Honolulu - May 5, 2004
There are a lot of issues to debate right now about the future of space flight, and we Space Cadets are debating them furiously among ourselves. But the only issue that has really fired up the wider public beyond January was the decision to scrap the scheduled Space Shuttle refurbishment mission to the Hubble Space Telescope.
My friend Dr. X recently discovered this in a particularly unpleasant way. He was walking down the street wearing one of his many space-related t-shirts. This one had the old "meatball" NASA logo prominently displayed. Without warning, a random passerby stopped and began berating Dr. X for the Hubble cancellation!
Of course Dr. X was innocent of any responsibility for this decision. The only high-level NASA advisory panels he has been on were related to Moon bases.
But this misguided citizen was expressing a common view among the general public. They correctly perceive that the Hubble refurbishment missions are the main contribution that the Shuttle program has made to real space exploration. They cannot understand why this valuable program is being scrapped while the moribund International Space Station is kept on life support at a cost of ~$6B/yr.
NASA Administrator Sean O'Keefe has fed this fire of criticism by offering an obviously phony rationale based on safety, and refusing to entertain any dissent or honest debate on the issue. O'Keefe has even told Congress that he would ignore a proposed National Academy of Sciences study on the question if it disagreed with his views! On this issue he has shown the same irrational confidence in his own personal infallibility that Dan Goldin did.
Looming in the background of this debate is the possibility that the Shuttle will never fly again to any destination.. When I wrote this dark heresy in a column a few months ago, I offered 5:1 odds against RTF and a member of the Aldridge Commission immediately offered to take up my bet. But now even Space.com is running articles on this theme, and reliable space booster Sen. Brownback has announced Congressional hearings to debate it.
But even if the Shuttle program were somehow brought back from the dead, it should not be used for a Hubble refurbishment mission. Using Shuttle to repair and upgrade a scientific spacecraft is a stupid idea from the dark days of the late 1970s, which unlike leisure suits and disco stubbornly refuses to go away.
When I was an astronomy graduate student, we had a "Hubble dartboard" in our student commune. It was a NASA poster of the "Large Space Telescope" taped to the living room wall. Since the commune was rented from a senior official in the local government, we couldn't actually throw darts at it without losing our damage deposit. But every time the future Hubble would come up in conversation, we would start throwing whatever objects were handy at the LST poster in frustration.
At that time NASA had just finished building a big IR telescope on Mauna Kea out of Project Voyager funds. But after construction was completed, it began to slowly die from lack of operating funds. A tiny fraction of the money wasted on Hubble overruns would have fixed this problem.
Eventually, the National Science Foundation agreed to fund instrument development for this telescope because NASA just wouldn't cough up the money. This arrangement is now standard for many observatories -- NASA provides some or all of the construction funds, but continuing expenses are always obtained from more reliable and less politicized sources.
This is an example of NASA's institutional bias toward Big Hardware Projects. They only want to fund things that cost a billion dollars and can keep an army of people employed. Once the Big Project is completed, NASA has little interest in keeping it operating for a long period of productive use, as interest and funding shifts to the next Big Project. Pressure then builds to close down the old Big Project to cover the inevitable cost overruns in the new one.
Since my fellow communards all needed data in the 1980s to finish their Ph.D.s, the prospect of Space Telescope data in the 1990s didn't interest them much. Every announcement of a cost overrun or launch delay in LST/Hubble would trigger a barrage of pens and books against the hated image on the wall.
Eventually these little tantrums became so common that one of us bought a pile of foam-rubber cat toys. The cats ignored them, but they were ideal for throwing across the room without causing any damage.
Today most of those people are working astronomers, many of whom have used Hubble data extensively. But I think that if we tracked them down today, they would still agree (off the record) with the basic list of defects with Hubble that we identified back in those grad school-debating sessions:
Wrong orbit: LEO is a bad location for a telescope, because the Earth obscures half the sky and any object you observe will swing behind the Earth after about 45min of continuous observation. Then you have to stop observing and wait 45min for the Earth to move out of the way. It is seldom worthwhile to repoint the telescope temporarily at another object because of the long time it takes to reorient and settle down on a new set of guide stars. So about half the potential observing time is wasted.
Also, the solar panels have to be huge since they are in darkness half the time, and the constant cycling wears the batteries out. Many other astronomy satellites have used high orbits like GEO for exactly these reasons, in spite of the higher cost of launching.
Difficult tracking: A LEO telescope must send back its data through the TDRSS satellite system. This requires that the data link be constantly shifted between different satellites in GEO. Also, TDRSS is a joint system which also serves military satellites such as Hubble's own half-sister "KH-11B". Military imaging needs had absolute priority -- especially in that curious weak spot in TDRSS coverage over central Eurasia. A telescope in GEO could have continuous contact with a single dedicated ground station.
Too many instruments: Since Hubble was to be the only Space Telescope, it had to satisfy the wants of every sub-group of astronomers. So it has a complex package of several instruments that shared the telescope by using slightly different parts of the focal plane.
