Interaction: STS-114 preview

Myers: Hello, and welcome to Cape Canaveral, FL, USA and Kennedy Space Centre, where Discovery is now sitting at pad 39B awaiting its chance to launch into space on STS-114. But one of the sensors in its external tank is acting up, and without all the sensors functioning adequately, it's not going to be going anywhere, except maybe back to the Vehicle Assembly Building. The current launch window extends to SUN 31 JUL 2005, and after that it will be more than a month before any Space Shuttle missions can be launched. Will STS-114 fly before September? Will the remaining missions before the Space Shuttle's retirement be worthwhile? Will the space food improve? We'll talk about all of these issues today, but first it's the Interaction IQ, the Initial Question. Sally from Hamilton, ON, Canada asks what relevance the Space Shuttle has in today's society. An interesting question, and we'll go first to science fiction author Ms Lisa Altobelli.

Altobelli: Well, space travel is the only area wherein everybody works together. Nobody ever wants a space mission to fail, whether you're American or Russian or Chinese or European or miscellaneous.

Myers: The editor of Spacegyro.com, Mr Tim Fum.

Fum: The Space Shuttle is neat. It's got a distinctive appearance, and it makes people smile.

Myers: The director of the Space Policy Centre of Maryland, Mr Arvin Gaskhul.

Gaskhul: The Space Shuttle is the most important thing that's going on right now, until it's replaced by something bigger, better, badder, and funnier.

Myers: And a professor of space travel at the University of East West Virginia, Ms Anne Randall.

Randall: Well, the Space Shuttle was the first to get us flying in reusable vehicles, a concept that's now finally being put to use in the private sector. SpaceShipOne, SpaceShipTwo, and various other things are going to be flying in the near term, and people will finally be able to do stuff like fly to an altitude of several hundred kilometres, fly into orbit, escape orbit, land on the Moon, land on Mars, land on Ganymede, land on Venus, land on Ceres, land on land, land on Donovan, land on their feet, land on Pluto, ... what was I talking about?

Myers: And I'm Debbie Myers. I think the Space Shuttle should be donated to US Space Camp so that the movie can be reenacted. And now let's discuss briefly the launch attempt earlier this week. The crewmembers had actually been ingressing Discovery; about half of the seven crewmembers were already in their seats when the launch control team decided to scrub the launch. So with a pad scrub like that, does it disappoint the crewmembers at all, Tim?

Fum: Well, it has to a little bit, Debbie. They're in this big thing that can take them into space and back, but nothing happens. They just have to get off and go back down the elevator. It's like they say, a good day is where you go up the elevator, but you don't have to go back down.

Myers: But which would be more annoying for them, an indefinite scrub like this where they don't know when they'll be on the pad again, or a short turnaround scrub where they still have to go back the very next day?

Fum: They shouldn't be complaining either way. They get to go into space.

Myers: But Arvin, is it really worthwhile to force the mission to remain on the ground for days, possibly weeks, just because of one sensor?

Gaskhul: Sure. Remember, these sensors tell you when the external tank is empty. And when the external tank is empty, the main engines have to shut down. There have been tests where the main engines were run without hydrogen or without oxygen, and without hydrogen, when there's just oxygen running through the engine, that can damage the engine. So they have to make sure that the engine cuts off in time.

Myers: But these sensors are redundant.

Gaskhul: They're redundant for a reason. The engines will cut off as soon as two of the four sensors in either portion of the external tank – the liquid hydrogen or the liquid oxygen – as soon as two of the four sensors read dry. But if one of the sensors has failed, and then a second one fails whilst you're in the air, that'll cut off the engines prematurely, which would be a big problem and it would force an abort situation. Nobody wants that.

Myers: All right, well, let's move on now to our viewer questions. Remember, you have plenty of ways to get your questions to us, either by E-mail, telephone, facsimile, text message, telegraph, snail mail, or paintball. Our first question is by paintball, and it's from Ryan in Carson City, NV, USA. Ryan asks whether all future Space Shuttle missions will be visiting the International Space Station. Tim?

Fum: Yes.

Myers: All right. Well, let's move on to our next question. Miriam in Conakry, Guinea, are you there?

Miriam in Conakry: Yes, hi.

Myers: Hello Miriam. What is your question?

Miriam in Conakry: How come there have only been 114 Space Shuttle missions? It's been around for, like, 25 years. It should be flying every month.

Myers: Anne, why has the Space Shuttle flown so infrequently?

Randall: Well, the Space Shuttle programme is really too big for its own good. It's too complex, and they haven't built any new orbiters since Endeavour. So they're working with thirty year old technology for the most part. That's like using eight tracks, vacuum tubes, mainframes, gasoline shortages, massive fros, the Village People, ... what was I talking about?

Myers: Lisa, how would a higher flight rate have changed the Space Shuttle programme?

Altobelli: Well, it means there would have been many more missions, and consequently, we would have had this discussion many years ago. In fact, by now the Space Shuttle may well have been replaced by something better, and we may well be on our way to the Moon and Mars and other places already.

Myers: Well, NASA are currently developing a successor to the Space Shuttle, one that will be able to travel beyond low Earth orbit. Is this a concept that is too little too late, Arvin, or is it going to be the cornerstone of space exploration in the 21st century?

Gaskhul: It makes me say, it's about freaking time. Because we need more stuff in space. We need a really freaking big space station, one that rotates to simulate gravity, and that has the Blue Danube playing all the time.

Myers: Okay, well, we have time for one more question. In a text message, Rosa from Oviedo, Spain asks which mission after STS-114 is going to be the most important. Tim, there are a couple of qualification missions, but most upcoming Space Shuttle missions will involve construction at the ISS. Is one of those going to be the most important?

Fum: They're all important. Most of the missions after STS-114 and STS-121 will be carrying truss segments, and we want all of those on there. But beyond that, the Kibo experiment module will be added at some point, as will the Express pallet for experiments. So these are going to be very important, plus a lot of fun.

Myers: All right. Well, with that, we'll wrap up this week's edition of Interaction and say thanks to Ms Anne Randall, Mr Arvin Gaskhul, Mr Tim Fum, and Ms Lisa Altobelli for joining us this week. We'll remain in Cape Canaveral next week, where we will hopefully have seen the launch of STS-114. We'll discuss the mission ahead with two space correspondents, a space engineer, and a photographer who takes pictures of people looking at launches. Until then, good night.

Altobelli: But it's afternoon.

Gaskhul: And if we'd invested properly in space exploration, we could solve that problem.