Saturday 28 November 2015
Gravity - your questions answered
Want to ask questions about gravity, want to talk to a Nobel prize winning physicist? Well then join the Google hangout with George Smoot and others on Monday 30th November
Thursday 26 November 2015
The final countdown... Part 3 D-9 and D-8
As a QA there are many exciting and interesting aspects of the campaign that I have to get involved in. Now the spacecraft is encapsulated in the fairing, you could be forgiven for thinking that my job here is done... not so fast!
I also have to act as a witness for the movements of the now fully encapsulated spacecraft (as I have nicknamed it, the egg, or more formally known as the PAC ).
This involves joining the convoy that will move the fairing with the spacecraft inside from the clean room to the Vega launch pad where it will be hoisted up to the top of the Vega rocket.
Exciting stuff! The 10km journey is made by road and took approximately 2.5hours, yes SLOW! It has to be very slow in order to ensure that the fiaring arrives safely. As this is a hazardous operation, everyone involved has to travel wearing the very fetching bright orange safety overalls which are both chemical and fie retardant to protect us in the event of an accident. It is also necessary to carry a gas mask with us at all times.
Once at the launch pad, it is time to don hard hats and safety shoes as well ready for the lifting of the fairing from the truck, to the 39.4m platform within the Vega launch tower.
Not sure orange is really my colour!
LPF is transferred by road to the launch tower.
Image Copyright ESA–Manuel Pedoussaut, 2015
Up into the launch tower...
Image Copyright ESA–Manuel Pedoussaut, 2015
Tuesday 24 November 2015
The final countdown... Part 2 D-10 16th November 2015
After a somewhat brutal alarm awakening at 02:45 this morning, myself and 3 others have made our way in fo a very early start at 04:00 in order to complete the removal of the remaining non-flight items from the spacecraft and to perform what should be, the last ever inspection.
Today is launch day -10, encapsulation day.
The so called "red tag" items are protective covers for the various sensitive equipments mounted to the spacecraft. We aim to keep these on fo as long as possible and only ever remove them for specific testing or (as now) for flight. They cover items such as thrusters, protecting them in terms of both cleanliness and also from accidental damage during other activities (such as lifting). In addition, we also have remove before flight covers on our optical equipments, such as the Sun Sensors and Star Trackers.
For the last inspection, this is the last opportunity for myself and my colleague to pick up any issues and have them corrected.
After the inspection, we perform a full "accountability" check of all the various emove before flight/install for flight items. We have to be absolutely sue that every item that should have been removed has been and every item that had to be installed for flight has been. All the items then get stored securly until the spacecraft is successfully commissioned in flight.
With everything confirmed to have been completed, we are ready to encapsulate the spacecraft within the fairing of the rocket. This is the last time human eyes will fall upon this spacecraft, going, going, gone! Now encapsulated, the fairing, will act like a mobile clean room until it is jettisoned around 4 minutes after lift off.
Image Copyright ESA–Manuel Pedoussaut, 2015
Image Copyright ESA–Manuel Pedoussaut, 2015
Monday 23 November 2015
LPF in The Guardian
http://www.theguardian.com/science/2015/nov/21/satellite-to-solve-einstein-last-theory
Friday 20 November 2015
The final countdown... Part 1 D-11 and counting
Here we are, after around 6 weeks in Kourou, we have now entered the so-called combined operations phase which is when the Spacecraft is finally prepared for launch.
Launch day - 11 and we are mating the now fully fuelled spacecraft with the payload adapter of the Vega rocket. This is the adapter through which we will power the spacecraft during the coming days for check out and during the launch.
You may remember the post from earlier this year titled "the shoe fits"... well that was the so called fit check with this adapter. Now, we are going to integrate the two for flight.
Tune in again for the developments in the countdown to the launch of Lisa Pathfinder.
Lifting up from the fuelling adapter
Over she goes...
Safely on the launcher adapter.
Thursday 19 November 2015
Time to fill up the tanks
As the loading of the propellant into the spacecraft propulsion module tanks takes place ready for launch, I caught up with members of the team responsible for undertaking the hazardous task of loading the fuel…
Q: What fuel are we loading into the propulsion module?
A: The LPF PRM has a bi-propellant system which means we have an oxidiser and a fuel. As with many spacecraft, the oxidiser is NTO (a mix of Nitrogen Oxides) and the fuel is MMH (Mono-methyl Hydrazine).
