WEEKLY WHINE

Horsegrenades and hand shoes

For those of you who were tuned into NASA Television today, you probably had a few anxious moments. The crew of Expedition 6 to the International Space Station were the first ISS long duration crew to return to Earth on a Soyuz capsule. But they missed.

Well, they didn't miss that badly. After all, they still hit Earth, and they did so at a slow enough velocity to survive with no apparent ill effects. But their touchdown was a bit to the north of the Aral Sea, some 460 km from their target point between Baikonur and Astana.

It took the search crews two hours just to find their capsule. As we write this, crews are still figuring out how to get the astronauts and cosmonaut to their medical checks in Baikonur, rather than Astana as was originally planned. Since much effort is being expended on this recovery effort, it probably makes sense to determine just why this happened and what can be done about it. That's where the GoobNet Special Projects Enhancement and Enforcement Division [SPEED] comes in. Here are some potential causes that they identified, or made up as the case may be.

PILOT ERROR

The Expedition 6 crew - commander Ken Bowersox, flight engineer Nikolai Budarin, and science officer Don Pettit - were expecting to come back on STS-114 on the Atlantis orbiter. But with the loss of STS-107, all orbiters are grounded, and the Soyuz TMA-1 was their only way back. Everyone was worried: Do they remember their training on how to fly a Soyuz? Do they know where to go after they land? Will they get confused and try to sit in the middeck?

The first thing that pilots do when their fellow pilots are involved in a mistake such as this, one that causes no casualties, is blame their counterparts on board. It was obviously the crew's error, because a good pilot [eg, whichever one you're talking to] would never screw it up like that.

So what specific lapse in judgment was it? Either Pettit forgot to disconnect a duct before the landing, Budarin left some mass in the wrong place somewhere, or Bowersox forgot to click on the desired landing site when he programmed the computer. In fact, it probably was the computer. The next Soyuz capsule will probably have a reprogrammed computer that will ask the commander "Are you sure you want to land here?"

PROPULSION FAILURE

It may also help to blame the propulsion subsystem. Early indications are that the spacecraft entered Earth's atmosphere at a steeper angle than planned, which suggests that a deorbit burn went on a little too long. Why? Were the valves a little too slow to close? Were there problems depressurising a tank? Did somebody throw a sandbag into a propellant tank as a gag?

Maybe the crew should be looking out the window as they reenter. "Hey, I don't recognise that plasma stream! We must be off course!"

SPACECRAFT PROBLEM

A new, unproven spacecraft could have been to blame. Any number of problems with the Soyuz TMA-1 could have sent it veering off course. For example, the most prominent change made in this spacecraft was the new seating arrangement. The seats can be configured for a greater height range, allowing more of NASA's astronauts to fit into the capsule.

But did anybody think about what effects this change would have? Clearly, if you permit shorter or taller crew members, the spacecraft's centre of mass will move about unpredictably from mission to mission. Furthermore, tall astronauts breathe more, which means that the lithium hydroxide canisters absorb more carbon dioxide. An astronaut whose atmospheric requirements are lower will put less strain on the LiOH.

And what does all this mean? Simply put, when all those saturated LiOH canisters are thrown at one end of the spacecraft, they vent. Yes, used carbon dioxide can actually escape, changing the spacecraft's velocity enough to push it off course. This has actually occurred in the past on the Space Shuttle, but people didn't notice because the commanders would do more S-turns to dissipate that excess velocity.

That's just one of the potential problems with the Soyuz TMA series that may have caused this problem. Other possibilities include:

• Painted letters on the exterior. The extra mass of paint to put "Soyuz TMA" on the exterior of the spacecraft instead of "Soyuz TM" could easily have caused a big change in the centre of mass.

• Super springy springs. Did anyone test the spring constant of the springs on the docking adapter? When they undocked from the ISS, they could have been given too big a push.

• Excessive noise. We hear Budarin likes loud Russian hip hop. Did the 400W subwoofer that's now standard equipment on the Soyuz have anything to do with it?

EARTH'S CORE IS SPINNING DOWN

Well, at least they didn't land in the Los Angeles River.