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08/14/2020
Three Mars Missions and a Revisited Catastrophe
CHAPTER 115 Bright Spots and A Very Dark Spot
Today, as I begin this column, it's August 10, 2020. I began my last column with the following: "On June 22, 2020, I had one of the more memorable experiences of my life. I got a haircut!!! (My previous haircut was on February 7, making it some 4 and a half months between cuts.)" The reason for the long interval between cuts was the pandemic, of course. I just had another haircut, this time delayed by power outages caused by Tropical Storm Isaiah, which left New Jersey and New York with the worst amount of power outage due to downed trees, branches and power lines since Hurricane Sandy. One big tree is down around the corner from my house. My generator has performed well in keeping me powered up during the hours when others, some for a week, have been powerless.
For me there were a couple of bright spots during this pandemic. One bright spot for this space enthusiast was the successful launch and safe return of the SpaceX crew, Doug Hurley and Bob Behnkento, from the International Space Station (ISS). I hadn't realized that the wives of the two SpaceX astronauts, Karen Nyberg and Megan McArthur, are also astronauts and that one of them could also ride the SpaceX Dragon to the ISS. Another very significant space venture was the launch of the Perseverance mission to Mars, with one objective being to dig up samples for later return to Earth to look for signs of past life on the red planet. The finding of any signs of past life would, of course, be a monumental discovery. Also on board is a helicopter they hope will be able to fly in Mars' thin atmosphere!
The helicopter, named Ingenuity, only weighs 4 pounds and is powered by 6 lithium-ion batteries. Having spent some 15 years at Bell Labs working on lithium batteries, I was intrigued by an emailed press release I got from NASA/JP saying that they have just successfully charged the lithium-ion batteries and will keep them charged at a relatively low level until Perseverance arrives on Mars in February next year. Once the helicopter is turned loose, onboard solar cells will charge the batteries with enough power to hopefully fly the craft for 90 seconds. This may not sound like much but I'm sure the NASA team will be ecstatic if Ingenuity just gets off the ground!
A Chinese spacecraft, Tianwen-1, is also on its way to Mars after launching successfully from Hainan Island in southern China. The Chinese spacecraft contains a lander, an orbiter and a rover. If both the NASA and Chinese efforts are successful there should be a good bit of interesting activity going on next year. Not only that, but the United Arab Emirates (UAE) launched its Hope orbiter earlier this week. There could be a real traffic jam up there.
In contrast to these space missions so full of promise, there was a devastating event involving chemistry that never should have happened, the horrific catastrophe in Lebanon. caused by the explosion of ammonium nitrate. For me, the event brought back a memory of a remark by my chemistry professor at Dickinson College and a column I posted on 6/12/2001. I think it's worth repeating portions of that column here:
"Remember Oppau!
Last week, I wrote about Fritz Haber and how his process for making ammonia affected the course of history. After posting the column, I had this feeling that I had missed something important. While anticipating my 55th reunion at Dickinson College last week, I realized what it was. It was a remark made by Professor E. A. Vuilleumier in our freshman chemistry class some 58 years ago. Vuilleumier was a colorful teacher and had a peculiar way of illustrating the difference between concentrated hydrochloric and sulfuric acids. He poured the two acids into beakers and then dipped his hands into the beaker with the hydrochloric acid. As I recall, he also quickly washed his hands under the tap. Turning to the other beaker, he did not dip his hands in the sulfuric acid. Sulfuric acid is really nasty stuff. I hasten to say that I don't recommend you dip your hands in either acid!
But we're concerned here with ammonia. It was in one of Prof. Vuilleumier's classes that a coed classmate fainted. As she was coming to, someone handed her a container with ammonia to sniff. She drank it! I'm happy to report that this feisty coed was none the worse for the incident. But let's get to Professor Vuilleumier's remark that made such a lasting impression on me. We were considering the chemistry of ammonium salts, particularly ammonium nitrate, when Vuilleumier told us in no uncertain terms to "Remember Oppau!"