Q: Its sounds like a dangerous job, how dangerous is it?
A: This is by far the most dangerous activity that the team face. The fuel is toxic so we have to take measures to ensure we don’t come into contact with it directly as it can cause chemical burns and anoxia (which is a severe lack of oxygen in your system that in this case could occur if there was a leak in the atmosphere, especially as the oxidiser has a boiling point of approx. 21degC). The risks are mitigated by the use of special suits which are worn by those undertaking the loading of the propellants. In addition there are a number of safety features built into the design of the spacecraft to ensure that the oxidiser and the fuel don’t inadvertently meet each other during ground operations. In addition there is constant monitoring of the level atmosphere in the facility to ensure any potential leaks are quickly detected and contained.
Q: Tell us more about the SCAPE suit you have to wear – you look like a deep sea diver, or an Astronaut?!
A: SCAPE stands for Self Contained Atmospheric Protection Ensemble. It protects the propellant loading team from coming into contact with hazardous and toxic propellants. It provides a positive pressure inside the suit to ensure no toxic vapours can enter and protects any liquid propellant coming into contact with your skin. Underneath we wear a fetching cotton onesie as the suit itself is basically plastic. Over the onesie we wear a vest containing our communications equipment. The suit is finished off with a pair of plastic boots and a helmet.
Q: What is it like working in a SCAPE suit?
A: Working in a SCAPE suit can be very hard work if you have to do a lot of movements, the suits are quite heavy and hence we prepare the facility in advance so minimum effort is required in the suit. We set out all equipment and ensure the area is clear of as many obstructions as possible. These suits are very safe but become very uncomfortable after 5 hours in them. We also have a team in the control room that dictate all commands to the team in the facility; these are then repeated and performed. In addition, they will often ask us to solve a few brain teasers and puzzles, just to check we are still OK.
Q: What will you do after the fuelling is finished?
A: Relax and have big BBQ for the team!
After the loading activities we have to decontaminate our loading equipment to make it safe for transport back to the UK. Some of this activity is carried out in what is called a Splash suit and breathing apparatus, when we have to disassemble the different parts. We have to flush the system with demineralised water to neutralise the oxidiser and fuel. After this the equipment is purge dried with nitrogen ready for shipment to the UK. This process reduces the ppm (parts per million) level of propellant in the equipment so that it complies with safe levels for transportation.
The team get ready - first the onesie!
Checking out the flexibility of the suit...
More flexibility checks!
Time for a team photo!
Ready for action!
Now for the seious part... the fuelling activity begins
Friday 6 November 2015
Interview with a scientist
For this post, I've been speaking with ESA Project Scientist Dr Paul McNamara... read on to find out more about Paul, his role on LPF and what makes Gravitational Waves so cool!
- What’s your name?
Dr Paul McNamara
I’m the LISA Pathfinder Project Scientist based at the European Space Agency’s (ESA) European Space Technology Centre (ESTEC) in the Netherlands. My role in the project is to lead the scientific aspects of the mission, and to liaise between ESA and the scientific community (universities). The Project Scientist’s role really comes to life after the mission is launched and when we have ensured everything is working as planned. We then start the science operations - the fun part of any project! For LISA Pathfinder this means we will run different experiments each day (for 90 days) with the goal to understand the physics of all the types of disturbances which can push a test mass away from a perfect gravitational free-fall.- What’s your role on LPF?
I started studying gravitational waves back in October 1994, when I started my PhD in the Gravitational Waves group at the University of Glasgow. My undergraduate degree (also at Glasgow University) was a joint honours degree in Physics and Astronomy - I loved astronomy, but also wanted to work in experimental physics. The gravitational waves group offered both: theoretical astrophysics of the sources of gravitational waves (black holes & neutron stars), combined with the laboratory development of gravitational wave detectors. At this time, LISA was in the early stages of design - I was lucky to be the first PhD student whose thesis was dedicated to the LISA mission, and have seen the mission change and grow over the last ~20 years.- How long have you been studying gravitational waves? What first got you interested in studying them?
Gravitational waves are a direct consequence of Einstein’s General Theory of Relativity, however, almost 100 years after gravitational waves were first proposed, we have not yet directly detected them! Gravitational waves remain the last major prediction of general relativity which we have not yet confirmed. Therefore, making a direct detection of gravitational waves will provide a final confirmation that general relativity is the correct theory of gravity.- In your opinion, what would be the most exciting part about discovering gravitational waves?
