Watch the latest edition of SPACE from Euronews featuring an extended piece on LISA Pathfinder with a few familiar faces...
SPACE-Euronews
Wednesday, 5 August 2015
"The shoe fits" - Fit check with the launch vehicle
Exciting times for LISA pathfinder as the fit check with the Launch vehicle adaptor is successfully completed.
This adaptor will act as the flight interface between the spacecraft and the Vega rocket. The fit check is performed just after the manufacture of the adaptor and six or so months before the launch in order to confirm that the interface is correct and that the harness connects properly with the spacecraft enabling the ground operations team to successfully power and control the spacecraft once inside the rocket on the launch tower.
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| The full LPF Spacecraft atop the Vega launch vehicle adaptor - Image reproduced here with permission from Airbus Defence & Space Ltd. |
The final piece of the jigsaw...
After many years in the making, the beating heart of the LISA Technology Package has arrived...
An exciting time for everyone involved in the Project. The exterior doesn't give much away regarding the delicate and highly sensitive instrument contained within it including the two solid gold test masses which will be carefully released, controlled and captured in flight.
An exciting time for everyone involved in the Project. The exterior doesn't give much away regarding the delicate and highly sensitive instrument contained within it including the two solid gold test masses which will be carefully released, controlled and captured in flight.
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| The LISA Instrument Core Assembly - Image reproduced here with permission of Airbus Defence & Space Ltd |
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| Installed into the Spacecraft - Image reproduced here with permission of Airbus Defence & Space Ltd |
Thursday, 21 May 2015
How cold is it in Space?
How cold is it in Space?
Well the answer is pretty cold. With no atmosphere to protect it, the spacecraft will experience an "outside" temperature of around -140degC. When the sun shines on a surface of the spacecraft it can change the external temperature that the spacecraft sees to around +140degC.
As you can imagine, these changes in temperature aren't great for electronics on board the spacecraft which generally prefer to be kept at a nice ambient temperature of around 22degC. A bit like a mobile phone, if the spacecraft gets too cold, the systems onboard will eventually begin to fail. Equally the same will happen if they become too hot.
So, how can ambient temperature be maintained out in the hostile space environment?
The answer is with a thermal control system.
A thermal control system can consist of two main elements:
- passive control elements which make use of the environment and,
- active control elements which actively seek to change the spacecraft internal environment.
The usual ways of transporting energy (in this case heat) around are:
- Conduction
- Convection
- Radiation
In space we can generally only harness two of these three physical phenomena. Due to the vaccum conditions, convection is not possible in a space environment, unless a specific fluid environment to support convection is located within the spacecraft.
Examples of active elements are things like heaters. LPF has a great number of heaters all over it. Most are fitted to electronic units in order to control their temperature and some are also fitted to the actual structure of the spacecraft. Each heater can be turned on and off by sending a command to it to switch it on and off to acheive the desired temperature. In addition some spacecraft also essentially have their own central heating system. Using a series of pipes filled with a voltaile substance which easilly changes state from liquid to gas, heat can be transported around the spacecraft via convection currents, moving the warmth from hotter areas to cooler ones.
Passive elements include items such as blankets or painted finishes. Blankets are wrapped around particular units and more routinely, the outside of the spacecraft is covered by them - they're the shiny gold foil you see in the photograph below. These work by insulating the spacecraft from the cold space environment. On the Picture below you can also see some areas of white uncovered by blankets, these are painted areas, which use Special paint finishes to provide a reflective surface such that when the sun shines on this surface the radiation is reflected away. This can be used to make sure that certain parts of the spacecraft don't get too hot when facing direct sunlight.
The types of finishes and blankets used vary depending on the specific aspects of the Space Mission. Factors such as the orbit, the size of the spacecraft and the type of equipment onboard all Impact on the overall thermal system design.
Well the answer is pretty cold. With no atmosphere to protect it, the spacecraft will experience an "outside" temperature of around -140degC. When the sun shines on a surface of the spacecraft it can change the external temperature that the spacecraft sees to around +140degC.
As you can imagine, these changes in temperature aren't great for electronics on board the spacecraft which generally prefer to be kept at a nice ambient temperature of around 22degC. A bit like a mobile phone, if the spacecraft gets too cold, the systems onboard will eventually begin to fail. Equally the same will happen if they become too hot.
