Archive for the ‘Rosetta Spacecraft’ Category


An Interview with Warwick Holmes Aero-space Engineer, Rosetta Project, ESA!

November 28, 2014
Warwick Holmes with the Rosetta lander 10 years ago!!!!

Warwick Holmes with the Rosetta lander 10 years ago!!!!

What is an aero-space engineer?

An Aero-Space engineer is responsible for turning an “idea” or a “need” into physical reality by creating an “hardware” or “Software” Engineering solution.  In the case of the ESA Rosetta and Philae mission, the “idea” was to make a spacecraft to orbit and land on a comet outside the Asteroid belt.  Aero-space engineers turned that idea into the physical reality of the Rosetta and Philae spacecraft by applying Science, Technology, Engineering and Mathematics to create the spacecraft.  Rosetta then flew for more than 10 years through the solar-system on an interplanetary trajectory, four times around the Sun, a total distance of 6.5 billion km to successfully orbit and land on Comet-67P.

Warwick Homes 2
What got you hooked on Aero-space engineering?

I saw Neil Armstrong stepping on the Moon when I was only 8 years old on a flickering black & white television set from my Grade-2 class in Adelaide. From that moment, I was determined to work in space engineering to build spacecraft and experience the excitement of space exploration and science.

Where did you go to school?

(1)  St. Peters college (Adelaide)
(2)  Red-Hill Primary and Telopea Park High school (Canberra)
(3)  The Kings school Parramatta (Sydney)

What maths did you like?

I liked everything about mathematics, I like solving functions (polynomials) and differential calculus.
Warwick Holmes ABC News
What maths did you hate?
None !!!

Were you a nerd or simply a student with a passion?

Definitely not a nerd, definitely a student with a passion with a really well defined objective, to become an engineer and become involved in building and launching a spacecraft (that actually ended up becoming 10 spacecraft!)

How do you become an aero-space engineer? What maths do you need?
I completed three degrees, two at Sydney University and one at UNSW

(1)  Science (majoring in Physics and Pure Mathematics)
(2)  Electrical Engineering.
(3)  Masters of Technology Management
It depends what stream of engineering you choose, but the most common mathematics involved in Space Engineering includes:  Matrix algebra, statistics, conformal mappings and complex transformations, differential calculus, Fourier analysis, Laplace transforms and series expansions.

What was your job on the Rosetta project?

I had two roles:
(1)  Assembly Integration and Test Engineer – working directly with the companies that built the Rosetta spacecraft
(2)  Avionics Systems Engineer with the European Space Agency – performing complete integrated system tests of the spacecraft mission operations.

I performed the initial electrical integration of several electronic units on the Rosetta spacecraft (NAVCAM, gryoscopes, reaction wheels, Antenna pointing mechanism, etc).  Then followed complex system testing where as many of the spacecraft modes and functions were tested as possible.  After several years of testing , the engineers follow the spacecraft to the launch site to launch the spaceraft for the start of its long mission.

What was the biggest challenge in the entire project?

The spacecraft has a lot of built-in software “intelligence” so the it can look after itself when very far from Earth.  This software was very complex and difficult to understand the decisions and actions it was making sometimes.  Getting all the systems working together in one spacecraft was difficult.

The_Rosetta_spacecraft_with_thermal_blankets_node_full_image_2Rosetta Spacecraft with Thermal Blankets from the ESA webpage

Did anything go wrong?

During the testing 100’s of things were wrong, and that was our job as test engineers to find (hopefully) all the errors before launch.  The design of the spacecraft has a lot of flexibility in the software ad hardware which means even after launch many problems can still be solved.

What can we learn from this project?

This project will potentially prove two very important and currently unknown questions here on Earth.
(1) Possibly prove that the Earth’s sea water comes from Comets and
(2) The reason life started so quickly after the oceans formed was because the comets also seeded the water with exotic carbon compounds (specifically amino acids) that gave the formation of life a big kick-start.

What advice would you give to any student who wants to be an aero-space engineer?

There is only one secret, work hard and do as well as you can because there are many others people who want to do the same work. The only thing managers want to see and that is you are doing good work and working well in the team with other engineers (scientists, mathematicians, etc).

Warwick Holmes, for your dedication to maths and to inspiring the next generation of young aero-space engineers, you are declared an HONORABLE MATHSPIG.


The Rosetta Project scaled down to a Lego Universe

November 28, 2014

According to Warwick Holmes, ESA:

The images were taken by the OSIRIS-Narrow-Angle-Camera on-board Rosetta spacecraft orbiting 15.5km above the surface of Comet-67P. They show the Philae trajectory before and after the first touchdown, which occurred at 15:34 GMT (12 Nov).  As previously reported the harpoons did not fire into the comet to hold Philae down.

The small inserted images show the imprint of the three Philae foot-pads left in the dusty surface of the comet (compare “before” 15:23 image and the “after” images at 15:43)  Philae first touchdown was at 15:34 GMT.

1 OSIRIS_spots_Philae_drifting_across_the_comet  2
Philae bounced off the comet surface after the first touchdown and remained “airborne” for 1hr 50min.  The first bounce was 1km high and went 1km directly east on this image.

Philae then touched down a second time resulting in a much smaller second bounce which lasted only 7 minutes.  The gravitational force on the surface of Comet-67P is 1/50,000th of (“g”) Earth’s gravity, hence the very high and long re-bounds.

This image does not show the second or final third touchdown positions as they were outside the field of view of this image as Philae continued heading east with respect to this image.
1a Rosetta lander on comet

Finally, Philae completed 100% of the science data acquisition sequence that was planned on the surface despite the “rough” landing(s).  It will probably be several months before exact scientific findings are being published as the scientists shall be spending many weeks processing and examining the plethora of scientific data from Philae and Rosetta over the landing site.

 This is fabulous. Live Comet up date here

To appreciate the distances involved we will scale everything down to the

Lego Universe:

2 Lego Space Cadet Human Ratio Mathspig

3 Lego Scale philae and comet

4 Lego Universe 1 mathspig

5 Lego Universe 2  Mathspig More Rosetta data from Warwick Holmes, ESA.

6 Rosetta Data


The Rosetta Project … like throwing a dart from Sydney to Perth and hitting the bullseye

November 28, 2014

Many commentators in Australia claimed that the Philae landing was:

This is equivalent to hitting the bullseye of a dartboard in Perth from Sydney. With a billion euro ($1.4bn) dart. While blindfolded (as the mission was powered down for almost the entire journey). ABC The Drum

Did they get the maths right?

Inner bullseye of dartboard = 12.7 mm

1 Dartboard

67P comet = 4.1 km = 4,100 m at widest point

Distance comet from earth = 520 million km

 Actually, hitting the 67P comment was more like roulette as the Rosetta mothership swung into orbit. And, as the earth and the comet are moving, the distance constantly changes, but you can watch the distance changing here.

Fabulous Graphics from the Daily Telegraph

Fabulous Graphics from the Daily Telegraph

In the Dart Throwers Universe

We will assume someone can stand on earth and throw a dart at the comet … Yes! They would need very big triceps.

3  Dart throwers universe correction


So the commentators aren’t even close. It would still be a feat hitting a bullseye with a dart from 160km, but that would be from Sydney to, um, Nowra on the coast. 


Comet vs bullseye ratio mathspig

Mt Everest RAtio

4 Dart Throwers universe 3

The distance from Sydney to Perth is 4100 km. At best the commentators would be talking about throwing a dart from Brisbane to Adelaide is 2044km (below).

Brisbane to Adealide