This week will see, finally, the launch of space shuttle Atlantis carrying the astronauts for STS-125, the final Hubble servicing mission. This mission was delayed after Hubble developed some new faults late last year, but it looks like this time everything is going to happen as expected. As I write this, the countdown stands at 1 day, 8 hours, putting the launch in the early hours of this Tuesday, Melbourne time. At the same time, space shuttle Endeavour also sits on the launch pad, ready to act as Atlantis' rescue ship should anything go seriously wrong while in orbit.
But this week will also see two other important launches, neither of which is getting as much attention as it deserves. On 14 May at 23:12 Melbourne time (13:12 UTC), an Ariane 5 rocket will be launched from the Guiana Space Centre carrying two European observatories into orbit:
- the Herschel Space Observatory is a 3.5 metre telescope, the largest space telescope ever launched; it will look at the universe in the low energy range of the far infrared, looking at what its creators call "the cool universe" — objects that are either not hot enough to emit visible light or far enough that their light is shifted into the far infrared by the time it gets to use
- the Planck observatory is a microwave telescope that will look into the light emitted by the Big Bang, investigating variations in the temperature of the background radiation that permeates the universe; it intends to look at the Cosmig Microwave Background with a level of detail never before achieved and to bring us new insights into the properties of our universe during its early years
Both Herschel and Planck will be far away from the Earth, orbiting around L2 (the second Lagrangian point); this puts them around 1.5 million kilometres away and permanently in our night side. This allows both to operate without any interference from Earth's radiation belts and reduces the area of sky that is "off limits" to their instruments (since both the Earth and the Sun will be in the same general area of sky from the point of view of the observatories).
Hubble has certainly given us and our scientist an amazing amount of information about the universe over the years, and I do hope this servicing mission goes according to plan. But let's also hope that Herschel and Planck lift off without problems and bring us much more information over the next few years.