Lutetia at closest approach

10 July 2010

The European Space Agencies (ESA) space probe Rosetta executed its flyby of asteroid Lutetia a few hours ago.

Here is the image taken at closest approach.

Lutetia’s name is derived from the Latin name for Paris. It is roughly 100 km large.

Rosetta is named after the Rosetta stone. Rosetta passed by asteroid Steins 5th September 2008.


25th May 1961 – Kennedy’s Moon Speech

25 May 2009

On May 25, 1961, President John F. Kennedy announced before a special joint session of Congress the dramatic and ambitious goal of sending an American safely to the Moon before the end of the decade. A number of political factors affected Kennedy’s decision and the timing of it. In general, Kennedy felt great pressure to have the United States “catch up to and overtake” the Soviet Union in the “space race.” Four years after the Sputnik shock of 1957, the cosmonaut Yuri Gagarin had become the first human in space on April 12, 1961, greatly embarrassing the U.S. While Alan Shepard became the first American in space on May 5, he only flew on a short suborbital flight instead of orbiting the Earth, as Gagarin had done. In addition, the Bay of Pigs fiasco in mid-April put unquantifiable pressure on Kennedy. He wanted to announce a program that the U.S. had a strong chance at achieving before the Soviet Union. After consulting with Vice President Johnson, NASA Administrator James Webb, and other officials, he concluded that landing an American on the Moon would be a very challenging technological feat, but an area of space exploration in which the U.S. actually had a potential lead. Thus the cold war is the primary contextual lens through which many historians now view Kennedy’s speech.

The above clip is from NASA’s page on President Kennedy’s announcement of the decision to go to the Moon.

Here is an audio recording of the speach I found on YouTube.

Twelve people have walked on the surface of the Moon.

Apollo 11

  • Neil Armstrong – Commander
  • Edwin E. Aldrin, Jr. – Lunar Module Pilot

Apollo 12

  • Charles Conrad, Jr – commander
  • Alan L. Bean – lunar module pilot

Apollo 14

  • Alan B. Shepard, Jr – Commander
  • Edgar D. Mitchell – Lunar Module Pilot

Apollo 15

  • David R. Scott – Commander
  • James B. Irwin – Lunar Module Pilot

Apollo 16

  • John W. Young – Commander
  • Charles M. Duke Jr. – Lunar Module Pilot

Apollo 17

  • Eugene A. Cernan – Commander
  • Harrison H. Schmitt – Lunar Module Pilot

Apollo 17 left the surface of the Moon on 14th December 1972. We have not been back since then.

Remembering Apollo

9 April 2009

The flight computer onboard the Lunar Excursion Module, which landed on the Moon during the Apollo program, had a whopping 4 kilobytes of RAM and a 74 KB “hard drive.” In places, the craft’s outer skin was as thin as two sheets of aluminum foil.

This quote is from an article at titled Beyond Apollo: Moon Tech Takes a Giant Leap.

The above facts made me curious so I took a quick look at Wikipedia’s page on Apollo’s Guidance Computer (AGC).

This is a photograph of the AGC user interface:


By today’s standards that computer was tiny.

The AGC was used in the Lunar Excursion Module (LEM) – later called the Lunar Module (LM). The LM was the bit that landed on the Moon. Here is a photograph of the LM:

Apollo 16 Lunar Module

The Apollo program is on my mind because this July it will be 40 years since the Apollo 11 mission. Michael Collins, Buzz Aldrin and Niel Armstrong took that small step – the beginnings of humanity’s journey out of the cradle. You may have guessed that I think this event is significant in the history of humanity. It will still be remembered in thousands of years as one of the major milestones in our development.

Incidentally; the guidance computer was one of the driving forces behind early research into integrated circuits – necessary for development of that computer you are using to read this.

20th November 2008 – International Space Station 10 years old

20 November 2008

Now the largest spacecraft ever built, the orbital assembly of the space station began with the launch from Kazakhstan of its first bus-sized component, Zarya, on Nov. 20, 1998. The launch began an international construction project of unprecedented complexity and sophistication.

via NASA – Nations Around the World Mark 10th Anniversary of International Space Station

International Space Station

International Space Station

In the photograph above of the International Space Station, Zarya is the third “bit” from the bottom. It’s solar panels are folded up. below it is Zvezda with it’s solar panels ‘horizontal’ and below that is ESAs Automated Transfer Vehicle Jules Verne with it’s X-shaped solar cells. Jules Verne has been deorbited so it is no longer docked to the ISS. Below is a detailed image of Zarya.


The orbit of ISS is inclined about 51-52 degrees which means it never passes directly overhead where I live (above 60 degrees North). Here we see it passing in the South low on the horizon about every 14 days or so. Even so it is great fun to see this man made object brighter than the brightest stars. I visiteed the South of France earlier this year and had the opertunity of watching the ISS pass over the zenith. Jules Verne was about to dock so we saw that pass over about 10-15 degrees in front of ISS. The ISS has been continually staffed since 2nd November 2000. Think about that. Humans have been continually in space for the last eight years.

Mercury – MESSENGER images – flyby 2

7 October 2008

MESSENGER has successfully completed its second flyby of Mercury. Her is a sample of the first images returned. Clicking on the images sends you to the MESSENGER image gallery where you can see high resolution versions of these images.

Links of interest:

Wikipedias entry on Messenger
Wikipedias entry on Mercury
My post on MESSENGERs first flyby

Hybrid rocket demonstration

6 September 2008

I was at an amateur astronomy congress last weekend. One of the talks was by an rocket builder who later demonstrated the principle behind hybrid rockets. The rocket motor consisted of a combustion chamber made of a perspex tube. This made it possible to see inside the combustion chamber during the demonstration. The solid component of the fuel was also perspex and the gaseous component of the fuel was nitrous oxide. The demonstration rocket did not have a nozzle since this was just a demonstration of the basic principles of hybrid rocket fuels. The point of the demonstration was to show that hybrid rockets can be cheap, controllable and safe.

Rosettas flyby of Steins

6 September 2008

The first images from ESAs space probe Rosettas closest approach to the asteroid Steins are now available.

Images from Rosetta flyby of Steins

Images from Rosetta flyby of Steins

Steins is a main belt asteroid in orbit around the Sun between Mars and Jupiter. Rosettas closest distance to Steins was 800 kilometers. Steins is about 5.9 by 4 kilometers large – mountain sized.

Emily Lakdawalla at The Planetary Society has updated her montage that compares the sizes of comets and asteroids that have been imaged. Here you can see the relative size of Steins to other objects imaged by space probes.

Relative sizes of asteroids and comets

Relative sizes of asteroids and comets