Space

Where no man has gone before...

Space simulation

This famous phrase refers to the enormous extension of space and the fascinating objects that can be found therein.

Leybold offers a broad range of vacuum technology to explore them. Vacuum pumps are needed to simulate space conditions to test the equipment for space missions.

Deep space on the other hand needs to be investigated with the help of telescopes. Coating large mirrors of optical telescopes is an essential technique in which vacuum pump systems are also mandatory.

The only possibility to evacuate large scale vacuum chambers within a reasonable time under clean conditions is the use of cryopumps. Leybold, with experience in vacuum technology since 1850 and also many years in cryogenics, has been equipping large volume vacuum chambers for space simulation and mirror coating for several decades. Not only pumps are supplied for this purpose, but also gauges, leak detectors and fittings.

Space simulation systems

Space simulation chambers are systems used to recreate the environmental conditions that spacecraft experience in space. They also serve to qualify components and materials used in spacecraft. Space simulation chambers are capable of analyzing system behavior, evaluating thermal balance, and verifying functionalities to ensure mission success and survivability.

If space equipment fails during a mission, it is nearly impossible to fix it.
Such a failure would trigger astronomical costs and hence producers of space equipment are making a big effort to test their products as long as they are on earth.

Space travel, scientific and Commercial satellites, extraterrestrial research such as ESA’s Rosetta mission or NASA’s mars rover Opportunity can only be successful if all involved materials, components and devices are successfully tested under high-vacuum and ultrahigh-vacuum conditions. Space simulation chambers vary in size from a few liters for testing of small PCB boards up to several thousand cubic meters to prove space compatibility of complete spacecrafts. However, also terrestrial space observation often requires vacuum, e.g. for mirror coating in telescopes. Extreme temperatures in space often range from -200°C to +150°C.

All products for space missions must withstand these conditions. Space simulation chambers are equipped with vacuum pumps and a shroud to thermally decouple the test equipment from the surroundings.

Electrical heaters inside the chamber simulate the temperature conditions in space. The vacuum equipment must resist the resulting heat radiation. A high tolerance against this influence is provided by the COOLVAC series which consists of cryopumps with the highest thermal stability on the market.

The required pumping speed of a vacuum system is determined by several parameters like chamber size, desorption rates, or utilized materials.

In addition, the sealings define the total leak rate which limits the reachable ultimate pressure. When process gases are used, the desired working pressure is crucial. Depending on these requirements, Leybold configures an appropriate vacuum system consisting of cryopumps, turbomolecular pumps and corresponding fore-vacuum pumps.

Optimized solution for ion thruster testing

Today, electrical propulsion is the keyword for the movement of space crafts beyond our atmosphere where the high vacuum of space is entered.

In comparison to chemical propulsion systems, electrical propulsion has the advantage that the thruster material does not need to resist high temperatures.
Electrical propulsion uses ionized particles, usually xenon, which are accelerated by an electric field. Xenon has the highest mass of all stable noble gases. Thus, it produces a large thrust per particle. State-of-the-art xenon thrusters emit a gas flow of 0.1 to 10 mg/sec.

In order to maintain a high vacuum pressure at this flow in thruster test chambers, a large pumping speed is required, often in the range of 10,000 to 100,000 l/s for xenon. The benefit of a large mass for propulsion on the one hand is an enormous challenge for vacuum pumps on the other hand.

We have developed an optimized and simple cryogenic solution for xenon pumping.

A COOLPOWER coldhead cools a metal disc down to cryogenic temperatures which freezes solid xenon to this cryopanel.

This solution supplies a nominal pumping speed of more than 10,000 l/s for xenon. Prior to the thruster test, a high vacuum is usually supplied by turbomolecular pumps and dry fore-vacuum pumps. During the thruster test, they remove gases, e.g. from external leaks, which cannot be removed by the cryopanel as this is at a temperature that is optimized for the pumping of xenon gas.