Last week, we noted that one of the uses for the ammonia is to make ammonium nitrate for use as a fertilizer. Oppau, Germany, was the location of the first synthesis plant for ammonia production using the Haber-Bosch process. At the Oppau plant, established in 1913 by the German company BASF, ammonium nitrate and ammonium sulfate were two of the fertilizers that were being produced. What BASF did was to make these compounds and pile them up in big piles - I mean really big piles containing several thousand tons of the materials. The particles of these ammonium salts tended to stick together, making clumps of material that were hard to break up when ready to be shipped. Rather than go in with sledgehammers or the like, they typically used a brute force method of breaking up the piles. They broke them apart with blasting powder!
This blasting method had apparently been used many, many times without incident so there was no reason for concern on September 21, 1921. BASF had a pile containing roughly equal amounts of ammonium nitrate and ammonium sulfate. The pile contained well over 4,000 tons of the stuff. You've probably guessed that "Remember Oppau!" concerns this date. The explosion was devastating, killing over 500 people and injuring over a thousand more! The plant and a goodly portion of the town were leveled. Until Oppau, there was no indication that ammonium nitrate was hazardous. Now the world knew that ammonium nitrate is one of those compounds that can be treated with impunity most of the time but, under the right conditions, it can be deadly.
The Oppau explosion was prophetic of things to come. Only three years after I heard Professor Vuilleumier's remark, Texas City, Texas had its own encounter with ammonium nitrate. This waterfront boomtown of 18,000 was full of chemical plants and oil refineries and occasional fires and even explosions were not out of the ordinary. The populace was used to stopping work and watching the fires if they seemed particularly interesting. On April 16, 1947, when a small fire broke out on the French ship, the S. S. Grandcamp, the peach or reddish orange color of the smoke attracted more than the usual amount of spectators. The Grandcamp was already loaded with such things as peanuts, sisal twine and oil field machinery. It was docked in Texas City to be loaded with ammonium nitrate destined for Europe.
It became clear to the crew on the Grandcamp that the fire needed more than just jugs of water or portable extinguishers. The hatches were closed and covered with tarpaulins to protect the cargo. Now came a mistake in chemistry. To preserve the contents of the ship from water damage, instead of hosing down the fire, the decision was made to employ the ship's steam fire-fighting system. The steam was intended to smother the fire, avoiding using all that water. The problem is that ammonium nitrate doesn't like high temperature. The hot steam heated up the compound, which started decomposing. The gases emitted blew the hatches and the ship became so hot that, when the Texas City Volunteer Fire Department started spraying water on the deck, the water vaporized! Remember Oppau! The ship blew up.
But that wasn't all. There was another ship in the harbor that day, the High Flyer. Guess what that ship contained - ammonium nitrate! Over 900 tons of it! It too caught fire and some 16 hours later it also blew up. The two explosions sent debris onto the oil tanks and pipes and secondary fires and explosions abounded. When it was all over, at least 581 people were dead and 3,500 injured. No resident of the town was untouched by the tragedy, which is profiled in detail on what I believe is the Houston Chronicle Web site chron.com.
Fast forward to today, Monday, June 11. The person who represents the essence of evil, Timothy McVeigh, is history. What was his choice of fertilizer to use in his bomb destined for Oklahoma City? Ammonium nitrate! ..............(I've eliminated a substantial portion of the original column here )
Well, I'm back from my 55th reunion, a most enjoyable affair with a dozen of us from the class of 1946 in attendance. That may not seem like many but during World War II there weren't too many of us at Dickinson. And the ratio of 5 females to 1 male held true at our reunion - Bob and I were the only men. And would you believe that Bob said he had a challenge - could anyone spell Vuilleumier (pronounced Vee-yuh-may)? Having started this column before the reunion I could whip it off with no hesitation!"
That's the end of my earlier 2001 column, which harkened back to an incident that happened almost a century ago. From news accounts, it seems that officials in Lebanon were warned repeatedly about the danger of storing that ammonium nitrate where it was. I can't help thinking that the virus is like the ammonium nitrate, lying in wait to kill us. Not in a spectacular explosion, but in more deadly numbers and too many of us ignore or have ignored obvious solutions - moving piles of ammonium nitrate away from population centers; masks and distancing for the virus.
Stay safe.
Allen F. Bortrum
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