As Mars begins to recede from Earth and

fades from view, new data from

NASA’s Mars Global Surveyor (MGS)

spacecraft continue to enrich scientists’ under-

standing of our small planetary neighbour.

One of the major surprises has been the

strength of the localized magnetic fields on

Mars. Although Mars has no global magnetic

field, research by David Brain (University of

Colorado at Boulder) shows that its crust is

highly magnetized in certain areas, creating

“mini-magnetospheres” which may shield the

planet’s surface in certain areas from solar and

cosmic radiation.

The magnetometer on MGS has shown that

some parts of the crust are at least 10 times

more strongly magnetized than anything mea-

sured on Earth. In fact, these regions of mag-

netization are so strong that they can influence

magnetometer readings to altitudes of 960 to

1440 km, or about a third of the planet’s

radius. According to Brain, the intense magne-

tization occurs almost exclusively in the

planet’s southern hemisphere, which is much

older than the northern plains. “It’s likely that

early on, traces of Mars’ magnetic field were

frozen in the planet’s crust when its internal

dynamo shut down. Later on, ‘resurfacing’ of

the planet’s northern hemisphere by some type

of heating mechanism and large impact events

in the southern hemisphere demagnetized

much of the planet,” he said. “What we are

seeing may be the remnants of that process.”

Brain’s research has implications for the

escape of atmospheric gases into space and

climate evolution on the Red Planet, as well as

the radiation environment of these areas –

possibly making them safer landing sites for

future human expeditions. “In the absence of

these crustal sources, what you have is a sit-

uation similar to Venus,” said Brain. “The

planet’s smooth ionosphere acts as a balancing

force to the powerful solar wind.”

However, the influence of local areas of mag-

netization on Mars is so strong that the “mini-

magnetospheres” form small bumps above the

ionosphere. This surface varies as the solar

wind changes in intensity and the planet rotates.

The Martian magnetic field may be lumpy

but recent MGS images suggest that large areas

of the planet’s surface have been smoothed by

the action of water. According to Devon Burr,

Alfred McEwen (University of Arizona) and

Susan Sakimoto (NASA GSFC), vast quantities

of lava and water have recently flooded from

fissures near Mars’ equator.

The team analysed high-resolution images

and Mars Orbiter Laser Altimeter (MOLA)

data of the Athabasca Valles channel system

that branches south and southwest from the

Cerberus Fossae. The data show that the fos-

sae, or fissures, stretch more than 1000 km

across the lava-covered Cerberus Plains, just

north of the Martian equator. Their sharp

edges, steep slopes – more than 80° – and

lightly cratered lava plains indicate that the fis-

sures must have been active recently.

Not only have they extruded vast amounts of

lava over the surrounding landscape, but they

have also created catastrophic floods. Accord-

ing to the report in Geophysical Research Let-ters, some 600 km3 of water – one-and-a-

quarter times the volume of Lake Erie – may

have been released. “The water here gushed

from volcano-tectonic fissures,” said Burr.

“While the fissures themselves may be older,

the latest eruption of water was probably only

about 10 million years ago.”

Floods on Mars

The most distinctive evidence for aqueous

flooding is the discovery of streamlined, flat-

topped mesas in the middle of channels. These

teardrop-shaped features rise 100 m above the

channel floors at their upslope ends and range

from a few hundred to a few thousand metres

in length. The mesas are composed of fine, hor-

izontal layers, evidence that they were formed

by deposition in the lee of impact craters. The

new images also show grooves and ridges run-

ning parallel to the mesas or to the channel

walls. The grooves, about 100 m wide and

10 m deep, cover hundreds of square kilome-

tres. All of the fluvial features occur down-

slope, that is, south, of the Cerberus Fossae.

Further evidence, previously reported by

Peter Lanagan, McEwen and colleagues,

includes “rootless cones” at the downstream

ends of the channel. Similar cones in Iceland

are known to form when surface lava interacts

explosively with near-surface groundwater.

The most plausible source of the water that

produced the Martian rootless cones is a cata-

strophic flood.

Because the water flowed over permeable

lava, much of it may have been absorbed and

still persist in the Cerberus Plains as shallow

ground ice, the scientists conclude. The site is

Mission update

2.29April 2002 Vol 43

Space shorts

� FUSE FAILS, BUT NOT FOR LONG.

