They are also going horizontally then and the small loss of thrust might
not matter much.
Therefore less gravity loss, Makes sense.
Ken
On Tue, Jan 18, 2022 at 9:25 PM Peter Fairbrother <peter@xxxxxxxxxx> wrote:
On 18/01/2022 05:56, Henry Spencer wrote:
One problem John has mentioned in conversation in the past is that the
second stage jettisons spent batteries partway through its burn, there
doesn't seem to be any public information about how much they weigh, and
it really matters to performance modelling.
I wonder whether they change they chamber pressure after jettisoning the
battery - they are at altitude, and a large change in Pc might result in
a small change in Isp.
Thereby lowering the required mass of the final battery and perhaps
increasing payload.
They are also going horizontally then and the small loss of thrust might
not matter much.
But you'd have to model the whole flight to find out if it was worthwhile..
Peter Fairbrother
