The Launch of MAP
The MAP satellite is scheduled to launch from Cape Canaveral,
Florida in Fall 2000. The launch vehicle is a Delta II 7425-10 rocket. Once
the rocket launches, it will revolve around its axis at a rate of about 60
rpm. This spinning will slow by a process called the "yo-yo despin." After
MAP is released from the rocket, its own propulsion system carries it to its
destination at L2, 5 times farther from the Earth than the Moon.

Delta Rocket
- The Delta
II 7425-10 rocket is part of the Med-Lite family of launch vehicles built
by Boeing.
Yo-yo Despin
- The yo-yo despin is a technique used to stop the Delta rocket from
revolving around its axis after it has launched. Weights on strings are
attached to the side of the rocket. Once it is activated, the strings unwind
like a yo-yo and the weights are released. Due to the conservation of angular
momentum, the rocket's angular velocity (its spin rate) must decrease. This
process is analogous to a figure skater who is spinning at high speed on ice
and extends her arms to slow herself down.
Deployment of the solar array / Sun shield
- The picture below shows MAP in its deployed confuration. The panels that
hold the solar arrays are folded up against the spacecraft so that it may fit
in the Delta fairing. After the spacecraft is spun down, the panels are
released by cutting a kevlar cable and they fold down, somewhat like a
vegetable steamer, to form a single flat Sun shield across the bottom of the
spacecraft. Not shown in the picture is the multi-layered insulating blankets
that fill the gaps between the panels to form a continuous shield.
The following is an image of the spacecraft stowed for launch:
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Last updated:
Friday, 05-21-1999