You may want to refer to this page on the New England Repeater Directory (http://www.nerepeaters.com/simplex.htm).
All simplex nodes in MA are listed. Most of the IRLP nodes have standard codes: (*0 – node status /XXXX – The node number you want to dial would be an “X” /73 – clear node). EchoLink nodes have mostly standard codes: (Dial the node number / # to clear). If you are not sure about the node, contact the node owner or control operator.
You can listen to the space shuttle audio on IRLP reflector 9877 on either 147.000+, 145.490-, or my node 147.540s. Just dial 9877. You can also listen on EchoLink *NASA* conference #13599.
Chris Washburn, W1EAV