Science operations for the Far Ultraviolet

Spectroscopic Explorer (FUSE) mission

ceased on 10 December 2001 when the

second of four reaction wheels, used to

point and maintain the spacecraft’s atti-

tude precisely, stopped working. Their

efforts met with success in early March,

after the team developed an innovative

guidance system that lets controllers use

electromagnets in FUSE to orientate the

satellite. The method involved actively

changing the electricity flow to the torquer

bars with revised software so that engi-

neers could use the Earth’s magnetic field

to help point the satellite.

It is a great relief to project scientists,

because FUSE was performing very well

before its loss. “I am very excited to have

FUSE back,” said George Sonneborn,

FUSE project scientist at Goddard. “This

remarkable recovery will enable NASA to

complete the remaining year of the FUSE

prime mission, and perhaps two additional

years of science,” (fuse.pha.jhu.edu).

� YOHKOH LOSES POWER. Scientific opera-

tions with the Yohkoh solar observatory

have been terminated, due to a power loss

associated with an unexpected rotation in

the satellite as it crossed the path of an

annular eclipse over the Pacific Ocean on

15 December 2001. The satellite’s attitude

control switched from the normal Sun-

acquisition mode to standby mode as the

amount of sunlight reaching the space-

craft’s solar panels dipped during the

eclipse. The satellite is currently powered

down and spinning out of control (www

.lmsal.com/SXT/).

� MARS ODYSSEY BEGINS MAPPING.

NASA’s Mars Odyssey spacecraft has

begun its mapping mission after success-

fully completing aerobraking to attain a

nearly circular polar orbit. The mission

team turned on the thermal-emission

imaging system and the gamma-ray sensor

two weeks after the high antenna was

safely deployed (on 5 February). Both the

neutron spectrometer and the high-energy

neutron detector, also part of the gamma-

ray spectrometer suite, were already col-

lecting data about the location of hydro-

gen on Mars and the composition of the

planet’s surface. Having passed these mile-

stones, engineers planned to begin trouble-

shooting the Martian radiation environ-

ment experiment, which stopped

communicating and was turned off in

August 2001 (mars.jpl.nasa.gov/odyssey/).

Haunting imagesPeter Bond reports on Mars and Jupiter as never seen before, ghosts in

galaxy clusters and some surprising sunspots.

also likely to be a source of geo-

thermal activity, making it

an important target for

future Mars

exploration.

Mars Global

Surveyor is not

the only space-

craft to be

shedding new

light on the Red

Planet’s water

budget. NASA’s

Far Ultraviolet

Spectroscopic

Explorer (FUSE)

spacecraft has made the

first detection of molecular

hydrogen in the upper atmo-

sphere of Mars. Using the FUSE

data, Vladimir Krasnopolsky

(Catholic University of Amer-

ica, Washington, DC) and Paul

Feldman (Johns Hopkins University) report in

the 30 November issue of Science that they

were able to derive the quantity of Martian

water lost to space and estimate the amount of

water on Mars shortly after its formation.

“We calculate that if the initial quantity of

water on Mars could have been evenly distrib-

uted across the planet somehow, it would have

been equivalent to a global Martian ocean at

least three-quarters of a mile (1.25 km) deep,”

said Krasnopolsky. “This is 1.3 times more

water per mass than the Earth.”

Krasnopolsky and Feldman determined the

quantity of H2 molecules present (only about

15 parts per million) from the intensity of the

faint ultraviolet emission recorded by FUSE.

They compared the amount of H2 to the

amount of deuterium in the Martian atmo-

sphere, obtained from a 1997 Hubble Space

Telescope observation by Krasnopolsky.

Assuming that the Earth and Mars were cre-

ated with the same initial proportions of deu-

terium and water, and that the volume of the

Martian polar caps gives a reasonable estimate

of the water remaining on Mars today, they

worked backwards to determine how much

water was originally on Mars (www.gsfc.nasa

.gov/topstory/20011129marswet.html).

Water and carbonates

Solar system water also received top billing in

a research paper based on data from ESA’s

Infrared Space Observatory (ISO). According

to current ideas, planet-like bodies with liquid

water formed very early in the history of the

solar system, no more than 20 million years

after the first clumps of material formed

around the Sun. This theory is largely based on

the presence of carbonate minerals in primitive

objects such as meteorites. Since carbonates

form in liquid water, it seems rea-

sonable to assume that they

could only have come

into existence in

large, planet-like

bodies.