So, how can ambient temperature be maintained out in the hostile space environment?
The answer is with a thermal control system.
A thermal control system can consist of two main elements:
- passive control elements which make use of the environment and,
- active control elements which actively seek to change the spacecraft internal environment.
The usual ways of transporting energy (in this case heat) around are:
- Conduction
- Convection
- Radiation
In space we can generally only harness two of these three physical phenomena. Due to the vaccum conditions, convection is not possible in a space environment, unless a specific fluid environment to support convection is located within the spacecraft.
Examples of active elements are things like heaters. LPF has a great number of heaters all over it. Most are fitted to electronic units in order to control their temperature and some are also fitted to the actual structure of the spacecraft. Each heater can be turned on and off by sending a command to it to switch it on and off to acheive the desired temperature. In addition some spacecraft also essentially have their own central heating system. Using a series of pipes filled with a voltaile substance which easilly changes state from liquid to gas, heat can be transported around the spacecraft via convection currents, moving the warmth from hotter areas to cooler ones.
Passive elements include items such as blankets or painted finishes. Blankets are wrapped around particular units and more routinely, the outside of the spacecraft is covered by them - they're the shiny gold foil you see in the photograph below. These work by insulating the spacecraft from the cold space environment. On the Picture below you can also see some areas of white uncovered by blankets, these are painted areas, which use Special paint finishes to provide a reflective surface such that when the sun shines on this surface the radiation is reflected away. This can be used to make sure that certain parts of the spacecraft don't get too hot when facing direct sunlight.
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| LPF inside the TVAC chamber Pictures are property of Airbus Defence & Space Ltd and reproduced here with permission |
The types of finishes and blankets used vary depending on the specific aspects of the Space Mission. Factors such as the orbit, the size of the spacecraft and the type of equipment onboard all Impact on the overall thermal system design.
Creating Space, on Earth...
The usual engineering process of design, build, and test applies to a spacecraft the same as it applies to a car or aircraft. However, unlike a car or an aircraft, testing the item you've built in a realistic and representative environment is a little bit more tricky, after all, to do such a test, we literally need to recreate Space here on Earth!
How do you create Space on Earth?
To do this we use something called a Thermal Vacuum chamber. This device once the spacecraft is sealed inside of it, is first used to create a vacuum environment by evacuating all of the air from the chamber. For our recent test, we "pumped down" the chamber to around 1x10-6mbar of pressure (recall that atmospheric pressure is 1bar, so this is an air pressure of 0.0000000001bar!) once this vacuum condition is reached, the chamber is cooled to a chilly -140deg using liquid nitrogen. Prior to cooling the chamber, the spacecraft is powered on and the test team begin to activate the various heaters and monitor the temperatures of all the units to ensure they remain within their operating limits.
The TVAC (Thermal Vacuum test) was the first test that LISA Pathfinder under went on arrival in Germany.
How do you create Space on Earth?
To do this we use something called a Thermal Vacuum chamber. This device once the spacecraft is sealed inside of it, is first used to create a vacuum environment by evacuating all of the air from the chamber. For our recent test, we "pumped down" the chamber to around 1x10-6mbar of pressure (recall that atmospheric pressure is 1bar, so this is an air pressure of 0.0000000001bar!) once this vacuum condition is reached, the chamber is cooled to a chilly -140deg using liquid nitrogen. Prior to cooling the chamber, the spacecraft is powered on and the test team begin to activate the various heaters and monitor the temperatures of all the units to ensure they remain within their operating limits.
The TVAC (Thermal Vacuum test) was the first test that LISA Pathfinder under went on arrival in Germany.
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| LPF Installed in the TVAC Chamber ahead of the test Pictures are property of Airbus Defence and Space Ltd, reproduced here with permission |
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| LPF fully installed in the TVAC chamber Pictures are property of Airbus Defence and Space Ltd, reproduced here with permission |
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| One final look before closing the door for the 8 day test Pictures are property of Airbus Defence and Space Ltd, reproduced here with permission |
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| The door is closed and Space Simulation can begin Pictures are property of Airbus Defence and Space Ltd, reproduced here with permission |
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| LPF is removed from the chamber 8 days later following the test, time for a Team photoshoot! Pictures are property of Airbus Defence and Space Ltd, reproduced here with permission |
Monday, 27 April 2015
The journey begins... Preparing to leave Stevenage
The final few weeks before heading out to Munich with LISA Pathfinder were a flurry of activity.
