Thursday, August 04, 2005

To Boldy Go Where No One has Gone Before....

It has been interesting, but frustrating to watch the mission of STS-114 and to watch the reaction of the press and the public to the technical issues of this flight, the first shuttle flight since the Columbia accident. What is most frustrating is just how timid our nation has become about facing the dangers inherent in spaceflight. The attitude seems to be that no failure is acceptible. With this attitude, we would never have gotten to the Moon during Apollo. Despite how easy NASA has made spaceflight look, it is still very dangerous business. That is a tribute to NASA that they have done the business of spaceflight so well that it looks routine and to most, "boring".

As for the current mission, it is both a great enhancement and a heavy burden to see all of the extra imagery of the vehicle, both during launch and on orbit. During the first 113 missions of the Shuttle program, they would have no information about tile issues on the bottom of the orbiter and would not have detected the large bit of foam that fell off the external tank unless it hit the orbiter, so any engineering issues regarding such events would either not be addressed at all or would be discussed after the mission when the orbiter brought the evidence back with it in the form of damage to the tiles. Tile damage on the orbiter is a given. You've got the spacecraft mounted on the side of the launch vehicle where any bit of debris - foam, ice, bolts, whatever - that fall off of it risk impacting the spacecraft and its delicate thermal protection system. One thing we can learn for future spacecraft is to not only provide a continuously available abort system to get the crew away from a failing launch vehicle, but also, put the spacecraft on the front of the rocket where debris damage is much less likely.

So, while past missions suffered an AVERAGE of about 150 dings to the tiles, this mission, from the preliminary orbital inspection only had around 25 tile dings! That is a huge improvement! But while in the past, those dings and anomalies would not have been seen until the orbiter was on the ground, the engineers now see it in orbit and have to make a decision to repair or not during the approximately 2 week mission. We risk fixing a lot of things that are not going to bring the orbiter down like Columbia, for example the gap filler removed by EVA astronaut Robinson on Wednesday. We've seen this kind of anomaly before.

While there has been talk of scraping the shuttle right now instead of continuing its lame duck future and finishing the International Space Station with shuttle resources. We have more than 100 flights under our belt - we should be able to accept the risk and get on with the mission and finish the orbiter program. The new exploration program envisioned by NASA and supported by the current administration will not happen without risk. We must get back to business and accept that risk, for the future is worth that risk. Astronaut Gus Grissom, who died in the Apollo 1 spacecraft fire knew the risks he was taking and accepted them. He said, before the accident, that if he should die, he hoped the program would go forward despite that and Apollo did, as much because of his sacrafice. We learn, we get better and we go on, so its time to go on and keep flying the shuttle to its planned retirement.

Jim.

4 Comments:

Blogger Lennie Briscoe said...

I was under the impression that since the Columbia Disaster, many millions had been poured into the space program to fix the inherant problems. It seems that the money didn't go where it was needed most and that luckily the talented ground/space crew were able to work around a potential disaster. There have also bee musings that NASA management simply don't listen to the people on the ground and are more interested in bottom line then safety. Perhaps they should go and work for the Russian space tourist agency instead?

5:31 AM  
Blogger Chris said...

I think NASA should continue the shuttle program until it's retired, like you said. I thought they did a great job preparing discovery for flight. I think the problem is in the design of the shuttle...The payload (the orbiter) is smack in the middle of the launch vehicle, whereas any other rocket type vehicle (saturnV, delta and the like) the payload is on top and out of the way of any material that would fall off. However, I love the shuttle and still think it should fly. I think NASA has become gun shy.. by the way, I like your site, mind if I link it to mine?

9:07 AM  
Blogger Jim said...

Hey Lennie,
Yes, NASA did spend millions to fix problems uncovered by the investigation into the Columbia accident. You might have noticed that there was no foam to fall off of the Bipod Ramp area (which caused the Columbia accident). What you may not have noticed is that despite the one piece of foam falling off the tank, this orbiter has been called the cleanest on return yet. It had fewer dings to the tiles than any other shuttle returning from space. Sounds to me like they did a lot of things right. That's not to say there isn't room for improvement. On a vehicle of such complexity, there will always be things to improve or fix. On previous flights, we would never have known about that piece of foam that fell off the tank during STS-114's launch unless it impacted the orbiter, which this one did not. The crew also knew that their thermal protection system (TPS) was in excellent shape prior to re-entry which is something that no other shuttle crew has ever known for sure, thanks to the orbital inspection techniques added to the flight. Not to mention that they now have the capability to actually go and repair some of the flaws they might find on the TPS. Imagine if the only things you could fix on your car during a cross country trip were things you could get at from inside your car - maybe the stereo or a blown fuse. But a flat tire you were stuck with for the duration of the trip. Now, the shuttle crews can fix things outside their cabin - what a revolution.

If you think the Russian spacecraft are safer than our shuttles, I think you should look them over a bit more thoroughly. The one thing they do have is a launch escape system through the whole launch phase and they use a big dumb booster to get it into space.

I can't wait for the day that the shuttle is retired and we move onto the next manned spacecraft, but with an accident rate of only 2 in 114, that is pretty impressive - better than 98% success! We also know where most of the issues are with the vehicle (I'd still be more worried about the SRBs and the main engines during launch than about re-entry - heck, the Columbia accident was really a launch accident since the damage to the spacecraft occured then). But the shuttle has been a remarkable spacecraft, the most complex one ever built despite its flaws and limitations.

Keep in mind that we are still in the infancy of space travel. Imagine where we were with airplanes after only a few hundred total flights.

Jim.

9:59 AM  
Blogger Jim said...

Hi Chris,
I'd be happy if you linked to my site. Obviously, I agree with your comments. We need to work on the problems but get back to flight in a prudent manor. 20:20 hindsight is always much better than trying to predict the affects of anomalies, but having more data as we now have with the extra imagery during launch and on orbit makes any predictions you are forced to make a lot more reliable. On past flights, we would not have seen the foam fall off and we would not have known about the gap filler protruding which would probably have caused some amount of tile damage (most likely minor). And they also know about the thermal blanket damage near the CDRs window and were able to make a judgement about it before re-entry rather than just examining the damage after landing.

I sure hope NASA ends up with a CEV that takes all the lessons learned in spaceflight to date into account - and not only shuttle flight experience, but also Mercury, Gemini and Apollo. We can certainly make improvements on all those different spacecraft to make a much more durable, safe, and capable vehicle for spaceflight.

Jim.

10:09 AM  

Post a Comment

<< Home