However, acc-

ording to Ciska

Kemper (Univ-

ersity of Ams-

terdam) and

colleagues, ISO

has provided

spectroscopic evi-

dence for the pres-

ence of carbonates in

dust shells surrounding

evolved stars, where the

accretion of large bodies is

unlikely. The paper in Naturedescribes how large amounts

of calcite and dolomite were

found in the nebulae

NGC 6302 and NGC 6537, respectively the

Bug Nebula and the Red Spider Nebula. These

nebulae surround old stars that have spent the

past 10 000 years expelling material through

dense stellar winds and are about to collapse

into white dwarfs. The observations of these

carbonates cannot be explained through the

interaction with liquid water, or the existence

of a planetary system. “The amount of car-

bonates we find is equivalent to at least 30

Earth masses, far too large to be the relic of a

hypothetical planetary system present before

the star became a planetary nebula,”

explained Kemper. “On the other hand, the

age of the dust shell in the nebula is about

10 000 years, which is too short for a new

planetary system to form.”

It seems, therefore, that the carbonates in the

nebulae must have formed through an alterna-

tive mechanism that does not involve liquid

water – such as a reaction between water vapour

and carbon dioxide. If this alternative mecha-

nism was also at work in the early solar system,

the assumption that carbonates in primitive

solar system objects indicate the rapid forma-

tion of water-laden planets needs to be reviewed

(sci2.esa.int/press/20020117ISOwater/).

Non-magnetic Io

Galileo’s closest and last flyby at any of

Jupiter’s four major moons took place on 17

January, when it swooped to within 102 km of

Io’s volcanic surface. Although this grazing

encounter successfully used the moon’s gravity

to put the spacecraft on course for a September

2003 impact with Jupiter, the scientific return

was limited by Galileo entering standby mode

about half an hour before its closest approach

to Io. The reset was apparently caused by expo-

sure to the intense radiation environment and

Mission update

2.30 April 2002 Vol 43

Space shorts

� HESSI SAFELY IN ORBIT. NASA’S High

Energy Solar Spectroscopic Imager (HESSI)

spacecraft lifted off from Cape Canaveral

on 5 February – 18 months behind sched-

ule. The 293 kg satellite and its Pegasus XL

rocket were carried over the Atlantic under

a Stargazer L-1011 aircraft and then

released. The Pegasus then placed HESSI

into a 600 km circular orbit, inclined at 38°

to the equator. HESSI’s sole scientific pay-

load is an X-ray/γ-ray imaging spectrometer

designed to provide the first high-resolution

colour movies of solar flares in hard X-rays

and γ-rays. These images will be the first to

measure simultaneously the location and

energy output of radiation from the flare

material and should improve predictability

of flare occurrences at the Sun.

HESSI is the first NASA Small Explorer

mission to be managed in the “principal

investigator” mode. Robert Lin (UC Berke-

ley) is responsible for many aspects of the

mission, including the science instrument,

spacecraft integration and environmental

testing, operations and data analysis. The

HESSI scientific payload is a collaborative

effort between the University of California,

Berkeley, NASA’s Goddard Space Flight

Center, the Paul Scherrer Institut in

Switzerland, and the Lawrence Berkeley

National Laboratory in Berkeley. The mis-

sion also involves scientific participation

from the University of Glasgow (led by

Prof. John Brown) as well as France, Japan

and the Netherlands (hesperia.gsfc.nasa

.gov/hessi or hessi.ssl.berkeley.edu).

� CASSINI SEARCHES FOR GRAVITY WAVES.

With little more than two years to go

before it enters orbit around Saturn,

NASA’s Cassini spacecraft has completed

its latest 40-day search for gravitational

waves. The search assesses the Doppler

effect on radio waves travelling between

Cassini and Earth by analysing transmis-

sions between Cassini and NASA’s Deep

Space Network in California, Spain and

Australia. Engineers are correcting a prob-

lem of haze on the spacecraft’s narrow-

angle camera which occurred following

flawless imaging of Jupiter in late 2000

and early 2001. The haze appeared when

it was cooled to its usual operating tem-

perature of –90 °C after being heated to

30 °C during routine maintenance. Test

images taken of a star in January suggest

that gentle heating of the camera to only

4 °C over a period of a week improved the

situation. This treatment will be repeated

for longer in March (saturn.jpl.nasa.gov).

The oceans of Mars: how thewater Mars once had could lookas an ocean (NASA/Greg Shirah).

meant that images and other data were not col-

lected during the closest phase of the encounter.