As the Quality Assurance engineer for the spacecraft, I had my hands full juggling all the different activities that needed my support and also completing the final inspections on the spacecraft before it was shipped.
At the same time as the team were preparing the spacecraft, they were also busy preparing all of the supporting equipment required to enable the running of tests while in Germany to proove that the spacecraft works as intended.
An exciting day was had by all on the day we mated the spacecraft and the propulsion module (thats what we call it when we put the two halves of the spacecraft together) even the press turned up to watch! Click on the video below to see what happened.
Press coverage of the event can be accessed via the following links:
http://www.satnews.com/story.php?number=859969578&menu=1 )
http://www.bbc.co.uk/news/science-environment-31642215
http://www.itv.com/news/anglia/update/2015-02-28/pathfinder-prepares-for-space-launch/
http://www.theguardian.com/science/across-the-universe/2015/mar/03/european-space-agencys-gravity-probe-leaves-uk-for-final-tests-before-launch
Finally, after a long few weeks, we were ready to leave, the spacecraft safely tucked up inside the transport container.
As the Quality Assurance engineer for the spacecraft, I had my hands full juggling all the different activities that needed my support and also completing the final inspections on the spacecraft before it was shipped.
 |
| Final Inspection Pictures are property of Airbus Defence and Space Ltd, reproduced here with permission. |
At the same time as the team were preparing the spacecraft, they were also busy preparing all of the supporting equipment required to enable the running of tests while in Germany to proove that the spacecraft works as intended.
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| Moving all the test equipment out for packing Pictures are property of Airbus Defence and Space Ltd, reproduced here with permission. |
An exciting day was had by all on the day we mated the spacecraft and the propulsion module (thats what we call it when we put the two halves of the spacecraft together) even the press turned up to watch! Click on the video below to see what happened.
Press coverage of the event can be accessed via the following links:
http://www.satnews.com/story.php?number=859969578&menu=1 )
http://www.bbc.co.uk/news/science-environment-31642215
http://www.itv.com/news/anglia/update/2015-02-28/pathfinder-prepares-for-space-launch/
http://www.theguardian.com/science/across-the-universe/2015/mar/03/european-space-agencys-gravity-probe-leaves-uk-for-final-tests-before-launch
Finally, after a long few weeks, we were ready to leave, the spacecraft safely tucked up inside the transport container.
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| Safely installed into the container. Pictures are property of Airbus Defence and Space Ltd, reproduced here with permission. |
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| End of a long day! Pictures are property of Airbus Defence and Space Ltd, reproduced here with permission. |
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| Time to put the lid on – bye LPF, see you in Germany! Pictures are property of Airbus Defence and Space Ltd, reproduced here with permission. |
Monday, 30 March 2015
Calling all explorers!
First ever blog, desperately racking my brain for a
witty, killer opening line and well, coming up with nothing so I'm afraid I'll
have to go for something more predictable.
I guess I should start by introducing myself and more to the point the
subject of this blog...
I'm Vicki and I'd like to invite you to join me for an adventure.
I am an engineer (a quality assurance engineer to be
precise) working in the Space industry.
I'm about to embark on both the most exciting and gruelling adventure of
my career to date, an adventure that will take me away from home for around 8
months, see me travel across the globe and finally end in South America, where
I'll watch the spacecraft I've worked on for the last two years be blasted off
into Space.
So do I have any takers?
The spacecraft is called LISA Pathfinder.
While she might be a relatively small spacecraft, she's
pretty mighty. Her mission, to test out
technologies required to perform a groundbreaking experiment in space. An experiment to detect gravity waves,
predicted by Einstein in his theory of general relativity.
Pretty cool huh?!
So if you've ever wondered how to build to build a
spaceship or if you want to know what it's like to send a rocket into space
then join me on my adventure, from Stevenage to Space. Over and out.
Below: Artist's impression of LISA Pathfinder, courtesy of ESA.
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