this problem is first presented to

people, the most offered solution,Manning says, is to use airbags, since theyhave been so successful for the missionsthat he has been involved with. Thesemissions include the Pathfinder rover,Sojourner, and the two Mars ExplorationRovers (MER), Spirit and Opportunity.

But engineers feel they have reachedthe capacity of airbags with MER. “It’snot just the mass or the volume of theairbags, or the size of the airbagsthemselves, but it’s the mass of the beastinside the airbags,” Manning says. “Thisis about as big as we can take thatparticular design.”

In addition, an airbag landing subjectsthe payload to forces between ten totwenty G’s. Robots can withstand suchforce, but humans can’t. This doesn’tmean airbags will never be used again. Itonly illustrates that airbag landings cannotbe used for something human or heavy.

Even the 2009 Mars Science Laboratory(MSL) rover, which weighed 775kilograms (compared to MER, weighing175.4 kilograms each) requires an entirelynew landing architecture. Too massive for


(Source: Rob Manning/JPL)

airbags, the small-car sized rover will usea landing system dubbed the Sky Crane.“Even though some people laugh whenthey first see it, my personal view is thatthe Sky Crane is actually the most elegantsystem we’ve come up with yet, and thesimplest,” says Manning. MSL will use acombination of a rocket-guided entry witha heat shield and parachute, followed bythrusters to slow the vehicle even more,which will then be followed by a crane-like system that lowers the rover on a cablefor a soft landing directly onto its wheels.Depending on the success of the SkyCrane with MSL, it’s likely that thissystem can be scaled for larger payloads- but probably not to the size needed toland humans on Mars.

Atmospheric Anxiety and ParachuteProblems

“The great thing about Earth,” saysManning, “is the atmosphere.” Returning

to Earth and entering the atmosphere atspeeds between seven and ten kilometersper second, the space shuttle, Apollo andSoyuz capsules and the proposed CrewExploration Vehicle (CEV) will alldecelerate to less than Mach one at abouttwenty kilometers above the ground. Thiswill be accomplished simply by skimmingthrough Earth’s luxuriously thickatmosphere and using a heat shield. Toreach slower speeds needed for landing,a parachute may be deployed. In the caseof the space shuttle, drag and lift allowthe remainder of the speed to bleed away.

But Mars’ atmosphere is only one percent as dense as Earth’s. For comparison,Mars atmosphere at its thickest isequivalent to Earth’s atmosphere at about35 kilometers above the surface The airis so thin that a heavy vehicle like a CEVwill basically plummet to the surface.There’s not enough air resistance to slowit sufficiently. Parachutes can only be

opened at speeds less than Mach two, anda heavy spacecraft on Mars would nevergo that slow by using only a heat shield.“There are no parachutes that you coulduse to slow this vehicle down,” saysManning. “That’s it. You can’t land a CEVon Mars unless you don’t mind it being acrater on the surface.”

That’s not good news for the Vision forSpace Exploration. Would a higher liftvehicle like the space shuttle save the day?“Well, on Mars, when you use a very highlift to weight to drag ratio like the shuttle,”explains Manning, “in order to get gooddeceleration and use the lift properly,you’d need to cut low into the atmosphere.You’d still be traveling at Mach two orthree fairly close to the ground. If youhad a good control system, you couldspread out your deceleration to lengthenthe time you are in the air. You’d eventuallyslow down to under Mach two to open aparachute, but you’d be too close to the


“Supersonic parachute experts have concluded that to sufficientlyslow a large shuttle-type vehicle on Mars and reach the groundat reasonable speeds would require a parachute one hundredmeters in diameter.”

Showing heritage, the relative sizes of Pathfinder (center), Mars Exploration Rover (left),and Mars Science Laboratory (right) wheels keep growing. (Source: NASA/JPL)

ground. Even an ultra large supersonicparachute would not save you.”

Supersonic parachute experts haveconcluded that to sufficiently slow a largeshuttle-type vehicle on Mars and reachthe ground at reasonable speeds wouldrequire a parachute one hundred metersin diameter.

“That’s a good fraction of the RoseBowl. That’s huge,” says Manning. “Webelieve there’s no way to make a 100-meter parachute that can be opened safelysupersonically, not to mention the time ittakes to inflate something that large. You’dbe on the ground before it was fullyinflated. It would not be a goodoutcome.”

