Explorer 37

 1968-017A

---

The next Solrad was a more advanced design, with three axis stabilization and deployable solar panels.

Solrad 9 (SR 09, Solar Explorer B, Explorer 37, NRL PL155) was launched at 1828 on 1968 Mar 5 by a Scout B from LA3 at Wallops Island. The Algol first stage malfunctioned, and Scout was 100 m/s slow at stage 2 ignition; however the rocket managed to achieve orbit with only 16 m/s slow and 1 deg off the nominal flight path angle. The orbital parameters were 98.7 min, 513 x 881 km x 59.4 deg instead of the planned 840 x 840 km. SR 9 took over Solrad monitoring from OGO 4, and operated well until 1974 Feb when it lost attitude control. It stopped transmitting in 1974 Oct. By 1990 Nov 11 the orbit had decayed to 230 x 251 km x 59.3; the last orbital data was on 1990 Nov 16.8, when it reentered from an 87.5 min 145 x 152 km x 59.3 deg orbit. Mass of SR IX~was 119 kg. Size was 0.68m long 0.76m dia. Control via NRL/Blossom Pt.

SR 9/Explorer 37
Date	Time	Event	Orbit
1968 Mar 5	1828:00	Launch by Scout B S160C	WI LA3A
		T+1:20 Stage 2 burn
		T+2:04 Stage 3 burn
		T+2:40 Stage 3 burnout
	1832:01	T+11:01 Stage 4 burn
	1839:32	T+11:32 Stage 4 burnout
		Stage 4 sep	98.74 509 x 886 x 59.41
1974 Feb		Loss of attitude control
1974 Oct		End of ops
1990 Nov 11			230 x 251 x 59.3
1990 Nov 16		Reentered	87.5 145 x 152 x 59.3

Payload:

• Expt 1 XR Photometer 44-60A (NRL/Kreplin)

• Expt 2 XR Photometer 1-20A

• Expt 3 UV Photometer 1080-1350A

• Expt 4 UV Photometer 1225-1350A

• Expt 5A/5B XR Photometer 8-10A (2)

• Expt 6A/6B XR Photometer 0.5-2A (2) Geiger tube

• Expt 7A/7B XR Photometer 2-8A (2) Geiger tube

• Expt 8A/8B XR Photometer 2-8A (2)