Next month, a Russian spacecraft will try to turn night into day by reflecting the Sun’s rays towards the Earth. A crewless Progress spacecraft, used to carry supplies to the Mir space station, will detach itself from the station and unfurl a solar reflector 20 metres across that will reflect light down to the ground.

The aim of the Znamia, or ‘flag’, experiment is to test the feasibility of using mirrors in space to light cities or large construction sites in the north of Russia during the arctic winter. Space mirrors could also be used to light areas hit by natural disasters such as earthquakes or floods so that rescue operations can continue around the clock.

Russian space scientists have drawn up plans for a set of about a hundred solar reflectors arranged in a ring around the Earth at altitudes between 1550 and 5530 kilometres. As well as illuminating the Earth, these reflectors could also be used to propel spacecraft by focusing their beams onto a solar panel fitted to the craft. The heat of their beams could also destroy small pieces of space debris.

In the Znamia experiment, the reflector, built by NPO Energia, is wrapped around the body of the Progress craft to resemble a folded umbrella. Twelve minutes after leaving Mir, at a distance of 160 metres from the station, the Progress craft will start to spin at a rate of 570 degrees a second so that centrifugal force unfolds the reflector.

Between three and five minutes later, at a distance of 320 metres from Mir, the reflector will be fully unfurled and the spinning rate will be reduced to 84 degrees a second, which is sufficient to keep the reflector taut. Experiments to light up the ground with reflected sunlight will then begin and last three days.

When folded, the reflector is held onto the sides of the spacecraft with a frame which opens out as the craft spins, like the spokes of an umbrella. Between the spokes is a film of plastic 5 micrometres thick, coated with a layer of aluminium to make it reflective. The plastic film weigh 4 kilograms; together with the frame the whole structure weighs 40 kilograms.

The Znamia experiment has cost $60 000 and was devised by the Kosmitcheskaya Regata Consortium, which includes 15 research institutes and industrial firms.

Tolba’s man for the job is Esmond Bradley Martin, a consultant to the
World Wide Fund for Nature. This week he set off on a fact-finding mission
to China, South Africa, the United Arab Emirates, Yemen, Zambia and Zimbabwe.
He will also lobby governments to crack down on poachers and traders.

Since 1970, numbers of rhinoceros have fallen worldwide by 85 per cent
and the remaining wild herds in southern Africa are under threat from poachers
who kill them for their horns, which are traded across Asia.

Martin began investigating the rhino-horn business in 1978. He admits
that stopping the poachers and dealers will not be easy: rhino horn can
fetch up to $50 000 a kilogram in some markets. China alone uses more than
500 kilograms of horn every year in fever remedies. Martin is trying to
encourage Asian countries to switch to substitutes, such as horn from the
Siberian saiga antelope, which has the same fever-reducing properties.

Martin has also travelled to Yemen where many men wear daggers with
handles carved from rhino horn. He estimates that during the 1970s, an average
of 8 tonnes of rhino horn per year were sold to North Yemen, a trade that
cost the lives of 22 000 rhinos. In South Africa, rhino horn is an ingredient
of a treatment for jaundice, but its use is not extensive. Rhino hide is
more popular as a treatment for nosebleeds and snake bites.

Some 30 research institutes and companies will carry out preliminary
studies involving space technologies. These studies could lead to extensive
participation in the next phase of developing Hermes. The decision to let
the contracts was taken at an ESA meeting last month.

Last November European ministers met in Munich to discuss the long-term
space programme. They instructed the agency to cooperate more closely with
nonmember states such as Japan, the US and the Commonwealth of Independent
States to cut costs and limit the risks involved in technological development.

In the past, exchanges were limited. Direct contacts were restricted
to the Soviet Academy of Science and to representatives of Soviet foreign
trade organisations. East and West never really ‘met’ because the working
methods, safety regulations and economic setups were very different.

The new contracts are worth some 5 million Ecus ( £3.5 million),
which will pay the salaries of about 30 000 engineers in the Commonwealth
of Independent States for a year. The final decision on whether to go ahead
with Hermes will be taken by ministers during their next meeting in Spain
at the end of the year.

In small numbers the desert locust (Schistocerca gregaria) is no problem,
although this relatively harmless grasshopper still eats between 30 and
70 per cent of its body weight every day.