Heat Shields and ThrustersIt’s not that Mars’ atmosphere is

useless. Manning explains that withrobotic spacecraft, 99% of the kineticenergy of an incoming vehicle is takenaway using a heat shield in theatmosphere. “It’s not inconceivable thatwe can design larger, lighter heat shields,”he says, “but the problem is that rightnow, the heat shield diameter for a human-capable spacecraft overwhelms anypossibility of launching that vehicle fromEarth.” Manning adds that it wouldalmost be better if Mars were like themoon, with no atmosphere at all.

If that were the case, an Apollo-typelunar lander with thrusters could be used.“But that would cause another problem,”says Manning, “in that for every kilogramof stuff in orbit, it takes twice as muchfuel to get to the surface of Mars as themoon. Everything is twice as bad sinceMars is about twice as big as the moon.”That would entail a large amount of fuel,

perhaps over 6 times the payload mass infuel, to get human-sized payloads to thesurface, all of which would have to bebrought along from Earth. Even on afictitious air-less Mars, that is not anoption.

Using current thruster technology inMars’ real, existing atmosphere posesaerodynamic problems. “Rocket plumesare notoriously unstable, dynamic, andchaotic systems,” says Manning.“Basically flying into the plume atsupersonics speeds, the rocket plume isacting like a nose cone; a nose cone that’smoving around in front of you against veryhigh dynamic pressure. Even though theatmospheric density is very low, becausethe velocity is so high, the forces are reallyhuge.”

Manning likens theses forces to aCategory Five hurricane. This wouldcause extreme stress, with shaking andtwisting that would likely destroy thevehicle. Therefore, using propulsivetechnology alone is not an option.

Using thrusters in combination with aheat shield and parachute also poseschallenges. Assuming the vehicle hasused some technique to slow to underMach one, using propulsion just in thefinal stages of descent to gradually adjustthe lander’s trajectory would enable thevehicle to arrive very precisely at thedesired landing site. “We’re looking atfiring thrusters less than one kilometerabove the ground. Your parachute hasbeen discarded, and you see that you areperhaps five kilometers south of where


The Hypercone, an inflatable supersonic decelerator design, is a technology being developed to allow foreventual human landings on the surface of Mars. (Source: Vertigo, Inc.)

“Mars is really begging for a space elevator,” says Manning.

you want to land,” says Manning. “Sonow, you need the ability to turn thevehicle over sideways to try to get to yourlanding spot. But this may be anexpensive option, adding a large tax infuel to get to the desired landingrendezvous point.”

Additionally, on the moon, with noatmosphere or weather, there is nothingpushing against the vehicle and taking itoff target. Like Neil Armstrong provedduring Apollo 11, the pilot can “fly outthe uncertainties,” as Manning calls it, toreach a suitable or more desired landingsite. On Mars, however, large variations

in the density of the atmosphere coupledwith high and unpredictable winds conspireto push vehicles off course. “We need tohave ways to fight those forces, or waysto make up for any mis-targeting using thepropulsion system,” says Manning. “Rightnow, we don’t have that ability, and we’rea long way from making it happen.”

Supersonic DeceleratorsThe best hope on the horizon for making

the human enterprise on Mars possible isa new type of supersonic decelerator that’sonly on the drawing board. A few

companies are developing a newinflatable supersonic decelerator calleda Hypercone.

Imagine a huge donut with a skinacross its surface which girdles thevehicle, and inflates very quickly withgas rockets (like air bags) to create aconical shape. This would inflate aboutten kilometers above the ground whilethe vehicle is traveling at Mach four orfive, following peak heating. TheHypercone would act as an aerodynamicanchor to slow the vehicle to Mach one.

Glen Brown, Chief Engineer at Vertigo,Inc. in Lake Elsinore, California was also


Data from successful Martian exploration missions are used together. This image taken by theMars Reconnaissance Orbiter HiRISE instrument is being used to point out potentially interestinggeological samples for analysis by Opportunity, the nearby Mars Exploration Rover. (Source:NASA/JPL/University of Arizona)

a participant in the Mars Road Mappingsession. Brown says Vertigo has beendoing extensive analysis of theHypercone, including sizing and massestimates for landers from four to sixtymetric tons. “A high pressure inflatablestructure in the form of a torus is alogical way to support a membrane in aconical shape, which is stable and hashigh drag at high Mach numbers,”Brown says. Brown adds that thestructure would likely be made of acoated fabric such as silicon-Vectranmatrix materials. Vertigo is currentlycompeting for funding from NASA inorder to support further research. Theproject’s next step, deployment in asupersonic wind tunnel, is quiteexpensive.

