| | |  | Raffaello viewed from Endeavour | |
What is the MPLM?
For the men and women who work in the space programme, acronyms
are a convenient shorthand. For the rest of the world, though,
they can easily become a bewildering alphabet soup, with much
exciting technology concealed by cryptic initials.
The MPLM - Europe's major hardware contribution to the STS-100
shuttle mission - is a good example. Three of these Multi-Purpose Logistics Modules have been built for the Italian Space Agency ASI by Alenia Spazio in Turin. Over the next few years these three modules, named Leonardo, Raffaello and Donatello, will be key elements in International Space Station resupply. Leonardo first visited the station with STS-102 in March. Raffaello will dock around 21 April, and Donatello will make its first trip later in the year.
Essentially, each module is a cylinder 6.5 m long and 4.5
m in diameter, with conical endcaps that house docking
mechanisms and hatches. There is room for up to 16 payload racks
(to be precise, International Standard Payload Racks, you can add ISPR to the list of acronyms and there are more to come). The MPLM has its own life-support system, as well as a 3 kw internal power supply. Payload racks, along with other equipment and supplies, travel to and from the station in a pressurized environment. Once a is docked with the station, it provides additional shirt-sleeve workspace for the station crew for up to two weeks at a time.
| | Raffaello viewed from Endeavour | |
In some ways, the MPLM is a descendant of Spacelab, which flew
aboard the Shuttle between 1983 and 1996. But the new system takes full advantage of the improved technology that has been developed since then, particularly in welding. As a result, the MPLM is much lighter than its predecessor, which means that more than 9 tonnes of its 14-tonne launch weight can be given over to useful cargo. At the same time, the MPLM is robust enough for a service life of 25 return trips to space.
The MPLM also shares some basic systems with Europe's forthcoming Columbus science module, which will be permanently attached to the ISS. Their structures are similar - although Columbus has a ''skin' twice as thick as the MPLM - and both Columbus and the MPLM make use of ESA's ECLSS: the Environmental Control and Life Support Sub-system. The advantage of shared systems is twofold. Obviously, it saves money and the duplication of effort. It also helps increase general station reliability.
In the case of the MPLM, ESA was able to
'trade' with the Italian Space Agency, exchanging the ECLSS for
Italian-developed structural elements that were used in Columbus. Without such cash-free transactions, international space programmes would be much more expensive - if they ever got off the ground at all.
Last update: 15 October 2004 | |
