Profile: Delicate Balancing Act From Hubble to Webb

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  Space News Business

Profile: Delicate Balancing Act From Hubble to Webb

By BRIAN BERGER
Space News Staff Writer
posted: 29 May 2007
03:54 pm ET





Matt Mountain

Director , Space Telescope Science Institute








W


hen Matt Mountain took the helm of the Baltimore-based Space Telescope Science Institute (STScI) in September 2005, the NASA-funded operation faced an uncertain future.



NASA had yet to formally reinstate a long-planned space shuttle mission to service the Hubble Space Telescope and the launch of its successor, the James Webb Space Telescope, had just been delayed nearly two years, the




result of




development woes that boosted the mission’s price tag to $4.5 billion.



Today, STScI’s outlook is much improved. Mountain and the institute’s 380-person staff are looking forward to managing the science operations of a new and improved Hubble once its on-orbit service call is completed in mid-2008. And James Webb, which will be controlled from STScI, is on track for a mid-2013 launch aboard a European Space Agency-provided Ariane 5 rocket. NASA says Webb has been meeting all of its technical and budgetary milestones since the project was restructured some 20 months ago.

Mountain talked with Space News staff writer Brian Berger about some of the challenges the institute faces managing Hubble while getting ready for its successor.











Is STScI adequately staffed for the upcoming Hubble servicing mission?


We shed about 50 people back when we thought the Hubble servicing mission was not going to happen. We plan to hold to our current level of 380 people for the moment, so the staff will be a little




more stretched than usual. To help get us through the servicing mission, we plan to borrow about six people from the Johns Hopkins University. Once we see how many instruments we actually need to support – some may be put in hibernation – we will see what we can and cannot do with our current staffing levels.

How does a refurbished Hubble increase STScI’s workload?

After the mission, Hubble will have more working instruments than before. In addition to the two new instruments, the Space Telescope Imaging Spectrograph will be repaired and there is even talk of fixing the Advanced Camera for Survey. Interest in using Hubble is ramping up in anticipation.

Is there still good scientific research to be done with Hubble?

Yes. When the Advanced Camera for Surveys died




Jan. 27, we had just received 740 proposals in response to our annual call. Suddenly 500 of those proposals were now useless. We told the community we were extending the proposal deadline two weeks and would try to get Hubble’s infrared camera back on line. By the time the new deadline arrived, to our amazement we had received over 800 proposals. That’s almost seven times more proposals than we can afford to fund. So the community is still very interested in using Hubble.

Is STScI ready to manage Hubble and operate Webb at the same time?

If James Webb launches in 2013 as planned, the odds are fairly good there will be some overlap. Scientifically, that would be a very powerful combination. It presents some challenges, sure, but they are nice challenges to have. And Webb, in some ways, is closer than you think. Two years of intensive end-to-end instrument tests are due to begin at the end of 2008. We’ve got to be ready here to support that effort as though the telescope was already on orbit.

Why are Webb flight operations being based at STScI?

Having flight ops here is much more important for Webb than for Hubble, because with Webb the way the telescope operates – how you adjust the mirror,




schedule it, etc. – is a key part of how you get the science out of it. It’s going to be more like ground-based astronomy where the telescope, instruments and science are all totally interrelated.



Will Webb operations be leaner than Hubble operations?

Our current projection




shows that our peak staff on Webb will be less than peak staffing on Hubble, but only marginally so. Initially, Webb was thought to be simpler to operate. After all, Hubble is orbiting Earth every 97 minutes while Webb will be




1.5 million kilometers away in this gravitationally stable orbit. But as it turns out, scheduling Webb is going to be quite complicated. Part of it is about keeping the telescope cold at all times. The Near Infrared Spectrograph is designed to operate at about 40 degrees Kelvin – 233 degrees Celsius below zero. And unlike Hubble, Webb will have to burn fuel periodically to counteract




solar pressure that bears down on the spacecraft’s tennis court-length sunshields.

Additionally, Webb’s instruments are turning out to be more complicated than initially thought. On the other hand, Webb is not designed to be serviced, so there’s no large servicing infrastructure to support. And we are building in lessons learned from Hubble to make the operation more efficient and a little bit leaner. We won’t have to re




invent the wheel.








What fraction of STScI’s staff are research astronomers?






About one-fifth of our 380-person staff are PhD scientists. These are very technologically




intensive programs, requiring a lot of engineering and software development. When you add in the engineers at Goddard that support our programs, the real ratio of support staff to research scientists is more like 10 to 1, which is pretty typical of this type of organization. When I ran the Gemini Observatory, which operates telescopes in Chile and Hawaii, I had a staff of 200, about 20-30 of which were astronomers. So it was a similar ratio.

Is ground-based astronomy catching up with space-based astronomy?

Adaptive optics can help ground-based observatories compensate for some of the limitations that come with peering through the atmosphere, but as telescopes on the ground get bigger, the already challenging technology becomes even more difficult to pull off. Webb is going to be 10,000 times more sensitive than any ground based telescope could ever be because of the atmosphere. That’s why we are putting Webb in space. Webb will be able to




do astronomy the ground could never touch.

Does going to the Moon promise any benefit to astronomers?



For astronomers, the Vision for Space Exploration isn’t so much about the destination, but about the tools NASA is developing to get there, namely the really big rockets. Astronomers could make real use of the Ares 5 rocket. While dark side of the Moon could be a good place for a radio astronomy observatory, the big optical telescopes belong out at the Lagrange points. The Ares 5 could take you there and is big enough to accommodate a 10-meter telescope without having to fold it up like we are with Webb.