Exotic Spacecraft

Our first talk for January 2002 was called "Planetary Landers: Exotic Spacecraft for Strange Places" by Dr. Andrew Ball. He is a lecturer for the Open University and is a Postdoctoral Research Fellow at the Planetary and Space Sciences Research Institute (PSSRI).

Our first talk for January 2002 was called "Planetary Landers: Exotic Spacecraft for Strange Places" by Dr. Andrew Ball. He is a lecturer for the Open University and is a Postdoctoral Research Fellow at the Planetary and Space Sciences Research Institute (PSSRI).

The talk was different to other speakers who have talked to us about spacecraft as he had chronologically listed all the spacecraft into their sequence. He had a picture of each satellite and explained some of the strong points and weak points for each one. Some of the pictures he showed us of the older satellites were quite rare.

The design of the craft has to be tailored to the terrain it is going to visit. It is not much good having a craft with legs and then have it plunge into the a world that is mainly sea. So, scientists have to find out how the surface of a planet like Venus or another of our planets is made up before designing the craft. This is done by sending orbiting craft which can map the planet with radar etc and after receiving back the results the design of the craft can commence.

There are four different types of craft:

1. End of Mission Impactors – which impact the surface and the debris thrown up is measured.

2. Atmospheric Entry Probes – measure the atmosphere for different chemicals as it falls down to the surface.

3. Pod Landers – which use airbags to cushion the impact with the surface.

4. Leg Landers – which come down to the surface in a controlled fashion and have to slowed down enough not to damage the legs on impact.

The Russians started with their Luna Series and went on to have some degree of success. The first was Luna 1 which was a Luna Flyby, launched on 02 January 1959 and the last one was Luna 24 which was launched 14 August 1976. It landed on the Moon on 18 August and brought a Lunar sample back.

The US were not to be outdone so sent their Ranger Series 1 to 6 to the Moon with disastrous consequences. Ranger 1 was launched on 23 August 1961 but failed to leave Earth orbit. Ranger 6 had its cameras fail and impacted the Moon on 2 February 1964. They had more success with Ranger 7 launched 28 July 1964 to Ranger 9 launched on 21 March 1965. All were impactors and took close up photographs of the Moon on their way down to the surface.

The Russians sent their Venera Series to Venus. Venera 1 launched in 1961 missed Venus while in 1983 Venera 16 orbited Venus carrying imaging radar. While the Americans sent their Viking Lander 1 & 2 to Mars. The landers were leg landers had thrusters to slow them down. They were eventually switched off.

To bring us up to date the American built Galileo which was launched in October 1989 and arrived at Jupiter in December 1995. The probe made measurements as it descended through the atmosphere. Scientists are still measuring this data. The orbiter has orbited Jupiter and its moons ever since and now is nearly depleted of fuel. Scientists want to crash it into Jupiter in case it contaminated Europa which may hold primitive life. The Huygens probe onboard Cassini is still on its way to Saturn and is now between Jupiter and Saturn. It will enter the atmosphere of Titan, Saturn's moon in January/February 2005. Huygens will measure to see how much ethane and methane exists.

Future missions are planned with Mars Exploration Rover planed for 2003 which will measure minerals in the rocks on the surface. Beagle 2 planed for 2003 again will go to Mars where it will pick up soil and test to see if there was ever life there.

Also to be launched in 2003 is Rosetta (see artist's impression above), a European Space Agency (ESA) cornerstone mission, to be launched in January 2003 by Ariane 5. It is designed to rendezvous with comet 46P/Wirtanen and orbit it, while performing remote sensing investigations as well as carrying a lander to descend to the comet's surface and perform in situ measurements.

During the cruise phase, Rosetta will fly out to Mars for a gravity assist and return for an Earth flyby approximately 3 years after launch. Flybys of two asteroids on the way to the comet are also planned. After the asteroid flyby the spacecraft will intercept the comet at a distance from the Sun of more than 3 AU. The rendezvous will occur in August 2011, about 3150 days after launch. A landing site will be chosen and the lander will be released in August 2012. The lander will relay data via the orbiter for at least the next 84 hours. The orbiter will remain with the comet and make observations through perihelion on 21 October 2013.

Mars Netlander planned for 2007 which will study martian geophysics and archeology. Bepi Colombo will be launched in 2009 to Mercury where an element will land on the surface.