Commands radioed from Earth enabled the

spacecraft to resume gathering scientific infor-

mation later that day. Planned observations for

the remainder of the spacecraft’s current swing

near Jupiter included a series of images of the

planet’s atmosphere, a farewell colour study of

the icy moon Europa and navigational imaging

of Amalthea.

Although the farewell look at Io proved to be

rather disappointing, data previously gathered

by Galileo have improved our understanding

of this active little world. As it flew near Io’s

poles in August and October 2001, the space-

craft recorded a tenfold increase in the density

of charged particles when it crossed a “flux

tube” where electrons and ions from Io’s tenu-

ous atmosphere flow along magnetic field lines

between the moon and Jupiter. In a 1999 flyby

of Io, Galileo had provided some indication of

the higher density over the moon’s poles, but

the 2001 flybys were the first to show that

those denser areas coincide with the magnetic

flux tube (www.jpl.nasa.gov/videos/io).

Galileo also detected electric currents flowing

along magnetic field lines above two areas of

volcanic activity on Io. Material ejected from

eruptions apparently affects conductivity more

than 100 km above the surface. However, mea-

surements taken near the poles confirm that Io

has no intrinsic magnetic field. This indicates

that Io’s molten iron core does not have the

same type of convective overturning as the

Earth’s core and fits a model of Io being heated

by tidal flexing (www.jpl.nasa.gov/images/io).

SOHO’s solar storms

Following recent studies of processes taking

place beneath sunspots (see A&G 2002 43

1.17), scientists have used the Michelson

Doppler Imager (MDI) instrument on board

the Solar and Heliospheric Observatory

(SOHO) spacecraft to discover how large,

active regions form and grow.

By peering beneath the surface of AR 9393,

the largest active region in the current solar

cycle, a team led by Alexander Kosovichev

(Stanford University) found that such regions

comprise many small magnetic structures that

rise quickly from deep within the Sun. At one

point last year, AR 9393 stretched 240 000 km

across the Sun, more than 18 times the diame-

ter of the Earth. “We thought active regions

had a simple structure,” said Kosovichev. “But

instead of one large tube-like magnetic struc-

ture that rises from deep inside the Sun, we

find that active regions are made up of many

small magnetic structures emerging at adjacent

locations. Moreover, the magnetic structures

are replenished by others as they emerge,

which makes the active region grow.”

Unfortunately, the MDI data only extend to a

depth of about 100 000 km, while the magnetic

structures are probably generated at the bottom

of the Sun’s convection zone, the tachocline, a

further 124 000 km beneath the surface.

A second team, led by Junwei Zhao (Stanford),

used MDI to investigate why sunspots some-

times start rotating. One average-sized sunspot,

located in active region AR 9114, exhibited

unusually pronounced rotation, spinning more

than 200° counter-clockwise in less than three

days. Zhao’s team discovered that there was a

strong plasma vortex beneath the rotating

sunspot and that the magnetic fields lacing the

sunspot appeared to be twisted beneath the sur-

face. “Is it the vortex that twists the magnetic

field or does the twisted magnetic field somehow

create the vortex?” asked Zhao (www.gsfc.nasa

.gov/topstory/20011210insidesun.html or sun

.stanford.edu/Active_regions).

A series of rare, nearly identical solar flares

has also come under the scrutiny of the SOHO

and Yohkoh spacecraft. The events, which

took place in November 2000, may help to

reveal the link between flares and certain types

of coronal mass ejection.

Six flares were observed over a 60-hour

period, beginning at 04:50 UT on 24 Novem-

ber. The first three in the series were similar to

each other, as were the final two. The other

flare, however, was less powerful than the rest,

and lasted longer. The flares were similar in

shape, the way they developed over time, their

ejection of high-energy particles, and their gen-

eration of X-rays. According to a paper in Geo-physical Research Letters, each of the flares was

also associated with a coronal mass ejection

(CME). During the period, a total of 14 CMEs

was emitted from the flare region, six of which

were associated with the homologous flares.

“It was surprising that all six short-duration

flares in this sequence were associated with a

CME in a similar pattern, all within 60 hours;

that is, before the magnetic field could possibly

recover from the previous flare/CME event in

the sequence,” said Nariaki Nitta (Lockheed

Martin Solar and Astrophysics Laboratory). “It

may be due to a huge, organized magnetic struc-

ture rising from within the Sun to trigger these

similar great explosions, one after the other.