The structure would need to be aboutthirty to forty meters in diameter. Theproblem is that large, flexible structuresare notoriously difficult to control. Atpresent, there are also several otherunknowns involved with the developmentand use of a Hypercone.

One train of thought is that if theHypercone is able to slow the vehiclebelow Mach one, then subsonicparachutes could be used, much like theones employed by Apollo, or similar tothose which the CEV is projected to usefor landing on Earth. However, it takestime for the parachutes to inflate.Subsequently, there would only be amatter of seconds of use, allowing littletime to shed the parachutes beforeconverting to a propulsive system.

“You’d also need to use thrusters,” saysManning. “You’re falling ten times faster,because the density of Mars’ atmosphereis one hundred times less than Earth’s.That means that you can’t just land withparachutes and touch the ground. You’dbreak people’s bones, if not the hardware.So, you need to transition from aparachute system to an Apollo-like lunarlegged lander sometime before you getto the ground.”

Manning believes that those who areimmersed in these matters, like himself,see the various problems fighting each


Nancy Atkinson is a freelance journalistand a NASA/JPL Solar SystemAmbassador.

(Source: Rob Manning/JPL)

other. “It’s hard to get your brain aroundall these problems, because all the piecesconnect in complex ways,” he says. “It’svery hard to see the right answer in yourmind’s eye.”

The additional issues of creating newlightweight but strong shapes andstructures, with the ability to come apartand transform from one stage to anotherat just the right time means developing arapid-fire Rube Goldberg-likecontraption.

Other Options and IssuesAnother alternative discussed at the

2004 Mars Road Mapping session wasthe space elevator.

“Mars is really begging for a spaceelevator,” says Manning. “I think it hasgreat potential. That would solve a lot ofproblems, and Mars would be an excellentplatform to try it.” But Manning admitsthat the technology needed to suspend aspace elevator has not yet been invented.The issues with space elevator technology

lunar landing systems developmentsimultaneously. But NASA knows that thisis on its plate of things to do in the future,and is just beginning to get a handle onthe needed technology developments. I tryto go out of my way to tell this story,because I’m encouraging youngaeronautical engineering students,particularly graduate students, to startworking on this problem on their own.There is no doubt in my mind that withtheir help, we can figure out how to makereliable human-scale landing systems workon Mars.”

While there is much interest throughoutNASA and the space sector to try to tacklethese issues in the ensuing years,technology also needs a few more yearsto catch up to the dream of landinghumans on Mars. This story, like all goodengineering stories, will inevitably read likea good detective novel with technicaltwist and turns, scientific intrigue, andhigh adventure on another world.

“The honest truth of the matter,” saysManning, “is that we don’t have astandard canonical form, a standardconfiguration of systems that allows usto get to the ground with the right sizethat balances the forces, loads, and thepeople, allowing us to do all thetransformation that need to be done inthe very small amount of time that wehave to land.”

may be vast, even compared with thechallenges of landing.

Despite these known obstacles, thereare few at NASA currently spendingquality time working on any of the issuesof landing humans on Mars.

Manning explains, “NASA does not yethave the resources to solve this problemand also develop the CEV, complete theInternational Space Station, and do the

“I’m encouraging young aeronautical engineering students,particularly graduate students, to start working on this

problem on their own.”


AAS NEWS

The 45th Robert H. Goddard Memorial Symposiumwas held March 20-21, 2007 at the University of MarylandUniversity College Inn and Conference Center. This annualsymposium is sponsored by the American AstronauticalSociety (AAS) and supported by the NASA Goddard SpaceFlight Center.

This year’s theme, “Sputnik to Orion: Perspectives,Opportunities, and Future Directions,” provided a forum toreflect and wonder about humankind’s fascination with spaceexploration.

SYMPOSIUM EXPLORES PAST, PRESENT, FUTURESPACE EXPLORATIONBy Michael Calabrese, SGT, Inc.

