OFO

 1970-094A

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The Orbital Frog Otolith Satellite (OFO) was built by Aerojet General (El Monte) for NASA Ames to study the adaptation of the inner ear function of frogs to free fall. OFO was launched on 1970 Nov 9 at 0600 by Scout B from Wallops Island together with the RM satellite. Its orbit was 92.6 min, 304 x 518 km x 37.4 deg. OFO transmitted until Nov 15, and reentered on 1971 May 9. The experiment showed that the frog otolith function recovered in 3 days. OFO frog data were taken for 155 hours (6d 11h).

The project was originally intended to be an Apollo 2 experiment, and then to fly on Skylab, but delays and the need for a low acceleration enviroment needed forced a change to a free flying satellite. The OFO satellite contained the FOEP (Frog Otolith Experiment Package), developed by APL based on a propoasal by T. Gualtierotti of NASA-ARC (later of Milan). It contained two bullfrogs (Rana Catesbiana) completely submerged in water in a 0.5m high 0.5m dia centrifuge cylinder.

The satellite had a yo-yo despin system and four deployable booms for moment-of-inertia control.

Mass of OFO was 133 kg; an octagonal systems section is topped by a round-topped conical enclosure containing the FOEP. Size 0.76m dia 1.19m high with 2.0m booms giving a 4.8m span. OFO was based on the OV3 design.

Separation of OFO from RM/FW-4S happened 50s earlier than planned due to a malfunction of the vehicle timer, and the two probably bumped into each other, but no serious damage was done.

OFO
Date	Time	Event	Orbit
1970 Nov 9	0600:00	Launch by Scout B S174C	WI LA3A
		T+1:16 St 1 burnout
		T+1:21 Stage 2 burn
		T+2:03 Stage 2 burnout
		T+2:17 Fairing sep
		T+2:19 Stage 3 burn
		T+2:54 Stage 3 burnout
		Spinup
		T+7:23 Stage 3 sep
		T+7:28 Stage 4 FW-4S burn
	0608	T+8:02 Stage 4 burnout
	0608	T+8:02? OFO sep	92.83 304 x 520 x 37.4
	0608	T+8:53 Yoyo deploy from OFO
		T+8:58 Deploy inertia booms
		T+10m? Yo deploy from RM
		T+12:48 Unlock centrifuge
1970 Nov 15	1700?	end of frog data
1970 Dec 3			92.58 288 x 513 x 37.4