Hubble Servicing Mission 4 Blog

ESA HST team member Manfred Schmid is a mechanisms expert.

Name: Manfred Schmid

Title: Mechanisms Expert for ESA HST team

What is your area of expertise?

My experience in space systems started more than 30 years ago with the development of lightweight structures on the German Spacelab (flown on the Shuttle) and turned then over to the development of mechanical subsystems. Over the years I have been responsible for the conceptual design, development, system engineering or project management of many different space mechanisms flown on satellites or on the Shuttle. Typical examples for my field of experience are related to: scanning mechanisms, pointing mechanisms, solar array drives, hold-down and release mechanisms and large deployable antennas, among others.

Due to the movable components in every mechanism, such equipment is generally extremely mission-critical. Therefore in-depth knowledge and experience related to friction and wear, actuator design, bearing and gear design, and other factors is mandatory.

What made you choose this field?

I am not sure, but what I can say is that my grandfather owned a sawmill and when I was a child I watched the big frame saws working. Historical sawmills have a turbine, belt transmissions, a creek, a little lake to store the water and a lock to control the water flow. After studying all this during my first years and having trapped my first trout in the creek by hand, I developed a strong interest for engineering aspects and for nature and I recognized many analogies between these two fields.

This could have prompted me to join the merchant navy, to become a pilot or to study engineering. I chose the latter, probably because I wanted to be on the creative development side rather than to be on the application one.

How have the solar arrays and the drive mechanisms and electronics performed?

The equipment has performed perfectly over all the years. I am very satisfied that the Solar Array Drive Mechanism (SADM) which was designed more than 20 years ago in our mechanisms department (to which I am still assigned and which forms now part of Astrium GmbH) is working perfectly. This proves the soundness of the design concept which was developed and realised that time in close cooperation with ESA. Due to the continuity of our team over all the years (despite running through several company reorganization loops), we are today able to provide engineering support to missions such as SM4.

How do you feel about supporting what many call the most powerful astronomical tool of our time?

My working life has been closely aligned with the Shuttle’s life. We flew several scientific payloads on the Shuttle in the 1980s and in the beginning of the 1990s until the International Space Station was prioritized; but to have the chance to support a free-flying telescope such as Hubble for so long now has a different quality.

Do you have a favourite HST image?

There are two of them: One is a picture of the Hubble Spacecraft together with the earth in the background, taken from the Shuttle.

The other is a picture taken by Hubble and shows the Planet Uranus with its moon Ariel and the Ariel shadow on Uranus as well.

Have you worked all of the servicing missions?

No, my former (now retired) colleague Raimund Hostenkamp who was the Project and Engineering Manager during the Solar Array Drive Mechanism (SADM) and Solar Array Drive Electronics (SADE) development phases staffed the previous servicing missions. I was heavily involved in the project prior to SM 3 when the new solar array drives were built and tested.

What has been the most exciting part of SM4 for you so far?

A Shuttle launch is always very exciting since it is a manned mission. If such a mission is going to maintain and improve the hardware of an extremely important and complex system like Hubble, it gets even more exciting.

What has been the most stressful part of SM4 for you so far?

There is no real stress, but a constant tension that something could go wrong during the mission. Questions related to the solar array which have to be analyzed and resolved can come up at any time and the EVA (spacewalk) activities add additional tension as we have seen with the stubborn bolt during the STIS repair which did not want to come out - things like this can spoil a whole mission.

What is next for you?

I am responsible for several different projects in Europe and they are all in the critical test phase, therefore I am not sure whether I will have much time to relax from the night shift during this SM4 mission. What helps me a lot to manage the upcoming tasks is the support I get from my wife and the extremely good working atmosphere and cooperativeness I experience from all my colleagues.