Center Director Edward Weiler offers a warm welcometo attendees on the first day of the Symposium

(Source: Christopher Gunn/NASA GSFC)

Goddard’s Center Director Ed Weiler began thesymposium by welcoming attendees and introducing keynotespeaker NASA Administrator Michael Griffin. Dr. Griffinreflected on the last 50 years of space exploration and JohnF. Kennedy’s challenge which propelled our nation into aleadership role on the space frontier. “I do believe the mostsignificant and lasting outcome of our national reaction to

Sputnik was the creation of NASA in 1958 as the agencyresponsible for our nation’s civil space program,” Griffinsaid.

Looking into the future, Griffin cited his recentarticle in the online edition of Aviation Week and SpaceTechnology, in which he concluded that “If we continue toreceive today’s budget in inflation-adjusted dollars – nomore and no less – we will have enough money to do anApollo-scale program, three times over, and more, by the100th anniversary of Sputnik.”

In conclusion, Griffin spoke about programplanning and insisted that “We must bring forward realisticprograms, executable within the budget portfolios.” He alsoemphasized that these programs should not be relying onthe achievement of “miracles in series.” He described the“three mission areas of space exploration, scientificdiscovery, and aeronautics research as strategic capabilities


AAS NEWS

for our nation. And further, that they can operate in balanceand synergistically with each other.”

A “Sputnik to Orion: 50 Years in Space” video waspresented as an introduction for the first session of thesymposium. The video included a few memorable imagesthat captured some of the amazing accomplishments of thefirst 50 years of the space age.

The first day of the symposium also included technicalsessions covering The Space Age at 50: What Can HistoryTell Us? moderated by Roger Launius; Engineering SpaceExploration moderated by Doug Cooke; EngineeringSpace Commercialization moderated by Doug Comstock;and Engineering the Systems – Lessons Learnedmoderated by Joe Rothenberg.

Congressman Nick Lampson speaks toattendees at the Tuesday luncheon


During lunch, Congressman Nick Lampson (D-TX)addressed attendees and reflected on the importance ofkeeping the public informed as to the results and importanceof our space exploration, scientific discovery and aeronauticsresearch efforts.

Kathie Olsen, Deputy Director of the NationalScience Foundation (NSF), provided the keynote addresson the second day. She discussed the role of the NSFworking together with NASA and making contributions toAstronomy, Space Weather, and Astrobiology. Technicalsessions on the second day included The Science Enabled

by the Moon moderated by Jim Garvin and Space andEarth Science 2020 moderated by Laurie Leshin and RickObenschain.

Wednesday’s lunch speaker was Lon Rains, Editorof Space News. During lunch, AAS President Mark Craigpresented Wesley T. Huntress, Jr. with the RandolphLovelace II Award, Marcia Smith with the John F. KennedyAstronautics Award, Richard Williams with the MelbourneW. Boynton Award, and Dr. James Hansen with the EugeneM. Emme Astronautical Literature Award.

The 2006 co-recipient of the Nobel Prize for PhysicsDr. John Mather concluded the second day of presentations.

The first panel session discusses The SpaceAge at 50: What Can History Tell Us?


Dr. John Mather, Nobel Prize winner, concludesthe symposium with his presentation on COBE



AAS NEWS

Come to beautiful Mackinac Island, Michigan and join with leaders in the field of Astrodynamics at the 2007 AAS/AIAAAstrodynamics Specialist Conference. This annual event is hosted this year by AAS and cosponsored by the American Instituteof Aeronautics and Astronautics (AIAA). The conference will be held August 19-23 at the Mission Point Resort and is organizedby the AAS Space Flight Mechanics Committee. The technical program, special presentations and social events are not to be

missed – check www.space-flight.org for details and online registration. Registration is also available on-site.

2007 AAS/AIAA Astrodynamics Specialist ConferenceMission Point Resort Mackinac Island, Michigan

August 19-23, 2007

He spoke about his work with Cosmic Background Explorer(COBE) and winning the Nobel Prize, and provided a futureglance into space science with the James Webb SpaceTelescope (JWST). Dr. Mather concluded that JWST willcontinue our pursuit of improved understanding directed atthe major questions facing us in astrophysics.

Student and Goddard Research and DevelopmentPosters were presented in the lobby throughout thesymposium.

