Friday May 15th 2009. Day 1.
After the strong emotions of yesterday this was a much quieter day. Various people commented that they felt physically and emotionally exhausted after launch day. Today has basically been a quiet day, but with a difference: this is no longer a test, a simulation, or an exercise.
So far it seems
to be a sequence of unbroken good news. The launch was well nigh perfect and
the trajectory extremely accurate. A small trajectory correction manoeuvre was
carried out successfully around 12UT today. We are now well on our way to L2. Tonight Herschel passes from the constellation of Libra
into Serpens. At 00UT it will be at 280 000km (0.93 light seconds) from Earth.
I have just had confirmation that Peter Birtwhistle has observed Herschel,
Planck and the Scylda through a gap in the clouds from Great Shefford (MPC J95)
in
Various pieces of telemetry have been arriving giving basic
information of spacecraft health. The radiation detectors on Planck and
Herschel both detected a big peak in radiation as they passed through the Van
Allen Radiation Belts. Among the first telemetry to come through has been
spectacular images of the separation of Herschel from the Ariane upper stage (http://www.observadores-cometas.com/Herschel/Image_of_the_day/ImageVMC_H.gif)
and information on the temperature of various parts of the spacecraft. The
temperature of the parts of the spacecraft that are not actively cooled by
helium were expected to drop rapidly in the shadow of the sunshield. By this afternoon
the temperature of the outer shield of the PACS camera-spectrograph had already
dropped by 120º from the temperature that it had inside the fairing of the
Ariane. The rate of drop was slowing progressively; we expect it to drop to
around 70-80K over the next few weeks.
The amount of telemetry is limited everyone is throwing themselves
at it with gusto. The difference between months of simulations and tests and
having real data to study is tremendous and everyone has worked on the data,
such as it is, with real gusto.
Mission Control reports that the mission has been a textbook
exercise so far. They are tracking a couple of minor issues, neither of which
are particularly worrying. Things are going astonishingly well.
As we are now in operations and preparing for people to update their
observations. This means continuing acceptance testing of the new software
upgrade, writing documentation and preparing to contact astronomers with the
required updates.