Tag Archives: Messenger

NASA probe MESSENGER is first to enter Mercury’s orbit

Humanity has just reached another milestone in space exploration. Yesterday, on March 17, NASA’s MESSENGER probe entered orbit around Mercury becoming the first spacecraft to ever do so.

MESSENGER probe approaching orbit around Mercury

MESSENGER (actually short for Mercury Surface, Space Environment, Geochemistry and Ranging) was launched almost 7 years ago in August of 2004. It was designed to examine the magnetic field around mercury, as well as chemical composition and geology of the surface.

Since then, MESSENGER has made three flybys past Mercury and has made some interesting discoveries that have puzzled scientists for years.

Evidence of Volcanic activity on the surface of Mercury

Back in July of 2008, MESSENGER made the startling discovery of water present in Mercury’s exosphere (the uppermost later of the atmosphere). It also found evidence of extensive volcanic activity on Mercury’s surface. Previously, scientists believed that the volcanic gases would have long ago exited Mercury or had been absent at its formation.

MESSENGER’s new mission will have it begin to throughly examine the surface for the chemical signatures of these gases with an array of seven instruments (set to be activated on March 24). The probe will also study the presence of water on Mercury and also examine the planet’s core.

MESSENGER's gravity assist maneuvers

What made MESSENGER’s voyage to Mercury interesting were some of the challenges that scientists had to overcome. Normally, a probe approaching the planet would become too accelerated due to the force of the Sun’s gravity and fly past the planet before it could maintain orbit. MESSENGER had to overcome this by using a series of gravity assist maneuvers to slow it down. These maneuvers utilize the gravity of a planet to change the path of the spacecraft. If you’ve ever seen the movie “Armageddon”, this was like the scene where the spaceship did the “roadrunner thrust move” around the Moon. MESSENGER had to utilize the gravity from Mercury, Venus and Earth to perfect its trajectory to orbit the planet.

What’s truly remarkable is that these series of gravity assisted moves mean that MESSENGER has traveled 7.9 billion kilometers through space since 2004.

The other challenge for scientists was thermal damage due to Mercury’s high surface temperatures. They solved this by making MESSENGER have a highly elliptical orbit around the planet. The trajectory takes the probe within 200 km of the surface then 15,000 km away, presumably when the temperatures are hottest. One of these cycles takes 12 hours.

The probe’s first set of measurements are scheduled to be sent to Earth on April 4. Who knows what’s waiting to be discovered beneath the surface of Mercury!

The original article can be found here.

Mercury – NASA’s Fifth Planetary Conquest

Image of Mercury from previous Messenger missions. From NASA.

After years of planning and development, NASA’s space probe Messenger finally fell into Mercury’s orbit Thursday evening. At 9:10 p.m. of March 17, when the last rocket that projected Messenger shut off and the probe fell into Mercury’s gravity pull, scientists at the control room in John Hopkin’s University started in a round of applause.

Mercury is the fifth planet that NASA spacecrafts have orbited. Mercury is the closest planet to the sun and lacks an atmosphere. This means that Mercury’s surface is super heated by the sun during daytime but drops to hundreds of degrees below freezing at night. Also, without an atmosphere, Mercury’s surface is heavily cratered. The vast temperature different implies that ice could be found inside the craters. The Mercury probe hopes to bring back a year of photography that would help in the research of the creation of Mercury and its composition. With this goal in mind, surveillance of the probe is needed for the next few days. Constant checks on the probe’s health systems, testing of the scientific equipment that is on board is essentially so that the vast amount of data can be collected and  transmitted back to Earth.

This massive project started in 2004 with a budget of $446 million. Hopefully, the probe will bring back valuable data that would useful for planetary scientists to determine the evolution of Mercury.

Messenger also hits close to UBC as one of the Earth and Ocean Science professors, Dr. Catherine Johnson, participated in the project. Dr. Johnson is a participating scientist in the project and hopes to discover the reasons behind Mercury’s magnetic field. The probe Messenger hopefully will gather data that will be of use to Dr. Johnson.