The Herschel and Planck spacecraft have been successfully launched from the same rocket. Herschel is the largest infrared and submillimeter space telescope to date and is intended to observe the far infrared portion of the cosmic background, which should reveal details of how galaxies and stars formed in the earliest periods of the universe. Planck will observe the cosmic microwave background in unprecedented detail, which will let us check out several theories for the origin of the universe such as how inflation may have occurred or the shape of our universe.
It's great to see the successful launch of two spacecraft that will both study the early universe. Given that two spacecraft depended on this successful launch by the ESA, it's a huge relief.