[Date Prev][Date Next][Thread Prev][Thread Next] - [Date Index][Thread Index][Author Index]

*Subject*: [amsat-bb] Re: AO-40: more successful ARCJET operations*From*: Mineo Wakita <je9pel@xxxxxxxxxxxx>*Date*: Mon, 25 Jun 2001 00:18:44 +0900

Newton solution with Keprerian equation (1) M=MA*2*3.14/256 : Radian from MA (2) to=M＋e*sin(M)＋0.5*e^2*sin(2*M) : Initial value (3) mo=to-e*sin(to) : Keprerian equation (4) dto=(M-mo)/(1-e*cos(to)) : e=Eccentricity (5) t1=to+dto : 1st approximate value (6) m1=t1-e*sin(t1) (7) dt1=(M-m1)/(1-e*cos(t1)) (8) t2=t1+dt1 : 2nd approximate value (9) m2=t2-e*sin(t2) (10) dt2=(M-m2)/(1-e*cos(t2)) (11) t3=t2+dt2 : 3rd approximate value (12) t4=tan(t3/2) (13) u=root((1+e)/(1-e))*t4 (14) s=2*arctan(u) : Real anomaly (15) p=24*3600/n : Period(total seconds) (16) 4*3.14^2*(a^3/p^2)=G*Q : A law of the universal graviation (17) a=(((G*Q*p^2)/(4*3.14^2))^(1/3))*10^9 : Semi major Axis (18) r0=a(1-e^2)/(1+e*cos(s)) : Height from the center of the earth (19) r=r0-6371 : Height from the face of the earth The solution of this algorism Before After Perigee height : 286.0 288.4 ....... +2.4 km Apogee height : 58967.2 58966.8 ....... -0.4 km The report of Peter Guelzow, DB2OS Before After Perigee height : 279.754 282.2427 .... +2.5 km Apogee height : 58971.166 58971.024 .... -0.1 km EXCEL sheet of the range analysis http://www.ne.jp/asahi/hamradio/je9pel/a40range.zip > Date: Sat, 23 Jun 2001 10:08:15 +0000 > From: Peter Guelzow <peter.guelzow@arcormail.de> > To: amsat-bb@amsat.org, forum@amsat-dl.org > Subject: AO-40: more successful ARCJET operations > > Dear All, > > The arc-jet thruster has been invoked on Orbit 296, MA 118-135, > which gave about 1 hour of thrusting gas only. > > The S2 TX is OFF from MA 100-180 to spare power for the ATOS. > The gas generator for the ammonia draws about 120 - 130 W of power > when cycled on by the thermostat. > > The IHU-2 is running and logging telemetry into a circular buffer > and hold about 2.5 days worth of data. Downloaded telemetry from > this 1h burn indicated positive power budget and everything looks > nominally. > > The thrust on orbit 296 started at MA 121.4 and lasted for 3618s. > The acceleration is guestimated to be 54E-6 m/s^2 , > and the direction of acceleration is towards alon 274, alat -2 > (the current attitude). > > Give or take the unknowns, the expected outcome of this was: > > Before After > -------------------------------------------- > Epoch year 2001 2001 > Epoch time 173.12145 173.16312 > Inclination 5.2833 5.2833592 > R.A.A.N 180.71591 180.70361 > Eccentricity 0.815077 0.8150139 > Arg perigee 288.69088 288.71333 > Mean Anomaly 121.4 140.46836 > Mean motion MM 1.2711484 1.2710861 > Revolution 296 296 > SMA 36003.6 36004.773 > > Perigee height 279.754 282.2427 <<< +2.5 km > Apogee height 58971.166 58971.024 > -------------------------------------------- > > So the perigee was raised by this 1h burn by about +2.5 km, but only > a thrust rate of 50% was used. > > Since everything went so well, the computer onboard AO-40 was > commanded to initiate 2h "burns" starting around apogee on orbit 297 > for the next three orbits. > > The first 2-hour burn stopped at Orbit 297 MA 142, which is 2001 > Jun 23 0154 utc. Again, all telemetry is looking good and we may soon > expand to 4h "burns" and possibly increase the thrust level as well. > > While we haven't yet seen the latest NORAD data, some effects of the > changing orbit should be soon noticeable. > > Indeed, we all are very happy with the successful results of the ATOS > (Arcjet Thruster on OSCAR Satellite) so far. > > Some more information about the ATOS system is available here: > > http://www.irs.uni-stuttgart.de/RESEARCH/EL_PROP/PROJ/e_atos.html > > > best 73s > Peter DB2OS for the AO-40 team ---------------------------------------------- Name : JE9PEL/Mineo Wakita, JAMSAT member Mail : je9pel@jamsat.or.jp URL : http://www.ne.jp/asahi/hamradio/je9pel/ QTH : Yokohama Japan, GL:PM95TJ Date : Jun 24, 2001 ---------------------------------------------- ---- Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA. To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org

**Follow-Ups**:**RE: Re: AO-40: more successful ARCJET operations***From:*Tom Clark

- Prev by Date:
**Re: uo-14 congestion** - Next by Date:
**AO-27 Not Congested** - Prev by thread:
**Re: AO-40: more successful ARCJET operations** - Next by thread:
**RE: Re: AO-40: more successful ARCJET operations** - Index(es):