“Most CMEs are associated with long-

duration flares, those lasting more than two

hours, but all the flares in this series were

short-duration, and a bunch of CMEs hap-

pened anyway,” said Nitta. “This is exciting

because short-duration flares may sometimes

participate in the processes that launch CMEs,

but we don’t know how,” (www.gsfc.nasa.gov/

topstory/20011108cookieflare.html).

X-raying the galaxy

The Advanced CCD Imaging Spectrometer

(ACIS) on NASA’s Chandra X-ray Observatory

has provided a stunning panorama of the

Mission update

2.31April 2002 Vol 43

Space shorts

� JUPITER’S X-RAY HOT SPOT. A pulsating

hot spot of X-rays has been discovered in

the polar regions of Jupiter’s upper atmo-

sphere by NASA’s Chandra X-ray Obser-

vatory. Previous theories cannot explain

either the pulsations or the location of the

hot spot, prompting scientists to search

for a new process to produce the X-ray

emissions. The observations showed that

most of the auroral X-rays come from a

pulsating hot spot that appears at a fixed

location near Jupiter’s north magnetic

pole. Bright infrared and ultraviolet emis-

sions have previously been detected from

this region. The X-rays were observed to

pulsate with a period of 45 minutes, simi-

lar to the period of high-latitude radio

pulsations detected by Galileo and Cassini.

The current theory holds that the X-rays

are produced by energetic oxygen and sul-

phur ions (originally from Jupiter’s moon

Io) that collide with hydrogen and helium

in Jupiter’s atmosphere. Chandra’s ability

to tie down the location of the X-rays

proved this model incorrect, because ions

from the vicinity of Io cannot reach the

high Jovian latitudes where most of the

X-rays were observed. This result is hard

to explain, since there are not nearly

enough energetic oxygen and sulphur ions

at the large distances required for the

source of the ions – at least 30 times the

radius of Jupiter – to account for the

X-ray emission.

One possibility is that heavy ions in the

solar wind are captured in the outer

regions of Jupiter’s magnetic field, then

accelerated and directed toward its mag-

netic pole. The captured ions would travel

back and forth from pole to pole in an

oscillating motion that might explain the

pulsations (chandra.harvard.edu and

chandra.nasa.gov).

Chandra has revealed polar hot-spots of X-rays on Jupiter (NASA/Chandra).

central regions of our Milky Way galaxy. The

montage of 30 separate Chandra images, taken

between 16 and 21 July 2001, covers a 400 by

900 light year swath of the galactic centre.

Published in the 10 January issue of Nature,

the mosaic shows hundreds of white dwarf

stars, neutron stars and probable black holes

bathed in an incandescent fog of searingly hot

gas. Individual X-ray sources are clearly sepa-

rated from the diffuse glow of the hot gas.

“We can now see that the sources are respon-

sible for most of the X-rays from highly ion-

ized iron previously attributed to the diffuse

glow,” said Eric Gotthelf (Columbia Univer-

sity). “So we must now revise our notion of the

hot gas, which appears to be about 10 times

cooler than previously thought. It’s only a rel-

atively mild 10 million degrees!”

Although Chandra recently observed a small

flare from the vicinity of the central super-

massive black hole, the power output near the

black hole remains relatively low. However, an

unexplained fluorescence of iron atoms,

observed by the team to be associated with

molecular clouds a few hundred light years

away, may indicate that the black hole was

hundreds of times more active in the past.

Alternatively, the fluorescence could be due to

cosmic rays produced by supernovae or earlier

eruptions from the black hole.

“The galactic centre is dominated by very

high pressures due to the hot gas component

and the strong magnetic fields,” said Cordelia

Lang (University of Massachusetts). The Chan-

dra map shows that the high-pressure and

high-temperature gas is apparently escaping

from the centre into the halo of the galaxy.

Ghost cavities

Looking further afield, Chandra’s ACIS has

observed ghosts of an ancient eruption that

tore through a distant galaxy cluster. “Chan-

dra’s image revealed vast regions in the galaxy

cluster Abell 2597 that contain almost no

X-ray or radio emission. We call them ghost

cavities,” said Brian McNamara (Ohio Univer-

sity). “They appear to be remnants of an old

explosion where the radio emission has faded

away over millions of years.” The ghost cavi-

ties were probably created by material falling

toward a black hole millions of times more

massive than the Sun. As the matter swirled

around the black hole, located in a galaxy near

the centre of the cluster, it generated enormous

electromagnetic fields that expelled material at

high speeds.

