This laboratory module costs $1.4 billion. Will we get our money's worth?
Not right away. Destiny was designed to carry 13 refrigerator-sized science stations, called racks, each holding several experiments, but they'll be going up one or two at a time over the next several years. Altogether, the module and its science gear would have been too heavy to launch. The current space-station crew led by Bill Shepherd, the American commander, and Yuri Gidzeno and Sergei Krikalev, his Russian crewmates, will use the extra space for storage.
There really isn't any important science under way on the station now, but that's because this first crew arrived in November with little life
support, no way to cook their food and a toilet that wouldn't flush. They've
been working overtime just to make the place livable and science has not
been a priority. NASA hopes to have 30 or so experiments under way a year
from now and about 120 researchers are waiting their turn. The space agency
is only now starting to consider proposals that will find their way onto the
station as it nears completion in 2006.
So is that when the station pays off with big discoveries?
Even then, it's hard to say what the public should expect. NASA's Mars probes, and its orbiting observatories like the Hubble Space Telescope and Chandra X-Ray Observatory, have clearly defined missions, something the ISS lacks. Astronauts can study the long-term effects of weightlessness on their own bones and muscle, as they have since the 1970s, but it's hard to say what benefit will be derived back on Earth. In fact, the first important science study done onboard will try to determine whether the station is even a good place to study microgravity, seemingly the one advantage it would have over ground-based labs.
Despite the best efforts of NASA's engineers, there's a chance that
the minor adjustments the station makes to keep a stable orbit, or the
pounding astronauts give their treadmill, or even someone slamming a hatch
too hard, could jar the complex enough to disrupt some experiments that
depend on weightlessness.
How does NASA justify the price tag?
Space researchers say they have seen enough tantalizing evidence in 20 years of growing crystals and studying plants and small animals during two-week space-shuttle missions to design similar studies that last months or even years.
Roger Crouch, NASA's chief space-station scientist, uses the example of a space-shuttle study that looked at neonatal brain development in mice. It showed some significant acceleration in brain growth in weightlessness, but the shuttle could stay aloft for only two weeks, and it takes about 21 days for a mouse brain to develop. "Did it mean they were going to have more connections and bigger brains, or were they going to have bigger brains but cells that wouldn't talk to each other? You really don't know the significance of this snippet you get on a shorter mission," Crouch asked.
Ultimately, NASA is gambling that this kind of basic science will lead
to commercial development that pays top dollar to fly experiments on the
station, but in the short run, the Russians may do better selling Soyuz
seats to wealthy space tourists and game-show winners.
So is that the big deal about Destiny that experiments can last longer?
It's not just that. Destiny really does represent an advance over the facilities on Mir. When U.S. astronauts flew aboard Mir in the 1990s they were working with 20-year-old technology. Because the science racks on Destiny are modular, they can be returned to Earth on shuttles and replaced with newer technology whenever that is practical. If people are still living on the ISS 25 years from now, they won't be working with technology from 1995, when was Boeing started building the module.
Isn't control of the space station supposed to transfer from the Russians to the U.S. during the mission?
Actually, operational control shifts from Mission Control-Moscow to Mission Control-Houston whenever a shuttle launches from Cape Canaveral. This time, though, the shift may be permanent. Since the first segments were launched in 1998, the U.S. components have had to depend on Russian modules for power and navigation. With Destiny in place, that will change. Electricity generated by 240-foot solar paneled "wings" installed in December will now power most of the station. And Destiny carries the computers that will drive four large gyroscopes mounted beneath those wings. The gyros will control the station's position as it hurtles through space at five miles per second, doing the work previously done by thrusters on the Russian service module.
Both sides are playing down the significance of this transfer of
power. The symbolism could be painful for the Russians. With Mir scheduled
to de-orbit in March, the nation that has always led the world in
long-duration space flight may now take a backseat to a "partner" that was
once its bitter rival. The ISS blueprint calls for more Russian segments to
arrive, including a power station and science lab of their own. But while
most of the U.S. components are complete and waiting to be launched, and
European and Japanese segments are at least funded, the Russians are
struggling to find enough money to launch the necessary Progress supply
ships, and no money is budgeted for future modules.
Are there any spacewalks scheduled?
Count on it. Spacewalks are a part of every big ISS assembly job, and three are planned for this mission. Unlike a house, where most of the utilities run through walls, on the space station they run along the outside, and have to be connected by hand every time a new module is added. On this mission, shuttle astronauts Tom Jones and Robert Curbeam will have to make about 100 connections.
If there's time, they'll also try what NASA managers insist on calling
the Incapacitated Crewmember Demonstration, something those sensitive souls
in the Astronaut Office have also referred to as "the Dead-Guy Test." The
trick is to see if one astronaut can drag another astronaut, either dead or
severely incapacitated from micrometeoroid, aneurysm, whatever the case may be from one end of the shuttle payload bay to the other, then into the
airlock. They've done it in the large pool where spacewalkers practice, but
want to be sure it can be done in space without any extra tools.
So who has the toughest job on this mission?
That probably would be Marsha Ivins, the veteran astronaut who will use the shuttle's robotic arm to lift the 28-foot Destiny module from the shuttle's payload bay and move it into position on the space-station. Ivins will have only about two inches of clearance as she lifts the silver cylinder from its berth, then she has to rotate it, flip it over 180 degrees and put it in its place. Once that's done, she retrieves a docking port from where she previously parked it and puts it on Destiny's free end. Most of this she has to do without any direct line of sight, relying on video feeds and directions from spacewalkers Jones and Curbeam, who will have a better view.