The presentations and videos from the symposiumare available on the AAS website, www.astronautical.org.

A student explains his poster(Source: Christopher Gunn/NASA GSFC)


AAS NEWS

Fellows: To qualify as an AAS Fellow, a candidate must be a current active member with significant scientific, engineering,academic, and/or management contributions to astronautics and space. In addition, contributions to AAS are considered. Selectionprocedures and a complete list of Fellows elected since 1954 can be viewed on the AAS web site. Nominations may be submittedby any AAS member, and must be received by the AAS Business Office by June 15. The Fellows Committee will review allsubmissions, and their recommended candidates will be approved by the Officers, Directors, and Active Fellows.

Awards: Each year AAS presents awards to recognize the excellence and professional service of our own membership andmembers of the space community. All AAS members are invited and strongly encouraged to nominate worthwhile candidates forthis year’s awards. Award descriptions, previous recipients, and nomination procedures can be viewed on the AAS web site.Nominations will be accepted by the AAS Business Office through July 20, at which time the Awards Committee will review allsubmissions and forward names of recommended candidates to the Officers and Directors for vote. Recipients and newlyelected Fellows will be invited to accept their award at the annual AAS Banquet on November 13, 2007 at the South ShoreHarbour Resort in Houston.

Officers and Directors: Each year the Society must elect (or re-elect) a slate of eleven officers and one third of the Board ofDirectors. A Nominations Committee will select qualified candidates, who will then be placed on the ballot and voted on by theAAS membership. Are you interested in serving in an elected position, or would you like to nominate a qualified individual? If so,please contact the AAS Office.

AAS ANNUAL AWARDSSpace Flight Award (our highest honor – individual whose outstanding efforts and achievements have contributed most

significantly to the advancement of spaceflight and space exploration)

Flight Achievement Award (outstanding achievement as flight crew or flight crew member)

Victor A. Prather Award (honors researchers, engineers, and flight crew members in the field of extravehicular protection oractivity in space)

Lloyd V. Berkner Award (person who has made significant contributions to the commercial utilization of space technology)

Randolph Lovelace II Award (recognizes significant contributions to space science and technology)

Melbourne W. Boynton Award (conferred upon a physician who has made a significant contribution to the biomedical aspectsof spaceflight)

Dirk Brouwer Award (recognizes significant technical contributions to spaceflight mechanics and astrodynamics – nominatedby Space Flight Mechanics Committee)

John F. Kennedy Award (individual who has made an outstanding contribution to public service through leadership in promotingour space programs for the exploration and utilization of outer space)

Eugene M. Emme Astronautical Literature Award (selected by a subcommittee of the AAS History Committee)

Military Astronautics Award (for outstanding leadership in the application of astronautics to the development of space systemsfor national defense)

Industrial Leadership Award (individual in the space industry who has made an outstanding contribution through leadership indevelopment and acquisition of space systems)

Advancement of International Cooperation Award (for outstanding contributions in advancing international astronautics activities)

Carl Sagan Memorial Award (an individual who has demonstrated leadership in research or policies advancing exploration ofthe Cosmos – recipient is expected to give the Sagan Lecture at the National Conference – chosen by a joint committee of AASand The Planetary Society)

Lifetime Achievement Award (recognizes individuals who have made sustained, personal contributions to the field of Astronautics– last awarded in 2004 – awarded at every tenth anniversary of the Society)

Complete descriptions and past recipients available at www.astronautical.org

Attention All AAS Members

CALL FOR 2007 NOMINATIONS


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MARK YOUR CALENDARSfor the 2007 AAS National Conference and 54th Annual

Meeting in Houston, November 13-14!


NOTES ON NEW BOOKS

TWO SIDES OF THE MOON: OUR STORY OFTHE COLD WAR SPACE RACEReviewed by Mark Williamson

Two Sides of the Moon, by David Scottand Alexei Leonov, Simon & SchusterUK, 2005, 415 pages, £8.99, ISBN 0-7434-5067-1 [softcover]

Of the many people writing spacehistory books these days, some have thedistinct advantage of having actually beento space. Written by Apollo astronautDave Scott and Vostok cosmonaut AlexeiLeonov, Two Sides of the Moon is a goodexample. The book also benefits fromthe intrigue of celebrity, with a forewordby Neil Armstrong and an introductionfrom space buff Tom Hanks.