But in warm and wet weather the locusts breed very quickly, become gregarious
and migrate. These conditions occur every 10 to 15 years. The voracious
insects in these swarms consume their own body weight every day. Once the
locusts are flying they are difficult to control. A swarm of locusts covering
1000 square kilometres consumes about 80 000 tonnes of foliage a day.

In 1988 the FAO launched ARTEMIS, which stands for Africa Real Time
Environmental Monitoring Using Imaging Satellites, to help give early warning
of swarming locusts. This compiles maps from satellite data that is provided
by the National Oceanic and Atmospheric Administration in the US. The NOAA’s
environmental satellites pass over Africa twice a day. Data from the European
geostationary weather satellites are also fed into ARTEMIS.

The environmental satellites measure the reflection of light and near-infrared
radiation from the Earth’s surface. The resulting map corresponds closely
to the pattern of vegetation, and thus identifies areas which are vulnerable
to locusts. The weather satellites monitor rainfall. Moist soil is essential
for hatching locust eggs and the rainfall helps to identify likely breeding
sites.

The problem is that once the images have been processed in Rome they
are then sent to Nairobi and other parts of Africa by mail – which delays
the early warning.

In the new system the data will be sent down a land line to a ground
station at Fucino, in Italy, before being transmitted to an Intelsat satellite
located over the Indian Ocean and distributed to ground stations in Africa.
The new system will provide information about the breeding sites of locusts
in a couple of days, instead of several weeks, thus enabling local workers
to apply pesticides to the larvae before their wings have grown.

Barry Henricksen, the team leader at FAO, says: ‘A unique feature of
satellite-based networking is the fact that no matter what distance . .
. data can be sent and received in the most remote parts and the most hostile
³Ù±ð°ù°ù²¹¾±²Ô.’

Henricksen says that the system’s capacity to transmit information means
that remote sensing maps or reports of more than 70 pages long could be
sent from Italy to Africa in a couple of seconds.

In tests, the satellite will send information to a receiving station
at Nairobi. As well as hoping to curb the damage caused by locusts, the
ESA hopes that the one-year pilot project will demonstrate the commercial
potential of the system.

A European satellite launched in 1989 to map the positions of hundreds
of thousands of stars was thought to be a dead loss after a faulty booster
motor failed to lift it into its proper orbit. But last week, scientists
from the European Space Agency described how a mixture of luck and clever
improvisation will allow the Hipparcos satellite to complete its original
mission and probably do even better.

The original mission was to establish two catalogues. The Hipparcos
catalogue will be a ‘Who’s Who’ of 120 000 stars with an accuracy of two
thousandths of a second of arc, 30 000 times as accurate as the naked eye.
The less accurate Tycho catalogue was planned to include 400 000 stars.

ESA believes Hipparcos will improve its accuracy for the Hipparcos catalogue
and increase the size of the Tycho catalogue by lengthening the mission.
The satellite fixes positions by masking repeated observations of each star,
improving accuracy each time. So a longer mission means better positions.
ESA has funds to keep Hipparcos operating until the end of this year. But
it believes there is enough fuel in the satellite’s thrusters to last till
the end of 1993, and hopes to be able to continue operations until then.

Our galaxy has more than two hundred billion stars, and the Hipparcos
mission will help astronomers unravel their dynamics. Michael Perryman,
the project’s chief scientist, says, ‘Hipparcos will improve our knowledge
of scale within the galaxy, and for this we can infer the distance of other
²µ²¹±ô²¹³æ¾±±ð²õ.’

Hipparcos was meant to sit in geosynchronous orbit, following a fixed
point above the equator. The booster failure left Hipparcos in a highly
elliptical orbit, swooping to within 500 kilometres of the Earth and then
soaring 36 000 kilometres into space every 10 hours.

Following unsuccessful attempts to fire the booster motor to send the
satellite into its proper orbit, there was talk of trying to shake the satellite
to start the motor. But this might have damaged the instruments and it was
decided instead to revise the mission.

In its geosynchronous orbit, Hipparcos would have beamed all its data
directly down to a tracking station near ESA’s control centre at Darmstadt
in Germany. But the satellite now had a rapidly moving orbit that circled
the Earth in 10 hours.

Experts worked day and night to set up equipment to receive the data
at three other tracking stations: Perth in Australia, Kourou in French Guiana
and Goldstone, a NASA tracking station in California. With these stations
they could keep in contact with the satellite 70 per cent of the time.