During its early years, Hubble's time had to be divided up between these instruments that observed one at a time while the others lie idle, staring at random places in the sky. Later the Hubble operators recovered some of this dead time by an ingenious program of "parallel imaging", since many survey projects actually want randomly located samples of the sky.
Vast cost: The true cost of the Hubble program is hidden because it taps into the budget of the manned program in the form of five "free" Space Shutte missions which actually cost over $1B each. If the manned part of NASA had charged the Space Telescope project the real cost of these missions, or even the partial charge that it levied on non-NASA Shuttle users, the astronomy community would have closed its wallet and gone elsewhere.
All eggs in one basket: Like all "Battlestar Galactica"-class spacecraft, Hubble concentrated too much value in one package that could be destroyed by a single random hardware failure or human error.
This criticism was vindicated when the completed Hubble proved to have a massive manufacturing error in its mirror -- one that no respectable amateur telescope-builder would have made.
Hubble orbited almost useless for 3.5 years while corrective hardware was designed. The billion-dollar STS-61 repair mission was hailed as a great triumph for NASA, but actually it was just more proof that the entire concept was based on phony accounting.
Most of these fundamental defects are directly related to Hubble's symbiotic relationship with the disastrous Space Shuttle program. Believe it or not, there were plans before 1986 to make ALL future unmanned satellites Shuttle-tended. This idea collapsed under the harsh reality of Shuttle's low flight rate and high cost.
Hubble is the only unmanned spacecraft that still relies on regular Shuttle visits. This idea made sense back when Shuttle was supposed to cost only ~$10M per flight, but at the real cost of ~$1,000M per flight it is completely absurd.
The reason this absurdity continued for so long is that Shuttle was regarded as a fixed cost. It was assumed that if we didn't fly Hubble missions, we would have to fly an equal number of dumb missions loaded with Saudi princes, Congressmen or science fair experiments, just to keep the marching army of Shuttle workers employed.
This assumption was true in the early 1990s when the military had dropped Shuttle but the ISS assembly hadn't started yet. Hubble repair missions filled a real gap in the manifest. But now NASA is confronted with the semi-impossible task of lifting the rest of ISS to orbit by the end of 2010. The Hubble commitment has changed from a blessing to a curse. This is the real reason NASA wants to see the end of Hubble -- it no longer fills their political needs.
Someone at the Space Telescope Institute recently claimed that 7 Hubbles could have been built and launched for the total real cost of keeping one alive with Shuttle. I don't know what launch costs were assumed in this calculation.
Back in the 1990s the $400M Titan IV would have been the only US expendable big enough to launch Hubble-clones. But even this huge cost is still only about 1/3 that of a Shuttle mission. Today we have the much cheaper EELV-H boosters that could do the job for only about $170M.
So the logical way to recover the investment in those orphaned Hubble instruments is to build a Hubble-2 that can be launched into GEO by Delta 4H or Atlas 5H. (In fact, the relevant NASA advisory panel has suggested exactly this option if Hubble is not refurbished.) We could launch several more updated Hubbles with different instruments for the cost of the controversial HST refurbishment mission.
Unfortunately, many Hubble-huggers among the general public aren't viewing this issue from a logical perspective. Hubble has become more than a scientific instrument -- in some quarters it has become a holy icon.
There are even proposals to fly a special Shuttle mission to return Hubble to the National Air & Space Reliquary! It's hard to remember that only 14 years ago, the mis-manufactured Hubble was the poster boy for NASA incompetence and a laughing-stock with the public.
Even inside the space community, there are a lot of proposals to service Hubble with a Soyuz launched from the future pad at Kourou, or some sort of sophisticated robot craft. Many of these ideas are just plain silly -- like moving Hubble into the same hard-to-reach orbit as that other white elephant the International Space Station. Others are from people with an obvious vested interest, like getting NASA to fund development of robot technology they can later sell at a huge profit.
The instruments on Hubble were designed to be replaced by human hands, and robot servicing would require the development of very sophisticated handling devices that would be specific to this one task.
Of course this fits right in with NASA's bias towards expensive hardware development programs, so they are seemingly rushing toward this option without even considering Hubble-2. I don't think that anyone actually expects a Hubble servicing robot to fly. Like many NASA projects, it exists just to keep the boys busy and mollify the public.
This debate about repairing Hubble serves no useful purpose. It's time to stop bickering and get on with the task of designing, building, and launching Hubble-2. Congress should reallocate the cost of the cancelled refurbishment mission to this task, NASA should start doing it, and the rest of us should shut up and let them do it!
Jeffrey F. Bell is Adjunct Professor of Planetology at the University of Hawai'i at Manoa. All opinions expressed in this article are his own and not those of the University.
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NASA Considering Various Hubble Service Options
Washington (UPI) April 26,2004
A review of more than two dozen ideas for robotic servicing of the Hubble Space Telescope has identified several promising concepts that may be pursued by NASA before the end of the year, the space agency's space chief scientist told United Press International.
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