Though the book’s subtitle, Our Storyof the Cold War Space Race, places thebook neatly within its historical context,that race’s role in determining the courseof history will probably always remainopen to argument. Armstrong quotes thecommon belief that the Space Age beganbecause of the Cold War between theUS and USSR, but suggests this view is“not quite right,” citing the additionalinfluence of the InternationalGeophysical Year (IGY) and its pursuitof scientific understanding. In a jacketquote, Arthur C. Clarke states his opinionthat the book “provides a very valuableaccount of the way the Cold War wasended in space [reviewer’s italics].”

Although the book is a largelychronological story – from the early1930s to the early 2000s – it is, bynecessity, two tales woven into one. Thisis done by alternating relatively shortsections from each author, whichillustrate what each was doing andthinking througout his career. Thisassimilation nonetheless manages to bea seamless and engaging story. Much

of the credit for this must go to writerChristine Toomey, whose name does notappear on the cover. Obviously, the rawmaterial comes from the book’s principalsubjects, but somehow Toomey managesto ensure that respective sections areunified while still maintaining theindividual characters of the two spaceveterans.

Although the majority of the bookrelates to a bygone age, an epilogueprovides interesting opinions on recentevents. Leonov addresses criticism ofspace tourism pragmatically. “[Dennis]Tito had worked hard for his money,”states Leonov. “Why should he not beallowed to spend it as he wished?” Later,he adds, “Three space tourists likeDennis Tito each year would have beenenough to secure Mir’s financial future.”

Leonov also recalls Arthur C. Clarke’sbook 2010: Odyssey Two, which centerson the voyage of a spaceship named afterLeonov, and to whom the book was alsodedicated. Halfway through theserialisation of the story in a Soviet youthmagazine, Leonov remembers that hewas “hauled before a meeting” of theCommunist Party’s Central Committee.How could he allow this to happen, theyasked; the crew of the Alexei Leonovconsisted of Soviet dissidents! Leonov’sresponse was blunt. “You’re not worththe nail on Arthur C. Clarke’s little finger,”he told them.

Elsewhere, Scott explains his “left seat,right seat hypothesis” regarding how thesix Apollo landing missions affected theircrews. While the lunar modulecommanders, by convention occupyingthe left-hand seat, went on to pursue“more straightforward” business andacademic careers, he says, the right-seat

pilots “tended to follow more unusual,and sometime difficult, paths.” He citesBuzz Aldrin’s decent into alcoholism, AlBean’s career as a professional artist, EdMitchell’s research into “the nature ofconsciousness,” Jim Irwin’s career asan evangelist, and Jack Schmitt’s six-year term as a Senator in the U.S.Congress.

Scott suggests that reasons for theseunconventional choices might includefrustration in not commanding their ownlunar missions, or “not being burdenedwith the same level of responsibility” andtherefore having more time to think.Whatever your view, this book offersplenty to consider. It should be read notonly by those with an interest in spaceexploration, but also those who enjoybiographies. It will surely open eyes to aworld beyond typical celebrity, and mayeven encourage some to gaze at theMoon with a new-found wonder.

Mark Williamson is an independentspace technology consultant andauthor.


NOTES ON NEW BOOKS

WHERE’S MY JETPACK? A GUIDE TO THEAMAZING SCIENCE FICTION FUTURE THATNEVER ARRIVEDReviewed by Gideon Marcus

Where’s My Jetpack, by Dr. Daniel H.Wilson, Bloomsbury USA, 2007, 192pages, $14.95, ISBN 1-5969-1-136-0[softcover]

Fortune-telling is a tricky business.Sometimes, the future seems so obvious,one can’t help making accuratepredictions. In the early 1950s, everyoneknew that space travel was just aroundthe corner. In the late 1960s, it was asafe bet that electronics would get fasterand faster. But who would have guessedthat space travel would stagnate once wereached the moon? Who would haveforeseen that we’d have personalcomputers and iPods instead a giantMULTIVAC running the world?Sometimes, reality exceeds our wildestdreams - look at what we can do withbiotechnology these days. Most advanceswe expected as children still haven’tcome to pass, however. These frustratedvisions of the future are the subject ofWhere’s My Jetpack? A Guide to theAmazing Science Fiction Future ThatNever Arrived, a new book by Dr. DanielH. Wilson.

