Press Release

Hubble rejuvenated — an interview with Piero Benvenuti

By SpaceRef Editor
March 12, 2002
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As part of the on-going Hubble servicing mission a new instrument, the
Advanced Camera for Surveys (ACS) was installed on the ESA/NASA Hubble
Space Telescope on the morning of 7 March 2002 (European time). We
talked to Piero Benvenuti, ESA’s project scientist for Hubble, and
asked him to share some of his thoughts on this occasion.

Q1: What are the benefits for Europe by being part of the Hubble

Piero Benvenuti: The main advantage has been that European astronomers
have had guaranteed access to the world’s most powerful astronomical
observatory in space — between 15 and 20% throughout the 12 years
since Hubble was launched. But also, importantly they have established
or reinforced, very fruitful collaborations with their American
colleagues, both in scientific and in technological matters. This long
running collaboration has created a mutual ‘trust’, which will be an
essential component for success in the next ambitious project, Hubble’s
successor, the Next Generation Space Telescope.

Q2: How did it feel to see the Faint Object Camera (FOC) removed from
Hubble? After all this was developed and built in Europe.

Piero Benvenuti: The ESA-built Faint Object Camera (FOC) is the last
of the original Hubble instruments to be removed. It holds the world
record for the longest time any piece of space hardware has spent in
space before being retrieved and returned to the ground. I am very
proud of the fact that it has functioned perfectly since the beginning.
It has made some important contributions to our understanding of the

Normally I don’t get very excited by the actual exchange of ‘hardware’
such as this. My thoughts were not so much on the actual removal [of
the Faint Object Camera] from Hubble’s instrument bay, which naturally
marks the end of FOC’s life as an active instrument. I was more
thinking that this represents the beginning of something new. FOC is
chivalrously giving space to a newer and much better instrument [the
Advanced Camera for Surveys, ACS]. And also when FOC is on the ground,
it will be carefully analyzed in the laboratory. It will provide very
useful information on the behaviour of optics and electronics after
being exposed to the harsh environment in space for 12 years. This
information will be another invaluable contribution that this
successful ESA instrument has given to astronomy.

Q3: What is the scientific importance of this Servicing Mission?

Piero Benvenuti: The main feature of this servicing mission, from the
pure scientific point of view, is the installation of the Advanced
Camera for Surveys. It is a digital camera served by a modern light-
sensitive detector, much more efficient in many ways from the ones
previously installed. Let’s not forget that in the last two decades
we have seen a tremendous technological progress in the field of
digital imaging. Tomorrow [8 March 2002] the second big scientific
event of this mission will happen. The capabilities of Hubble’s
infrared instrument, NICMOS [Near Infrared Camera and Multi-Object
Spectrometer], will be partially restored. A ‘refrigerator’ will
be installed that will cool the instrument down to operational
temperatures [to observe in the infrared a cold instrument is
needed — in this case -195 C].

Also the more ‘technological’ side of the Servicing Mission is
naturally essential to the science — without a well-functioning
observatory, the science will not be world-class: Hubble’s new solar
panels and the reboost of Hubble to a higher orbit will ensure a much
longer operational life of our unique space observatory.

Q4: How much better will the upgraded Hubble be?

Piero Benvenuti: Hubble’s new ‘eye’ will improve Hubble’s vision, both
because it can see more [it has a larger field of view] and it is more
sensitive. It is always difficult to quantify such an improvement in a
simple and accurate manner. In one sentence, we can say that Hubble
will ‘see’ approximately ten times better than previously, or if you
wish, make the same observations ten times faster than before. For
instance we can make a new Hubble Deep Field in a few days instead of
20 days.

Q5: Can you give us some examples of the types of science you think
we’ll see with the ‘new’ Hubble?

Piero Benvenuti: Although all branches of astrophysics will benefit
from the improved imaging capabilities and from the resuscitated
infrared instrument, I believe that the main interest will be in the
distant [in space and time] Universe. The wider and deeper images of
the Advanced Camera for Surveys are indeed ideal to explore the
infant Universe and detect the possible signs of the first building
blocks of today’s galaxies. ACS will also deliver fantastic images
of objects in our own Milky Way, like nebulae and planetary nebulae,
that will be both scientifically interesting to explore for the
astronomers as well as beautiful to look at for the general public.

Q6: When are we going to see the first results from the new instruments?

Piero Benvenuti: After Hubble is released from the Shuttle bay, we will
have to wait about 4 to 6 weeks before the first images and spectra are
publicly released. The reason it takes so long is that there first is
a period during which the hardware and software will be tested. Then
there is ‘science verification’ — this is when the scientists will
check that the new images and spectra are scientifically correct.
After 4-6 weeks the first results, formally called ‘SM3B Early Release
Observations’, will be released to the public. I really look forward
to see what the new-look Hubble has in store for us.

Q7: Is Hubble in your opinion slowing losing ground in the
‘competition’ between space- and ground-based telescopes?

Piero Benvenuti: No, contrary to what many other people say and write,
I really don’t think so. Although ground-based astronomy is making
astonishing progress both in terms of light collecting area (the size
of the mirrors), which is now in the 8-10 metre range ramping up
to 30-100 metre in the near future, and in ingenuity of its
instrumentation, Hubble’s unique advantage in being above the
terrestrial atmosphere will never be surpassed. Rather, the synergy
and the complementarity between ground- and space-based astronomy
will be more and more important in the future, Hubble giving the
‘sharpness’ of vision and the large telescopes on the ground adding
their great light sensitivity.

[Piero Benvenuti, ESA’s Hubble Project Scientist is based at the Space
Telescope European Coordinating Facility in Munich, Germany. He has
been involved with Hubble since 1984. Prior to that he was Observatory
Director for the International Ultraviolet Observatory at the European
Space Agency’s Vilspa ground station, near Madrid, Spain.]


[Image 1:]
Piero Benvenuti, ESA’s Hubble Project Scientist is based at the Space
Telescope European Coordinating Facility in Munich, Germany. Copyright:

[Image 2:]
The new Advanced Camera for Surveys (ACS) is installed in the ESA/NASA
Hubble Space Telescope. Copyright: © NASA

SpaceRef staff editor.