However, detection is only the start. What I, along with the rest of the gravitational wave community, really want is the astrophysics we can accomplish with this completely new way of observing the universe. We have theories on what we expect to see…however, whenever we open a new window to the Universe (i.e. x-rays), we see things which we do not have theories for. These are the exciting sources of gravitational waves which may allow us to start to better understand the dark side of the Universe.
- Who is your scientific hero?
Good question. For obvious reasons, there is Einstein. Along with several other physicists at the end of the 19th century, he revolutionised the entire field, and even now, 100 years later, we are still trying to understand the consequences of his gravitational theory.
Also, being an undergraduate at the University of Glasgow, I was surrounded by the work of Lord Kelvin (Sir William Thomson). My first physics lecture at university was held in the same lecture theatre which Lord Kelvin taught in almost 100 years before - an old room, but bursting with history. You couldn’t help but sit there and think of what it must have been like to be in the presence of such an amazing person.
I grew up in the North West of Glasgow….very close to the river Kelvin! My father was a TV repair man, and as such I grew up surrounded by electronics, and was forever playing with the circuit boards from old TVs! This gave me an interest in electronics from a very young age, however, at school, electronics was covered under physics. This naturally led to my love for physics. Also, like most people of my age, I loved watching TV programmes such as Star Trek and Battlestar Galactica, as well as movies like Star Wars…I also wanted to flying around space visiting different planets!- Where did you grow up? When you were a kid what did you want to be?
When I applied to university, I planned to study physics and chemistry, however, my academic advisor suggested I take physics and astronomy instead….a life changing decision which I have never regretted, and which has led me to where I am today!
After my first post-doc, I decided to leave academic life, and took a job in industry, designing opto-electronic sensors. However, I was not cut out for industrial life….my interests lay in science, not in a large engineering company, where the main criteria is how much profit can we make! Luckily for me, a former collaborator in the LISA project had moved to the NASA Goddard Space Flight Centre as the LISA Project Scientist. He was building a team, and asked me if I was interested in applying to NASA. I jumped at the chance! I was then back where I belonged developing the laser interferometric system for LISA. After three years at NASA, the opportunity arose to return to Europe as the LISA Pathfinder Project Scientist at ESA. Ten years later, I still feel very fortunate to be working at the space agency - where else do you get to have coffee every day with the scientists from all of our missions currently observing the universe, or orbiting the planets of the solar system!- How did you end up where you are today?
- Who in the world would you most like to meet?
JK Rowling! My kids love the Harry Potter books and films…which I have now seen more times than I care to remember! I would love to ask her how she came up with all the details of the alternate world of wizards and muggles. Did she have a plan from the start, or did it grow as the years went by. Are the characters (especially the weird ones, e.g. Mad Eye Moody) based on real people, or only exist in her mind?
Although very far removed from science, I can see similarities with writing a series of novels - when designing a new mission (like LISA or LISA Pathfinder), the science team have to try to think of everything up front….which we always fail at! The final mission which we launch is similar to the one the scientists first proposed, but it has grown as we learn the details that come from building the satellite.
- What comes next for you after LPF?
As a scientist at ESA, I may be fortunate to work on another mission. This could be either the gravitational wave mission which will be selected for the 3rd large class mission of our science programme, or possibly in a completely different field of astronomy or physics. Personally, I would like to work on a new field of astronomy…..life is never boring when you’re learning something new.
- When you’re not studying gravitational waves what do you like doing (hobbies/free time etc)?
When not working on the LISA Pathfinder mission, I spend my time on the golf course. Fortunately, at ESTEC we have a small golf course on site - after a long day of meetings, there is no better way to wind down than a quick nine holes!
When not on the golf course, I like to spend time going for long walks with my family…and the dog. Its a great way to see the Dutch countryside.
However, when back in Scotland, we spend our time in the highlands, baggingMunros…hill walking is one activity we cannot do in the Netherlands!
- In one sentence, what would you say to teenagers to encourage them to study
science & maths?
Science is not about the equations you learn, it is about learning how to think differently, and how to perceive the world, and universe, around you….and to have fun!
Paul with LPF @ IABG in Munich, August 2015 - Picture Courtesy of ESA & Airbus Defence & Space.
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