With Only Months to Delivery, Work Intensifies on LIFE Experiment
Posted by Amir Alexander
15-09-2008 12:00 CDT
With less than four months to go before we are due to deliver the LIFE experiment to the Phobos-Grunt engineers, work on the project is moving along with ever-increasing intensity. During the summer the LIFE team successfully built an engineering model of the experiment's flight canister, and handed it over to the mission's project scientist, Sasha Zakharov of IKI � the Russian Academy's Space Research Institute. The model is nearly identical to the version that will fly on board the spacecraft, with the exception that it does not contain living organisms or radiation and temperature sensors. The mission engineers will use this model to finalize the experiment's placement on the Phobos-Grunt.
Even while this is going on, Bud Fraze and Tomas Svitek at Stellar Explorations Inc. are continuing to subject our own engineering model to severe tests, to ensure that the experiment will survive its arduous voyage structurally intact. To simulate a worst-case landing scenario, we used an air-gun to fire the entire sealed assembly at a target, producing an impact of 4000 g's. The experiment's sample tubes were filled with liquid for the impact test, producing a far tougher test of the seals' integrity that would be the case on the actual flight. In the event 27 tubes survived the impact unscathed, while three of the tubes leaked. While this is to be expected in a first test of the hardware, it is not good enough for the actual flight module. As a result we developed a new and improved procedure for sealing the individual sample tubes, and have scheduled a new round of tests. Stay tuned!
We are also conducting a series of random vibration tests, shaking the experiment canister to simulate launch conditions and other rough portions of LIFE's long journey. In an early run one out of the 30 canisters failed, which was apparently due to an error in filling the canister with liquid. We will now repack the canister carefully to avoid a repeat of the problem, and run the experiment again.
Once all the testing is completed, the final details of the canister's design finalized, we will move on to build the actual flight module. Unlike the flight module it will contain passive radiation and temperature monitors that were not included in the engineering model. Their job will be to record the extreme conditions inside the canister during the long journey through space.
While our collaborators at Stellar Explorations are concentrating on the physical integrity of the module, our colleagues at ATCC (the American Type Culture Collection) are working on the biological side of the experiment. They are testing different organisms and methods by which to pack them into the canister's sample tubes. The microbes they are working on are the hardiest of species, known to survive in the most extreme conditions. After all, if we want to find out if living things can survive a long journey through space, we should try out the toughest ones first. If anything can survive the brutally hostile conditions of space, it will be these organisms.
Less than four months are left before the scheduled delivery of the fully functional LIFE experiment. In this time we still need to decide the final details of the canister's physical structure, and settle all remaining issues relating to the experiment's biological content. And then we need to build the experiment, load it with its precious biological cargo, seal it, and deliver it to the mission engineers. True, much work remains to be done. But we are sure of this much: We will be ready.