The US$3.3 billion Cassini mission is about to rendezvous with Saturn, but if some had had their way the robot probe would never have left the ground.
Dr Kevin Grazier, a scientist from Nasa’s Jet Propulsion Laboratory (JPL), in California, was in New Zealand briefly and took the opportunity to give a public lecture on the mission at Waikato University. Afterwards he spoke to NZ Skeptic.
NZS: What brings you to New Zealand?
KG: About five years ago, Philip Sharp at Auckland University read a scientific article that I published, and it turns out that we have very similar research interests. He is interested in developing mathematical and computational methods for doing simulations of solar system celestial mechanics. I’m interested in that, but more interested in applying these methods to answer questions into our solar system’s origin and evolution. I’m in New Zealand to collaborate with Philip on a couple of papers on numerical methods, which we will be publishing soon.
NZS: What is your role on the Cassini mission?
KG: I’m investigation scientist for the Cassini Imaging Science Subsystem. There are 12 instruments on Cassini — associated with each is a team of scientists. These scientists provide me with lists of observations they would like Cassini to make. I then have to determine, to the second, when the spacecraft will be in the proper position to make the observations.
NZS: At your talk you mentioned there was a bit of a backlash on the Cassini mission in the early days. Can you expand on that?
KG: Because Cassini has 72.3lb of plutonium oxide on board encased in three RTGs (radioisotope thermoelectric generators), there was a small but vocal movement which wanted the launch stopped back in 1997. Their claim, which I think Nasa countered quite well, was that if there was a launch accident the plutonium could be dispersed widely. Ironically there are still people who think that somehow Cassini can come back to Earth with its radioactive payload to poison the Earth — sorry, that’s not possible.
NZS: How can you respond to people who think this way?
KG: Well, it seems like every year there is the “Astronomical Catastrophe du Jour”. Let’s go back to 1997 and Comet Hale-Bopp. First it was supposedly on a collision course with Earth. Then, after it passed, it was supposedly on a collision course with the sun, as if that would matter. Astronomers were saying otherwise, but there were folks in the media and folks who wrote books, and folks who made web pages, who were “in the know”, and “knew the real facts that astronomers won’t tell you”. What I tell people in this case is, this is an excellent opportunity for you to calibrate your sources. Here, astronomers are saying one thing, the detractors are saying another. When all this has come and gone, recall who said what, and keep that in mind next time (the next time, in this case, being the planetary alignment on the fifth of May 2000).
NZS: You’ve given public talks about Mars. Do you get asked about the Face?
KG: I talk to school groups fairly regularly, but I talk about the Cydonian face only when asked. Actually that’s not quite true. In my standard Mars talk, I build up to a slide in which I promise them I’m going to show them a photo of the face on Mars they’ve never seen. Then I show a smiley face imposed over a crater on Mars.
Actually, when I talk about Mars I usually have a slide with me showing the 1976 Viking image in which the formation in Cydonia looks like a face, as well as the much higher resolution 1997 Mars Global Surveyor images, in which we clearly see this is a naturally occurring feature.
Some people don’t want to believe that, and say it’s a Nasa cover-up. You just have to accept what’s staring you in the face. You know, my job is completely open, we don’t do anything with the military, everything we do is wide open, and people just can’t accept that. It’s not a conspiracy, we see what we see. We release what we see.
NZS: Are skeptics an endangered species?
KG: Sometimes it seems that way, and it’s astounding when I hear some of the beliefs some of my students hold, coming into the class. Am I a skeptic? Any scientist is a skeptic, or should be.
Coming Soon: The Cassini-Huygens Show
Cassini is the largest and most sophisticated spacecraft ever sent into deep space. It began its seven-year, three billion-kilometre journey in 1997. Speaking at Waikato University in February, Kevin Grazier told the audience 17 nations had contributed to building the spacecraft, and more than 200 scientists worldwide will study its data.
“We’re on course for a July 1 orbit insertion, and the spacecraft’s operating fantastically and sending back information already,” he said.
Riding piggy-back on Cassini is the Huygens probe, which is to detach from Cassini on December 23. It will plunge into the atmosphere of Titan, the largest of Saturn’s 31 known moons and the only moon in the solar system with an appreciable atmosphere — which makes it of great interest to scientists.
“Hopefully we’ll get images as it descends through that atmosphere, which we think is very similar to the atmosphere Earth had that gave rise to life. A term often applied to Titan is that it is the early Earth in a deep freeze.”
After watching the Gemini and Apollo launches as a child in Michigan, Dr Grazier decided when he got to college he would take up space. “My educational career was dedicated to getting into where I’m working now — at JPL.”
JPL, whose first director was New Zealand-born William Pickering, began as a laboratory dedicated to jet propulsion, which changed with the launch of Sputniks I and II — “we instantly saw we were behind in this thing called the space race!
“JPL became the Nasa centre building spacecraft for earth orbiting and then planetary exploration — we’ve been sending spacecraft to planets for over 40 years now.”
Dr Grazier has another claim to fame which he shared on the night. A fan of science fiction, he played a Cylon centurion (one of the bad robots) in the Battlestar Galactica: The Second Coming trailer. “I approached them about me being a science advisor to the show, and they stuck me in this Cylon outfit!”
It was, he says, an out of this world experience, if somewhat hot and restrictive. He’s just accepted the job of science advisor on the upcoming TV series of Battlestar, so might get a chance to wear the suit again. In the meantime, there’s Cassini to keep an eye on, and landing a probe on an unexplored moon.
For further updates on the Cassini mission, visit the JPL website: saturn.jpl.nasa.gov/index.cfm