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I see a weak signal… The Day Pathfinder Landed on Mars

Sami Asmar

3 July 1997

We arrived this afternoon at the NASA tracking station in Spain to start preparing for tomorrow's landing of the Pathfinder spacecraft on the surface of Mars. About an hour drive outside of Madrid, the complex is in a mostly uninhabited area between mountain ranges. It sneaks up on you; you'd expect to see the huge antenna structure from many miles away, instead, it reveals itself only from a few miles away with all the hills in-between. Due to the nature of the landing sequence, a communication blackout was expected during the entry, descent, and landing on Mars, the most risky period of the mission (riskier than launch in my opinion). I came here to overcome that blackout and get a signal from the spacecraft. A little blip on my monitor at just the right time would tell me that it had executed and survived the complicated landing sequence. My job here is to be the first person on this planet to hear word from the surface of Mars. There is a room-full of engineers, scientists, and managers at JPL waiting to hear my confirmation. This is the kind of assignment that can get a lot of attention if the landing was not successful and taken completely for granted if it was. I was happy to be taken for granted.

As I saw the overwhelming amount of communications equipment inside the control room, racks after racks of humming and blinking machines, I reminded myself that I was picked for this assignment because of my expertise in one specific rack of instrumentation. It can receive very weak radio signals from spacecraft moving at high speeds. We normally use this equipment for science experiments to study the atmospheres of the planets or to search for gravitational waves, but tomorrow, it will come down to getting Morse code from the most exciting deep space project in years.

One person I was looking forward to seeing is the cook, of all people. When we visited the station two months ago to do a landing communication rehearsal we joked with him after he offered us wine with lunch in the cafeteria, a normal thing in Europe but unheard of at JPL. We did not drink but had a big laugh with him especially after butchering the Spanish words for every item on the menu. Jeff, the other American on the trip had decided to ask for soup in Spanish and incorrectly asked for "soupa." David (Da-veed) the cook yelled out "que soupa, sopa, sopa!" From then on, every person in the station yelled out sopa and laughed whenever they saw us in the hallways. I had to get Da-veed on video this time, I said to myself, while driving the narrow country road out of Madrid to Robledo de Chavela.

As I was being shown the newest equipment by a proud engineer, I realized that I was still having some trouble getting over the few days of vacation I took in the South of Spain. It was best to do the sightseeing before the landing since I had to get back afterwards to lead the rover communications team. I could not believe how beautiful Spain is; I did not leave a castle or "alcazar" unvisited. I got carried away photographing the fountains of Alhambra palace in Granada, admiring the engineering that created this wonder, where melted ice water from the mountain tops was channeled into arches of water without mechanical pumps. The statue of Columbus getting his mission from the king and queen of Spain that led to the discovery of the new world made me think of how Spain is playing another critical role in the discovery of a newer world. The shift from ancient Anadalucia to a high-tech Mars mission was not easy. I later forced myself to read a boring technical manual only to get my brains in gear again.

I had been to the station yesterday too although there was nothing specific to do. I checked all my voice mail messages and a fraction of my 301 e-mail messages… just to get back in work mode. My 12-year-old nephew, Eric, traveled with me to see what his uncle does for a living. I told him this was a typical assignment for me, just to get a reaction; he laughed knowing we did not land robots on other planets everyday. He probably keeps up with space accomplishments better that I do. He had told all his friends and teachers about it and when I innocently said you can come along to see for yourself he took me seriously. There was no way on Earth (or Mars) to take that invitation back. He dragged his dad along all the way to Spain and took lots of pictures of the 70-meter diameter antenna that will receive the signal from Mars; a football field that moves and points at the sky. He took it very well when I told him that he couldn't really be there the day of landing itself. They went to Toledo (Spain).


4 July 1997

I arrived at the station before 11:00 am local time knowing that we'd probably put in a 20-hour shift. This is Independence Day in the US but nobody here made a mention of that. My Spanish colleagues suggested that we eat lunch around noon before we get very busy. They never eat lunch around noon in Spain; they probably had to make special arrangements with Da-veed that day. The cook worked the same long shift as well; he probably did not want to miss the excitement. I also found out later that he was in charge of the champagne so he had to stay until the end. Around noon, the cool calm, collected one, I suddenly felt extremely nervous. I felt that if I ate anything I was going to get sick so I skipped lunch. That was a big mistake, because a few hours later I was more nervous and stressed, jet-lagged, and working hard on several fronts, and I was starving too. I should have rehearsed the timing of the meals when we came two months ago.

While most people went to lunch, I entertained myself by watching a large number of Spanish and other European media people take turns interviewing the station director. He looked extremely proud explaining how, in a few hours, the spacecraft will be inside big balloons bouncing on the Martian surface. I understood every tenth word in his mile-a-minute Spanish but liked his clear hand gestures: balloons, bounce, etc. I hope for all our sakes that we don't face the same media to explain if something goes wrong. I kept thinking that there was no point getting excited, it was just another workday. Who am I kidding, it is a historical day and I am big part of it as much as I refused to use that cliché. My first assignment was the Voyager encounter with Neptune in 1989 and that was exciting but this seems a little unbelievable, a little toy roving the red planet.

Time flew. In the early afternoon, I got very busy helping the staff set up the equipment in the configuration I requested. It helped that the Spanish engineers were somewhat calm. Mr. Calbo was assigned to help me set up the final machine in a long chain of instruments that will display a spectrum of the radio signal we'll all be waiting for. The first thing he said when we met was that he knew very little about this machine; that scared me. He then proceeded to work smoothly and flawlessly, a very humble man.

Voice communication with JPL started with the usual "voice check" and greetings. I felt that managers, who came in just for the special occasion, monitored the network so I spoke slower that usual at first, then gave up as soon real events started taking place. I did not know that the media had also recorded portions of that communication so I joked saying things like "I have eight eyes watching the screen..." that my friends said they heard on CNN.

The spacecraft by now was on an unstoppable course to Ares Vallis, the chosen landing site, a valley where ancient water flow is suspected. We were there to confirm that events took place and that the spacecraft survived the complex sequence. At the critical time, the communications engineer at JPL addressed me over the voice net with unusually serious tone of voice and said "please report what ever you can see." I then saw the blip on the screen. I had once described to my nephew as similar to blips you'd see and hear in hospital rooms. "Comm, this is Madrid" I replied to him, "I now see weak signal …" When he pressed his hand set to reply, I heard an explosion of cheers in the control room based on my few words. That is all I had to say. We later got into the details and various confirmation but that moment went down in history marking the success of the return to Mars.