I think I'm missing something about the Falcon Heavy capacity. It uses the same
upper stage as the single, with presumably the same weight and fuel load. The
only way this stage can have greater performance is if it has a higher staging
velocity.
However, In order to recover the first stage, the staging velocity is similar
to the single stick staging velocity. Thus, the performance is similar to the
single, and <less> than the single expendable.
If a single can launch a heavy satellite to GTO, it can launch a much lighter
car to Mars.
What am I missing?
John
On Friday, February 9, 2018 2:30 AM, Uwe Klein <uwe@xxxxxxxxxxxxxxxxxxx>
wrote:
Am 08.02.2018 um 23:53 schrieb Henry Spencer:
On Thu, 8 Feb 2018, Uwe Klein wrote:
...imagining comsat builders salivating over how many transponders...
you can do endless numbers of downbeams.
But you can not easily do more than the available bandwidth slots as
uplink. How narrow can you do the receiving uplink antenna beam for
good geograhical separation?
Depends entirely on how big your ground station's transmitting antenna
is, and what uplink frequency you are using (doesn't *have* to have any
particular relation to the downlink frequency). To pick semi-random
numbers, an 8GHz X-band beam from a 10m dish is about 0.2deg wide.