Recent content by marrsc

I took a look at the link. Thanks again. They seem to be worried about the ablity of an ion engine to operate long enough to do the job. The copy of the one used on the Deep Sace One ran for over 24,000 hours. If they boosted it into a higher orbit would they get a larger percentage of time in...

Thanks Pervect. My original but apparently not unique idea was to realign the Hubble orbit with the ISS using ion propulsion, service it at the station using the shuttle then boosting it into a higher orbit in the same plane. It just seems a shame to drop it into the Pacific. The rebuild parts...

I think they are on the whole a good idea. However it won't be too long before someone "hacks" one and turns it against its operators.

Determine the time it takes to cross the river. In this period the swimmer drifts 67 m. Solve for the current speed.

I have done some very simlpistic calculations and I get something on the order of 5 k/sec delta v. Almost all the energy is used in changing the orbital inclination. Changing the orbital height seems to require only 0.13 k/sec. I must have missed something. If the required energy is really...

Thank you, Dayle for your eloquent post. There are many ways that off the shelf hardware can be used to save the Hubble. The current plan is to dock a maneuvering rocket with the Hubble and crash it into the Pacific. It is considered too dangerous to service the Hubble in its current orbit with...

The trucks are rear wheel drive. There would be no reason to keep the four wheel drive engaged while set up for running on the rails. There is some small lag between letting off the accelerator pedal and the reponse of the engine and drive train. When you blip the throttle the engine does not...

I assumed that the trucks in the pictures with the front wheels in the air were in the process of being set up for the tracks. In some of the other photos they appear to be in contact. When I have seen these in action they always have their front wheels in contact with the rails. Probably so...

The speedometer takes its reading from the transmission. Most automotive braking braking is done by the front wheels. These trucks have a high center of gravity. In the initial moments of braking the front wheels react first and unload the rear wheels breaking their traction and allowing them...

I heard the decision this morning to drop the Hubble Space Telescope into the Pacific Ocean. I wondered what the required delta v would be to move the Hubble into a "safe" service orbit nearer the ISS. The rescue options that have been most public have been either a robitic service mission or...