--- On Mon, 29/4/13, Stefan Wagener <wageners(a)gmail.com> wrote:
> maybe I didn't make myself clear:
> LEO (low earth orbit) from 400 to 2000km or something like that
> HEO (high earth orbit) >20000km
> Going from 310 to 700km in a year is not doing us anything.
Romit-1 and the other CubeSats testing ion engines will definitely give us something - proof that it works in practice or an opportunity to learn from any problems / design issues that arise.
Given that Space is a demanding environment I'm sure not all the ion motor CubeSats currently being developed will work as planned when deployed, it'll be a learning experience.
Going from a 310 to a 700 km orbit in a year using the limited solar power generated from a standard 2U CubeSat will be a major step forward.
It follows that to get up to 7200 km or even better 20000 km will take years but could be speeded up by having CubeSats with large fold-out solar panels and more powerful motor.
I say CubeSats rather than Microsats because of cost, a 35 kg microsat could cost $1 million just to get into LEO.
I hope the various groups that have developed ion motor CubeSats are eventually successful is getting launches to LEO to test them out.
73 Trevor M5AKA
----
>In addition, doesn't the process getting from GTO to HEO require some form
>of rapid acceleration? If yes, ion engines and solar sails are out.
The main requirement for escaping from LEO is that the engine thrust must
exceed the atmospheric drag force. The time required to reach a HEO orbit
mainly depends on how much electrical power you can generate, more power means
more thrust and a faster ride to the desired orbit. A Cubesat power budget
will be somewhat limited, deployable solar panels might help somewhat.
Most Cubesat launches are deliberately sent to low orbits to insure rapid
reentry and burn-up to meet orbital debris requirements, that is why Cubesat
launches to GTO are rare. A higher orbit will require a disposal plan, but
electric propulsion can help with that too. Please see my paper in the 2012
AMSAT Symposium Proceedings.
Dan Schultz N8FGV
I know that the earth is surrounded by radiation belts that have the
potential of damaging satellites. How dense are they and around what
altitudes do they have their most harmful affects? I am going to hazard a
guess that this is why higher leo satellites (let's say over 1500 miles
high) haven't been launched over the years. Any information would be
appreciated.
Dave Marthouse N2AAM
dmarthouse(a)gmail.com
Icom AG-25 mast mount 2 meter preamp
Mirage KP-1/440 70 cm GaAsFET preamp
G-5500 control box and elevation rotor (no az rotor)
Alinco ELH-730D 70 cm linear amp (3W in for 30W out) w/preamp
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Icom AG-25 mast mount 2 meter preamp
Mirage KP-1/440 70 cm GaAsFET preamp
G-5500 control box and elevation rotor (no az rotor)
Alinco ELH-730D 70 cm linear amp (3W in for 30W out) w/preamp
Radio Shack 2 meter amp (Cat. # 19-1122)
Pix available. If interested, please contact me off list.
Glenn AA5PK