The onboard software had to be reprogrammed by a team whose members
came from Matra, which was the main contractor for the satellite, as well
as from other companies and ESA.

The engineers were also concerned that as the satellite swoops close
to the Earth twice a day, protons and electrons trapped by magnetic forces
in the Van Allen belts above the equator would wear out the solar arrays
and shorten the life of the satellite. They found, however, that the arrays
were degraded much more slowly than expected and they believe that Hipparcos
will be able to operate for four years instead of its planned mission of
two-and-a-half years.

More hazards befell the satellite in March 1990 when the relative positions
of the Sun and Earth conspired to leave it in shadow for long periods, depriving
it of power. During the longest such eclipse, of 105 minutes on 16 March,
Hipparcos scraped through with just five minutes’ power in reserve.

Hipparcos collects 24 000 bits of data per second as it spins slowly
around its own central axis in space. To date, the satellite has sent back
600 gigabits of information from about two million stellar observations.

‘I am specially interested in the personality of the participants and
how isolation and stress influence their moods and social interactions,’
explains Ursin. The researchers videotaped every word and movement of the
six-man crew and analysed their hormones, blood, urine and saliva to assess
the level of their immune system and correlate the results with psychological
questionnaires. ‘This will tell us what each man experienced, how he was
perceived by the other crew members and by mission control, and how this
relates to his performance and what happened inside his body,’ says Ursin.

‘The Americans are specially interested in preparing themselves for
the International Space Station and this is the first multidisciplinary,
multinational study,’ Ursin added.

According to Jaques Collet, head of ESA’s long term programme office,
american astronauts and Soviet cosmonauts have not received the same attention
from psychologists. Until very recently, American astronauts were worshipped
as heroes. They were expected to perform and maintain their ‘can do’ philosophy
no matter what happened. ‘On the other hand, the Soviets have always been
interested in the psychological aspect of stress during space missions,’
he says.

Philip Harris, an American space psychologist agrees: ‘We’ve always
neglected the human side of the equation, because NASA is run by a bunch
of engineers.’

The experiment, called the Isolation Study for the European Manned Space
Infrastructure, was organised by the ESA’s directorate of space stations
and micro-gravity, and its long-term programmes office, and was partly funded
by the Norwegian Space Centre. The crew was confined in the hyperbaric chambers
of the Norwegian Underwater Technology Centre in Bergen from 17 September
to 19 October.

The six men were chosen according to the selection criteria for astronauts
and were aged between 25 and 33. They spent 28 days in the chambers at an
air pressure of 1.5 atmospheres so that the doors could not be opened before
being depressurised for several hours – this corresponds to the time lapse
necessary for returning to Earth in case of an emergency on board a space
station. The complete absence of daylight and the pale green colour of the
walls increased the sensation of being cut off from the outside world.

The crew’s only contact with the external world was through audio and
video links with ‘the ground’, and their work load was heavy: they were
on duty for 13 hours a day and performed 35 science experiments, while filling
in psychological questionnaires, taking blood and urine samples, and keeping
everything shipshape.

It was all rather too much at times, and there were some conflicts:
‘At one point there almost was a mutiny,’ says Paolo Nespoli, the appointed
commander – a former Italian soldier who had served in Beirut with the multinational
peacekeeping force. ‘I was trying to meet the demands of the principal investigators
on the ‘ground’ and the crew members found I was too ‘military’. So I adjusted
and toned down’.

A major concern in a remote isolated environment is illness. The crew
carried out many medical experiments using ‘telemedicine’ in which a member
of the crew is trained as a medic and acts as the hands and eyes of a doctor
on the ground. The Bergen telemedicine experiments simulated space conditions:
for instance in space it takes half a second for the doctor’s voice to be
beamed to the ground station via a geostationary satellite, and the medic
must learn to cope with this, especially when he is performing an operation.

To increase the medic’s efficiency and save time in the case of an emergency,
a computer system was developed at the Paul Sabatier University in Toulouse
to help establish a medical diagnosis. This so-called expert system contains
a database of medical information and can give the medic advice on treatment
depending on the symptoms he observes. Already the Norwegians are finding
that, together with telemedicine, the system could be very useful in the
offshore oil industry.