Moving Hubble to 51.6 degrees (near ISS)

"Jorge R. Frank" wrote in message ...
(Zoltan Szakaly) wrote in
m:

I worked out the numbers:

Assuming an ion engine with a thrust of 1 N (about a 5th of a pound)
it would take about a year to move the Hubble and the propellant mass
would be about 40kg. The electrical power used would be 100kW

Hubble's solar panels provide about 5.27 kW.

100 kW is more electrical power than ISS has at Assembly Complete. That's a
lot of solar arrays.

I understand. The propulsion package would have to dock with the
Hubble and it would have to use less power. For example you could
lower the Isp and this would lower the power useage. For example you
could go for 400 kg of propellant instead of 40 kg and use only 10kW
of electricity instead of 100kw. There is an optimum somewhere which
results in minimum mission cost.

From a practical point of view we should schedule one more Hubble
mission which attaches at least two new solid state gyros to ensure
continued operation and perhaps a propulsion package. Since this would
not be a large mass to carry to orbit it could be combined with a
space station mission perhaps.

Zoltan

Electrodynamic tether? Boing and Lockmart have been studying adding these to
satellites to use as de-orbiting devices at the end of their useful life. A
suitably long tether can not only lower Hubble's orbit, but generate power for
an ion engine to slowly evolve a new orbital plane over time, then maintain it
until serviceing is possible.

Mike Swift wrote in news:tomswift-
:

Why glue of course : ). The HST has docking points to be held on to by
the Shuttle's arm, and these are designed to take fairly large loads
used to maneuver the telescope for servicing.

It would be smarter to latch onto the bottom attach points used to attach
HST to the shuttle's flight servicing struction. You keep all the loads
axial that way.

A more difficult problem
is that I do not think the HST has a "cigar lighter plug" on it to allow
a connection to its power system. Most of the electrical system is
internal with very secure connectors designed to be worked on by hand.
Any maneuvering vehicle would have to supply all of it's own power and
propulsion.

Good points.

Does someone know what the delta-v is required to change orbital plane
from the HST orbit to the 56 degree space station orbit?

51.6 degrees, actually.

The required delta-V is around 3.1 km/s. Coincidentally, this is about the
same as would be required to send Hubble to the moon. It's a lot of delta-
V.


--
JRF

Reply-to address spam-proofed - to reply by E-mail,
check "Organization" (I am not assimilated) and
think one step ahead of IBM.

In article ,
Zoltan Szakaly wrote:
Since the hubble is already in orbit, you could easily move it with a
solar powered electric propulsion package, having an Isp of 100,000 or
something.

Except there are no Isp=100,000 electric thrusters. Try 5,000 or so.
--
MOST launched 30 June; science observations running | Henry Spencer
since Oct; first surprises seen; papers pending. |

(MSu1049321) writes:

Electrodynamic tether? Boing and Lockmart have been studying adding these
to satellites to use as de-orbiting devices at the end of their useful
life. A suitably long tether can not only lower Hubble's orbit, but
generate power for an ion engine to slowly evolve a new orbital plane
over time, then maintain it until serviceing is possible.

Electrodynamic tethers do not generate energy "for free" --- they simply
convert the kinetic energy of the orbiting object into electrical energy.
Plane changes are =VERY= expensive in terms of delta-vee. Powering an ion
drive with an electrodynamic tether simply causes the Hubble to auger in
even faster, without enough time to make a significant plane change.


-- Gordon D. Pusch

perl -e '$_ = \n"; s/NO\.//; s/SPAM\.//; print;'

"Remy Villeneuve" wrote in message
om...
"Jorge R. Frank" wrote in message
...
(Zoltan Szakaly) wrote in
m:

I worked out the numbers:

Assuming an ion engine with a thrust of 1 N (about a 5th of a pound)
it would take about a year to move the Hubble and the propellant mass
would be about 40kg. The electrical power used would be 100kW

Hubble's solar panels provide about 5.27 kW.

100 kW is more electrical power than ISS has at Assembly Complete.
That's a
lot of solar arrays.

Then let's move ISS to Hubble!

Just kidding ;-P

Hey, in some ways it might be a better idea. :-)



But I wouldn't mind if ISS went to more launch-friendly latitudes...
If only russia could launch Soyuz from French Guyana...