This explosive activity in Abell 2597 created

jets of highly energetic particles that created

voids in the hot gas. Though dim, the ghost

cavities contain a mixture of very hot gas, high-

energy particles and magnetic fields that pre-

vents them from collapsing under the pressure

of the surrounding hot gas. If dozens of these

cavities were created over the life of the cluster,

they could explain the surprisingly strong mag-

netic field of the gas that pervades it.

“Ghost cavities may be the vessels that trans-

port magnetic fields generated in a disk sur-

rounding a giant black hole to the cluster gas

that is spread over a region a billion times

larger,” said McNamara. Researchers also

found evidence of a more recent explosion in

the form of a small, bright radio source near

the centre of the cluster.

Explosive activity has also been explored in

quasar PKS 1127-145, where researchers found

an X-ray jet that extends over at least one mil-

lion light years. The jet reveals explosive activ-

ity that occurred around the quasar’s central

supermassive black hole some 10 billion years

ago. “The X-rays from the jet are likely due to

the collision of microwave photons left over

from the Big Bang with a high-energy beam of

particles,” said Aneta Siemiginowska (Har-

vard-Smithsonian Centre for Astrophysics).

According to the report that will appear in

the 10 May 2002 issue of the AstrophysicalJournal, the length of the jet and the prominent

knots of X-ray emission observed suggest that

activity in the vicinity of the central super-

massive black hole is long-lived but may be

intermittent, perhaps due to the mergers of

other galaxies with the host quasar.

In a separate result obtained by studying the

same quasar, scientists studied the X-ray spec-

trum of an intervening galaxy. Absorption of

X-rays from PKS 1127-145 passing through a

galaxy located about four billion light years

from Earth enabled astronomers to estimate

that the intervening galaxy contained only

about 20% as much oxygen as our Milky Way.

These observations will give new insights into

how the oxygen supply of galaxies is built up

over the aeons. The results were published in

the 20 November 2001 issue of the Astrophys-ical Journal (chandra.harvard.edu and chandra

.nasa.gov). �

Peter Bond, RAS Press Officer (Space Science).

Mission update

2.32 April 2002 Vol 43

“Ghost cavities” exist above left and below right ofthe centre of Abell 2597 (Chandra/ACIS/NASA).

Space shorts

� EUVE RE-ENTERS ATMOSPHERE. On 30

January NASA’s Extreme Ultraviolet

Explorer (EUVE) re-entered the Earth’s

atmosphere over Egypt. No damage was

reported from fragments. EUVE was

launched in July 1992 and science opera-

tions ended in December 2000. EUVE was

the first astrophysics mission to explore

the extreme ultraviolet universe and

observed more than 1000 nearby sources,

including more than three dozen objects

outside our galaxy (heasarc.gsfc.nasa.gov/

docs/euve/euve.html).

� THE HIGH PRICE OF FAME. NASA has

decided to stop funding the Full-Sky Astro-

metric Mapping Explorer (FAME) mission

after reviews indicated that it would con-

siderably exceed its $180 m cost cap. A

spokesman for the US Naval Observatory

admitted that the satellite is about $20 m

over the limit for NASA’s medium-class

Explorer missions. Other sources quoted

$40 m. FAME was intended to determine

the positions, distances, and motions of

about 40 million stars brighter than 15th

magnitude. Stellar distances were to have

been determined with a less than 10%

error for stars brighter than 9th magnitude

and within 2000 parsecs of the Sun (www

.usno.navy.mil/fame).

� NASA KILLS EUROPA ORBITER. NASA

announced the cancellation of the Europa

Orbiter mission during a briefing on 4

February on the agency’s 2003 budget

request. Less surprising was the decision

for the second year running not to request

funding for the New Horizon Pluto–

Kuiper Belt mission. Budget documents

condemned NASA’s Outer Planets, Inter-

national Space Station and Space Shuttle

upgrade programmes as “ineffective” and

in need of reform. They stated that the

Outer Planets programme, which included

plans for Pluto and Europa, “cannot be

implemented as planned because some

mission cost and schedule estimates have

nearly doubled”. The Outer Planets effort

is being reformulated into what NASA is

calling the New Frontiers programme.

New Frontiers missions will be capped at

$650 m and have development cycle times

of 48 months. Each New Frontiers mis-

sion will be selected through an open,

peer-reviewed competition.

NASA also announced it will resume the

development of in-space propulsion sys-

tems, including a five year, $950 m invest-

ment in nuclear power research (www

.nasa.gov/budget/budget2003_index.html).