As an historian, I’ve always enjoyedscientific what-if scenarios. I’ll oftenpage through my collection of ancientGalaxy magazines and see what the farfuture looked like to writers of the 1950s.If I’m in a more serious mood, I’ll porethrough my fourteen volume set ofpredictions commissioned during the late1960s by TRW. Wilson’s book is acollection of short essays grouped bysubject, each detailing the fate of apredicted technology that “failed tolaunch.”

In addition to the personal jetpacksfeatured on the cover, there are essayson flying cars, zeppelins, and sentientrobotic pets: all the staples of mid-century science fiction. To be fair, agood many of the essays featuretechnologies which are now on the cuspof being realized. These are the mostfun. For instance, slidewalks can befound in malls and airports. Self-guidingcars navigated by GPS are here to adegree. While humanity has not moveden masse into the oceans, there is onefive-star hotel currently underconstruction off the coast of Dubai.

And who’s to say that there won’t becolonies on the moon or city-skyscrapers in the future? This is thepoint of the book - to touch upon dreamsof the past, see which ones failed andwhy, and consider whether they mightyet come true.

Of course, the real point of such a bookis to entertain. Well written with tonguelodged firmly in cheek, Wilson’s book isa quick read. This is definitely noscholarly work, but the reader will comeaway with some amusing trivia, andperhaps successfully avoid watching theboring in-flight movie during atranscontinental flight. If you are atechnology buff, or someone who wantsto know why the local Wal-Mart doesn’tsell ray guns, or wonders why WaltDisney’s head probably won’t betraveling the lecture circuit anytime soon,you’ll enjoy this book.

Gideon Marcus is a space historian andmember of the AAS HistoryCommittee.


Feature articles (1500-3000 words), op-eds (500-1500 words), and book reviews (600 words or less) areaccepted. Exceptions to these lengths must be discussed with the editor. The editor and author will agree on a lengthat the time an assignment is made.

Articles may cover virtually any topic involving space science, technology, exploration, law, or policy. Ar-ticles that touch on issues relevant to the civil, commercial, and military and intelligence space sectors alike are alsowelcomed.

Articles should be written for a well-educated audience that has a great interest in space topics but may notnecessarily be familiar with your specific topic.

Space Times is a magazine, as opposed to a technical journal. Articles should therefore be written in activevoice, with a clear explanation of technical concepts provided. The tone should lean more toward conversationalrather than formal. References will not be included with any articles.

Submission deadlines are typically six to seven weeks prior to the first month of the issue (e.g., July 16 for theSeptember/October issue). Exceptions must be discussed in advance with the editor.

Articles should be submitted in Microsoft Word format, Times New Roman font. Other formatting will behandled by us during the editing process.

Please provide with your article: a title; a subtitle or one to two sentence summary of the subject matter;subheadings to provide separation between major sections of the article; and a one to two sentence author biographywhich will appear at the end of the article. Complimentary copies of the issue in which your article appears will bemailed to all authors, so please provide a mailing address.

Submission of photos or other visual support is encouraged, but not required, and must be provided in highresolution (at least 300 dpi) and JPG, TIF, or GIF format. Visuals may not be imbedded in an article but must beprovided separately. Please provide proof of permission from the owner of any photos or visuals, or contact infor-mation of the owner if permission has not already been obtained prior to submission of an article.

A few style suggestions: units of measurement should be conveyed in metric, not English, terms; acronymsshould be used sparingly and only when a term is used several times; names of specific spacecraft (e.g., Columbia)should be italicized, but general spacecraft names (e.g., space shuttle, Delta) should not be; and numbers onethrough one hundred should be spelled out.

Contact: Jeffrey Elbel, Editor ([email protected])

Your help is requested! Three important committees will meet later this summer, and eachis critical to the work of AAS. The Awards Committee reviews nominations for ten majorAAS annual awards and selects worthy candidates for election by the Board. The FellowsCommittee reviews candidates for the annual Fellows election; over 420 distinguishedmen and women have been chosen for this honor since 1954. Finally, the NominationsCommittee develops a slate of officer and director candidates for election by the member-ship. Although the AAS President selects the committee chairs, membership of each isopen to AAS members. If you are interested in serving as a committee member, pleasecontact the AAS office at [email protected].

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